Sinomenine Hydrochloride Regulates the Apoptosis of Endothelial Cells through PPAR-γ to Alleviate PAH

Pulmonary arterial hypertension is a progressive heart and lung disease that is caused by irreversible pulmonary vascular remodeling. Sinomenine hydrochloride is an alkaloid that is extracted from sinomenium acutum, which has strong anti-inflammatory effects. In this study, male rats were injected with monocrotaline, and endothelial cells were exposed to hypoxia for 24 hours to induce pulmonary arterial hypertension. Apoptosis, inflammation, and oxidative stress pathways were observed the in lungs and cells. Sinomenine hydrochloride repressed the increased right ventricular systolic pressure and attenuated the right ventricular hypertrophy and pulmonary artery remodeling in model rats. It reversed the expression of BCL2 and BAX and prevented the apoptosis of endothelial cells. Additionally, it increased the contents of IKBα and NRF2. P65, P-P65, TNFα, IL1β, and IL6 levels in the lungs decreased by it. Malondialdehyde contents decreased, and the superoxide dismutase and glutathione peroxidase activity and HO-1 level increased in the treatment group. In vivo, it promoted apoptosis of pulmonary artery endothelial cells. Moreover, by activating PPAR-γ, sinomenine hydrochloride attains the above effects. These data suggested that sinomenine hydrochloride could protect endothelial cells, restrain inflammation and oxidative stress, and enhance pulmonary vascular remodeling.