Sinomenine suppresses TNF-alpha-induced VCAM-1 expression in human umbilical vein endothelial cells

Sinomenine (SN), an alkaloid prepared from the root of Sinomenium acutum Rehd. Et wils, is used to alleviate the symptoms of rheumatism in Chinese medicine. In the present study, the potential inhibition of TNF-alpha-induced VCAM-1 expression on human umbilical vein endothelial cells (HUVECs) was evaluated in vitro. HUVECs were isolated from freshly collected umbilical cords. Positive controls were stimulated with TNF-alpha, omitting SN. Negative controls were cultured omitting TNF-alpha and SN. Experimental groups were co-cultured with TNF-alpha and SN at different concentrations (0.25, 0.5, and 1.0 mol/L), or TNF-alpha and Dexamethasone (Dex) at a concentration of 1.0 x 10(-6) mol/L. Cells were harvested after culturing with the above drugs for 12 h. VCAM-1 mRNA expression was detected by real-time quantitative PCR, and VCAM-1 expression was detected by flow cytometry. The experimental data indicated that VCAM-1 mRNA and VCAM-1 were induced by TNF-alpha. The relative VCAM-1 mRNA expression decreased in the experimental groups (p<0.05). Concentrations of SN at 0.5 and 1.0 mol/L inhibited expression of VCAM-1 (p<0.05). SN at concentration of 0.25 mol/L and Dex at concentration of 1.0 x 10(-6) mol/L did not show an inhibitory effect on VCAM-1 expression in TNF-alpha-induced HUVECs. Our preliminary data indicates that SN has an inhibitory effect in vitro on TNF-alpha-induced VCAM-1 expression at both mRNA level and protein level in HUVECs, and suggests that SN may be a novel method of immunotherapy for rheumatic carditis or rheumatic heart disease.