Green Tea May Protect Bladder From Becoming Inflamed

Daily Science Journal (Jan 21, 2007) — Herbal agents could be used to treat inflammatory bladder diseases, according to a preliminary study that looked at the ability of green tea to protect bladder cells from inflammation. The University of Pittsburgh School of Medicine study, being presented at the annual meeting of the American Urological Association (AUA) in Anaheim, Calif., found that components of green tea protected bladder cells from damage in culture.

Green tea, reported to have many health benefits, is rich in powerful antioxidants that make it a possible remedy for many medical conditions. It is comprised of catechins -- plant metabolites that provide it with many anti-oxidative properties.

"We discovered that catechins found in green tea protected both normal and cancerous bladder cells from inflammation when we exposed the cells to hydrogen peroxide," said Michael B. Chancellor, M.D., professor of urology and gynecology at the University of Pittsburgh School of Medicine. "Although further studies are needed, these results indicate herbal supplements from green tea could be a treatment option for various bladder conditions that are caused by injury or inflammation."

In the study, normal and cancerous bladder cells were exposed to two major catechin components of green tea, epigallocatechin gallate (EGCG) and epicatechin gallate (ECG), for 23 hours. Both significantly protected cell lines from exposure to hydrogen peroxide, which damages or kills cells. The concentrations of EGCG and ECG used in the study were at levels that may be achieved through dietary intake.

Approximately ten million American adults have problems controlling their bladders. Bladder disease affects both men and women and can include incontinence or interstitial cystitis, a chronic inflammatory condition that causes frequent, urgent and painful urination and pelvic discomfort.

Co-investigators of the study include Shelby Morrisroe, M.D., Christian Coyle, Ph.D., Brian Phillips, Ph.D., William de Groat, Ph.D., and Naoki Yoshimura, M.D., Ph.D., all with the University of Pittsburgh School of Medicine. The study is Abstract 299 in the AUA proceedings.

The study is funded by the Fishbein Family CURE-IC Program.

Adapted from materials provided by University of Pittsburgh Schools of the Health Sciences, via EurekAlert!, a service of AAAS.

Read the rest of this entry »

Indian Medicinal Plant May Combat Liver Cancer

Daily Science Journal (Jan. 17, 2008) — Liver cancer is the fifth most common cancer in the world with a poor prognosis. About three quarters of the cases of liver cancer are found in Southeast Asia, including China, Hong Kong, Taiwan, Korea, India, and Japan. The frequency of liver cancer in Southeast Asia and sub-Saharan Africa is greater than 20 cases per 100,000 population. Moreover, recent data show the frequency of liver cancer in the U.S. overall is rising.

With the increasing trend in the incidence of cancers in our country, biomedical research directed at early detection and diagnosis, prognosis and survival, as well as prevention of progression of malignancy, is of prime importance. The aim of cancer chemoprevention is to circumvent the development and progression of malignant cells through the use of non-cytotoxic nutrients, herbal preparations/natural plant products, and/or pharmacological agents.

Encouraging dietary intake with herbal supplements may therefore be an effective strategy to limit DNA lesions and organic injuries leading to cancers and other chronic degenerative diseases.

A research team led by Prof. Malay Chatterjee from Jadavpur University investigated the primary chemopreventive mechanisms of Acanthus ilicifolius in an in vivo tumor-transplanted murine model. A. ilicifolius, popularly known as ¡°Harkach Kanta¡± is distributed widely throughout the mangroves of India, including Sunderbans in West Bengal, west coasts, and the Andamans, and in other Asian countries like Singhal, Burma, China, Thailand etc.

The results showed the aqueous leaf extract (ALE) of the plant was substantially effective in preventing hepatic DNA alterations and sister-chromatid exchanges (a type of chromosomal damage) in tumor-bearing mice. The study further demonstrated that ALE treatment was able to limit liver metallothionein expression, a potential marker for cell proliferation, and lengthen the mean survival of animals to a significant extent. The findings suggest that A. ilicifolius may be used as a potential chemoprotector against hepatic neoplasia.

This research from Prof. Chatterjee¡¯s laboratory opens up a promising avenue in cancer chemoprevention with the use of indigenous plants. The results obtained from this in vivo study seem interesting and encouraging. Lack of toxicity favors further preclinical evaluation of A. ilicifolius in a defined chemical carcinogenesis model. Elucidation of its anticarcinogenic mechanisms of action at the intricate molecular circuits, and isolation and characterization of its active principles, will provide a better understanding of the anti-cancer/chemoprevention strategy of A. ilicifolius. If these studies are found to be really functional, we will have the beginning of a new chemoprevention program with herbal supplements that could have the broadest implications for the well-being of society.

Journal reference: Chakraborty T, Bhuniya D, Chatterjee M, Rahaman M, Singha D, Chatterjee BN, Datta S, Rana A, Samanta K, Srivastawa S, Maitra SK, Chatterjee M. Acanthus ilicifolius plant extract prevents DNA alterations in a transplantable Ehrlich ascites carcinoma-bearing murine model. World J Gastroenterol 2007; 13(48): 6538-6548 http://www.wjgnet.com/1007-9327/13/6538.asp

Adapted from materials provided by World Journal of Gastroenterology, via EurekAlert!, a service of AAAS.

Read the rest of this entry »

Green Tea And EGCG May Help Prevent Autoimmune Diseases, Cup Of Green Tea To Keep The Bacteria Away

Daily Science Journal (Jan. 16, 2008) — Green tea may help protect against autoimmune disease, Medical College of Georgia researchers say.

Dr Stephen Hsu and colleagues found that green tea may help protect against autoimmune disease. (Credit: Image courtesy of Medical College of Georgia)

Researchers studied an animal model for type I diabetes and primary Sjogren’s Syndrome, which damages the glands that produce tears and saliva.

They found significantly less salivary gland damage in a group treated with green tea extract, suggesting a reduction of the Sjogren’s symptom commonly referred to as dry mouth. Dry mouth can also be caused by certain drugs, radiation and other diseases.

Approximately 30 percent of elderly Americans suffer from degrees of dry mouth, says Dr. Stephen Hsu, a researcher in the MCG School of Dentistry and lead investigator on the study. Only 5 percent of the elderly in China, where green tea is widely consumed, suffer from the problem.

“Since it is an autoimmune disease, Sjogren’s Syndrome causes the body to attack itself and produce extra antibodies that mistakenly target the salivary and lacrimal glands,” he says. There is no cure or prevention for Sjogren’s Syndrome.

Researchers studied the salivary glands of the water-consuming group and a green tea extract-consuming group to look for inflammation and the number of lymphocytes, a type of white blood cells that gather at sites of inflammation to fend off foreign cells.

The group treated with green tea had significantly fewer lymphocytes, Dr. Hsu says. Their blood also showed lower levels of autoantibodies, protein weapons produced when the immune system attacks itself, he says.

Researchers already know that one component of green tea – EGCG – helps suppress inflammation, according to Dr. Hsu. "So, we suspected that green tea would suppress the inflammatory response of this disease. Those treated with the green tea extract beginning at three weeks, showed significantly less damage to those glands over time.”

