Hibiscus sabdariffa, Therapeutic Uses for Treating Pulmonary Hypertension.

Pulmonary hypertension (PH) is a devastating disease that leads to progressive right heart failure and death. despite limited success with current therapeutic approaches, PH remains a fatal disease. It has been proposed that risk factors coupled with predisposing genetic factors lead to imbalance between vasoconstrictive and vasodilator mechanisms, initiating a cascade of pathophysiological events in the lung leading to PH. This vasoconstrictor/vasodilator imbalance has made vasodilator therapy the main treatment for PH. Angiotensin II, a key component of the renin-angiotensin system, is abundant in pulmonary endothelial cells. (ACE2) a key endothelial cell enzyme, produces Angiotensin, when enhanced attenuates the proliferative and fibrotic effects of Ang II. A balance between ANGII/(ACE) and Ang 1-7/ACE2 is critical in maintaining normal pulmonary vascular homeostasis. Strategies to enhance ACE2 and Ang 1-7 have proven to be effective targets in animal models of PH (1,2). The dried calyxes of Hibiscus sabdariffa Linn (HS) have demonstrated antihypertensive properties in models of dydtemic hypertension (3). Yet the effects of HS on Ang 1-7 expression in pulmonary vascular endothelial cells, whose dysfunction appears to be the key in the initiation of PH, have never been investigated. Therefore, in collaboration with Auburn University and the University of Florida we have harvested two cultivars of HS adapted to local conditions, prepared extracts, and treating human pulmonary micro vascular endothelial cells (PMEC). We hypothesize that HS enhances ACE2 and Ang (1-7) and decreases ANGII in PMECs. Utilizing our resources and expertise in organic and biochemistry, the results of this study has determined the role of HS as a potential therapeutic alternative for PH