Protective effects of Mentha piperita L. leaf essential oil against CCl(4) induced hepatic oxidative damage and renal failure in rats

BACKGROUND: Mentha piperita L. is a flowering plant belonging to the Lamiaceae family. Mentha plants constitute one of the main valuable sources of essential oil used in foods and for medicinal purposes. METHODS: The present study aimed to investigate the composition and in vitro antioxidant activity of Mentha piperita leaf essential oil (MpEO). A single dose of CCl(4) was used to induce oxidative stress in rats, which was demonstrated by a significant rise of serum enzyme markers. MpEO was administrated for 7 consecutive days (5, 15, 40 mg/kg body weight) to Wistar rats prior to CCl(4) treatment and the effects on serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and γ -glutamyl transpeptidase (γ-GT) levels, as well as the liver and kidney superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) activity and thiobarbituric acid reactive substances (TBARS) levels were evaluated. In addition, histopathological examinations of livers and kidneys was performed. RESULTS: The in vitro antioxidant activity of MpEO was lower than that of silymarin. Pretreatment of animals with MpEO at a dose of 5 mg/kg did not have a significant effect on ALT, AST, ALP, LDH, γGT, urea or creatinine levels in CCl(4)-induced stress. Whereas pretreatment with MpEO at doses of 15 and 40 mg/kg prior to CCl(4), significantly reduced stress parameters (ALT, AST, ALP, LDH, γGT, urea and creatinine) compared to the CCl(4)-only group. Moreover, a significant reduction in hepatic and kidney lipid peroxidation (TBARS) and an increase in antioxidant enzymes SOD, CAT and GPx was also observed after treatment with MpEO (40 mg/kg) compared to CCl(4)-treated rats. Furthermore, pretreatment with MpEO at 40 mg/kg can also markedly ameliorate the histopathological hepatic and kidney lesions induced by administration of CCl(4). CONCLUSIONS: We could demonstrate with this study that MpEO protects liver and kidney from CCl(4)-induced oxidative stress and thus substantiate the beneficial effects attributed traditionally to this plant.