Apigenin combined with aerobic exercise alleviates oxidative stress and inflammation in high-fat diet-induced NAFLD mice by modulating the Keap1/Nrf2/ARE pathway.

Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disease worldwide, and its global prevalence has shown a significant upward trend in recent years. Oxidative stress and inflammatory responses are key processes in the initiation and progression of NAFLD. This study aimed to investigate the effects of aerobic exercise combined with apigenin on hepatic oxidative stress and inflammation in mice with NAFLD. To establish the NAFLD model, 52 mice were fed a high-fat diet (HFD) with a fat content of 60%. After eight weeks, HE staining was performed to examine the pathological status of the mouse livers for confirmation of successful NAFLD model establishment. The intervention strategies included aerobic exercise (AE), apigenin (API), and their combination. The amounts of pro-inflammatory substances (tumor necrosis factor-α, TNF-α; interleukin-6, IL-6; interleukin-1β, IL-1β), and parameters of lipid peroxidation (malondialdehyde, MDA) and antioxidant enzymes (superoxide dismutase, SOD; catalase, CAT) in the liver, as well as the levels of gene expression (Kelch-like ECH-associated protein 1, Keap1; nuclear factor erythroid 2-related factor 2, Nrf2; heme oxygenase-1, HO-1; SOD; NAD(P)H quinone dehydrogenase 1, NQO1; TNF-α; IL-6; IL-1β) and protein expression (Keap1; phosphorylated nuclear factor erythroid 2-related factor 2, P-Nrf2; Nrf2; HO-1; SOD; TNF-α; IL-6), were examined using biochemical techniques. Lipid metabolism (triglyceride, TG; total cholesterol, TC; high-density lipoprotein cholesterol, HDL-C; low-density lipoprotein cholesterol, LDL-C) was assessed as well. In mice with NAFLD, aerobic exercise combined with apigenin significantly attenuated oxidative damage and inflammatory responses, ameliorated hepatic steatosis, and reduced hepatic total cholesterol and triglyceride levels, thereby improving overall metabolic homeostasis. Both aerobic exercise and apigenin were able to activate the Keap1/Nrf2/ARE pathway, as evidenced by enhanced phosphorylation of Nrf2, which further promoted the transcription of downstream antioxidant genes and negatively modulated the expression of pro-inflammatory proteins. All treatment groups exhibited significantly downregulated expression of Keap1 and downstream pro-inflammatory factors, with the HFD + API+AE group showing the most pronounced reduction. Similarly, all treatment groups displayed markedly upregulated expression of Nrf2 and downstream antioxidant genes, with the HFD + API+AE group demonstrating the greatest increase. Furthermore, all treatment groups exhibited significantly lower MDA levels compared with the HFD group, and the HFD + API+AE group showed the most prominent reduction. Collectively, apigenin and aerobic exercise exert a favorable synergistic effect against NAFLD.