The consumption of botanical supplements in the United States has been increasing at a rapid rate and this trend is expected to continue. In many cases, the original indications of the putative beneficial effects of botanical supplements appear to have come from their use by Native Americans. Yet, scientific research is still confined to only a handful of the hundreds of substances sold in health food stores.
As this review shows, most available research is still confined to in vitro investigations. Only a few studies on the effects of Native American medicinal botanicals have been conducted in experimental animals, and there are even fewer reports of clinical trials. Nonetheless, what little scientific data have been gathered tend to confirm that many of the plant species contain bioactive constituents that are effective in treating the very ailments for which they were used by Native Americans. Particularly noteworthy are the indications that some of these medicinal botanicals might be useful in the treatment of chronic inflammatory diseases such as rheumatoid arthritis and SLE. The therapies currently available for both of these conditions are often quite ineffective and are almost invariably accompanied by serious adverse effects. It would, therefore, be highly desirable to find less toxic alternatives, and some medicinal botanicals might be candidates for such alternatives.
Note, however, that the safety of medicinal botanicals has only rarely been investigated, particularly with respect to long-term use and to drug interactions. Instead, much of the current research appears to focus on attempts to isolate and characterize bioactive principles. However, it should by now be clear that isolated chemical constituents of plant extracts seldom have the same effect as does the complex mixture of bioactive molecules present in whole-plant (or plant part) extracts. In view of the increasing popularity of botanical supplements, new scientific approaches for investigating these supplements need to be developed to allow research to move away from the reductionist principles that have been applied to their study so far.