Botanic evidence

It is remarkable that cultures native to the American continent knew about a relatively large number of natural mind-altering substances compared to early cultures that evolved in Europe or Asia. Botanical evidence does not support the notion that Europe is home to fewer hallucinogenic plants than other regions. Furthermore, the growing number of recently discovered European mushroom species containing psilocybin indicate a flourishing psychotropic mycoflora in Europe similar to those found in other countries. 

Tomas-Barberan, F. A., Garcia-Viguera, C., Vit-Olivier, P., Ferreres, F., and Tomas-Lorente, F. (1993b). Phytochemical evidence for the botanical origin of tropical propolis from Venezuela. Phytochemistry 34,191-196. 

The United States Pharmacopeial Convention, Inc. (USP) in 2000 issued the USP criteria for levels of evidence for botanical articles [117]. While issued for botanicals, the criteria have application to all therapeutic agents. The USP criteria rank evidence from I to IV, with Level I being the strongest. Within Level I, the randomized controlled clinical trial is ranked highest, followed by meta-analysis and epidemiological studies. Level II consists of the same designs, but with methodological flaws. Level III includes inconclusive studies, and Level IV is anecdotal evidence. 

USP Announces Criteria for Levels of Evidence Policies for Botanical Articles, [Internet], URL http //www.usp.Org/frameset.htm7http //www.usp.org/ aboutusp/releases/2000/pr 2000-23.htm top, accessed 10-31-2000. 

The full version of this table is available from the National Auxiliary Publications Service (NAPS). (See NAPS document no. 05609for33pages of supplementary material. Toorder, contact NAPS, c/o Microfiche Publications, 248 Hempstead Tpke., West Hempstead, NY 11552.) Adverse effects of multiple-herb therapies are not included. Case reports do not always provide adequate evidence that the remedy in question was labeled correctly. As a result, it is possible that some ofthe adverse events reportedforaspecific herb were actually due to a different, unidentified botanical or another adulterant or contaminant. 

Note In column 2 (7), sales rankings, by dollars, for the top 20 sold in the United States for the year 1999 are given. Column 3 (12) gives the top 10 products in 2002 in an ambulatory adult population (13). Reported sales in dollars are present in column 4. Columns 5 and 6 (66) give the conditions the botanicals have been used for. The Natural Medicines Comprehensive Database at http //www.naturaldatabasc.com (66) distinguishes gradations of evidence for effectiveness, which we have not done here. There is much variability in the data from report to report even data within the same trade journal data are inconsistent with that from previous reports. This in no way endorses the utilization of dietary supplements for treatment of these conditions. Patients should always seek the advice of their health care provider. 

However, the information derived from a detailed pharmacokinetic study will help to anticipate potential botanical product-drug interactions, to optimize the bioavailability, the quality, and hence the efficacy of herbal medicines, to support evidence for the synergistic nature of herbal medicines, and to better appreciate the safety and toxicity of the plant. Because pharmacokinetic studies with herbal medicines are often complicated by their chemical complexity and by the fact that the active compounds are often unknown, it could be one future issue to assess bioavailability by measuring surrogate parameters in plasma or tissue instead of directly assaying putative active compounds in the blood. In summary, to use HMPs in an evidence-based approach and to achieve the status rational phytomedicine, more experimental studies are needed to characterize the bioavailability and pharmacokinetics of botanical products. 

---