Puerarin, a major isoflavonoid compound from Chinese herb Kudzu roots, has been widely used for the treatment of hypertensive and cardiovascular diseases in China. Here, we investigated puerarin's beneficial effects on the cardiovascular system in angiotensin (Ang) II-induced hypertensive rats. Sprague-Dawley rats were treated with Ang II for 5 days or with puerarin for 10 days followed by Ang II and puerarin for 5 days. Endothelium-dependent relaxation (EDR) to acetylcholine was determined using an organ chamber bath. Ang II increased the systolic blood pressure (SBP: 178 ± 5 mmHg vs. 112 ± 3 mmHg in control, p < 0.05), aortic (30%, p < 0.05), and left ventricular (LV) weight (23%); puerarin reduced SBP (160 ± 2 mmHg, p < 0.05), aortic, and left ventricular weight in Ang II-infused rats. Puerarin also reduced aortic medial thickness and myocardial cell surface area in Ang II-infused rats. Compared with control rats, Ang II infused rats exhibited an impaired EDR with reduction in the protein expression of phosphor-eNOS at Ser 1177 and an increase in the expression of gp91phox (85%), p22phox (113%), transforming growth factor β1 (145%) and vascular cell adhesion molecule 1 (82%). Puerarin improved EDR and reversed the changes in Ang II-induced protein expression of above molecules. Our results demonstrate that in Ang II-induced hypertensive rats, puerarin protects against endothelial dysfunction and end organ damage with a mild reduction in SBP, and that the cardiovascular beneficial effects of puerarin may be in part attributed to its anti-oxidant and upregulation of phosphor-eNOS.
Keywords: Angiotensin II; endothelial function; herbal medicine; hypertension; oxidative stress.