Researchers also suspect that the EGCG in green tea can turn on the body’s defense system against TNF-alpha – a group of proteins and molecules involved in systemic inflammation. TNF-alpha, which is produced by white blood cells, can reach out to target and kill cells.

“The salivary gland cells treated with EGCG had much fewer signs of cell death caused by TNF-alpha,” Dr. Hsu says. “We don’t yet know exactly how EGCG makes that happen. That will require further study. In some ways, this study gives us more questions than answers.”

These results, published in a recent issue of Autoimmunity, reinforced findings of a 2005 study showing a similar phenomenon in a Petrie dish, Dr. Hsu says. Further study could help determine green tea’s protective role in other autoimmune diseases, including lupus, psoriasis, scleroderma and rheumatoid arthritis, he says.

Adapted from materials provided by Medical College of Georgia.

--------------------------------------------------------------------------------

Add On Article :

Cup Of Green Tea To Keep The Bacteria Away

Beneficial effects of green tea have been known for millenia, particularly in Asian cultures. An ancient Chinese proverb says: "Better to be deprived of food for three days, than tea for one". A cup of green tea contains up to 200 mg of catechins, whose biological activity has been mainly attributed to its antioxidant activity. Efficiency of green tea extract in oral hygiene has been known for centuries and this gave researchers a clue that antibacterial activity might be involved.

Now researchers from the National institute of Chemistry in Ljubljana, Slovenia discovered that the main ingredients of green tea are able to perform other tricks. They found out that green tea catechins inhibit essential bacterial enzyme DNA gyrase, which is the target of several existing clinically used drugs. By the use of NMR spectroscopy, researchers from Slovenia have now pinpointed the ATP-binding site of DNA gyrase as target of EGCG, the most abundant catechin from the green tea extract. Up to now several compounds targeted against the ATP-binding site of bacteria gyrase have been known but couldn't be used as drugs due to their side effects on mammalian cells.

Lead researcher Roman Jerala, the head of the Laboratory of Biotechnology at NIC explains: "We can anticipate to avoid the problem of toxicity using the compounds based on the green tea catechins, which have centuries of established safety record in the human diet."

This finding may be used to develop even more potent antibacterial compounds. Results were recently published in the Journal of Medicinal Chemistry.

Adapted from materials provided by National Institute Of Chemistry, Slovenia.

Read the rest of this entry »

Herbal Extract Found To Increase Lifespan

Daily Science Journal (Dec. 10, 2007) — The herbal extract of a yellow-flowered mountain plant indigenous to the Arctic regions of Europe and Asia increased the lifespan of fruit fly populations, according to a University of California, Irvine study.

Rhodiola rosea. (Credit: Image courtesy of University of California - Irvine)

Flies that ate a diet rich with Rhodiola rosea, an herbal supplement long used for its purported stress-relief effects, lived on an average of 10 percent longer than fly groups that didn’t eat the herb.

“Although this study does not present clinical evidence that Rhodiola can extend human life, the finding that it does extend the lifespan of a model organism, combined with its known health benefits in humans, make this herb a promising candidate for further anti-aging research,” said Mahtab Jafari, a professor of pharmaceutical sciences and study leader. “Our results reveal that Rhodiola is worthy of continued study, and we are now investigating why this herb works to increase lifespan.”

In their study, the UC Irvine researchers fed adult fruit fly populations diets supplemented at different dose levels with four herbs known for their anti-aging properties. The herbs were mixed into a yeast paste, which adult flies ate for the duration of their lives. Three of the herbs – known by their Chinese names as Lu Duo Wei, Bu Zhong Yi Qi Tang and San Zhi Pian – had no effect on fruit fly longevity, while Rhodiola was found to significantly reduce mortality. On average, Rhodiola increased survival 3.5 days in males and 3.2 days in females.

Rhodiola rosea, also known as the golden root, grows in cold climates at high altitudes and has been used by Scandinavians and Russians for centuries for its anti-stress qualities. The herb is thought to have anti-oxidative properties and has been widely studied.

Soviet researchers have been studying Rhodiola since the 1940s on athletes and cosmonauts, finding that the herb boosts the body’s response to stress. And earlier this year, a Nordic Journal of Psychiatry study on people with mild-to-moderate depression showed that patients taking a Rhodiola extract called SHR-5 reported fewer symptoms of depression than did those who took a placebo.

Jafari said she is evaluating the molecular mechanism of Rhodiola by measuring its impact on energy metabolism, oxidative stress and anti-oxidant defenses in fruit flies. She is also beginning studies in mice and in mouse and human cell cultures. These latter studies should help understand the benefits of Rhodiola seen in human trials.

Study results appear in the online version of Rejuvenation Research. Jeffrey Felgner, Irvin Bussel, Anthony Hutchili, Behnood Khodayari, Michael Rose and Laurence Mueller of UC Irvine participated in the study. Sun Ten Inc. provided the herbs.

Adapted from materials provided by University of California - Irvine.

Read the rest of this entry »

UCLA Researchers Find Gingko Biloba May Help Improve Memory

Daily Science Journal (Nov. 15, 2007) — Researchers at the UCLA Neuropsychiatric Institute found significant improvement in verbal recall among a group of people with age-associated memory impairment who took the herbal supplement ginkgo biloba for six months when compared with a group that received a placebo.

The UCLA study, released at the annual meeting of the Society for Neuroscience, held Nov. 8–12, in New Orleans, LA, used positron-emission tomography (PET) and found that for subjects taking gingko biloba, improved recall correlated with better brain function in key brain memory centers.

However, actual changes in brain metabolism, measured by PET for the first time, did not differ significantly between the study's two volunteer groups. Researchers noted that although all volunteers taking gingko biloba experienced better verbal recall, a larger sample size might be needed to effectively track brain metabolism results.

"Our findings suggest intriguing avenues for future study, including using PET with a larger sample to better measure and understand the impact of gingko biloba on brain metabolism," said Dr. Linda Ercoli, lead author of the study and an assistant clinical professor at the UCLA Neuropsychiatric Institute.

Gingko biloba is a Chinese herb often used as a dietary supplement to treat memory loss. The UCLA study and previous controlled clinical trials on ginkgo biloba's effects on verbal recall have yielded conflicting results.

"The research also raises questions regarding the significance of supplement quality and treatment duration," said principal investigator Dr. Gary Small, a UCLA professor on aging and director of the Aging and Memory Research Center at the UCLA Neuropsychiatric Institute. "The Food and Drug Administration does not regulate dietary supplements, and the quality of retail supplies varies widely. We used only the highest grade of ginkgo biloba in conducting our research."

Small also noted that the six-month UCLA study is one of the first to measure the effects of gingko biloba over a longer period of time. Most previous studies have measured the effect of the supplement over 12 weeks or less.

The study examined the impact of ginkgo biloba, compared to a placebo, in 10 patients, aged 45 to 75, who did not have dementia but complained of mild age-related memory loss. Four subjects received 120 mg of ginkgo biloba twice daily, and six received a placebo or inactive substance such as a sugar pill.

