Simultaneous quantification and antiatherosclerosis effect of the traditional Korean medicine, Hwangryunhaedok-tang

BACKGROUND: Hwangryunhaedok-tang (HHT) is a traditional herbal medicine that is used for the treatment of fever, inflammation, gastritis, and hypertension. In this study, we performed simultaneous determination of the five components, geniposide (1), baicalin (2), coptisine (3), palmatine (4), and berberine (5) in HHT by using a high-performance liquid chromatography–photodiode array (HPLC–PDA) analysis. We also evaluated the antioxidative activity of HHT and compounds 1–5 by measuring their effects on low-density lipoprotein (LDL) oxidation and antiproliferative abilities in vascular smooth muscle cells (VSMCs). METHODS: Five compounds were separated within 40 min by using a Gemini C(18) column (temp. 35°C; two-component gradient elution; flow rate 1.0 mL/min; detector 240 and 277 nm). The activities of HHT and compounds 1–5 were tested with the radical scavengers 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt and 2,2-diphenyl-1-picrylhydrazyl, in thiobarbituric acid reactive substance assays, and in relative electrophoretic mobility assays using CuSO(4)-induced LDL oxidation systems. The antiproliferative effects of samples on platelet-derived growth factor (PDGF)-induced VSMC proliferation were studied by using a cell proliferation assay. RESULTS: Regression analysis of the five major compounds showed good linearity (r(2) ≥ 0.9997) in different concentration ranges. The recoveries of the five compounds were in the range 86.31–110.78%, with relative standard deviations below 2.1%; those of intra- and interday precision were 0.04–3.78% and 0.04–1.69%, respectively. HHT reduced the oxidation properties of LDL induced by CuSO(4) and inhibited cell proliferation in PDGF-treated VSMCs. Among the five components, compound 2 could effectively suppress LDL oxidation and PDGF-induced VSMC proliferation. CONCLUSIONS: The established HPLC–PDA method will help to improve quality control of HHT. The results demonstrate that HHT has antiatherosclerotic activity and that it functions by modulating LDL oxidation and VSMC proliferation. The effects of HHT may be attributed, at least I part, to compound 2.