Ginkgolide B (BN-52021), an important active terpenoid from Ginkgo biloba leaves, is reported to increase cell viability and decrease cell apoptosis. IC50 value: Target: In vitro: Ginkgolide B (0.2 or 0.4 μg/ml) was added to the culture medium in vitro led to increases in cell viability and decreases in the number of hippocampal cells undergoing AAPH-induced apoptosis [1]. Ginkgolide B caused a dose-related protection against dysrhythmias; the antiarrhythmic effect of ginkgolide B was comparable to that of diltiazem and superior to the activity of metoprolol. Ginkgolide B can presumably prevent the re-entry mechanism involved in the development of ischemia-induced rhythm disturbances [2]. In vivo: Oral administration of ginkgolide B (2 mg/kg/day, p.o.) caused a significant increase in cell viability and a highly significant decrease in the numbers of both spontaneously occurring and AAPH-induced apoptoses.