Researchers used cognitive tests to measure verbal recall and PET to measure brain metabolism before and after the treatment regimen. Magnetic resonance imaging was used to determine regions of interest to be examined by PET.

Funding for the study was provided by Dr. Willmar Schwabe GmbH & Co., the John Douglas French Alzheimer's Foundation, the Louis and Harold Price Foundation, the Larry L. Hillblom Foundation and the UCLA Center on Aging.

The UCLA Neuropsychiatric Institute is an interdisciplinary research and education institute devoted to the understanding of complex human behavior, including the genetic, biological, behavioral and sociocultural underpinnings of normal behavior, and the causes and consequences of neurophychiatric disorders. More information is available online at http://www.npi.ucla.edu.

Adapted from materials provided by University Of California - Los Angeles.

Read the rest of this entry »

Herbal, Nutritional Supplements Linked To Ocular Side Effects

Daily Science Journal (Oct. 22, 2007) — An estimated 42 percent of Americans use herbal medicines or nutritional supplements. Many people taking these products and their physicians are unaware of the adverse reactions they can cause. An Oregon Health & Science University researcher reviewed reported cases of ocular side effects associated with these products. His findings are published in the American Journal of Ophthalmology this month.

The researcher, Frederick W. Fraunfelder, M.D., assistant professor of ophthalmology in the OHSU School of Medicine and the OHSU Casey Eye Institute, found side effects ranging from dry eye to retinal hemorrhages and transient visual loss. Most of the side effects were associated with higher doses and topical application. While none of the reported cases caused permanent damage, many could have if the patient had not discontinued use of the product.

"A large segment of the population uses herbal medicines and nutritional supplements, many times without the treating physician's knowledge," said Fraunfelder, who also is director of the National Registry of Drug-Induced Ocular Side Effects based at the Casey Eye Institute. "These products can cause ocular side effects and clinicians need to recognize these adverse events."

Herbal medicines and nutritional supplements are not regulated by the Food and Drug Administration (FDA) as prescription and over-the-counter medications are. The World Health Organization (WHO) published guidelines on the use of herbal medicines in 2004, including recommendations on cultivating, collecting, classification, quality control, storage, labeling and distribution. However, there are no official standards governing the production of herbal medicines in the United States and the potency and purity of these products vary widely.

Fraunfelder reviewed cases of adverse ocular side effects reported to the WHO, the FDA and the National Registry of Drug-Induced Ocular Side Effects, and reviewed world literature for reported instances of adverse ocular side effects caused by herbal medicines and nutritional supplements. Out of 323 reported cases he found eight products associated with clinically significant ocular side effects: ginkgo biloba, Echinacea purpurea, chamomile, licorice, canthaxanthine, Datura, niacin and vitamin A.

One of the best-selling herbal medicines in the United States and worldwide is ginkgo biloba, which is used to treat tinnitus, asthma and tonsillitis among other things. Fraunfelder found two cases of hemorrhaging in the anterior chamber of the eye as well as reports of retinal hemorrhages in patients taking this agent. Ginkgo biloba inhibits platelet aggregation, and should be used with caution in patients taking aspirin because the effects could be amplified. Echinacea purpurea is used to treat colds, coughs, fevers, urinary tract infections, burns and influenza. Reports of eye irritation and conjunctivitis have been associated with its topical use.

Chamomile is used to treat eye disease as well as insomnia, indigestion, migraine headaches, bronchitis, fevers, colds, inflammation and burns. Chamomile tea is used by some topically in and around the eyes to treat styes and runny, irritated eyes. Fraunfelder found reported cases of severe conjunctivitis related to chamomile's topical use.

Licorice is used to treat upper respiratory tract infections, ulcers, appendicitis and constipation. American Indians use licorice to treat inflammatory eye diseases. Fraunfelder found cases of transient vision loss after licorice ingestion, similar to what one might see with an ocular migraine without headache. The side effects appear to be associated with large doses.

Canthaxanthine, a carotenoid used in cosmetics, as a food coloring and to produce an artificial suntan when taken orally, causes deposits of the drug in the retina. The deposits appear to be absorbed over time, but take years to disappear. Visual changes from this nutritional supplement are related to retinal abnormalities detected with visual field testing and electroretinography (a test of retinal function).

Jimson Weed is the most common member of the genus Datura. The dried leaves of this flower are used to treat eye inflammation as well as asthma, bronchitis, influenza and coughs. Fraunfelder found several instances of mydriasis, a prolonged dilation of the pupil.

Niacin can cause some of the most severe ocular reactions of all the products reviewed. Its cholesterol-lowering effects have proved successful in treating cardiovascular and cerebrovascular disease. It also is used for treatment of schizophrenia, diabetes, arthritis, hypertension, sexual dysfunction and migraine headaches. A comprehensive review of ocular side effects from niacin indicates a possible association with decreased vision, cystoid macular edema (CME), dry eyes, discoloration of the eyelids, eyelid edema and loss of eyebrows and eyelashes, among others. The ocular side effects appear to be dose related, but some instances would require discontinuation of niacin therapy.

Vitamin A is used primarily as an oral dietary supplement for vitamin A deficiency and for treatment of acne. Fraunfelder found reports linking high doses of vitamin A to cases of intracranial hypertension. In the majority of cases this condition resolves when vitamin A is discontinued.

Many herbal medicines interact with prescription medicines, and if the treating physician doesn't know what a patient is taking, it can be detrimental. For example, a patient taking ginkgo biloba plus aspirin or a nonsteroidal anti-inflammatory medication such as ibuprofen, may thin the blood too much, leading to ocular hemorrhage or even intracranial hemorrhage.

"Herbal medicines and nutritional supplements are being used without strong evidence of efficacy or safety. Ocular side effects from these products are often undiagnosed and unreported," said Fraunfelder. "Physicians must remain vigilant in recognizing adverse ocular side effects and inquiring whether a patient is using alternative therapies."

This study was supported in part by a grant from Research to Prevent Blindness.

Adapted from materials provided by Oregon Health & Science University.

Read the rest of this entry »

OHSU Study Finds Ginkgo Beneficial For MS Symptoms

Daily Science Journal (Sep. 28, 2007) — PORTLAND, Ore. -- When it comes to her health, Janice Winfield of Portland, Ore., does her research.

That's why the stay-at-home mom, who was diagnosed with multiple sclerosis in July 2000, was willing to turn to popular, over-the-counter herbal supplements like ginkgo biloba to deal with memory problems, fatigue and occasional muscle pain.

"I'm definitely interested in alternative medicine," said Winfield, 49, whose form of the neurological disease -- relapsing-remitting MS -- is characterized by frequent symptom flare-ups. Ginkgo "is not only given to someone like me with MS. There's benefit to anyone taking it."

Findings by scientists in the Oregon Health & Science University School of Medicine's Department of Neurology and the OHSU MS Center of Oregon appear to back up that claim. A study presented this month at the American Academy of Neurology's 57th Annual Meeting in Miami Beach, Fla., suggests that ginkgo may be effective in improving attention in MS patients with cognitive impairment. Side effects also were minimal.

