Aliskiren attenuates cardiac dysfunction by modulation of the mTOR and apoptosis pathways

Aliskiren (ALS) is well known for its antihypertensive properties. However, the potential underlying the molecular mechanism and the anti-hypertrophic effect of ALS have not yet been fully elucidated. The aim of the present study was to investigate the role of ALS in mammalian target of rapamycin (mTOR) and apoptosis signaling using in vivo and in vitro models of cardiac hypertrophy. A rat model of cardiac hypertrophy was induced by isoproterenol treatment (5 mg·kg-1·day-1) for 4 weeks, with or without ALS treatment at 20 mg·kg-1·day-1. The expression of hypertrophic, fibrotic, and apoptotic markers was determined by RT-qPCR. The protein expression of apoptotic markers mTOR and p-mTOR was assessed by western blot analysis. The proliferation of H9C2 cells was monitored using the MTS assay. Cell apoptosis was analyzed using flow cytometry. In vivo, isoproterenol-treated rats exhibited worse cardiac function, whereas ALS treatment reversed these dysfunctions, which were associated with changes in p-mTOR, Bcl-2, Bax, and cleaved caspase-3 expression, as well as the number of apoptotic cells. In vitro, H9C2 cardiomyocyte viability was significantly inhibited and cardiac hypertrophy was induced by Ang II administration, but ALS reversed Ang II-induced H9C2 cardiomyocyte hypertrophy and death. Furthermore, Ang II triggered the activation of the mTOR and apoptosis pathways in hypertrophic cardiomyocytes that were inhibited by ALS treatment. These results indicated that ALS alleviated cardiac hypertrophy through inhibition of the mTOR and apoptosis pathways in cardiomyocytes.

Vitexin induces apoptosis through mitochondrial pathway and PI3K/Akt/mTOR signaling in human non-small cell lung cancer A549 cells

BACKGROUND: Currently, the prognosis of patients with non-small cell lung cancer (NSCLC) remains dismal; hence, it is critical to identify effective anti-NSCLC agents with limited side effects. This study aimed to evaluate the therapeutic potential of flavonoid compound vitexin in human NSCLC cells and the underlying mechanisms. RESULTS: The experimental results indicated that vitexin reduced the viability of A549 cells in a dose-dependent manner with nearly no toxicity against normal human bronchial epithelial 16HBE cells. Vitexin also dose-dependently increased A549 cell apoptosis, accompanied by the decreased Bcl-2/Bax ratio and the increased expression of cleaved caspase-3. Moreover, the in vivo anticancer activity of vitexin was further determined in nude mice bearing A549 cells. In addition, vitexin induced the release of cytochrome c from the mitochondria to the cytosol and the loss of mitochondrial membrane potential. Vitexin also significantly reduced the levels of p-PI3K, p-Akt and p-mTOR, and the pro-apoptotic effect of vitexin on A549 cells was partly blocked by SC79, an Akt activator. CONCLUSIONS: Accordingly, we believed that vitexin could be used as a potential therapeutic agent for the treatment of NSCLC in the future.