New macrofilaricidal leads from plants?

The continuing need for a new safe and effective macrofilaricidal drug for the treatment of filarial infections in man is outlined, together with the possibility that structural leads for the identification and synthesis of such drugs might be derived from higher plants. Many of todays successful drugs were derived from plants and it is interesting to note that the majority were discovered through follow-up research on the folk or ethnomedical uses of plants. In this review an attempt has been made to compile a list of those plant species for which there is evidence supporting their usefulness in the treatment of filarial conditions in endemic areas. Perhaps surprisingly the use of such plant medicines appears quite widespread, and details of 90 plant species are summarised. The value of this information is discussed in the light of the fact that few of these citations are supported by clinical or scientific investigations into their efficacy, and the lack of knowledge regarding the antifilarial active constituents. It is concluded that in view of apparent failure of more rational approaches to yield macrofilaricidal leads there is justification for examining further medicinal plants, and that the data summarised might be a useful starting point for such a screening programme.