Induction of apoptosis by magnolol via the mitochondrial pathway and cell cycle arrest in renal carcinoma cells.
Biochem Biophys Res Commun. 2019 Jan 22 ;508(4):1271-1278. Epub 2018 Dec 17. PMID: 30573364
Magnolol (Mag), an effective natural compound isolated from the stem bark of Magnolia officinalis, was found to have the potential for antitumor activity by inducing apoptosis in tumor cells. However, the effect of Mag on renal carcinoma cells and its molecular mechanism are unexplored. Our study provided evidence that Mag induced apoptosis in 786-O and OS-RC-2 cell lines via the mitochondrial pathway and cell cycle arrest. In this work, we found that Mag induced morphological changes and inhibited the proliferation of 786-O and OS-RC-2 cells in a dose- and time-dependent manner but exerted no notable inhibitory effects on normal human renal proximaltubular (HK-2) cells. Treatment with Mag suppressed the migration and invasion ability of renal carcinoma cells. Moreover, Mag caused the openness of mPTP, the accumulation of intracellular ROS and decreased △Ψm, leading to mitochondrial dysfunction. However, pretreatment with the antioxidant N-acetyl cysteine (NAC) reversed the apoptosis induced by Mag and decreased the generation of ROS. In addition, the increased proportion of the G1/G0 phase indicated that Mag caused cell cycle arrest. Further analyses suggested that magnolol-induced apoptosis was related to the abnormal expression of p53, Bax, Bcl-2, cytochrome c and caspase activation. Together, the results above revealed that Mag had antitumor effects in renal carcinoma cells via ROS production as well as cell cycle arrest and the apoptotic mitochondrial pathway was suppressed in part by NAC.