Inhibition of Rat Adjuvant-Induced Arthritis by Ginkgetin, a Biflavone from Ginkgo biloba Leaves

Abstract

Ginkgetin, a biflavone isolated from Ginkgo biloba leaves, was previously reported as an inhibitor of group II phospholipase A₂. In this study, ginkgetin was evaluated for in vivo antiarthritic and analgesic activities. Ginkgetin (10- 20 mg/kg/day) strongly reduced arthritic inflammation in an animal model of rat adjuvant-induced arthritis (86% inhibition at 16 days at a dose of 20 mg/kg/day) via intraperitoneal injection, while prednisolone (5 mg/kg/day) showed 79% reduction. Histological examination of the knee joints confirmed our findings. When analgesic activity was measured, ginkgetin showed a dose-dependent inhibition in an animal model of acetic acid-induced writhing. ED₅₀ values for ginkgetin and indomethacin were 8.9 and 3.8 mg/kg, respectively. All these results indicate that ginkgetin may be a potential antiarthritic agent having analgesic activity.