Curcumin protects murine lung mesenchymal stem cells from H(2)O(2) by modulating the Akt/Nrf2/HO-1 pathway

OBJECTIVES: Oxidative stress within the idiopathic pulmonary fibrosis microenvironment decreases the survival of lung mesenchymal stem cells (LMSCs), resulting in disease progression. Herein, the effects of curcumin (CUR) against hydrogen peroxide (H(2)O(2))-mediated damage to murine LMSCs were examined. METHODS: Apoptosis, reactive oxygen species, and mitochondrial membrane potential were detected by flow cytometry. Protein levels of B-cell lymphoma-2 (Bcl-2), Bcl-2 associated x (Bax), cleaved caspase-3, protein kinase B (PKB/Akt), phosphorylated-Akt, nuclear factor erythroid-2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1) were evaluated by western blot analysis. RESULTS: Apoptosis rates in the 2.5, 5, and 10 µM CUR groups were 23.27% ± 0.31%, 14.87% ±0.41%, and 6.47% ± 0.50%, respectively, all of which were lower than in the H(2)O(2) group (24.46% ± 1.35%). Reactive oxygen species levels were decreased, while mitochondrial membrane potential levels were increased in concentration-dependent manners in the CUR groups compared with the H(2)O(2) group. Compared with the H(2)O(2) group, all CUR groups showed reduced cleaved caspase-3 expression, increased Nrf2 and HO-1 expression, and increased Bcl-2/Bax and p-Akt/Akt ratios. CONCLUSIONS: The protective effects of CUR against H(2)O(2)-mediated damage in murine LMSCs may be mediated through the Akt/Nrf2/HO-1 signaling pathway.