NIH announces five Botanical Research Centers

Studies of the safety, effectiveness, and biological action of botanical products are major focuses for the five dietary supplement research centers selected to be jointly funded by the Office of Dietary Supplements (ODS) and the National Center for Complementary and Alternative Medicine (NCCAM), two components of the National Institutes of Health. The NIH’s National Cancer Institute is co-supporting two of the five centers.

The competitive awards, approximately $1.5 million each per year for five years, were made to Pennington Biomedical Research Center, Baton Rouge, La.; University of Illinois at Chicago; University of Illinois at Urbana-Champaign; University of Missouri, Columbia; and Wake Forest University Health Sciences, Winston-Salem, N.C.

These five interdisciplinary and collaborative dietary supplement centers, known as the Botanical Research Centers (BRC) Program (http://ods.od.nih.gov/Research/BRCProgram), are expected to advance understanding of how botanicals may affect human health. “Eventually, the program may provide data that translates to new ways to reduce disease risk,” explained Paul M. Coates, Ph.D., director of ODS. “Until then, the research from these centers will help the public make informed decisions about botanical dietary supplements.”

“Botanicals are usually complex mixtures of many active constituents,” said Josephine P. Briggs, M.D., director of NCCAM. “This complexity poses some unique research challenges that these centers are well positioned to address.”

The 2007 National Health Interview Survey shows that about 18 percent of adults reported taking a non-vitamin, non-mineral, natural product, spending about $15 billion on the purchase of these products. These products contain a dietary ingredient intended to supplement the diet other than vitamins and minerals, such as single herbs or mixtures.

Botanical products, including supplements, are among the most popular and use appears to be on the rise. Nutrition Business Journal (NBJ) data show that sales of dietary supplements have steadily increased by about 24 percent from 2003 to 2008. Elderberry supplement sales, for example, grew by almost 50 percent during this time. Furthermore, NBJ forecasts that sales of herbs/botanicals will increase about 19 percent over the next five years. Many of the botanicals proposed for study by the five centers appear on NBJ’s list of Top 100 Dietary Supplements According to U.S. Sales, 2002-2008: Part II. They include plant oils, garlic, soy, elderberry, licorice, black cohosh, St. John’s wort and dong quai. The safety and efficacy of these products has not been adequately studied, despite their widespread use.

In 1999, ODS received funding to develop a botanical research initiative that resulted in the BRC Program. The BRC Program is entering its third five-year cycle. Three of the five centers are renewals; that is, they received funding in the last cycle. The renewed centers are Pennington Biomedical Research Center, Wake Forest University Health Sciences, and University of Illinois at Chicago.

Award Highlights

Botanicals and Metabolic Syndrome
Principal Investigator: William Cefalu, M.D.
Institution: Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge
Partner Institutions: Biotechnology Center for Agriculture and the Environment, Rutgers University, New
Brunswick, N.J.; Louisiana State University, Baton Rouge

This center was supported from 2005-2010 and in the next five years aims to provide a comprehensive evaluation of specific, compelling hypotheses about the molecular, cellular, and physiological mechanisms by which botanicals, such as Artemisia and St. John’s wort, may reduce the chance of developing conditions that often lead to metabolic syndrome and of developing metabolic syndrome itself. Metabolic syndrome, a grouping of risk factors that may develop into diabetes and heart disease, has always been this center’s focus.

Botanical Dietary Supplements for Women’s Health
Principal Investigator: Norman Farnsworth, Ph.D.
Institution: University of Illinois at Chicago

This center has been supported for 10 years and has always focused on women’s health. In this new cycle, the center’s mission has evolved to a focus on the safety of botanical dietary supplements, such as black cohosh and licorice, which are widely available. The investigators will study how multi-component mixtures work together; how they are absorbed, distributed and eliminated by the body; how they affect chemical and physical processes within the body; how they interact with drugs; and how they impact women’s own estrogenic hormones.

Botanical Estrogens: Mechanisms, Dose and Target Tissues
Principal Investigator: William Helferich, Ph.D.
Institution: University of Illinois at Urbana-Champaign
Partner Institutions: University of Mississippi, University; Oregon State University, Corvallis;
National Center for Toxicological Research, Jefferson, Ark.

This new center will address safety, efficacy, and mechanism of action of botanical estrogens, such as wild yam,
soy and dong quai, currently being consumed by women. The projects will look at biological effects of botanical
estrogens on molecular mechanisms and cellular pathways, and their actions on bone, uterus, breast tissue, breast
cancer metastasis, and cognition.

