Inhibitory Effect of the Water-Soluble Extract of Salvia miltiorrhiza on Neutrophil-Endothelial Adhesion

Abstract

The effect of the water-soluble extract (WSE) of Salvia miltiorrhiza on neutrophil-endothelial cell adhesion was investigated. Cell adhesion was evaluated by testing neutrophil myeloperoxidase activity: expression of adhesion molecules in human umbilical vein endothelial cells (HUVEC) was measured by ELISA: the neutrophil activation rate induced by N-formyl-methionyl-leucyl-phenylalanine (fMLP) was tested by the method of nitroblue tetrazolium (NBT) reduction. The results showed that the adhesion rate of neutrophils to unstimulated HUVEC was very low. TNFalpha (50 - 800 U/ml) increased the adhesion of neutrophils to TNFalpha-stimulated HUVEC in a concentration- and time-dependent manner. The WSE of Salvia miltiorrhiza (0.01 - 1 mg/ml) dose-dependently inhibited the adhesion of neutrophils. The inhibitory rate of the WSE of Salvia miltiorrhiza at 0.01, 0.1 and 1 mg/ml was 6.2%, 17.0% and 28.0%, respectively. fMLP (10(-9) - 10(-5) M) increased the activation rate of neutrophils concentration-dependently. The WSE of Salvia miltiorrhiza also concentration-dependently inhibited the adhesion of fMLP-activated neutrophils to HUVEC. The inhibitory rate of the WSE of Salvia miltiorrhiza at 0.001, 0.01 and 0.1 mg/ml was 5.3%, 26.3% and 28.9%, respectively. Moreover, TNFalpha upregulated expression of adhesion molecule E-selectin, ICAM-1 and VCAM-1. The WSE of Salvia miltiorrhiza had an inhibitory effect on TNF alpha-induced expression of these molecules. These results indicated that the WSE of Salvia miltiorrhiza inhibited neutrophil-endothelial adhesion. The action mechanism of the WSE of Salvia miltiorrhiza was partly related to suppressing the expression of adhesion molecules.