Nigerian Bonny Light Crude Oil Disrupts Antioxidant Systems in Testes and Sperm of Rats

Abstract

Nigerian Bonny light crude oil (BLCO) is commonly used by the local population in folklore medicine for the management of various forms of gastrointestinal problems and male reproductive capacity. The study investigated the effects of BLCO on the antioxidant systems of the testes and epidydimal sperm in rats by oral exposure to 0, 200, 400 and 800 mg/kg BLCO for 7 days. In testes and sperm, BLCO treatment at all doses significantly (p<0.05) decreased superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST) activities, whereas it markedly increased glucose 6-phosphate dehydrogenase (G6PD) and gamma glutamyl transferase (GGT) activities as well as increased glutathione (GSH), hydrogen peroxide, and malondialdehyde (MDA) levels in all treatment groups. Although epididymal sperm number (ESN), daily spermatozoa production (DSP), and sperm motility were significantly decreased, total sperm abnormalities were significantly increased without affecting sperm viability at all dose levels compared with controls. The adverse effect of BLCO on TSN was noted at the 800 mg/kg dose only. Histopathology results showed treatment-related lesions of the testes characterized by severe congestion of interstitial vessels, decreased germinal epithelium, and increased number of vacuolization. These results suggest that exposure to BLCO, such as its use in ailment management, may promote infertility by altering the function of the testes and sperm, particularly by way of induction of oxidative stress.