Protective effect of Fisetin against angiotensin II-induced apoptosis by activation of IGF-IR-PI3K-Akt signaling in H9c2 cells and spontaneous hypertension rats

Background: Fisetin, a polyphenolic compound, has drawn notable attention owing to its antioxidant, anti-inflammatory, anti-cancer and neuroprotective effects. However, the cardiac effects of fisetin are not clear yet. Hypothesis: The aim of the present study is to examine the cardioprotective effect of fisetin against Ang-II induced apoptosis in H9c2 cells and in spontaneous hypertensive rats (SHR). Methods/study design: The in vitro protective effect of fisetin was evaluated after the cells were treated with fisetin (50 mu M/ml/24 h) for 2 h prior or after Ang-II administration to induce apoptosis. For in vivo experiments, SHRs were orally administered with fisetin (10 mg/kg) twice a week for 6 weeks. Cellular apoptosis was analyzed by TUNEL staining assay and the modulation in the expression levels of proteins involved in apoptosis and cell survival were determined by western blotting. Results: Our results demonstrate the potent cardioprotective efficacy of fisetin against Ang-II induced apoptosis in H9c2 cells and in SHR models. Fisetin administration reduced the apoptotic nuclei considerably And reduced the expression of apoptotic proteins such as TNF-alpha, Fas L, FADD, Cleaved caspase-3 and Cleaved PARP and increased the cell survival and anti-apoptotic proteins like Bcl-2, Bcl-x(L), p-IGF1R, p-PI3K and p-AKT in both in vitro and in vivo models. Conclusion: In conclusion, the results of the present study reveal that fisetin activates the IGF-IR-dependent p-PI3K/p-Akt survival signaling pathway and suppresses the caspase dependent apoptosis.