REN and hypertensive disorder: The antihypertensive activity can be modulated through the renin-angiotensin system and natriuretic hormone; in terms of molecular mechanism, OA was able to fight hypertension by down-regulating the renin-angiotensin-aldosterone system in the kidneys, thus inhibiting the plasmatic levels of renin, angiotensin, and aldosterone as well as up-regulating the expression of natriuretic peptide receptor C in the heart, hence improving blood pressure balance [175].