The study's lead author, Jesus Lovera, M.D., a research fellow and instructor in neurology, OHSU School of Medicine, said those receiving ginkgo "performed better on a test that measures a person's ability to pay attention and to sort conflicting information."

Of 39 patients completing the study, 20 received ginkgo biloba and 19 received placebo. Researchers found there were no differences in results between the two groups in the areas of gender, education, type of MS, years since onset, or baseline performance on a battery of neuropsychological tests.

But the ginkgo group was four seconds -- about 13 percent -- faster than the placebo group on a timed color and word test that measures attention and such "executive functions" as planning, decision making, and controlling goal-directed behavior and execution of deliberate actions.

During the test, called a "Stroop," patients are shown colored boxes and asked to name the colors. They are then shown the names of colors printed with different-colored inks, such as the word "green" printed in red, and asked to read the word. Finally, patients are asked to describe the ink used for each word.

Lovera said the differences in the Stroop result would be comparable to differences in scores between healthy people ages 30 to 39 and those ages 50 to 59.

Ginkgo appeared to be more beneficial for MS patients having specific problems in the Stroop, so "we would like to do another study in which we choose patients that are impaired in this particular test," Lovera said. "We would also like to test it at higher doses."

Ginko biloba is among several complementary and alternative medicine therapies being investigated by OHSU's Department of Neurology for their effects on symptoms of neurological disease. Studies have ranged from clinical trials of lactoferrin for treating Alzheimer's disease to the use of yoga as a therapy for MS fatigue.

Ginkgo is derived from the leaves of the ginkgo tree, one of the oldest species of trees, and has been used for thousands of years by the Chinese as an herbal remedy for a variety of ailments. It contains potent antioxidants called flavoglycosides that have been shown to have neuroprotective effects in animal models of spinal cord injury. It also has terpene-lactones that block a substance known as platelet activitating factor, which is important in regulating blood vessel function as well as the mediating inflammation and the sticking of inflammatory cells to blood vessels.

Many MS patients have long suspected that ginkgo improves disease symptoms. In a recent survey of 1,913 patients in Oregon, 20 percent reported using the supplement and 39 percent found it to be beneficial. However, until now, there was no evidence the supplement had any effect on memory.

"It has been shown to be of benefit in Alzheimer's, but we did not know if it would work for MS," Lovera said. "We wanted to see if there was any suggestion that it could help patients with MS that are having cognitive problems."

Lovera said the study results demonstrate that ginkgo shouldn't be discounted for treating MS, but its safety and efficacy must be tested in much larger clinical trials before doctors should recommend it to their patients.

"The study suggests that for cognitive problems, it may only help a certain group of patients," he said. "We need to study this further."

And for MS sufferers like Winfield, who participated in the ginkgo study, the herbal supplement will remain one of the many weapons in her arsenal for fighting the disease.

"I would do it again," she said of taking ginkgo. "It could have a benefit for me that I didn't have before." But she emphasizes that "every MS is different, so what might work for me may not work for anybody else. But when it comes to alternative medicine, I'm all for that."


The study was supported by the National MS Society, the National Institutes of Health, the U.S. Department of Veterans Affairs and the Nancy Davis Center Without Walls.


Adapted from materials provided by Oregon Health & Science University.

Read the rest of this entry »

Ginkgo Herbal Supplements Vary Widely In Content

Daily Science Journal (Sep. 21, 2007) — Consumers of Ginkgo biloba herbal products, offered in alternative medicine circles as a remedy for just about everything from dementia to impotence, may not be getting their money's worth, according to a new study by scientists at the University of Idaho. Using a new analytical chemistry technique they developed specifically to examine Ginkgo samples, the researchers found variations of up to tenfold in the Ginkgo products they tested.

"Consumers seldom can be sure exactly what they are buying," says chemistry professor Chen Wai, Ph.D., lead researcher for the study, which was published in the science journal Analytical Chemistry, published by the American Chemical Society.

"The large variation of active ingredients found in Ginkgo biloba products could be a problem for the consumers," the researchers write in the journal article.

Ginkgo products are based on herbal extracts from the leaves of the Ginkgo biloba tree, also known as the maidenhair tree, which first appeared on Earth during the time of the dinosaurs about 200 million years ago. Widely marketed as a way of improving mental alertness and slowing the development of Alzheimer's disease, Ginkgo supplements are among the top selling herbal products in both Europe and the U.S. and have long been a staple of Chinese herbalists.

Chemical substances known as ginkgolides and bilobalide, found in the leaves of the tree, are believed to be the most pharmacologically active compounds, say the researchers. However, they point out, as is the case with many herbal products, the active ingredients are usually present in only trace amounts along with large quantities of other compounds. Determining the amount of ginkgolides and bilobalide in Ginkgo products generally is a time-consuming and tedious process, which has added to the difficulty of establishing efficient quality control programs for the products, claim the researchers.

"The lack of simple and reliable separation and analytical processes for herbal products is probably a major cause of the quality-related problems found in the herbal medicine market today," according to the researchers.

The process developed by Wai and colleague Qingyong Lang could help solve that problem by reducing the time required to separate the active ingredients from hours to just a few minutes. It essentially involves boiling the leaves of the tree, or Ginkgo extract products, to separate the ginkgolides and bilobalide and then using a common analytical instrument called a gas chromatograph to measure the compounds.

"Compared to other reported methods for ginkgolide separation, this method can significantly reduce the operation time," say the researchers. "The principle of this analytical method may also be applied to other medicinal herbs," they add.

Adapted from materials provided by American Chemical Society.

Read the rest of this entry »

Pros And Cons Of Antioxidants From Fruits And Vegetables

Daily Science Journal (Sep. 19, 2007) — Nutrition: It's not just the four basic food groups any more.

Researcher Dr. Susanne Mertens-Talcott of Texas A&M University is looking into how plant-based phytochemicals, including antioxidants and herbal supplements, can be useful in the promotion of health and prevention of chronic diseases.

This field is still growing. In the U.S. more than $20 billion was spent on dietary supplements in 2005, said Talcott, who is in a joint research and teaching position with the department of nutrition and food science and the department of veterinary physiology and pharmacology.

"Over $7 billion was spent on herbal dietary supplements in 2005." These supplements are plant-based, including grape seed extract, St. John's wort, ginseng and biloba extract, she added. "In addition to that there is the segment of so-called ‘functional foods,' including antioxidant foods – for example, fruit juices and beverages and grain-based products," Talcott said.

The amount spent on these foods each year "has increased drastically; however, we do not know yet how efficacious these different antioxidants really are in the prevention of chronic diseases such as cardiovascular disease and cancer," she said. "We also do not know very much about the mechanisms, which appear to include antioxidant and anti-inflammatory effects of these phytochemicals."

This can be important to health since these reactive oxygen species or ‘free radicals' may play a role in some diseases, including Alzheimer's, cancer and atherosclerosis, she said.

"However, other mechanisms, including the prevention of chronic inflammation and interaction with intracellular mechanisms, may be as important in the prevention of chronic diseases," she said. But are they safe? Are they efficient? How much is required? And how much is too much? Talcott is looking for the answers to these questions through her research.