Center for Botanical Interaction Studies
Principal Investigator: Dennis Lubahn, Ph.D.
Institution: University of Missouri
Partner Institutions: Missouri Botanical Garden, St. Louis

This new center will look at safety and efficacy of botanical dietary supplements, such as elderberry and garlic. The center’s main emphasis will be on interactions among five pathways. Signaling pathways describe a group of molecules in a cell that work together to control one or more cell functions. After the first molecule in a pathway receives a signal, it activates another molecule. This process is repeated until the last molecule is activated and the cell function involved is carried out. The function can be normal or abnormal. The primary focus being antioxidant signaling and how it relates to other pathways and mechanisms of action in preventing prostate cancer and deterioration of nerve function, as well as in improving resistance to infectious diseases.

Center for Botanical Lipids and Inflammatory Disease Prevention Principal Investigator: Floyd Chilton, III, Ph.D. Institution: Wake Forest University Health Sciences, Winston-Salem, N.C. Partner Institutions: University of Colorado Health Sciences, Aurora; Brigham and Women’s Hospital, Boston; Bent Creek Institute, Asheville, N.C.; The Johns Hopkins University, Baltimore

The goal of this renewed center is to delineate the molecular mechanisms by which botanical oils, such as borage oil, may prevent or affect disease (cardiovascular disease, asthma and metabolic syndrome) while focusing on immunity and inflammation. The center will also examine the influence of genetic differences in the metabolism of botanicals to determine the populations where they are most likely to be effective.

The mission of the NIH Office of Dietary Supplements (ODS) is to strengthen knowledge and understanding of dietary supplements by evaluating scientific information, stimulating and supporting research, disseminating research results, and educating the public to foster an enhanced quality of life and health for the U.S. population. For additional information about ODS, visit ods.od.nih.gov.

The National Center for Complementary and Alternative Medicine’s mission is to explore complementary and alternative medical practices in the context of rigorous science, train complementary and alternative medicine researchers, and disseminate authoritative information to the public and professionals. For additional information, call NCCAM’s Clearinghouse toll free at 1-888-644-6226, or visit the NCCAM Web site at nccam.nih.gov.

The National Cancer Institute leads the National Cancer Program and the NIH effort to dramatically reduce the burden of cancer and improve the lives of cancer patients and their families, through research into prevention and cancer biology, the development of new interventions, and the training and mentoring of new researchers. More information about cancer, screening, and prevention is available on the NCI Web site at www.cancer.gov or from NCI’s Cancer Information Service at 1-800-4-CANCER (1-800-422-6237).

The National Institutes of Health (NIH) — The Nation’s Medical Research Agency — includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. It is the primary federal agency for conducting and supporting basic, clinical and translational medical research, and it investigates the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.

Special Turmeric Extract Benefits Osteoarthritis Patients

Source: American Botanical Society

(Austin, TX) September 15, 2010. A new clinical trial supports the benefits to people with osteoarthritis who used a unique extract of turmeric (Curcuma longa). [1] Scientists in Italy have studied the pain-relief, increased flexibility, and other effects of a special, patented extract of the roots of turmeric, the flavorful spice that has been used for centuries as a traditional remedy. Turmeric formulations have shown a wide range of safety and significant scientific and clinical benefits in recent animal research and human clinical trials. [2,3]

The characteristic yellow color of turmeric, which is found in many yellow mustards and yellow curry preparations, derives from compounds known collectively as curcuminoids, whose most abundant member is curcumin. Curcumin is difficult to absorb into the human bloodstream from the gastrointestinal tract when consumed orally. [4]

Researchers in Italy selected 50 patients with X-ray diagnosed osteoarthritis in either one or both knees to evaluate if the special turmeric formulation called Meriva® could provide more benefits to their standard medical therapy. In this trial, the patients were split into two groups: the first one received standard medical treatment as determined by patients’ physicians, while patients in the second group added the special curcumin extract to their standard medical treatment.

After 90 days, the following benefits were observed: Compared to the controls, patients in the Meriva group experienced a 58 percent decrease in their overall pain, stiffness and physical functionality as measured by the widely used medical scoring method developed by Western Ontario and McMaster Universities (WOMAC). In addition, the Social and Emotional Index (SEI) score resulted in a greater than 300 percent improvement in Meriva patients compared to patients not taking the curcumin extract. Blood tests indicated that in patients having elevated levels of C-reactive protein (CRP), a 16-fold decrease of this inflammation marker was observed in the Meriva group. Finally, the subjects using Meriva were able to reduce their reliance on standard painkillers (NSAIDs, non-steroidal anti-inflammatory drugs) by 63 percent compared to patients on conventional medical therapy alone.

Taken together, these data show that Meriva turmeric extract improves the clinical benefit of a standard NSAIDs-based treatment of osteoarthritis, making it possible for patients to decrease their medication load and increase its efficacy.

