Evaluation of the anti-inflammatory, anti-nociceptive and gastric effects of Ginkgo biloba in the rat

Ginkgo biloba extract (GbE) was assessed in models of acute inflammation induced by carrageenan, formalin or capsaicin in the rat, in models of nociceptive pain, such as hot-plate (55 degreesC) latency, tail-electric stimulation assay and capsaicin-induced paw licking and in the model of acute gastric damage induced by indomethacin. The agent showed marked anti-inflammatory activity in the carrageenan model of paw oedema. When given subcutaneously (s.c.) (25 and 50 mg kg(-1)) 30 min before challenge, GbE inhibited paw oedema with a maximal effect of 43.7 and 56.9%, respectively, at 2h post-carrageenan. Significant inhibition of oedema was also observed when GbE (50 mg kg(-1), s.c.) was given 30 min after carrageenan challenge. The agent was also active p.o. in acute inflammation caused by carrageenan. The administration of GbE with indomethacin, rofecoxib, celecoxib, dexamethasone or melatonin resulted in an additive effect. GbE (50 mg kg(-1), s.c.) caused significant inhibition of formalin-induced paw oedema, but did not reduce the capsaicin-induced paw oedema. In tests of nociception, GbE (25, 50 or 100 mg kg(-1)) decreased in dose-dependent manner the capsaicin-induced hind paw licking time and was similarly effective in the hot-plate assay of nociception. In contrast, when assessed in the tail-electric stimulation test, GbE was only effective in the highest dose (100 mg kg(-1)). In pylorus-ligated rats, GbE (25 or 50 mg kg(-1)) increased gastric acid secretion, but reduced gastric mucosal damage caused by IND. Results suggest that GbE may be of clinical value as an anti-inflammatory and analgesic drug alone or in conjunction with NSAIDs. (C) 2003 Elsevier Ltd. All rights reserved.