"My overall goal is to find out more about the safety and efficacy of phytochemical dietary supplements," she said. Because these items are already popular with consumers, "we need to follow up with research. We know very little about (dose) recommendations and how safe (they are)."

Phytochemicals, also called secondary plant compounds – including antioxidants – have been defined as chemicals found in plants that have protective or disease-fighting properties.

Pomegranate juice and extract have been the focus of much of her studies. Because these are used in different food products, they are found as ingredients in many different items in supermarkets, Talcott said.

She has also done research on the properties of muscadine grapes and acai, a palm fruit from Brazil, as well as isolated compounds including quercetin and ellagic acid, which are also sold as dietary supplements.

The results of some of her studies were published in the Oct. 13, 2006, edition of the Journal of Agricultural and Food Chemistry. The article was titled "Absorption, Metabolism and Antioxidant Effects of Pomegranate (Punica granatum L.) Polyphenols after Ingestion of a Standardized Extract in Healthy Human Volunteers."

In addition to her research, Talcott teaches a class on "Special Topics in Phytochemicals of Fruits and Vegetables" for students who are majoring in nutrition and food science. Many of the students are planning to enter medical or pharmacy school, she added.

"It is my goal to give students as much relevant information, which they directly can apply in their desired profession," Talcott said. "Consumers and patients have many questions about herbal dietary supplements, and health care professionals and (members of the) food industry are and will be even more confronted with these questions."

For example, Dr. Joseph M. Betz was a recent guest lecturer in Talcott's class. Betz is the director of the Dietary Supplement Methods and Reference Materials Program Office of Dietary Supplements at the National Institutes of Health in Bethesda, Md. He discussed Food and Drug Administration rules as to the differences between foods and drugs and how each must be labeled. With regard to herbal supplements, this can sometimes be a little tricky, he said.

During the question and answer period at the end of his talk, one of the students asked about a recent study on antioxidants. According to news reports, the study seemed to find that antioxidants – especially vitamins A and E – don't have the beneficial properties they are thought to have and may even increase mortality.

Talcott offered this clarification in regard to the study: "This study statistically analyzed many different clinical studies with vitamins A, E (and) C, beta-carotene and selenium. The performed statistical analysis indicated that vitamin A and E and beta-caraotene may increase mortality in some of the selected studies. The meaning of this study currently is being discussed."

The study looked at synthetic antioxidants, she said, which are not the same compounds that she is researching. "Even though we still have a lot to learn about the efficacy, safety and dosing recommendations for herbal supplements and antioxidant foods, we can be confident to recommend a healthy balanced diet according to the food-pyramid rich in fresh fruits and vegetables. I also would not see a problem with the intake of reasonable amounts of standardized high-quality antioxidant dietary supplements," she said

"It is my long-term goal to see science-based intake recommendations developed for those herbal plant compounds which have a proven potential in the promotion of health and prevention of chronic disease."

Adapted from materials provided by Texas A&M University - Agricultural Communications.

Read the rest of this entry »

Consumption Of Green Tea Associated With Reduced Mortality In Japanese Adults, Drinking Tea Associated With Lower Risk Of Ovarian Cancer

Daily Science Journal (Sep. 13, 2007) — Adults in Japan who consumed higher amounts of green tea had a lower risk of death due to all causes and due to cardiovascular disease, according to a study in the September 13 issue of JAMA. But there was no link between green tea consumption and a reduced risk of death due to cancer.

Tea is the most consumed beverage in the world aside from water. Three billion kilograms of tea are produced each year worldwide, according to background information in the article. Because of the high rates of tea consumption in the global population, even small effects in humans could have large implications for public health. Among teas, green tea polyphenols have been extensively studied as cardiovascular disease (CVD) and cancer chemopreventive agents. Although substantial evidence from in vitro and animal studies indicates that green tea preparations may impede CVD and carcinogenic processes, the possible protective role of green tea consumption against these diseases in humans remains unclear.

Shinichi Kuriyama, M.D., Ph.D., of the Tohoku University School of Public Policy, Sendai, Japan, and colleagues examined the association between green tea consumption and mortality (death rate) due to all causes, CVD, and cancer within a large population. The study, initiated in 1994, included 40,530 adults (age 40 to 79 years) in northeastern Japan, where green tea is widely consumed. Within this region, 80 percent of the population drinks green tea and more than half of them consume 3 or more cups and day. The participants, who had no history of stroke, coronary heart disease, or cancer at baseline, were followed for up to 11 years (1995-2005) for all-cause death and for up to 7 years (1995-2001) for cause-specific death.

Over 11 years of follow-up, 4,209 participants died, and over 7 years of follow-up, 892 participants died of cardiovascular disease and 1,134 participants died of cancer. The researchers found that green tea consumption was inversely associated with death due to all causes and due to cardiovascular disease. Compared with participants who consumed less than 1 cup/d of green tea, those who consumed 5 or more cups/d had a risk of all-cause mortality and CVD mortality that was 16 percent lower (during 11 years of follow-up) and 26 percent lower (during 7 years of follow-up), respectively.

These inverse associations of all-cause and CVD mortality were stronger among women, although the inverse association for green tea consumption was observed in both sexes. In women, compared with those who consumed less than 1 cup/d of green tea, those who consumed 5 or more cups/d had a 31 percent lower risk of CVD death.

The researchers found there no significant association between green tea consumption and death from cancer. There were weak or neutral relationships between black tea or oolong tea and mortality.

"Clinical trials are ultimately necessary to confirm the protective effect of green tea on mortality," the authors write.

This study was supported by a Health Sciences Research Grant for Health Services, Ministry of Health, Labour, and Welfare, Japan.

Adapted from materials provided by JAMA and Archives Journals, via EurekAlert!, a service of AAAS.

-------------------------------------------------------------------------------

Add On Article :

Drinking Tea Associated With Lower Risk Of Ovarian Cancer

Women who drank at least two cups of tea a day had a lower risk of ovarian cancer than those who did not drink tea, according to a study in the December 12/26 issue of Archives of Internal Medicine, one of the JAMA/Archives journals.

Evidence from laboratory studies indicates that green and black tea preparations may protect against various cancers. But few epidemiological studies have examined the relationship specifically between tea consumption and the risk of ovarian cancer, according to background information in the article.

Susanna C. Larsson, M.Sc., and Alicja Wolk, D.M.Sc., of the National Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden, prospectively examined the association between tea consumption and the risk of ovarian cancer in 61,057 women, aged 40 to 76, who were participants in the population-based Swedish Mammography Cohort. Participants completed a validated 67-item food frequency questionnaire at enrollment between 1987 and 1990, and were followed for cancer incidence through December 2004. At baseline, 68 percent of the participants reported drinking tea (mainly black tea) at least once per month. During an average follow-up of 15.1 years, 301 women were diagnosed as having invasive epithelial ovarian cancer.

"We observed a 46 percent lower risk of ovarian cancer in women who drank two or more cups of tea per day compared with non-drinkers," the authors report. "Each additional cup of tea per day was associated with an 18 percent lower risk of ovarian cancer."

