Metformin and low dose radiation modulates cisplatin-induced oxidative injury in rat via PPAR-γ and MAPK pathways

Cisplatin (CIS) is a chemotherapeutic agent used for therapy of many tumors and has been limited by its toxicity. The aim of this study was to investigate the role of Peroxisome proliferator-activated receptor-gamma (PPAR-γ), mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B(NF_kB) in the pathogenesis of hepatic damage induced by CIS, and investigated the modulatory effect of metformin (MET) and/or low dose gamma radiation (LDR) on CIS-induced hepatotoxicity in rats. CIS(7.5 mg/kg, i.p.) hepatotoxicity was evidenced by alteration of serum hepatic indices (ALT and AST) accompanied with decreased hepatic PPAR-γ, superoxide dismutase (SOD) activities and reduced glutathione (GSH) content, whereas the levels of malondialdehyde (MDA), total nitrate/nitrite (NOx) and NF_kB significantly increased as well as MAPK activity compared with the control, MET and LDR groups. Furthermore, CIS induces apoptosis as indicated by an elevation of hepatic caspase-3. Treatment with MET (150 mg/kg, orally for 14 days) and/or LDR (0.5 Gy), prior to CIS alleviates CIS-induced hepatic damage by mitigating oxidative/ nitrosative stress and PPAR-γ activity reduction, hepatic caspase-3 elevation, and inhibition of NFκB, and MAPK activity levels.

Modulation of PPAR-γ, MAPK and NF_kB might contribute to amelioration of CIS-induced hepatic toxicity.