Consistent with data from other human studies on various types of turmeric extracts, Meriva demonstrated a high degree of safety without producing any serious adverse side effects.

“This is great news for people who suffer from osteoarthritis and the physicians who treat them,” said Mark Blumenthal, Founder and Executive Director of the nonprofit American Botanical Council, an independent herbal medicine research and education organization in Austin, Texas.

“Turmeric has long been known to have anti-inflammatory and pain-relieving properties and this trial, on this special turmeric extract, is another important step towards validating the curcumin in turmeric as an increasingly popular herbal dietary supplement. When one considers the overall safety of turmeric extract and curcumin, especially compared to some of the pharmaceutical drugs which have had to be removed from the market due to serious safety concerns, the growing clinical evidence for the use of turmeric extract is compelling,” he added.

The authors of this trial write that “curcumin is one of the most extensively investigated products of natural origin. Its broad spectrum of bioactivity and low oral toxicity have expanded its use to several clinical conditions. Many potential beneficial properties of the natural product [i.e. curcumin] have not produced effective clinical results because curcumin shows a poor water solubility and stability, a low and unpredictable oral absorption, and a quick metabolism.” [1] Researchers believe that these problems have hampered the clinical development of curcumin as a pharmaceutical product and as a dietary supplement. Meriva has exhibited high levels of oral bioavailability in a previous comparative animal pharmacokinetic* study. [5]

The Meriva curcumin extact used in this clinical trial is a special patented combination of curcumin with soybean-derived phosphatidylcholine (1:2 ratio). Produced and distributed by Indena SpA of Milan, Italy, the world’s largest manufacturer of standardized botanical extracts for the food, dietary supplement, pharmaceutical and cosmetic industries. Meriva has recently been introduced into the market as a dietary supplement ingredient marketed in the USA and Europe. In this clinical study, Meriva capsules prepared by Thorne Research Inc. (Dover, Idaho, USA) were used at a dosage of 1 gram Meriva curcumin complex per day (standardized to contain 18-22 percent curcuminoids, and corresponding to 200 mg curcumin per day).

About Turmeric

Turmeric is a traditional spice, food and medicine, native to southeast Asia, and widely used in Ayurvedic system of traditional medicine in India. Turmeric is made from the roots and rhizomes (lateral roots) of the turmeric plant, a member of the same plant family as ginger. According to a recent review article, over 2,500 preclinical scientific investigations have supported the activity of curcumin from turmeric as a potential agent to treat directly or as an adjunct treatment for various chronic diseases such as inflammatory diseases, some forms of cancer and possibly also Alzheimer’s disease. Turmeric’s popularity has risen tremendously in the past few years as consumers learn more about its safety and wide spectrum of health benefits. [2,3] Turmeric dietary supplements were ranked 5th in sales in natural food stores in 2009, up about 23 percent from the previous year, generating over $10 million in sales in that market channel alone, according to a report in the American Botanical Council’s journal HerbalGram, based on information from SPINS, a market research firm which monitors sales of dietary supplements in the natural food channel of trade. [6]

About the American Botanical Council

Founded in 1988, the American Botanical Council is a leading international nonprofit organization addressing research and educational issues regarding herbs and medicinal plants. ABC’s members include academic researchers and educators, universities and libraries, health professionals and medical institutions, botanical gardens and arboreta, government agencies, members of the herb, dietary supplement, cosmetic, and pharmaceutical industries, journalists, consumers and other interested parties from over 70 countries. The organization occupies a historic 2.5-acre site in Austin, Texas where it publishes the quarterly journal HerbalGram, the monthly e-publication HerbalEGram, HerbClips (summaries of scientific and clinical publications), reference books and other educational materials. ABC also hosts HerbMedPro, a powerful and time-saving herbal database covering scientific and clinical publications on 225 herbs, and co-produces “Herbal Insights” segments on the Healing Quest television program, available on more than 145 public television stations in the United States.

ABC is tax-exempt under section 501(c)(3) of the IRS Code. Information: Contact ABC at P.O. Box 144345, Austin, TX 78714-4345, Phone: 512-926-4900. Website: http://www.herbalgram.org/.

* Pharmacokinetics is the study of the absorption, metabolism and excretion of specific nutritional or drug compounds in humans or animals.

References

1. Belcaro G, Cesarone MR, Dugall M, Pellegrini L, Ledda A, Grossi MG, Togni S, Appendino G. Product-evaluation registry of Meriva®, curcumin-phosphatidylcholine complex, for the complementary management of osteoarthritis. PanMinerva Med. 2010;52 (Suppl. 1 to No. 1):55-62.

2. Aggarwal BB, Sung B. Pharmacological basis for the role of curcumin in chronic diseases: an age-old spice with modern targets. Trends Pharmacol Sci. 2009;30:85-94.

