Functional proteomics reveal the effect of Salvia miltiorrhiza aqueous extract against vascular atherosclerotic lesions

Salvia miltiorrhiza is a Chinese herb widely used for cardiovascular disorder regimens, yet little is known about the cellular mechanisms that contribute to attenuated growth of smooth muscle cells (SMCs) under oxidative stress such as homocysteine (Hcy) treatment. As anticipated, a low dose (0.015 mg/mL) of S.miltiorrhiza aqueous extract (SMAE) significantly inhibited (> 60%) the growth of a rat smooth muscle cell line (A10) under Hcy stimulation and the intracellular reactive oxygen species (ROS) concentration obviously decreased after SMAE treatment in terms of reducing p47phox translocation and increasing catalase activity. Signaling profile suggests that SMAE inhibited Hcy-induced A10 cell growth via the PKC/MAPK-dependent pathway. Two-dimensional electrophoresis (2-DE) coupled with mass spectrometry revealed statistically significant changes in the intensity of 14 proteins in response to Hcy and Hcy/SMAE. Meanwhile, SMAE attenuated carbonyl-modification of specific cytoskeleton and chaperone proteins leading to cell type transformation. Moreover, a network analysis using MetaCore™ shed more light on the molecular basis associated with SMAE efficacy. SMAE exerts its protective effect through the scavenging of ROS and subsequent modulation of protein carbonylation to inhibit cell proliferation. These signature networks and functional proteomics highlighted herein may facilitate the evaluation of potential therapeutic targets and elucidate novel mechanisms through which protein functions can be regulated by the redox status.