A dose-effect relationship of Ginkgo biloba extract to nerve regeneration in a rat model

The effect of Ginkgo biloba extract (EGb(50)) on nerve regeneration and its dose-effect relationship was investigated in a rat model. Sciatic nerve transection and repair was done in 120 Sprague-Dawley rats. The animals were divided into four groups and given normal saline, low-dose EGb50 (50 mg kg(-1) d(-1)), moderate-dose EGb50 (100 mg kg-1 d-1), and high-dose EGb(50) (200 mg kg(-1) d(-1)), respectively. Electrophysiological, histological examinations, and functional evaluation were conducted at various postoperative intervals. Sensory regeneration distance, sciatic functional index (SFI), motor nerve conduction velocity, compound muscle action potential, axon regeneration index, and muscle mass were significantly higher in EGb50 groups than in saline groups. All but SFI of those parameters were better in high-dose group when compared with those in moderate- and low-dose groups. EGb50 has the effect of promoting regeneration of injured peripheral nerve. The higher the dose, the better the result. (C) 2007 Wiley-Liss, Inc.