[en] Strychnos ; Pharmacological properties ; Review of recent studies
[en] During the past fifteen years, African Strychnos species have been pharmacologically and chemically screened by some European Universities, sometimes with the collaboration of some African Institutes. Strychnos usambarensis will be discussed here because of interest in it, after the discovery of its use in the preparation of an arrow poison with curarizing activity.The European studies have shown that the African species of Strychnos chemically are very similar to certain South-American species. Indeed, the occurrence in the African species of curarizing quaternary bases, and in the American species of tetanizing bases, such as akagerine, emphasizes the unity of genus Strychnos in terms of its alkaloids.Many biological activities (antimicrobial, hypotensive, spasmolytic,amoebiidal...) have been detected. Finally the antimitotic properties of some alkaloids will be presented. Besides known antitumor drugs e.g. ellipticine and alstonine, African species possess new antimitotic products, e.g. strychnopentamine present in Strychnos usambarensis. Because of these findings, the main reasons why further investigate Brazilian Strychnos species are the lack of knowledge about: -the distribution of the species in the Southern part of the great Amazon basin. According to KRUKOFF, it is possible that new species may be found there.-the distribution of alkaloids in many of known species. Indeed, there is little information on the variation in composition of the alkaloidal mixtures in the different parts of the plants. -the biological activities of alkaloids. in the past, interest has been focused too narrowly on possible curarizing properties. Why should Brazilian species not contain alkaloids with properties similar to those found in the African species?