Yiqi Huaju formula, a Chinese herbal medicine, reduces arterial pressure in salt‑sensitive hypertension by inhibiting renin‑angiotensin system activation.

Hypertension is a chronic disease with a high prevalence, and is associated with a high risk of vascular disease and premature death. Traditional Chinese medicine has been administered to treat hypertension for many years. In the present study, the effects of Yiqi Huaju formula (YQ; a compound used in traditional Chinese herbal medicine) were observed in salt‑sensitive hypertension, which was induced by a high‑salt and high‑fat (HSF) diet and the potential mechanism was investigated. YQ was prepared from five plant extracts and was dissolved in normal sodium chloride prior to use. Male Sprague‑Dawley rats were randomly divided into three groups, and fed either a normal diet (control), an HSF diet or an HSF diet with YQ. At week eight, blood pressure was measured and 24‑h urine samples were collected from all of the rats. The rats were subsequently sacrificed, and their blood was collected for biochemical analyses and kidney tissue samples were dissected for the immunohistochemical assay. YQ was observed to decrease the high arterial pressure and serum total cholesterol level, which had been induced by the HSF diet. It also enhanced the excretion of urinary angiotensinogen, Na+, and decreased the loss of urinary aldosterone, K+ and microalbuminuria. In addition, YQ inhibited the high mRNA expression level of renal renin, angiotensin II (Ang II), and Ang II receptor, type 1 (AT1R), and inhibited the protein expression of renal AT1R and Ang II receptor type 2, which had been induced by the HSF diet. These results indicate that YQ may reduce the arterial pressure in salt‑sensitive hypertension via the inhibition of renin‑angiotensin system activation.