Abstract
Tianma is a traditional Chinese medicine (TCM) often used for the treatment of hypertension and heart diseases. To elucidate the function of tianma at the molecular level, we investigated the effect of tianma on vascular functions and aortic protein metabolism. We found that long-term treatment with tianma (~2.5g/kg/day for three months) in one-year-old rats could enhance acetylcholine (ACh)-induced vasorelaxation in endothelium-intact thoracic aortic rings against both KCl (80 mM)- and phenylephrine (PE)-induced contraction. By using the iTRAQ (isobaric tag for relative and absolute quantification) technique, we confirmed from the functional data at the proteome level that tianma treatment down-regulated the expressions of contractile proteins (e.g. Acta2) and other related structural proteins (e.g. desmin), and up-regulated the expressions of extracellular matrix (ECM) glycoproteins (e.g. Fbln5) and anti-thrombotic proteins (e.g. Anxa2) in aortic tissue. By inductive reasoning, tianma could perform its vasodilatory effect not only by inhibiting vascular smooth muscle contraction, but also by enhancing blood vessel elasticity and stabilizing the arterial structure. Thus, tianma might become a novel therapeutic herbal medicine for cardiovascular diseases by regulating the aortic proteome metabolism.