HMOX1 and metabolic syndrome: In conclusion, the findings of this study add to the current knowledge about the effects of hawthorn extract on ovariectomy-induced dyslipidemia and oxidative stress, particularly regarding serum GPx activity, the hepatic MDA level, hepatic mRNA expression of Nrf2, HO-1, and GPx and protein expression of Nrf2, HO-1, and GPx.