Background: Mounting experimental evidence highlights the testicular and neuronal toxicity of environmental/industrial chemicals in experimental animals via the mechanism involving oxidative damage. Nigerian Bonny Light crude oil (BLCO) has been reported to exhibit reproductive and neuronal toxicity in male rats. Studies have shown that vitamin E and quercetin protect rat neuronal and testicular cells from environmental chemical-induced oxidative damage. We investigated the possible protective role of quercetin and vitamin E in BLCO induced-neuronal and testicular toxicity.
Methods: Male rats were administered BLCO at doses of 400 and 800 mg/kg body wt/day p.o. three times/week for 6 weeks. Other groups were co-administered BLCO (400 and 800 mg/kg body wt/day p.o.) with/without vitamin E (50 mg/kg body wt/day p.o.) or quercetin (10 mg/kg body wt/day p.o.) three times/week for 6 weeks, respectively.
Results: Semen quality deteriorated, testosterone and luteinizing hormone (LH) levels were significantly decreased, and follicle stimulating hormone (FSH) increased following BLCO reatment. There was a significant decline in the activities of superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), and glutathione-S-transferase (GST) with concomitant increased levels of lipid peroxidation and activities of xanthine oxidase (XO) in a dose-dependent manner, in testes and brain of rats. Co-administration with vitamin E or quercetin reversed BLCO-induced neuronal and testicular toxicity by preventing oxidative stress, improving sperm quality, and restoring hormonal levels relative to controls.
Conclusions: BLCO altered reproductive indices and induced neuronal toxicity via the mechanism of oxidative stress. Quercetin and vitamin E showed possible chemoprotection against the toxicity.