Protective effect of dl-α-lipoic acid in cyclophosphamide induced oxidative injury in rat testis

The aim of the present study was to evaluate the protective effect of dl-α-lipoic acid on the biochemical changes, tissue peroxidative damage and abnormal antioxidant levels in the rat testis during cyclophosphamide (CP)-induced injury. Adult male Wistar rats were divided into four treatment groups: (I) control, (II) 15 mg/kg CP once a week for 10 weeks by gavage, (III) 35 mg/kg lipoic acid once a week for 10 weeks by intraperitoneal injection, and (IV) CP plus lipoic acid (24 h prior to CP administration). Testicular toxicity, assessed by decreased enzymatic activities of lactate dehydrogenase and glucose-6-phosphate dehydrogenase, was reversed with lipoic acid pretreatment. CP-exposed rats (group II) showed abnormal levels of enzymes (superoxide dismutase, catalase, glutathione peroxidase, glutathione- S-transferase and glutathione reductase) and antioxidants (reduced glutathione, ascorbate and α-tocopherol) along with high malondialdehyde levels. In contrast, rats pretreated with lipoic acid (group IV) showed normal lipid peroxidation and antioxidant defenses. These findings indicate a cytoprotective role of lipoic acid in this experimental model of testicular toxicity.