Protective Effects and Mechanism of Curcumin on Oxidative Damage of Mice Small Intestinal Epithelial Cells
This experiment was conducted to study the protective effects and mechanism of curcumin on oxida-tive damage of mice small intestinal epithelial cells(MODE-K cells).The mice small intestinal epithelial cells were induced by H2O2 to establish the oxidative damage model,and the optimal modeling concentration of H2O2 was determined.The cells in the control group were cultured in a normal medium without any treatment.The cells in the model group were cultured in a normal medium and treated with H2O2 for 4 h.The cells in the curcumin group were cultured in a normal medium and treated with curcumin of different concentrations(1.25,2.50,5.00,10.00 and 20.00 µmol/L)for 12 h,and subsequently treated with H2O2 for 4 h.The survival rate and apoptosis rate of mice small intestinal epithelial cells and reactive oxygen species(ROS),malondialdehyde(MDA)contents and lactate dehydrogenase(LDH),total superoxide dismutase(T-SOD),glutathione per-oxidase(GSH-Px)activities in cells were measured,the mRNA relative expression levels of B-cell lymphoma-2(Bcl-2),B-cell lymphoma-2-associated X protein(Bax)and cysteinyl aspartate specific protein-ase-3(Caspase-3)were detected by real-time fluorescence quantitative PCR,the dominant conformation and interaction of curcumin and Kelch-like epichlorohydrin-associated protein 1(Keap1)pocket combination were studied using molecular simulation,and the protein relative expression levels of nuclear factor E2-related factor 2(Nrf2),Keap1 and heme oxygenase-1(HO-1)were detected by Western blot.The results showed as fol-lows:1)the optimal modeling concentration of H2O2 was 150 µmol/L.2)Compared with the control group,the survival rate and SOD,GSH-Px activities in cells of the model group were significantly decreased(P＜0.05),and the ROS,MDA contents and LDH activity in cells were significantly increased(P＜0.05).Com-pared with the model group,the survival rate and SOD,GSH-Px activities in cells of 5.00 to 20.00 μmol/L curcumin groups were significantly increased(P＜0.05),and the ROS,MDA contents and LDH activity in cells were significantly decreased(P＜0.05).3)Compared with the control group,the cells apoptosis rate of the model group was significantly increased(P＜0.05),the mRNA relative expression level of Bcl-2 in cells was significantly decreased(P＜0.05),and the mRNA relative expression levels of Bax and Caspase-3 in cells were significantly increased(P＜0.05).Compared with the model group,the cells apoptosis rate of 10.00 μmol/L curcumin group was significantly decreased(P＜0.05),the mRNA relative expression level of Bcl-2 in cells was significantly increased(P＜0.05),and the mRNA relative expression levels of Bax and Caspase-3 in cells were significantly decreased(P＜0.05).4)The molecular docking results indicated that the curcumin occupied the binding site of Nrf2 in the Kelch domain of Keap1 and prevented the interaction of Keap1-Nrf2,thus played an antioxidant role.Western blot results further indicated that compared with the mod-el group,the protein relative expression levels of Nrf2 and HO-1 in cells of 10.00 μmol/L curcumin group were significantly increased(P＜0.05),and the Keap1 protein relative expression level was significantly de-creased(P＜0.05).In conclusion,the suitable concentration(10.00 µmol/L)of curcumin can protect the ex-pression of Nrf2 and HO-1 proteins in Nrf2/HO-1 signaling pathway,inhibit the Keap1 protein expression,al-leviate the oxidative damage in intestinal epithelial cells of mice induced by H2O2.[Chinese Journal of Animal Nutrition,2024,36(7):4654-4664]
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维普
