Naringin prevents the impairment of hepatic mitochondrial function in diabetic rats.

We previously demonstrated that naringin (NAR) protects against liver damage in streptozotocin (STZ)-induced diabetes in rats. The aim of this study was to elucidate whether NAR is also able to protect the functioning, biogenesis and dynamics of the liver mitochondria in diabetic rats (DM). The activities of isocitrate dehydrogenase and malate dehydrogenase from the Krebs cycle, complex I-III from electron chain and adenosine triphosphate synthase were decreased in DM rats, effects that were blocked by NAR. The gene expression of mitofusin-2 and GTPase dynamin-related protein 1, markers of mitochondrial fusion and fission, were decreased in DM rats, which was prevented by NAR. Total glutathione was decreased and protein carbonyl contents as well as the activity of the antioxidant enzymes were increased in DM rats. All these changes were blocked by NAR. In conclusion, NAR protects the liver mitochondria from DM rats avoiding changes in the activity of Krebs cycle, the respiratory chain and the oxidative phosphorylation as well as preventing alterations in the fusion-fission processes. These effects are mediated, at least in part, by decreasing oxidative stress and anomalies in the enzymatic antioxidant system. Further studies are necessary to validate efficacy and safety of NAR for human use.