ABSTRACT
This study was carried out to investigate the effects of Allium cepa(onion extract) on ciprofloxacin induced testicular toxicity. Twenty five adult male Wistar rats weighing between 150g - 250g assigned randomly to five groups (A-E) were used for this study. The control group (A) received 1 ml of distilled water daily while group B was given 22.86 mg/Kg body weight(b.w) of ciprofloxacin. Group C was administered 22.86 mg/Kg b.w. of ciprofloxacin plus 100 mg/Kg b.w. of onion extract. Group D received the same dose of ciprofloxacin plus 200 mg/Kg b.w. onion extract while group E was given 100 mg/Kg b.w. of onion extract only. The experiment lasted for 25 days to cover two seminiferous cycles in rats and the route of administration was oral. Semen samples from the epididymis were collected at the end of the experimental period and used for the analysis of sperm count, sperm motility and sperm viability. Blood samples were also collected for the determination of haematological parameters and the blood serum was used for the determination of antioxidant biomarkers. The haematological parameters i.e red blood cell count (RBC), heamoglobin count (Hb), Hematocrit (HCT), white blood cell count (WBC) and platelet count (PLT) were studied. Superoxide dismutase (SOD), catalase (CAT) and Malondialdehyde (MDA) were the antioxidant biomarkers investigated. Testicular protein concentration and caspase-3 activity were also determined. The animals were sacrificed and the testes removed and used for histopathological studies, Flourescence microscopy was also employed to study the DNA integrity of the sperm cells following administration of ciprofloxacin and onion extract. The results obtained revealed that weights of the testes were comparable in all the groups. Allium cepa administration led to a significant (p<0.05) decrease in body weights in a dose-dependent manner. It was also observed that administration of ciprofloxacin significantly ix (p<0.05) decreased sperm count, motility and viability, and SOD activity. Similarly, administration of ciprofloxacin caused a significant increase (p<0.05) in MDA level, testicular apoptosis (as marked by caspase-3 activity level) and DNA fragmentation. Rats given ciprofloxacin and 100 mg/Kgb.w of onion extract showed significant(p<0.05) increase in sperm parameters with less testicular apoptosis and DNA fragmentation compared to the group given only ciprofloxacin. However, administration of 200 mg/Kgb.w of onion extract to ciprofloxacin-given rats potentiated the toxic effect of ciprofloxacin on sperm parameters, testicular apoptosis and DNA fragmentation. Histological studies showed that ciprofloxacin caused testicular damage characterized by disruption of spermatogenesis. Onion extract at low dose was observed to protect against the damage caused by ciprofloxacin administration. In conclusion, ciprofloxacin induced caspase-dependent apoptosis in the testis and this was ameliorated by the low dose of Allium cepaextract as the high dose of the extract was found to exacerbate the effect of ciprofloxacin, onion extract was also found to be apoptogenic both at low and high doses.