Inhibition of 5-alpha reductase attenuates cardiac oxidative damage in obese and aging male rats via the enhancement of antioxidants and the p53 protein suppression

In aging and metabolic syndrome oxidative stress is a causative factor in the cardiovascular pathology. Upregulation of 5-⍺ reductase is associated with cardiac hypertrophy but how inhibition of 5-⍺ reductase affects cardiometabolic function during oxidative damage under those conditions is unclear. Our hypothesis was that Finasteride (Fin), a 5-⍺ reductase inhibitor, promotes an antioxidant response, leading to an improvement in cardiac function in obese and aging rats. Male rats were divided into 3 groups including normal diet (ND) fed rats, ND-fed rats treated with d-galactose (D-gal) to induce aging, and high-fat diet (HFD) fed rats to induce obesity. Rats received their assigned diet or D-gal for 18 weeks. At week 13, rats in each group were divided into 2 subgroups and received either a vehicle or Fin (5 mg/kg/day, oral gavage). Cardiometabolic and molecular parameters were subsequently investigated. Both D-gal and HFD successfully induced cardiometabolic dysfunction, oxidative stress, mitochondrial dysfunction, and DNA fragmentation. Fin treatment did not affect metabolic disturbances; however, it reduced cardiac sympathovagal imbalance, cardiac dysfunction through the inhibition of oxidative stress and promoted antioxidants, resulting in reduced p53 protein levels and DNA fragmentation. Surprisingly, Fin induced insulin resistance in ND-fed rats. Fin effectively improved cardiac function in both models by enhancing antioxidant levels, suppressing oxidative stress and DNA fragmentation. However, Fin treatment did not confer any beneficial effects on metabolic status. Fin administration effectively improved cardiac sympathovagal balance and cardiac function in rats with oxidative damage induced by either D-gal or HFD.