Effect of EGb-761 on vasospasm in experimental subarachnoid hemorrhage

Based on the previously suggested hypothesis that the generation of free ra dicals leading to lipid peroxidation is involved in the genesis of vasospas m and vasculopathy following subarachnoid hemorrhage, the therapeutic effec t of EGb 761 as an antioxidant on experimental vasospasm and vasculopathy w as evaluated in a double hemorrhage dog model of chronic cerebral vasospasm . For this study 14 dogs were randomly assigned to two groups, a control an d a Ginkgo biloba group. The control group was only administered saline in a volume equivalent to a dose of 100 mgEGb 761/kg while the treatment group was given 100 mg EGb 761/kg. The diameter of the basilar artery decreased from 1.95+/-0.16 mm at day 0 to 1.11+/-0.07 mm at day 8 in the control grou p, while in the treatment group the vessel diameter decreased from 2.01+/-0 .17 mm at day 0 to 1.72+/-0.16 mm at day 8. These results correspond a decr ease in vessel diameter of 15.1% in the treatment group and of 43.1% in the control group (P<0.05). Histopathological studies of the specimens obtaine d from basillar arteries showed that pathological signs of proliferative va sculopathy, including narrowing of the vessel lumen, corrugation of the lam ina elastica and subendothelial thickening, were present in all the animals in the control group, while they could not be demonstrated in the Ginkgo b iloba group. These results suggest that Ginkgo biloba may have a protective effect against subarachnoid hemorrhage-induced vasospasm and vasculopathy as a result of antioxidants.