Nephroprotective activities of the aqueous seed extract of Carica papaya Linn. in carbon tetrachloride induced renal injured Wistar rats: a dose- and time-dependent study
In the present study, the dose related effect of the aqueous seed extract of Carica papaya Linn. extract (CPE) was evaluated by pre-treating three groups of rats (made up of six male rats per group) with 100 – 400 mg/kg body weight per oral of the extract for 7 days before challenging with 1.5 ml/kg body weight of 20% carbon tetrachloride in olive oil in addition to the untreated control and model control rats. Also, the time-course effect of 400 mg/kg per oral of the extract were determined at 3 hr pre-, 0 hr, 1 hr post-, 3 hr post-, and 6 hr post-CCl4 induction, respectively, in addition to the untreated control and model control groups. After 72 hours, serum levels of uric acid, urea and creatinine of all study groups were measured using standard procedures. Histological studies of rat kidneys of all study groups were also done. Results showed that intraperitoneal injection of CCl4 caused a significant (p<0.001) elevation in the serum levels of uric acid, urea and creatinine and induced histological features of severe tubulointerstitial necrosis. However, elevations in the measured biochemical parameters were significantly (p<0.05, p<0.01 and p<0.001) attenuated in rats pre-treated with the graded oral doses of the extract, in dose related fashion. Maximum nephroprotection was offered by the extract at 400 mg/kg/day CPE which lasted up to 3 hours post-CCl4 exposure and these biochemical evidences were corroborated by improvements in the renal histological lesions induced by CCl4 intoxication. In conclusion, our study showed that CPE has nephroprotective effect on CCl4 renal injured rats, an effect which could be mediated by any of the phytocomponents present in it via either antioxidant and/or free radical scavenging mechanism(s).