3. Engels G. Turmeric (Curcuma longa). HerbalGram. 2010;86:1-3.

4. Anand P, Kunnumakkara AB, Newman RA, Aggarwal BB. Bioavailability of Curcumin: Problems and Promises. Mol Pharmaceutics. 2007;4(6):807-818.

5. Marczylo T, Verschoyle R, Cooke D, Morazzoni P, Steward W, Gescher A, Comparison of systemic availability of curcumin with that of curcumin formulated with phosphatidylcholine. Chemother Pharmacol. 2007;60:171-177.

6. Cavaliere C, Rea P, Lynch ME, Blumenthal M. Herbal supplement sales rise in all channels in 2009. HerbalGram. 2010;86:62-65.

Peppermint Oil for IBS

Irritable Bowel Syndrome (IBS) is one of the more common gastrointestinal disorders seen in clinical practice today. The prevalence of IBS is high: affecting approximately 10-20% of the general population. This disorder not only impacts the quality of life of those affected, but it also accounts for many missed work days and increased financial burden upon patients seeking conventional medical treatments that often do not work. Patients with this functional bowel disorder commonly experience non-specific gastrointestinal (GI) symptoms such as abdominal pain or cramping, change in stool consistency or frequency, and bloating.

Peppermint oil (PO) is one of the most extensively studied and widely used CAM treatments in IBS patients. PO has an antagonistic effect on calcium channels, helping relax GI smooth muscle. This effect helps relieve cramping and pain associated with IBS. Enteric-coated PO is usually recommended over other forms because it dissolves lower in the GI tract; this reduces the risk of esophageal reflux (PO may relax the lower esophageal sphincter). Many recent studies have shown the benefit of using PO in IBS. A clinical trial of 110 patients who had IBS (excluding patients with small bowel bacterial overgrowth, lactose intolerance, or celiac disease) was conducted. [PubMed] After patients took 4 capsules of enteric-coated PO (225 mg/capsule) daily for 4 weeks, symptoms improved in 75% of those taking peppermint oil (compared to 38% of those taking placebo). A similar study [PubMed] involving 110 patients tested the effects of PO in patients with IBS. Patients took 1 capsule of PO (187 mg) or placebo three to four times daily and 15-50 min before meals for 1 month. At the completion of study, 79% of patients in the PO group experienced a reduction in the severity of abdominal pain; 83% had less abdominal distention; 83% had reduced stool frequency; and 79% had less flatulence. Comparatively, 43% in the placebo group had reduced abdominal pain; 29% had reduced distention; 32% had reduced stool frequency; and 22% had less flatulence. Another important study [PubMed] looked at the use of enteric-coated PO in children with IBS that were between the ages of 8 and 17. In this randomized, double-blind controlled trial 43 children with IBS were given 2 PO (0.1 – 0.2 mL) or placebo capsules t.i.d. for two weeks. At the conclusion of the trial 75% of the patients receiving PO reported a significant reduction in the severity of pain associated with IBS (compared with 19% receiving placebo).

Based on this latest research, PO should be considered in IBS patients because it is safe, effective, and cost-effective in treating global symptoms and pain due to its spasmolytic and anti-flatulent effect. It is suggested that a dose of 500 to 900 mg of PO be administered per day; however, this may depend on the severity of symptoms. Enteric-coated PO is usually recommended over other forms because it dissolves lower in the GI tract reducing the occurrence of esophageal reflux.

Studies of interest:

* Irritable bowel syndrome – The role of complementary medicines in treatment. Aust Fam Physician. 2009 Dec;38(12):966-8.
* The effect of enteric-coated, delayed-release peppermint oil on irritable bowel syndrome. Dig Dis Sci. 2010 May;55(5):1385-90. Epub 2009 Jun 9.
* Review: fibre, antispasmodics, and peppermint oil are all effective for irritable bowel syndrome. Evid Based Med. 2009 Jun;14(3):84.

Source: www. validus.myompi.com

Saccharomyces boulardii improves the eradication rate of Helicobacter pylori.

Helicobacter pylori is a growing infectious disease with a prevalence rate of 70-90% in developing countries and 25-50% in industrialized countries. Typical eradication therapy consists of one PPI along with two antibiotics; most commonly omeprazole is used along with amoxicillin and clarithromycin. While this therapy is effective in some, reports show this triple therapy is not as effective as it once was. In 2003, the eradication rate using triple therapy was reported to be 75%, while in 1995 it was 85%. Besides leaving 25% of the population with an active infection, triple therapy can be very difficult for patients to tolerate the side effects of the drugs. Many patients complain of diarrhea, upset stomach, and nausea while taking triple therapy.

