Chinese herbs Danshen and Gegen modulate key early atherogenic events in vitro

Danshen (Salvia miltiorrhiza) and Gegen (Radix puerariae) are two herbs used in traditional Chinese medicine, most commonly for their putative cardioprotective and anti-atherosclerotic effects. In this study, we investigated the effect of a preparation of these herbs on two key processes in the early stages of atherosclerosis; macrophage lipid loading and monocyte adhesion to endothelial cells. Human monocyte derived macrophages (HMDMs) were treated with 0.1-1.0 mg/ml of the herbal mixture in aqueous buffers and loaded with acetylated LDL (AcLDL) (50 microg/ml) for 72 h, and analyzed for cholesterol (C) and cholesteryl esters (CE), via HPLC. Human endothelial cell monolayers were also treated with 0.1-1.0 mg/ml of the herbal mixture and monocyte adhesion measured. Cell adhesion molecules E-selectin, ICAM-1 and VCAM-1 were assessed via ELISA. Compared to control conditions, the herbal mixture induced a significant dose-related decrease in the total cholesterol (free and esterified) in the HMDMs (p<0.001 by ANOVA). By contrast, the herbs also induced an increase in ICAM-1 expression (p<0.001) and monocyte adhesion at higher concentrations (p<0.05). In conclusion, treatment of cells with this preparation of Danshen and Gegen, a commonly used Chinese health supplement, results in a dose-related suppression of AcLDL uptake by human macrophages, and an increase in the level of ICAM-1 expression and adhesion of monocytes to endothelial cells. These herbs therefore show the ability to modulate key early events in atherosclerosis.