Traditional herbal medicines: a guide to their safer use.

摘要

As a pharmacology student I was taught that 'alkaloids' are basic drugs derived from plants. Atropine, nicotine, tubocurarine, quinine, ephedrine, cocaine, morphine and the rest featured heavily in the course both as therapeutic drugs and as tools for investigating physiological function. Pure substances are extracted from natural sources (vegetable, fungal, microbial or animal) using a variety of physical chemical separative techniques coupled with bioassay to identify fractions where activity is located. This leads to the identification of pure substance (or substances) and is followed by structural analysis and chemical synthesis of the pure drug. Many such drugs remain in first-line therapeutic use, and many others formed the starting point for the synthesis of chemical variants with more selective biological activities, or other desirable properties. Many of today's drugs were derived in this way, and so it comes as no surprise to the practitioner of scientific medicine that herbs contain substances with potent biological activities that may cause either good or ill. Pharmaceutical scientists looking for leads remain interested in natural products and traditional herbal remedies for this reason.