In vitro anti-tumor promoting and anti-parasitic activities of the quassinoids from Eurycoma longifolia, a medicinal plant in Southeast Asia

Some quassinoids (1-6) isolated previously as plant growth inhibitors from the leaves of Eurycoma longifolia Jack. (Simaroubaceae) were subjected to in vitro tests on anti-tumor promoting, antischistosomal and plasmodicidal activities. The most active compound for inhibition of tumor promoter-induced Epstein-Barr virus activation (anti-tumor promotion) was 14,15beta-dihydroxyklaineanone (5, IC50 = 5 muM). Longilactone (1) gave significant antischistosomal effect at a concentration of 200 mug/ml. 11-Dehydroklaineanone (3) and 15beta-O-acetyl-14-hydroxyklaineanone (6) showed potent plasmodicidal activity (IC50 = 2 mug/ml). Thus it was suggested that E longifolia possesses high medicinal values due to the occurrence of a variety of quassinoids. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.