Phenformin attenuates the oxidative-nitrosative stress in the liver of rats under long-term ethanol administration

Abstract

Modulation of the AMP-activated protein kinase (AMPK) pathway activity is considered to be a promi­sing option in the development of approaches to chronic alcoholic hepatitis treatment. Phenformin, which is a biguanide, has been reported to increase AMPK activity. The aim of this work was to estimate the effect of phenformin as AMPK activator on the development of oxidative-nitrosative stress in the liver of rats under conditions of long-term ethanol administration. The experiments were performed on 24 male Wistar rats, divided into 4 groups: control; animals, which received phenformin hydrochloride orally at a dose of 10 mg/kg daily for 63 days; animals with a forced intermittent alcoholization for 5 days by intraperitoneal administration of 16.5% ethanol solution in 5% glucose at the rate of 4 ml/kg b.w. and subsequent transfer to 10% ethanol as the only source of drinking; animals with chronic alcohol hepatitis simulation and phenformin administration. Superoxide dismutase, catalase, NO synthase isoforms activity, superoxide anion radical production, concentration of malonic dialdehyde, peroxynitrite, nitrites, nitrosothiols concentration and oxidative modification of proteins (OMP) were estimated in liver homogenates. The increased production of oxygen and nitrogen active forms and OMP intensification in the liver of rats under long-term administration of ethanol was detected. Phenformin introduction under long-term ethanol administration was shown to limit the excess peroxynitrite formation and to prevent oxidative damage to rat liver proteins. Keywords: AMP-activated protein kinase., chronic alcoholic hepatitis, liver, oxidative and nitrosative stress, phenformin