A study out this month in the journal Helicobacter, examines the effects of adding Saccharomyces boulardii to typical triple therapy for the eradication of H.pylori. 991 patients with an active H.pylori infection who had not previously been treated for the infection before, were included in the study. Patients were randomized into three groups; group A received triple therapy only (20 mg omeprazole, 1000 mg amoxicillin, and 500 mg clarithromycin twice a day for 7 days) and group B received the triple therapy for seven days along with 250 mg (five billion CFU) three times a day of S.boulardii for four weeks, while group C received the triple therapy along with 250 mg (five billion CFU) three times a day of S.boulardii along with a mucoprotective agent, DA-9601an extract from Artemisia asiatica, for four weeks. At the end of the study, the results showed those in group A had an eradication rate of 71.6%, while in group B the rate was 80% and in group C it was 82.1%. Patients in group B and C reported they had less diarrhea than those in group A (3.3%, 3%, and 6% respectively). Patients in group A also reported more general side effects (taste disturbance, nausea, epigastric pain) than those in group B and C.

This study shows that supplementation with S.boulardii can be an effective adjunct to triple therapy for H.pylori infections. S.boulardii is well tolerated and resists the kill of antibiotics better than other strains of probiotics like Lactobacillus and Bifidobacterium. Besides increasing the rate of eradication, S.boulardii lowered the rate of some side effects including diarrhea. While more studies are needed to learn the exact mechanism of how S.boulardii acts specifically on H.pylori, we know it has immunomodulating and anti-inflammatory properties that may be playing a role.

For a comprehensive review on S.boulardii, please see the Point Institute’s Paper titled “Saccharomyces boulardii in Gastrointestinal Related Disorders.”

Source: www. validus.myompi.com

Small Intestinal Bacterial Overgrowth and Irritable Bowel Syndrome

Since this article does not have an abstract, we have provided the first 150 words of the full text and any section headings.

To the Editor: On reading Dr Lin’s discussion of the hypothesis of small intestinal bacterial overgrowth (SIBO) as a framework for understanding irritable bowel syndrome (IBS),1 I have concerns that the only data put forward are at best indirect, and that alternate conclusions could be drawn from the given findings.

Our report of whole-body calorimeter measurement of 24-hour excretion of hydrogen and methane2 (reference 19 in the article) is referred to incorrectly. Higher hydrogen volumes and 4-fold greater maximal rates of excretion were observed in patients compared with controls, all of whom were eating the same “standard Western diet,” not following lactulose ingestion as was stated. Patients and controls were provided identical food for 14 days prior to measurement, with 3-day rotation of fixed diet. The second reported study from the same group3 (reference 21 in the article) used the same methodology, which is also misstated. Whole-body excretion of hydrogen . . . [Full Text of this Article]

Small Intestinal Bacterial Overgrowth: A Framework for Understanding Irritable Bowel Syndrome

Henry C. Lin, MD

JAMA. 2004;292:852-858.

Context Irritable bowel syndrome (IBS), which affects 11% to 14% of the population, is a puzzling condition with multiple models of pathophysiology including altered motility, visceral hypersensitivity, abnormal brain-gut interaction, autonomic dysfunction, and immune activation. Although no conceptual framework accounts for all the symptoms and observations in IBS, a unifying explanation may exist since 92% of these patients share the symptom of bloating regardless of their predominant complaint.

Evidence Acquisition Ovid MEDLINE was searched through May 2004 for relevant English-language articles beginning with those related to bloating, gas, and IBS. Bibliographies of pertinent articles and books were also scanned for additional suitable citations.

Evidence Synthesis The possibility that small intestinal bacterial overgrowth (SIBO) may explain bloating in IBS is supported by greater total hydrogen excretion after lactulose ingestion, a correlation between the pattern of bowel movement and the type of excreted gas, a prevalence of abnormal lactulose breath test in 84% of IBS patients, and a 75% improvement of IBS symptoms after eradication of SIBO. Altered gastrointestinal motility and sensation, changed activity of the central nervous system, and increased sympathetic drive and immune activation may be understood as consequences of the host response to SIBO.

Conclusions The gastrointestinal and immune effects of SIBO provide a possible unifying framework for understanding frequent observations in IBS, including postprandial bloating and distension, altered motility, visceral hypersensitivity, abnormal brain-gut interaction, autonomic dysfunction, and immune activation.

Author Affiliation: Division of Gastrointestinal and Liver Diseases, Department of Medicine, Keck School of Medicine, University of Southern California, Los Angeles.

Gastroesophageal reflux symptoms in patients with celiac disease and the effects of a gluten-free diet.

Nachman F, Vázquez H, González A, Andrenacci P, Compagni L, Reyes H, Sugai E, Moreno ML, Smecuol E, Hwang HJ, Sánchez IP, Mauriño E, Bai JC.

