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Aug. 25, 2011 Volume 33, No. 1

Three new studies target claims of botanical-based dietary supplements


FIELD TEST Dennis Lubahn heads the Center for Botanical Interaction Studies. He will lead 21 MU researchers in the study of dietary supplements. Lana Eklund photo


One-third of Americans use herbal remedies

The Center for Botanical Interaction Studies has launched three studies to see if popular botanical-based supplements have a real, positive and provable scientific effect on the body.

The first study will test five widely-used botanical dietary supplements that purport to prevent prostate cancer. The second will see if certain botanicals promote brain health and prevent neuro-degeneration. The third project will investigate if botanical compounds claimed to have anti-oxidant and anti-microbial properties are effective at changing cellular events associated with an effective microbial defense.

Dennis Lubahn, center director and project leader of the prostate cancer study, is leading a team of 21 MU researchers whose expertise ranges from agronomy to the diseases of laboratory animals. The team will take an interdisciplinary research approach utilizing the unique range of backgrounds and skills on MU’s Columbia campus and the Missouri Botanical Garden in St Louis. The research was made possible by the NIH’s National Center for Complementary and Alternative Medicines, the Office of Dietary Supplements and the National Cancer Institute.

The research is aimed at understanding a large and growing part of American healthcare. Nearly one-third of Americans use dietary supplements for medicinal purposes. Financially, the market has progressed steadily from 5.5 percent annual growth in 2007 to 6.5 percent in 2008 to 7.5 percent in 2009, bringing US retail sales to $9.4 billion in 2009.

Not much science has been collected on how effective these plant compounds are. Worse, the pills and extracts are being consumed in a hard-data vacuum. A New England Journal of Medicine study found that nearly 70 percent of people taking herbal medicines or dietary supplements, most of whom were well educated and had a higher-than-average income, were reluctant tell to their doctors that they used complementary and alternative medicine. Many dietary supplements can interact with prescription medications and cause unwanted or dangerous reactions.

The MU prostate cancer research will use an animal prostate cancer model to test the safety and efficacy of certain supplements that show anecdotal promise as a cure for the disease. Here, mice with a genetic propensity that protects them against poorly differentiated carcinoma (PDC) and mice that are susceptible to PDC will be tested with certain plant compounds thought to inhibit “hedgehog signaling.”

The hedgehog signaling pathway gives cells information that they need to make the embryo develop properly. The pathway also has roles in the adult mouse. When the pathway malfunctions, it can result in diseases like basal cell carcinoma.

In the second research program, it is known that excessive oxidative and nitrosative activities in the brain are the basis for neural toxicity and cell inflammation. These effects underlie many neuro-degenerative diseases, including stroke. The research strives to test the hypothesis that stroke-mediated neural toxicity and glial inflammatory responses are due in part to the presence of proteins in certain signaling pathways. The research hopes to identify botanicals that can positively modify the effects of these proteins.

The third research effort will conduct pre-clinical screening of selected antioxidant botanicals for their potential to modulate in vivo anti-microbial and anti-viral activity. Crude extracts as well as putative bioactive components of each botanical will be tested against two bacterial infections, E. coli-mediated sepsis and systemic listeriosis.

Plants had been used as medicine long before recorded history. Ancient Chinese and Egyptian papyrus writings describe medical plants. Indigenous cultures in Africa and ancient North America used herbs in their healing rituals. Others developed traditional medical systems, such as Ayurveda and Traditional Chinese Medicine, in which herbal therapies were used.

In the early 19th century, when chemical analysis became available, scientists began to extract and modify the active ingredients from plants. Later, chemists began making their own version of plant compounds creating aspirin and digitalis. Over time, use of herbal medicines declined in western nations, although the World Health Organization estimates that 80 percent of people worldwide rely on herbal medicines for some part of their primary health care.

US consumers are turning to supplements as an affordable way to stay healthy. According to the dietary supplement industry, older Americans are more likely to use supplements, sometimes as a replacement for expensive prescription drugs.

The MU center is looking at herbal and botanical products, probably the largest part of this industry. These products are generally taken for reasons other than nutrition, although FDA labels them as a food supplement.

Probably the most common plant-based supplement is Ginkgo, which us used in traditional medicine to treat circulatory disorders and enhance memory. Kava kava is said to elevate mood, well-being, and contentment and produce a feeling of relaxation. Saw palmetto is used by more than two million men in the US for the treatment of a non-cancerous enlargement of the prostate gland. Should the excited claims of the supplement industry be dismissed out-of-hand? Maybe, but maybe not, said Lubahn.

“There must be some sort of recognizable benefit to this use, or why would they continue using them,” Lubahn said. “Nature has thousands of secrets that we have yet to discover. What we are doing may be a step in uncovering some of those secrets.”

— Randy Mertens