Herbal medicine Oryeongsan (Wulingsan): Cardio-renal effects via modulation of renin-angiotensin system and atrial natriuretic peptide system

Background: Oryeongsan (Wulingsan, Goreisan) has long been used for the treatment of impaired body fluid metabolism. However, the action mechanisms have not been clearly defined. Recently, effects of Oryeongsan on the body fluid and Na+ metabolism and the action mechanisms have been shown more clearly. The present review focuses on the recent findings on the effects of Oryeongsan in the cardio-renal system in relation with body fluid metabolism and action mechanisms leading to a decrease in blood pressure in animal models of hypertension. Methods: The new and recent findings were searched by using searching systems including PubMed-NCBI and Google-Scholar. Results: Oryeongsan induced an increase in glomerular filtration rate, and natriuresis and diuresis with a decreased osmolality and resulted in a contraction of the body fluid and Na+ balance. These findings were associated with a suppression of abundance of Na+-H+-exchanger isoform 3 expression and V2 receptor/aquaporin2 water channel signaling pathway in the kidney. Further, treatment with Oryeongsan accentuated atrial natriuretic peptide secretion in the atria from spontaneously hypertensive rats in which the secretion was suppressed. In addition, Oryeongsan ameliorated impaired vasodilation in spontaneously hypertensive rats. Conclusion: The effects of Oryeongsan in the kidney, atria, and vessel were accompanied by a suppression of AT1 receptor and concurrent accentuation of abundance of AT2/Mas receptors expression and modulation of the natriuretic peptide system in these organs from hypertensive rats. The review shows multiple sites of action of Oryeongsan and mechanisms involved in the regulation of volume and pressure homeostasis in the body.