Abstract
The present study was aimed to investigate the role of alpha-lipoic acid ( ALA) as an antioxidant against in ameliorating histological disorders of pituitary- testicular axis- induced by hydrogen peroxide (H2O2) in adult Wistar rats. Forty adult male rats were randomly divided into four equal groups (10 rats /group) and were handled daily as follows for 56 days: Control group ( C) were intubated distilled water and received ordinary tap water; group T1 were intubated 60mg/kg B.W of ALA and received ordinary tap water; group T2 were administered H2O2 in tap water at a concentration of 0.05%, while group T3 were intubated 60mg/kg B.W of ALA and received ordinary tap water containing 0.05% H2O2. At the end of the experiment, body weights were recorded, then pituitary and testes were excised for histopathological study and testicular weight was recorded too. Rats administered H2O2 showed a significant decrease in testes weight to body weight ratio accompanied with major histopathological changes of the testes in comparison with other groups including; a significant decrease in the diameter of seminiferous tubules, high of germinal epithelial cell and degenerative changes with incomplete spermatogenesis. Besides, a significant decrease in the number of Leydig's cells in comparison with other experimental groups. Furthermore, pituitary gland of group T2 manifested a severe histological alteration in architecture characterized by atrophy with marked necrotic and degenerative changes. Whereas, rats administered ALA (group T3) shows an improvement of histological changes of pituitary and testicular tissues induced by hydrogen peroxide. In conclusion, the results indicated that alpha-lipoic acid mitigated pituitary-testicular dysfunctions induced by H2O2 through its antioxidant effects via scavenging free radicals.

Key words: Hydrogen peroxide, Alpha lipoic acid, Testes, Pituitary gland, Leydig's s cells