Women who drank less than one cup of tea per day had an 18 percent lower risk of ovarian cancer than non-drinkers. The risk was 24 percent lower for women who drank one cup of tea per day.

"This association does not depend on lower coffee consumption among women with high tea consumption; coffee is not associated with ovarian cancer risk in this cohort," the authors write.

"In summary, our results from a large population-based cohort of Swedish women suggest that tea consumption may lower the risk of ovarian cancer," the authors conclude. "Because prospective data on this relationship are scarce, our findings need confirmation by future studies."

(Arch Intern Med. 2005;165:2683-2686. Available pre-embargo to the media at www.jamamedia.org.)

Editor's Note: This work was supported by research grants from the Swedish Cancer Foundation and the Swedish Research Council/Longitudinal Studies, Stockholm, Sweden.


Adapted from materials provided by JAMA and Archives Journals, via EurekAlert!, a service of AAAS.

Read the rest of this entry »

Pomegranate Fruit Shown To Slow Cartilage Deterioration In Osteoarthritis

Daily Science Journal (Sep. 1, 2007) — Pomegranate fruit extracts can block enzymes that contribute to osteoarthritis according to a Case Western Reserve University School of Medicine study published in the September 2005 issue of the Journal of Nutrition.

The study looked at the ability of an extract of pomegranate fruit against Interleukin-1b (IL-1b), a pro-inflammatory protein molecule that plays a key role in cartilage degradation in osteoarthritis. Current treatments for osteoarthritis -- which affects 20 million people nationwide, according to the National Institutes of Health -- offer limited effectiveness and do little to slow joint destruction and disease progression.

"This has generated considerable interest in the identification and development of new approaches and reagents to treat and inhibit, if not abolish, the progress of the disease," said Tariq M. Haqqi, Ph.D., professor of medicine at Case.

"Arthritis is one of the foremost diseases for which patients seek herbal or traditional medicine treatments. However, all the extracts and herbs have not yet been scientifically evaluated for their efficacy and safety. Indeed, some of them may even interfere with the current treatments," Haqqi said. "Therefore, careful use of supplements and herbal medicines during early stages of disease or treatment may be made to limit the disease progression."

Plant-based flavonoids found in fruits, leaves and vegetables have attracted a lot of attention for their beneficial health effects in various diseases. Pomegranate, in particular, has been found to possess antioxidant and anti-inflammatory properties that have potential therapeutic benefits in a variety of diseases. The Case study demonstrated for the first time the ability of pomegranate fruit extracts to slow the deterioration of human cartilage.

"It has been revered through the ages for its medicinal properties," said Haqqi. "Studies in animal models of cancer suggest that pomegranate fruit extract consumption may be anticarcinogenic, whereas studies in mice and humans indicate that it may also have a potential therapeutic and chemopreventive adjuvant effect in cardiovascular disorders."

A bonus with the native Persian fruit is that its antioxidant constituents are rapidly absorbed by the body and are non-toxic.

Using tissue samples of human cartilage affected by osteoarthritis, researchers added a water extract of pomegranate fruit to the culture using a well-established in vitro model. The findings showed a new activity for pomegranate fruit extract -- namely cartilage protection -- in addition to its previously discovered antioxidant and anti-inflammatory properties.

The IL-1b protein molecules create an overproduction of inflammatory molecules including matrix metalloproteases (MMP), which are tightly regulated enzymes necessary for tissue remodeling. When overproduced in a disease state, such as osteoarthritis, they degrade the cartilage resulting in joint damage and destruction.

The Case study results indicate that pomegranate fruit extracts inhibit the overproduction of MMP enzymes in human cartilage cells.

"This suggests that consumption of pomegranate fruit extract may help in protecting cartilage from the effects of IL-1b by suppressing cartilage degradation in OA," Haqqi said.

More studies are needed to determine the absorption rate of pomegranate fruit extracts in the joints. Future plans include animal model studies in osteoarthritis to determine whether the fruit extract promotes cartilage repair, and whether it can also be effective in treating rheumatoid arthritis.

This research was supported in part by grants from the National Institutes of Health National Institute of Arthritis and Musculoskeletal and Skin Diseases and from the National Center for Complementary and Alternative Medicine.

Adapted from materials provided by Case Western Reserve University, via EurekAlert!, a service of AAAS.

Read the rest of this entry »

New Skin-healing Chemicals, Green Tea And The 'Asian Paradox'

Daily Science Journal (Aug. 30, 2007) — Researchers have made synthetic lipids called pseudoceramides that are involved in skin cell growth and could be used in treating skin diseases in which skin cells grow abnormally.

Ceramides are lipids found in the outermost skin layer called the stratum corneum, which is made of dead skin cells and mainly serves as a physical barrier. Ceramides' main biological function is to control how skin cells grow and differentiate -- a process through which skin cells become specialized.

Scientists have created in the laboratory synthetic ceramides, called pseudoceramides, to treat skin diseases such as atopic dermatitis, a form of eczema characterized by red, flaky and very itchy skin; psoriasis, a disease that causes red scaly patches on the skin; and glucocorticoid-induced epidermal atrophy, in which the skin shrinks due to skin cell loss.

Jeung-Hoon Lee and colleagues have developed a new series of pseudoceramides and examined their effects on skin cells. They found that three pseudoceramides called K6PC-4, K6PC-5, and K6PC-9 significantly increased the amount of proteins produced when skin cells differentiate. These results were obtained both on cultured skin cells and on a reconstituted epidermis. K6PC-4, K6PC-5, and K6PC-9 may be used to treat skin diseases arising from abnormal growth of skin cells, the scientists concluded.

Article: "Novel synthetic ceramide derivatives increase intracellular calcium levels and promote epidermal keratinocyte differentiation," by Yoo Bin Kwon, Chang Deok Kim, Jong-Kyung Youm, Hyung Sub Gwak, Byeong Deog Park, Seung Hun Lee, Saewha Jeon, Bo Joong Kim, Young-Joon Seo, Jang-Kyu Park, and Jeung-Hoon Lee

Adapted from materials provided by American Society for Biochemistry and Molecular Biology, via EurekAlert!, a service of AAAS.

---------------------------------------------------------------------------------------------------

Add On Article :

Green Tea And The 'Asian Paradox'

There is a lower incidence of cardiovascular disease and cancer in Asia where people smoke heavily, which may be accounted for by high consumption of tea, particularly green tea, according to a review article published by a Yale School of Medicine researcher.

"We do not yet have a full explanation for the 'Asian paradox,' which refers to the very low incidence of both heart disease and cancer in Asia, even though consumption of cigarettes is greater than in most other countries," said Bauer Sumpio, M.D., professor and Chief of Vascular Surgery in the Department of Surgery. "But we now have some theories."

Sumpio, the lead author of the review in the Journal of the American College of Surgeons, said he and his colleagues reviewed more than 100 experimental and clinical studies about green tea in writing the article.