Department of Medicine; Dr. C. Bonorino Udaondo Gastroenterology Hospital; Buenos Aires; Argentina.
Abstract

BACKGROUNDS & AIM:: Celiac disease (CD) patients often complain of symptoms consistent with gastroesophageal reflux disease (GERD). We aimed to assess the prevalence of GERD symptoms at diagnosis and to determine the impact of the gluten-free diet (GFD). METHODS:: We evaluated 133 adult CD patients at diagnosis and 70 healthy controls. Fifty-three patients completed questionnaires every three months during the first year and more than 4 years after diagnosis. GERD symptoms were evaluated using a sub-dimension of the Gastrointestinal Symptoms Rating Scale for heartburn and regurgitation domains. RESULTS:: At diagnosis, celiac patients had a significantly higher reflux symptom mean score than healthy controls (p <0.001). At baseline, 30.1% of CD patients had moderate to severe GERD (score >3) compared with 5.7% of controls (p <0.01). Moderate to severe symptoms were significantly associated with the classical clinical presentation of CD (35.0%) compared with atypical/silent cases (15.2%, p <0.03). A rapid improvement was evidenced at 3 months after initiate treatment with a GFD (p <0.0001) with reflux scores comparable to healthy controls from this time point onward. CONCLUSION:: GERD symptoms are common in classically symptomatic untreated CD patients. The GFD is associated with a rapid and persistent improvement in reflux symptoms that resembles the healthy population. Copyright © 2010 AGA Institute. Published by Elsevier Inc. All rights reserved. PMID: 20601132 [PubMed - as supplied by publisher]

Consumption of Green Tea May Help Prevent Obesity

Grove KA, Lambert JD. Laboratory, epidemiological, and human intervention studies show that tea (Camellia sinensis) may be useful in the prevention of obesity. J Nutr. 2010;140: 446-453.

Green tea (Camellia sinensis), a popular beverage worldwide, contains large amounts of polyphenols known as catechins: (-)-epicatechin, (-)-epigallocatechin, (-)-epicatechin-3-gallate (ECG), and (-)-epigallocatechin-3-gallate (EGCG). A cup of brewed green tea contains 240-320 mg of catechins, with EGCG accounting for 30% to 50% of that amount. Green tea also contains the xanthines: caffeine, theophylline, and theobromine. It has been studied for its potential health benefits and its effects on certain chronic diseases. Obesity, which affects about 20% of U.S. adults, is a risk factor for chronic diseases (e.g., diabetes, cardiovascular diseases, and cancer). These authors summarize the literature on the potential efficacy of tea to prevent obesity.

In their review of laboratory studies, the authors focus on mechanistic data from animal model studies that have examined the effects of tea on obesity and related pathologies, including diabetes, hypercholesterolemia, and fatty liver disease. Most studies have used green tea, green tea extract (GTE), or pure EGCG in both genetic and dietary models of obesity.

One cited study reported that treatment with 7.0 µmol/g dietary EGCG for 15 weeks reduced body weight gain in male mice fed a high-fat diet compared with control mice. The treated mice had significantly lower adipose tissue weight, fasting blood glucose, fasting plasma cholesterol, and plasma alanine aminotransferase levels. The same investigators reported that short-term dietary EGCG treatment of obese mice tended to reduce body weight gain compared with high-fat-fed controls. “This treatment regimen represents a more realistic obesity-related application of EGCG or green tea supplementation, because the most likely consumers of these products would have a preexisting weight problem,” state the authors. Other cited studies, as well as one including rats fed a normal-fat diet, support these findings.

Regarding tea and genetic animal models of obesity, the authors cite a study of the efficacy of GTE in obese, leptin-deficient mice, in which there was no significant effect on body weight. The study did, however, report higher plasma high-density lipoprotein cholesterol and lower hepatic triglyceride levels in the GTE-treated mice.

Few studies have examined the interaction between tea polyphenols and exercise; however, the animal studies cited by these authors support the benefits of tea polyphenols plus exercise in reducing body weight gain.

According to the authors, the “in vivo effects of EGCG may be explained by underlying mechanisms suggested by in vitro studies of de novo lipogenesis, lipid absorption, and carbohydrate absorption and utilization.” Several studies have begun to examine the effects of tea polyphenols on fatty acid synthase. Two studies have reported that EGCG can inhibit pancreatic lipase activity, but the effective concentrations in these studies varied.

The authors cite several studies in dietary models of obesity that have examined the role of green tea-mediated modulation of glucose uptake and disposition in obesity prevention. The findings from two studies indicate that treatment with green tea can increase carbohydrate catabolism. In vitro studies have suggested that EGCG and ECG play a role in inhibiting glucose uptake in the gut.

