X-Message-Number: 12399 Date: Sat, 11 Sep 1999 10:02:28 -0700 (PDT) From: Doug Skrecky <> Subject: bilobalide may be the main active ingrediant in ginkgo Authors Klein J. Chatterjee SS. Loffelholz K. Institution Department of Pharmacology, University of Mainz, Germany. Title Phospholipid breakdown and choline release under hypoxic conditions: inhibition by bilobalide, a constituent of Ginkgo biloba. Source Brain Research. 755(2):347-50, 1997 May 2. Abstract A marked increase of choline release from rat hippocampal slices was observed when the slices were superfused with oxygen-free buffer, indicating hypoxia-induced hydrolysis of choline-containing phospholipids. This increase of choline release was suppressed by bilobalide, an ingredient of Ginkgo biloba, but not by a mixture of ginkgolides. The EC50 value for bilobalide was 0.38 microM. In ex vivo experiments, bilobalide also inhibited hypoxia-induced choline release when given p.o. in doses of 2-20 mg/kg 1 h prior to slice preparation. The half-maximum effect was observed with 6 mg/kg bilobalide. A similar effect was noted after p.o. administration of 200 mg/kg EGb 761, a ginkgo extract containing approximately 3% of bilobalide. We conclude that ginkgo extracts can suppress hypoxia-induced membrane breakdown in the brain, and that bilobalide is the active constituent for this effect. Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=12399