Flavopiridol Inhibits Proliferation and Induces Apoptosis of Rat Airway Smooth Muscle Cells

Cell proliferation and apoptosis are involved in the pathogenesis of many diseases. Abnormal proliferation of airway smooth muscle cells (ASMCs) is a key pathological feature of asthmatic airway remodeling. Flavopiridol is a plant-derived flavonoid that exhibits multifaceted biological activities such as regulating cell proliferation, migration, apoptosis, and autophagy. However, its effect on ASMCs has not been reported yet. Using CCK-8 and EdU assays, we demonstrated that flavopiridol reduced the viability and proliferation of ASMCs. Flow cytometric analysis of the cell cycle revealed an increased proportion of cells in the G2/M phase, accompanied by elevated expression of Cyclin B1 and CDK1, as determined by Western blot. In addition, Western blot showed that flavopiridol downregulated Bcl-2 and upregulated Bax and cleaved caspase-3. Flow cytometry further confirmed the induction of apoptosis in ASMCs. Collectively, our results indicate that flavopiridol suppressed proliferation and triggered apoptosis in rat ASMCs. This in vitro evidence highlights the possible role of flavopiridol in modulating ASMC hyperplasia, a key feature of airway remodeling.