Jacobson R L, Schlein Y
Department of Parasitology, Hebrew University-Hadassah Medical School, Jerusalem, Israel.
Ann Trop Med Parasitol. 1999 Jun;93(4):351-6. doi: 10.1080/00034989958348.
Leishmania major promastigotes are agglutinated and die in their vector, Phlebotomus papatasi, after the sandflies feed on some plants that are found in their natural habitat. In in-vitro assays, extracts of Ricinus communis (Euphorbiaceae), Capparis spinosa (Capparaceae), Prosopis farcta (Mimosaceae) and Tamarix nilotica (Tamaricaceae) agglutinated and killed the parasites. This activity could be inhibited by specific carbohydrates, indicating that it was the result of various lectins in the extracts. An extract of Solanum luteum (Solanaceae) lysed the promastigotes under similar conditions and this cytotoxicity was not abated by the sugars tested. High mortality of promastigotes occurred in infected flies after they ingested an extract of R. communis, even when the extract fed to the flies had been pre-mixed with glucose, a carbohydrate that inhibited the agglutination caused by such an extract in vitro. The results indicate that the lectins and toxins found in the vegetation in L. major foci may decrease the transmission of the parasite.
硕大利什曼原虫前鞭毛体在白蛉吸食其天然栖息地中某些植物后，会在其传播媒介巴氏白蛉体内发生凝集并死亡。在体外试验中，蓖麻（大戟科）、刺山柑（山柑科）、法氏牧豆树（豆科）和尼罗柽柳（柽柳科）的提取物能凝集并杀死这些寄生虫。这种活性可被特定碳水化合物抑制，表明这是提取物中各种凝集素作用的结果。黄果茄（茄科）提取物在类似条件下可裂解前鞭毛体，且这种细胞毒性不受所测试糖类的影响。感染的白蛉摄取蓖麻提取物后，前鞭毛体死亡率很高，即便喂给白蛉的提取物已预先与葡萄糖混合，而葡萄糖是一种能在体外抑制此类提取物引起凝集的碳水化合物。结果表明，在硕大利什曼原虫疫源地植被中发现的凝集素和毒素可能会减少该寄生虫的传播。
