Abstract：Abstract: To study the effects of curcumin on nuclear factor-erythroid 2-related factor 2 (Nrf2) pathway-associated protein expression and apoptosis in skeletal muscle of overtraining rats, seventy-two 7-week-old Wistar rats were divided into control group (C), curcumin group (CC), overtraining model group (OM), and curcumin treatment combined with overtraining group (COM). There was no exercise intervention in C and CC groups, and the other groups underwent 8-week incremental load swimming. During the training period, the CC and COM groups were intragastrically administered with curcumin at a dose of 200 mg/(kg·d) and 5 mL/kg, and the other groups were intragastrically administered with an equal volume of 0.5% carboxymethylcellulose. All the rats were dissected 24 h after the last training, and skeletal muscle samples were taken for histopathological diagnosis after HE staining. The apoptosis of skeletal muscle cells was detected by TUNEL, and the related biochemical indexes were detected by immunohistochemistry, ELISA and radioimmunoassay. The biochemical indicators included testosterone (T), corticosterone (Cor), creatine kinase (CK) and lactate dehydrogenase (LDH) in serum, and superoxide dismutase (SOD), malondialdehyde (MDA), Nrf2, heme oxygenase-1 (HO-1), Bcl-2, Bcl-2-associated X protein (Bax) in skeletal muscle. Compared with the C group, the CC group had no significant changes in histopathology of the skeletal muscle and biochemical indexes, but the OM group had significant pathological changes in the skeletal muscle, and the content of T/Cor in serum and the expressions of SOD, Nrf2, HO-1, Bcl-2 and Bcl-2/Bax in skeletal muscle were significantly decreased (P<0.05 or P<0.01), while the levels of CK and LDH in serum, and apoptosis level, MDA and Bax in skeletal muscle were increased significantly (P<0.01). Compared with the OM group, the pathological changes of skeletal muscle in COM group were improved, the content of T/Cor in serum, and the levels of SOD, Nrf2, HO-1 and Bcl-2/Bax in skeletal muscle were significantly increased (P<0.05 or P<0.01), while the levels of CK and LDH in serum, and apop-tosis level, MDA and Bax in skeletal muscle were significantly decreased (P<0.05 or P<0.01). In conclusion, 8-week incremental load swimming induced overtraining in rats, with increased oxidative stress and apoptosis of skeletal muscle, and decreased antioxidant capacity, leading to pathological changes and functional impairment of skeletal muscle. Moreover, the results indicate that curcumin can increase the antioxidant enzyme activity and antioxidant capacity of skeletal muscle by regulating the expression of Nrf2 pathway-related proteins, then scavenge free radicals, and alleviate structural and functional damages caused by apoptosis and overtraining.
引用本文:
牛衍龙, 曹建民, 王 祯, 周海涛, 龚 平, 胡 戈, 田旭宸, 邵芙蓉. 姜黄素对过度训练大鼠骨骼肌Nrf2通路相关蛋白质表达及细胞凋亡的影响[J]. 生命科学研究, 2020, 24(5): 367-375. NIU Yan-long, CAO Jian-min, WANG Zhen, ZHOU Hai-tao, GONG Ping, HU Ge, TIAN Xu-chen, SHAO Fu-rong. Effects of Curcumin on Nrf2 Pathway-associated Protein Expression and Apoptosis in Skeletal Muscle of Overtraining Rats. Life Science Research, 2020, 24(5): 367-375.
