Editors' pick 2009

Herbal medicines and beverages: beyond SJW and GFJ!

Much continues to be written regarding the evidence (or lack thereof) underpinning therapeutic claims for the use of herbal medicines. Compounding the uncertainty is the potential for interactions with chemically-synthesised western medicines as exemplified by the interaction of St John's Wort (SJW) with ciclosporin that can culminate in organ rejection. These interactions with herbal medicines segue into interactions between fruits/fruit juices and drugs, with grapefruit juice (GFJ) interactions pointing up new mechanisms of drug ‘absorption’ and incomplete bioavailability. Whereas such interactions are predictable from in vitro data for chemically-synthesised small molecule medicines, the same cannot be said for herbal and fruit-derived medicines because of the myriad of compounds that these contain. Indeed, quantitative variation in the constituents of such preparations, even between different lots of the same product, is a major unresolved problem. Hence human and not animal studies remain the primary source of information. Three recent publications in the Journal highlight new and important aspects of such interactions.