The effect of Rooibos ( Aspalathus Linearis) supplementation on Tert-Butylhydroperoxide-Induced Oxidative Damage in Liver and Kidney of Rats

Abstract

Oxidative stress has been implicated in the aetiology of most chronic diseases. This study investigates a possible protective effect of rooibos on tert-butyl hydroperoxide (t-BHP)-induced oxidative stress in the liver and kidney of Wistar rats. Forty animals (n=10/group) were randomly divided into four groups receiving either water or rooibos (2% w/v) as the only source of drinking fluid for 6 weeks followed by a daily t-BHP (30 µmol/100 g body weight, i.p) or vehicle control injection for 2 weeks. Serum aminotransferases, blood urea nitrogen (BUN), and uric acid as marker of organ damage as well as lipid peroxidation (MDAHPLC), oxygen radical absorbance capacity (ORAC), catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR) and glutathione peroxidase (GPx) were estimated as indices of oxidative stress. Injection of t-BHP induced oxidative stress, evidenced by significant (P<0.05) increase in MDA, elevated levels of ALT, AST, BUN and uric acid in the serum and depletion of ORAC status. Rooibos supplementation significantly decreased MDA level in the liver, returned the ORAC status to a level comparable to the control in the kidney and was effective in reducing the level of the serum enzymes. in the liver, t-BHP exhibited varying effects on the level of antioxidant enzymes, with a significant (P< 0.05) to marginal (P<0.1) reduction of GPx and CAT, respectively while activity of GR was significantly (P<0.05) increased when compared with the controls. the levels of antioxidant enzymes, measured in the kidney, were significantly (P<0.05) decreased by t-BHP injection with the exception of SOD that was significantly (P<0.05) elevated. Rooibos supplementation was able to alleviate the t-BHP-induced changes in the liver and kidney, suggesting that consuming rooibos is capable of protecting against hepato- and nephrotoxicity by modulating oxidative damage.