He said one theory is that the average 1.2 liters of green tea consumed daily by many people in Asia offers the anti-oxidant protective effects of the polyphenolic EGCG. EGCG may prevent LDL oxidation, which has been shown to play a key role in the pathophysiology of arteriosclerosis. EGCG also reduces the amount of platelet aggregation, regulates lipids, and promotes proliferation and migration of smooth muscle cells, which are all factors in reducing cardiovascular disease, he said.

Sumpio said other reports show that EGCG prevents growth of certain tumors. Tea, according to studies, also can improve gastrointestinal function, alcohol metabolism, kidney, liver and pancreatic function, protect skin and eyes and alleviate arthritis. Tea has been used in managing and preventing allergies, diabetes, bacterial and viral infections, cavities, reduce or cure diseases with an inflammatory component and improve neurologic and psychological health.

"More studies are necessary to fully elucidate and better understand green tea's method of action, particularly at the cellular level," Sumpio said. "The evidence is strong that green tea consumption is a useful dietary habit to lower the risk for, as well as treat, a number of chronic diseases. Certainly, however, smoking cessation is the best way to prevent cardiovascular disease and cancer."

Reference: Journal of the American College of Surgeons 202: 813-825 (May 2006)

Adapted from materials provided by Yale University.

Read the rest of this entry »

Extracts From Butterbur Are An Effective Non-drowsy Treatment For 'Hay Fever'

Daily Science Journal (Aug. 23, 2007) — The largest trial so far conducted using Butterbur extract to treat intermittent allergic rhinitis (hay fever) shows that this plant extract is as effective as a commonly used antihistamine (Telfast 180).

In recent years there have been a few reports of small research trials that give a mixed view about the effectiveness of Butterbur extract for treating intermittent allergic rhinitis (IAR). Now researchers from Germany and Switzerland have published results from a randomised, double-blind, parallel group comparison study involving 330 patients in 11 centres. They found that treatment with butterbur extract was as effective at combating symptoms of IAR as treatment with a conventional antihistamine (Telfast 180). In addition they found that Butterbur extract did not cause drowsiness.

'Despite being a herbal drug, Butterbur Ze339 has now been subject to a series of well controlled trials and should be considered as an alternative treatment for IAR,' says lead researcher Andreas Schapowal.

Butterbur (Petasites hybridus) is a plant found throughout Europe and Asia and parts of North America. The roots of this plant have been used in herbal remedies for centuries while the leaves have only been introduced recently as a new herbal medicine. An extract can inhibit the body's ability to produce leukotrienes, biomolecules that are involved in the inflammatory response to allergens. They also help stimulate the body's production of prostaglandins, chemicals that play a role in reducing inflammation.

Finding an alternative therapy for IAR is important partly because up to 20 per cent of people living in Western countries suffer from it.

'Because Butterbur does not cause the sort of drowsiness that is so often associated with other anti-histamines it could be particularly useful for patients who can not tolerate other therapies,' says Schapowal.

"Treating Intermittent Allergic Rhinitis: A Prospective, Randomized, Placebo & Antihistamine-Controlled Study of Butterbur Extract," by Schapowal, Phytotherapy Research, Published Online: August 22, 2005. Available via Wiley InterScience at http://www.interscience.wiley.com/journal/ptr.

Adapted from materials provided by John Wiley & Sons, Inc., via EurekAlert!, a service of AAAS.

Read the rest of this entry »

Determining The Quality Of Ginkgo

Daily Science Journal (Aug. 17, 2007) — The National Institute of Standards and Technology (NIST) has issued a suite of Standard Reference Materials (SRMs) for ginkgo biloba, one of the most popular dietary supplements in the marketplace, with annual worldwide sales estimated at $1 billion.

Ginkgo leaves. (Credit: NIST)

The NIST reference materials are designed to help researchers validate the accuracy of analytical methods for flavonoids and terpene lactones (plant constituents that may be associated with the perceived effectiveness of ginkgo) as well as toxic elements in ginkgo*. In addition to supporting measurements associated with clinical trials or verifying product label claims, the reference materials also can be used by dietary supplement manufacturers to improve product consistency.

The fruits and seeds of the female ginkgo are used for a variety of purposes in traditional Chinese medicine. In the West, dietary supplements are more commonly formulated from ginkgo leaves and standardized leaf extracts. They are used in the treatment of asthma, bronchitis, fatigue and tinnitus (ringing in the ears); for memory improvement and for the prevention and treatment of Alzheimer's disease, although these uses have not been backed by rigorous clinical trials.

Ginkgo biloba contains a family of chemical constituents known as ginkgolides which have been associated with reduced platelet aggregation. The National Institute of Health's (NIH) National Center for Complementary and Alternative Medicine (NCCAM) notes promising results in a number of areas, but says "larger, well-designed research studies are needed."

The new ginkgo reference materials include: SRM 3246 Ginkgo biloba (leaves); SRM 3247 Ginkgo biloba Extract; and SRM 3248 Ginkgo-Containing Tablets. In addition, the three ginkgo SRMs are available packaged together as SRM 3249. The reference materials come with certified values for five terpene lactones, three flavonoid aglycones and four potentially toxic trace elements (arsenic, cadmium, lead and mercury).

The goal of NIST's ongoing effort with dietary supplements such as ginkgo biloba is to provide tools to the dietary supplement industry and measurement communities that will lead to improved quality of dietary supplements and the studies of their efficacy, as well as to ultimately reduce public health risks that could potentially be associated with the use of these products.

Support for the development of the gingko-related SRMs was provided in part by the National Institutes of Health (NIH) Office of Dietary Supplements (ODS) and the Food and Drug Administration (FDA) Center for Drug Evaluation and Research (CDER).

* C.A. Rimmer, S.B. Howerton, K.E. Sharpless, L.C. Sander, S.E. Long, K.E. Murphy, B.J. Porter, K. Putzbach, M.S. Rearick, S.A. Wise, L.J. Wood, R. Zeisler, D.K. Hancock, J.H. Yen, J.M. Betz, A.N. Pho, L. Yang, C. Scriver, S. Willie, R. Sturgeon, B. Schaneberg, C. Nelson, J. Skamarack, M. Pan, K. Levanseler, D. Gray, E.H. Waysek, A. Blatter and E. Reich. Characterization of a suite of ginkgo-containing standard reference materials. Analytical and Bioanalytical Chemistry. Published online: 7 July 2007. DOI 10.1007/s00216-007-1398-5.

Adapted from materials provided by National Institute of Standards and Technology.

Read the rest of this entry »

Green Tea Holds Promise As New Treatment For Inflammatory Skin Diseases, Tea Extracts Help Treat Damaged Skin In Cancer Patients

Daily Science Journal (Aug. 7, 2007) — Green tea could hold promise as a new treatment for skin disorders such as psoriasis and dandruff, Medical College of Georgia researchers say.

Dr Hsu says, "There are no cures for autoimmune diseases. But it is possible that this is a non-toxic way to regulate them. We need further study -- on humans -- to determine the full effects." (Credit: Medical College of Georgia)

Researchers studied an animal model for inflammatory skin diseases, which are often characterized by patches of dry, red, flaky skin caused by the inflammation and overproduction of skin cells. Those treated with green tea showed slower growth of skin cells and the presence of a gene that regulates the cells' life cycles.

