Effects of Ginkgo biloba on airway histology in a mouse model of chronic asthma.

Platelet-activating factor (PAF) is an inflammatory mediator involved in the pathophysiology of asthma, suggesting a therapy antagonizing its effects may play a role in the disease treatment. The aim of the study was to determine the effects of Ginkgo biloba, a PAF antagonist, on lung histology. Thirty-five BALB/c mice were divided into five groups; A, B, C, D, and the control. All mice except controls were sensitized and challenged with ovalbumin. Mice in group A (placebo) received saline; group B received G. biloba, 100 mg/kg; group C received G. biloba, 150 mg/kg; and group D received dexamethasone, 1 mg/kg via orogastric gavage for 7 consecutive days. Chronic structural changes and airway remodeling were evaluated by using light and electron microscopy in all groups. Evaluation of lung histology indicated that the number of goblet cells, mast cells, thicknesses of epithelium, and basement membrane were significantly improved in groups B and C when compared with group A. There was no statistically significant difference in thicknesses of subepithelial smooth muscle between groups A, B, and C. When doses of G. biloba were compared with each other, only the number of goblet cells was significantly lower in group C than in group B. When G. biloba and dexamethasone groups were compared with each other, thicknesses of basement membrane and subepithelial smooth muscle were found to be lower in group D than in groups B and C. G. biloba alleviates all established chronic histological changes of lung except smooth muscle thickness in a mouse model of asthma.