Most studies of animal models of obesity and tea have found no significant effect of tea or tea components on energy intake. The exceptions are two studies cited by these authors: one reported a significant decrease in food intake by mice treated with Oolong tea extract compared with untreated mice, and the other study reported that 0.5% tea catechins reduced energy intake by 5.6% (the trend was not significant, however).

Regarding human studies, the authors note that there are few epidemiological studies examining the impact of tea on body weight and other obesity-related markers. More interventional studies have been conducted. In one study of healthy Japanese men, the participants consuming high-catechin tea for 12 weeks had lower body weight, waist circumference, and body fat mass compared with baseline values. In a follow-up study by the same investigators, 240 obese subjects were treated with a catechin-enriched green tea beverage or a control green tea beverage for 12 weeks. Those in the high-catechin beverage group had a significant decrease in body weight, total fat area, and visceral fat compared with baseline values. These decreases were greater than those in the low-catechin control group. The authors note that the results of studies on tea and body weight and body fat have not been “universally positive,” citing some studies that reported no significant effects of green tea consumption on body weight.

The authors further cite a study that reported a beneficial effect on weight loss and weight maintenance following weight loss with green tea consumption and a study that showed a trend toward a greater decrease in body weight with green tea and exercise, compared with exercise only. “Further studies on the interaction between tea and exercise in humans are warranted,” say the authors.

U.S. sales of green tea-based dietary supplements are increasing, partly because of the number of reports describing the potential antiobesity and other beneficial effects of tea and tea polyphenols. Green tea-based dietary supplements can potentially deliver a much higher dose of catechins than do green tea beverages. Since 1999, say the authors, 34 case studies have linked the consumption of green tea-based supplements to hepatotoxicity. Laboratory studies in animals have generally supported the supplements’ potential toxicity at high doses. “These findings suggest that caution should be exercised in the use of green tea-based dietary supplements and that further studies are needed to determine the upper limit of safety for bolus dosing with tea polyphenols as well as the underlying mechanisms of toxicity.”

The authors conclude that “laboratory studies in animals, a limited number of epidemiological studies, and small-scale human intervention studies support the hypothesis that tea and tea polyphenols have beneficial effects on weight gain, weight loss, and prevention of obesity.”

—Shari Henson

DNA robots get sophisticated by Jef Akst

Scientists are one step closer to creating molecular robots that may eventually perform complex tasks, such as building nanomolecules or delivering drugs to target tissues.

They have constructed DNA-based robots that can walk along a specific path unaided or collect various nanoparticles along an assembly line, according to two studies published this week in Nature.

“This has the feel to me of the beginning of a technology revolution,” said Andrew Ellington, an evolutionary engineer at the University of Texas at Austin and the vice president of the International Society for Nanoscale Science, Computation and Engineering, who was not involved in the research. “This work will absolutely pave the way for how you build molecular robots.”

The robots built in one study are a type of DNA walker, called a molecular “spider.” They are minute, mobile molecules that move along a flat surface made out of folded DNA, known as DNA origami, binding to and unbinding from the surface as they go.

The movement of these spiders is largely random, however, said biochemist and study co-author Milan Stojanovic of Columbia University. But together with several other big players in the nanotechnology and DNA computing fields, including Nils Walter of the University of Michigan, Erik Winfree of the California Institute of Technology, and Hao Yan of Arizona State University, Stojanovic designed a DNA origami surface that directed the DNA spider down a specified path (see video).

“You just have to start it, and it walks the path,” said chemist Kurt Gothelf, director of Centre for DNA Nanotechnology at Aarhus University in Denmark, who was not involved in the research.

The spider is fueled by the chemical interactions its single-stranded DNA “legs” have with the origami surface. In order to take a “step,” the legs first cleave a DNA strand on the surface, weakening its interaction with that part of the origami surface. This encourages the spider to move forward, pulled towards the intact surface, where its interactions are stronger. When the spider binds to a part of the surface that it is unable to cleave, it stops.

In essence, the researchers created a DNA spider that can “sense the environment,” Stojanovic said — “molecules that respond [to environmental] cues and behave [in] certain programmable ways on their own.” The next step, he added, is to increase the complexity of movements performed by such autonomous robots by compiling “a collection of rules [of] interactions between molecules and between molecules and environment.”

A fluorescence video microscopy-generated animation of a DNA spider moving along the designated path from the green-labeled start site towards the red-labeled goal. Each colored dot represents its position at a given time over the 40-minute observation period (see legend).

