STUDIES ON IN-VIVO ANTIOXIDANT AND HEPATOPROTECTIVE PROPERTIES OF CITRUS SINENSIS (L.) OSBECK PEEL EXTRACT IN WISTAR RATS

STUDIES ON IN-VIVO ANTIOXIDANT AND HEPATOPROTECTIVE PROPERTIES OF CITRUS SINENSIS (L.) OSBECK PEEL EXTRACT IN WISTAR RATS

Abstract:

Citrus sinensis is the commonest, most widely cultivated and consumed citrus fruit. Large amounts of peel wastes are formed when citrus is consumed or processed; and suitable methods have to be adopted to utilize these waste materials for conversion into value-added products. Flavonoids, the major component of citrus peel have been reported to exert antioxidant and hepatoproective activity. This study was designed to investigate the in-vivo antioxidant and hepatoprotective properties of the methanol extract of citrus fruit peel in Wistar rats. Qualitative and quantitative phytochemical screening was carried out on extracts of three different citrus species fruit peels for comparison and selection, after which C. sinensis fruit peel extract was selected for further studies because it had the highest flavonoid content. Oxidative stress and liver damage was induced in rats using 2 ml/kg subcutaneous injection of CCl4 every 72 h for 10 days. Biochemical parameters were assessed as indices of oxidative stress and liver damage. Acute toxicity studies suggests that the LD50 (oral route) is above 5,000 mg/kg. The extract showed significant protection (at P<0.001) against the depletion of liver tissue catalase levels observed in the CCl4 treated group at 500 mg/kg (89% protection) comparable to that of the standard drug sylimarin (84% protection). The extract reduced liver enzymes significantly (at P<0.001 for alanine aminotransferase and aspartate aminotransferase; and P<0.05 for alkaline phosphatase as well as P<0.05 for bilirubin) similar to sylimarin. Furthermore, the extract also had similar protective effect to sylimarin on oxidative stress induced ischemia in kidney tissues. Urea levels were significantly (P<0.05) reduced from 6.86±0.80 mmol/L observed in the CCl4 treated group to 3.72±0.58 mmol/L by the 500 mg/kg extract. Preliminary phytochemical screening of methanol extract of C. sinensis fruit peels revealed the presence of flavonoids, phenols, tannins, saponins, steroids, carbohydrates and cardiac glycosides; with total flavonoids and phenol content of 17.3 mg QE/g and 13.6 mg GAE/g respectively. The pathological evaluations of liver sections of rats treated with C. sinensis peel extract showed mild distortion revealing less damage comparable to the control and sylimarin treated groups. Thus, it can be concluded that the methanol extract of C. sinensis peel is relatively safe orally in rats and possess antioxidant activity that may be effective in the management of liver damage and possibly other oxidative stress induced diseases. Thus, supporting the development of the biologically active compounds from C. sinensis as antioxidants for the management of hepatic disorders.

STUDIES ON IN-VIVO ANTIOXIDANT AND HEPATOPROTECTIVE PROPERTIES OF CITRUS SINENSIS (L.) OSBECK PEEL EXTRACT IN WISTAR RATS