"Psoriasis, an autoimmune disease, causes the skin to become thicker because the growth of skin cells is out of control," says Dr. Stephen Hsu, an oral biologist in the MCG School of Dentistry and lead investigator on the study published in the Aug. 18 edition of Experimental Dermatology. "In psoriasis, immune cells, which usually protect against infection, instead trigger the release of cytokines, which causes inflammation and the overproduction of skin cells."

Other autoimmune diseases with similar side effects include lupus, which can lead to skin lesions, and dandruff.

Green tea, already shown to suppress inflammation, helps by regulating the expression of Caspase-14, a protein in genes that regulates the life cycle of a skin cell.

"That marker guides cells by telling them when to differentiate, die off and form a skin barrier," Dr. Hsu says. "In people with psoriasis, that process is interrupted and the skin cells don't die before more are created and the resulting lesions form."

Animal models treated with green tea also showed reduced levels of proliferating cell nuclear antigen, a gene expressed when skin cells multiply. In psoriasis, the gene is over-expressed and speeds production of skin cells.

"Before treatment, the antigen, PCNA, was present in all layers of the skin," Dr. Hsu says. "Typically, PCNA is only found in the basal layer, the innermost layer where skin cells continually divide and new cells push the older ones to the skin surface, where they eventually slough off. After being treated with green tea, the animal models showed near-normal levels of PCNA in only the basal layers."

This research is important because some treatments for psoriasis and dandruff can have dangerous side effects, he says.

"The traditional treatment of ultraviolet light and medication, while it can control the lesions and be used long term, may cause squamous cell carcinoma – the second most common form of skin cancer," Dr. Hsu says. "Some of the most effective anti-dandruff shampoos also have carcinogens in them. While the U.S. Food and Drug Administration allows that in small amounts, the bottom line is that we don't know the long-term effects of using those products continuously."

Green tea, which is plant-derived, may be an alternative, he says. But scientists must work to overcome some barriers with the treatment.

The chemicals in green tea are so active that they are oxidized too quickly when mixed with other ingredients. They also dissolve in water, which cannot penetrate the skin's barrier.

Researchers are looking for a balanced formula that can dissolve in fats, which can permeate the skin, Dr. Hsu says.

Adapted from materials provided by Medical College of Georgia.

-------------------------------------------------------------------------------------------

Add On Article :

Tea Extracts Help Treat Damaged Skin In Cancer Patients

Tea extracts work as an effective treatment for patients who suffer from damaged skin following radiation treatment for cancer. Researchers show that this might partly be due to the anti-inflammatory properties of tea.

In a study published in the open access journal BMC Medicine, researchers show that tea acts at the cellular level, by inhibiting inflammatory pathways, to reduce inflammation. They also show that tea extracts reduce the duration of radiation-induced skin damage by up to 10 days in patients who received radiation treatment.

Frank Pajonk, from the University of California in Los Angeles, USA, and colleagues from the University of Freiburg, Germany, studied the effects of green tea and black tea extracts on patients who had been treated with radiotherapy, which can damage the skin. The authors then analysed the effects of the same tea extracts on human and mouse white blood cells in culture.

Pajonk et al. find that tea extracts reduce the duration of skin toxicity following radiotherapy by 5 to 10 days. Green tea extracts are more effective than black tea extracts in some patients. Pajonk et al. also show that tea extracts reduce the release of pro-inflammatory cytokines, such as IL-1beta, IL-6, IL-8, TNFalpha and PGE2, in human white blood cells in culture, with green tea having higher anti-inflammatory properties than black tea. Both black tea and green tea inhibit one major inflammatory pathway in mouse white blood cells.

Pajonk et al. add that tea's high content of polyphenols is likely to be responsible for its high anti-inflammatory activity, but that other pathways are probably involved in its clinical effectiveness.

Adapted from materials provided by BioMed Central, via EurekAlert!, a service of AAAS.

Read the rest of this entry »

Ginseng, Ginko Biloba Do Not Interfere With Drug Absorption If Taken At Recommended Doses

Daily Science Journal (Aug. 04, 2007) — Recent findings that the widely-used herbal supplement Saint John's wort could dramatically affect the absorption and metabolism of many prescription and non-prescription drugs raised concerns that other popular herbal supplements might cause similar changes, thus significantly altering drugs' therapeutic or toxic effects. What, for example, about ginseng and ginkgo biloba, two of the most widely used herbal supplements in this and other countries?

Speaking on May 1 at Experimental Biology 2007, University of Kansas Medical Center scientist Dr. Gregory Reed reports a study that found daily use of ginseng or ginkgo biloba supplements at the recommended doses, or the combination of both supplements, are unlikely to alter the pharmacokinetics - by which drugs are absorbed, distributed, metabolized, and eliminated by the body - of the majority of prescription or over-the counter drugs. Dr. Reed's presentation was part of the scientific program of the American Society for Pharmacology and Experimental Therapeutics.

The research team, led by Dr. Reed and the late Dr. Aryeh Hurwitz, recruited 72 healthy non-smoking adults (31 men and 41 women, ages 20 to 59) who were not taking any prescription drugs or dietary supplements. The participants were given a "cocktail" of five drugs, each drug in the cocktail chosen because it provides a measure of the activity of a key drug metabolism pathway. Taken together, the five drugs in the cocktail provide measurements of the pathways that determine the pharmacokinetics of over 90 percent of prescription drugs. The scientists then measured the presence of these drugs or their metabolites in each subject's blood and urine in order to establish a baseline for how each individual absorbed and metabolized the different prescription drugs in the absence of herbal supplements.

The 72 individuals next were randomly assigned to one of four groups. For four weeks, the first group received a ginseng supplement and a placebo for ginkgo biloba; the second received ginkgo biloba and a placebo for ginseng; the third received both ginseng and ginkgo biloba supplements; and the fourth received placebos for both supplements. The prescription drug cocktail was again administered and blood and urine samples taken in order to determine the absorption and metabolism of these drugs in the presence of either or both of the herbal supplements.

The scientists found no significant differences between those who received one, both, or none of the ginseng and ginkgo biloba supplements in how their bodies absorbed or metabolized any of the five prescription drugs. This suggests, says Dr. Reed, that neither ginseng nor ginkgo biloba will affect the pharmacokinetics of the majority of prescription or over-the counter drugs. He does note, however, that the team did not investigate any possible effects of the herbal supplements on pharmacodynamic interactions: the way drugs produce desired therapeutic effects or cause adverse side effects. The possibility of these pharmacodynamic, as opposed to pharmacokinetic, interactions remains to be investigated.

Studies in Dr. Reed's laboratory continue with an examination of the effects of Saint John's wort on pharmacokinetics of prescription and non prescription drugs and the role of an individual's genetic makeup in determining the magnitude of the herbal supplement's effects. This work was supported by the National Center for Complementary and Alternative Medicine of the National Institutes of Health.

Adapted from materials provided by Federation of American Societies for Experimental Biology, via EurekAlert!, a service of AAAS.

Read the rest of this entry »