The effect of alpha lipoic acid useage on polychlorinated biphenyl toxicity in testicular tissue of rat

The aim of the present study was to investigate the antioxidant, histologic and biochemical effects of alpha lipoic acid (ALA) in polychlorobipheniyl (PCB)-induced testicular toxicity. Fourty adult male albino Wistar rats (180-200 g/ 90 days) were used. The animals were randomly divided into 5 groups consisting of 8 animals each. Group I rats (control group) did not receive any chemicals for during experimental period. Group II (control sham) received 2 ml/kg body weight (BW) corn oil by oral gavage. Group III rats received Aroclor 1254 (5 mg/kg BW) dissolved in corn oil (2 ml/kg BW) by oral gavage. Groups IV rats received ALA (25 mg/kg BW) dissolved in corn oil. Groups V rats received ALA (25 mg/kg BW) by oral gavage 24 hours prior to the administration of Aroclor 1254 (5 mg/kg BW). Applications were practiced by oral gavage with feeding needle for a period of 30 days. At the end of experimental period, all animals (120 days old) were weighted and their testis weights were determined. Total oxidant status (commercial kit/TOS Assay Kit, Rel Assay Diagnostics, RL0024) and total antioxidant status (commercial kit/Total Antioxidant Status-TAS Assay Kit, Rel Assay Diagnostics, RL0017) and, serum testosteron levels (Testosterone EIA Kit, Cayman Chemical 582701) were analysed in serum samples. Right testes were taken, for analysis of TOS and TAS levels and HO-1 band intensity, Sperm samples were taken from epididymal ducts and the slides were prepared. The slides were stained with eosin-nigrosin, in order to determine the number of abnormal spermatozoa. Crossman's triple staining methods, TUNEL method and strept avidin-biotine complex (sABC) were applied to the serial paraffin sections. Histological apparence, histological alterations, incidences of stage XIV tubules, apoptotic cells, HO-1 density were defined in tissue sections and the count of abnormal spermatozoa were determined with light microscope examination. Seminiferous tubule diameter and seminiferous epithelium height were measured at stage VII-VIII and stage XII-XIV tubules with image analyze system which was linked to a microscope (Leica Q Win Standart). An increase in sub-basal vacuolization, epithelial desquamation, the presence of germ cells across to tubular lumen and capillary congestion was determined in PCB group. Seminiferous tubule diameter were decreased at stage VII-VIII and stage XII-XIV tubules. Apoptosis, HO-1 density, total oxidant status in serum and testis and the count of abnormal spermatozoa were significantly increasedin PCB group. In ALA-PCB groups, sub-basal vacuolization, desquamation of germinal cells in the epithelium, germ cells across to tubular lumen, capillary congestion and apoptosis were decreased. At the end of the study, we determined the protective effect of alpha lipoic acid (ALA) in PCB-induced testicular toxicity. In this study, in contrast to published data, serum testosterone levels were not effected in PCB groups. The reason for this discrepancy could be due to the fact that PCB was given via oral route. This study is the first research investigating the antioxidant effect of alpha lipoic acid (ALA) against PCB toxicity in the testes. Future work in the field by changing the utilization rate and the administration method of ALA, will contribute to determine the antioxidant and antiapoptotic effects of ALA in the male reproductive system. Key words; Aroclor 1254, alpha lipoic acid (ALA), histometry, TUNEL, HO-1, testosterone, total oxidant status, total antioxidant status, abnormal spermatozoa, rat.