Credit: Nils Walter, Anthony Manzo, Nicole Michelotti and Alexander Johnson-Buck, University of Michigan

Meanwhile, Nadrian Seeman of New York University and his colleagues have designed another type of DNA walker that can collect nano-sized “cargo” as it moves. Unlike the autonomous spider, the cargo-collecting walker is controlled by single strands of DNA added by the researchers to direct the robot. These strands instruct the robot to move past an “assembly line” of three small loading devices, also made out of DNA, each containing a gold nanoparticle. Each loading device can be programmed to either donate its cargo to the passing walker, or keep it, such that the walker can receive anywhere from zero to three particles along its short (less than 200 nanometers) journey.

It’s “like an automobile assembly line,” Seeman said. “We have the option to either add or not add various components to [the walker] depending on how the devices are programmed.”

One possibility for future experiments will be to combine the advances of each of the two papers into one complex, autonomous DNA robot, said Lloyd Smith of the University of Wisconsin, who wrote an accompanying review in Nature. “It’s going to take more work to take it to that next level, [but] bringing those two things together is going to be the next step towards” a fully autonomous, functional nano-sized robot.

Another future direction, the researchers agree, would be to scale up the length of the pathways and the complexity of the behaviors. But even once greater levels of complexity are achieved, what can actually be done with the little robots is still up for debate. “This whole field,” which is still in its early stages, Smith said, “hasn’t really found the application yet.” DNA robots have thus far proven to be capable of fairly sophisticated manipulation at the nanoscale, but the practical uses of this novel technology are still a little unclear.

One popular idea is to use cargo-collecting robots to construct nanomolecules that would be difficult to make using traditional methods, because of the control they offer researchers at such a tiny scale. “The ability to hold a molecule in a particular position and hold another molecule in a defined position could open up possibilities in organic synthesis,” said Smith. Another possibility is their use in drug delivery, said biochemist William Shih of Harvard University, who did not participate in the studies. “Having a very smart robotic delivery system could do a lot better job of killing the disease tissue and do far less damage to our otherwise healthy tissue,” he explained.

But most agree that these potential applications are yet to be realized; the current work merely shows “proof of principle” that such complex behavior might one day be achieved using this technology, Seeman said.

“I think these are both really, really significant papers, not because of what we can do with [these robots] now, but because of what we can do with them in the future,” said Ellington. They are “paving the way to a future where we can do practical DNA technology.”

H. Gu, et al., “A proximity-based programmable DNA nanoscale assembly line,” Nature, 465:202-5, 2010.

K. Lund, et al., “Molecular robots guided by prescriptive landscapes,” Nature, 465:206-10, 2010

Read more: DNA robots get sophisticated – The Scientist – Magazine of the Life Sciences http://www.the-scientist.com/blog/display/57400/#ixzz0oz3tm7it

Supplements Better Than Nothing By Sheah Rarback

srarback@hotmail.com

It would be a healthier world if everyone enjoyed fruits and vegetables, but unfortunately, that is not the case. Most Americans are not eating the recommended minimum of five servings a day, and for kids the most commonly consumed “vegetable” continues to be potatoes — as in French fried.

At least once a month someone sits down with me and starts our counseling conversation with, “I don’t like vegetables and I don’t want to be told to eat them.” It is challenging. Research demonstrates a reduced risk of chronic disease with a plentiful intake of produce, so sometimes an alternative is required for the vegetable-resistant.

One option is a powdered fruit and vegetable supplement. These supplements are made by juicing and then drying fruits and veggies at low temperatures, removing water, sugar and fiber.

The companies that produce the supplements fund academic research that is published in peer-reviewed journals. The most recent was in the April 2010 online edition of Molecular Nutrition and Food Research. This double-blind study of 117 healthy men and women measured changes in inflammatory blood markers after subjects consumed either placebo or two different powdered fruit and vegetable supplements. The goal is to have low levels of inflammatory markers, since inflammation increases risk for heart disease, diabetes and cancer.

After 60 days, the subjects receiving the fruit and vegetable supplements had lower levels of inflammatory markers, as well as higher blood levels of antioxidant vitamins, when compared to the group receiving placebo.

These findings are consistent with most previous research. Similar findings have been reported for people eating fruit and vegetables or enjoying a Mediterranean vegetable soup. These results show changes in blood levels — though not less disease — in people taking supplements. Long-term studies are needed to demonstrate disease changes.

For optimal nutrition, food is always the first choice.

Any whole food pill or powdered drink is meant to be a supplement to a varied food intake. But it’s good to know there are tested alternatives available if you are not getting your five servings a day.

Sheah Rarback is a registered dietitian and on the faculty of the University of Miami Leonard M. Miller School of Medicine. Her column runs every other week.

Read more: http://www.miamiherald.com/2010/05/18/1634231/supplements-better-than-nothing.html#ixzz0oZ02TFHA

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