Wogonin ameliorates lipotoxicity-induced apoptosis of cultured vascular smooth muscle cells via interfering with DAG-PKC pathway

Aim： To investigate the effects of wogonin （5,7-dihydroxy-8-methoxyflavone） extracted from Scutellaria baicalensis Georgi （S baicalensis） on lipotoxicity-induced apoptosis of vascular smooth muscle cells （VSMCs） and the underlying mechanisms. Methods： Cultured VSMCs were used. Apoptosis of VSMCs was induced by palmitate （0.75 mmoi/L）, and detected using TUNEL assay The expression levels of protein and phosphorylated protein were measured using Western blot analysis. Results： Treatment of VSMCs with wogonin （10, 25 and 50 pmol/L） significantly attenuated the apoptosis and endoplasmic reticulum （ER） stress induced by palmitate in concentration- and time-dependent manners. Wogonin （50 pmol/L） decreased palmitate-induced reactive oxygen species （ROS） generation. The ER stress inhibitor 4-phenyl butyric acid （5 mmol/L） significantly decreased palmitate- induced apoptotic cells, and occluded the anti-apoptotic effect of wogonin （25 pmol/L）. Wogonin （10, 25 and 50 pmol/L） significantly reduced the intracellular diacylglycerol （DAG） accumulation and expression levels of phosphorylated PKCs in palmitate-treated VSMCs. Conclusion： Our results suggest that wogonin inhibits lipotoxicity-induced apoptosis of VSMCs via suppressing the intracellular DAG accumulation and subsequent inhibition of PKC phosphorylation. Wogonin has therapeutic potential for the prevention and treatment of atherosclerosis.