Testosterone propionate activated the Nrf2-ARE pathway in ageing rats and ameliorated the age-related changes in liver. 
The present study aimed to evaluate the protective efficacy of testosterone propionate (TP) on age-related liver changes via activation of the nuclear factor erythroid 2-related factor 2-antioxidant response element (Nrf2-ARE) pathway in aged rats.  Aged rats received subcutaneous injections of TP (2 mg/kg/d, 84 days).  Oxidative stress parameters and the expression levels of signal transducer and activator of transcription 5b (STAT5b), Kelch-like ECH associating protein-1 (Keap1), Nrf2, haem oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase-1 (NQO1) in liver tissues were examined to check whether the Nrf2-ARE pathway was involved in the age-related changes in liver.  Our results showed that TP supplementation alleviated liver morphology, liver function and liver fibrosis; improved oxidative stress parameters; and increased the expression of STAT5b, Nrf2, HO-1 and NQO-1 and decreased the expression of Keap1 in the liver tissues of aged rats.  These results suggested that TP increased the expression of STAT5b, and then activated the Nrf2-ARE pathway and promoted antioxidant mechanisms in aged rats.  These findings may provide new therapeutic uses for TP in patients with age-related liver changes.