Medical Herbalism and Herbal Clinical Research: A Global Perspective

Abstract

This review aims to sensitize researchers, regulators and other stakeholders to the centrality of clinical research to drug development from herbs used in Traditional Medicine (TM). The review uncovered and dwelt on the fact that: while clinical trials of chemical medicines (pharmaceuticals) tend to come late in the drug development chain, the reverse is often the case with herbal medicines (phytomedicines). Once the decision is made to develop a single phytochemical entity (phytopharmaceutical, example: artemisinin) from a plant, the need for such sensitization is particularly desirable, given their huge socioeconomic implications. The review emphasized that drug development from a traditional herb can: i) take the route of standardization of the herb or its extract for immediate use without further chemical manipulations; or ii) proceed along the line of isolation and other manipulations aimed at optimising bioactivity. By the first route, development proceeds directly from confirming that the pharmacological property of the herb tallies with its traditional indication, leading instantly to value addition to traditional knowledge accumulated over years. This is because herbal medicines based on time tested traditions need not undergo phased trials as would a novel pharmaceutical (or an old herb for a new indication), since their long histories often offer evidence of their safety and efficacy. In the second route, clinical studies usually come later in the chain. This is because, unlike the traditional therapeutic, the new phytopharmaceutical, taken out of its natural microenvironment and subjected to various chemical manipulations, including purification, is no longer the equivalent of the ancient remedy with predicable effects. Moreover, in this later case, interest in the new entity (an artificially concentrate isolate) may shift completely from the traditional indication of the herb, hence the need for phased trials of phytopharmaceuticals (or an old herb for a new indication), despite their natural origin.