Chrysin Alleviates Monocrotaline-Induced Pulmonary Hypertension in Rats Through Regulation of Intracellular Calcium Homeostasis in Pulmonary Arterial Smooth Muscle Cells.

Chrysin (CH) is the main ingredient of many medicinal plants. Our previous study showed that CH could suppress hypoxia-induced pulmonary arterial smooth muscle cells proliferation and alleviate chronic hypoxia-induced pulmonary hypertension by targeting store-operated Ca entry (SOCE)-[Ca]i pathway. In this study, we investigated the effect of CH on monocrotaline-induced pulmonary hypertension (MCTPH) and the mechanism behind it. Results show that, in MCTPH model rats, (1) CH significantly reduced the enhancement of right ventricular pressure, right ventricular hypertrophy, and pulmonary vascular remodeling; (2) CH markedly suppressed the promotion of SOCE and [Ca]i in pulmonary arterial smooth muscle cells; and (3) CH obviously inhibited the MCT-upregulated proliferating cell nuclear antigen, TRPC1, TRPC4, and TRPC6 expression in distal pulmonary arteries. These results demonstrate that CH likely alleviates MCTPH by targeting TRPC1,4,6-SOCE-[Ca]i pathway.