Zhengganxifeng Decoction Affects Gut Microbiota and Reduces Blood Pressure via Renin–Angiotensin System

Zhengganxifeng decoction (ZGXFD) is a traditional Chinese medicinal formula, from “Medical Zhong parameter West recorded” by Xichun Zhang, which has been applied to the treatment of clinical essential hypertension. Besides its effect in blood pressure reduction, ZGXFD is also known to be a radical therapy with little or no side effects. Compared with western medicines, Chinese medicinal formulas have the advantage of simultaneously attacking multiple targets. However, such a property brings trouble to the pharmacological studies of Chinese medicines. This study investigated the composition of gut microbiota in spontaneously hypertensive rats (SHR) treated with ZGXFD. ZGXFD was shown to cause similar effects in the treatment group as benazepril: both were able to reduce in SHR the microbial diversity, Firmicutes to Bacteroidetes (F/B) ratio and coccus to bacillus (C/B) ratio. Meanwhile, ZGXFD can maintain the integrity of intestinal mechanistic barrier and elevate the percentage of bacteria producing short chain fatty acids (SCFA). By investigating renin–angiotensin system (RAS) system, we found that ZGXFD can decrease the expression of angiotensin-converting-enzyme (ACE) in lungs, which in turn causes a increase in AngI produces angiotensin1–7 (Ang1–7) and decrease in AngII. ZGXFD regulate blood pressure in SHR via RAS.