Cellular and molecular mechanisms in vascular smooth muscle cells by which total saponin extracted from tribulus terrestris protects against artherosclerosis

Abstract

Background/Aims: Total saponin extracted from Tribulus terrestris (TSETT) has been reported to protect against atherosclerosis. We here investigate the cellular and molecular mechanisms of TSETT underlying protection against atherosclerosis. Methods: Cell proliferation was measured with Methyl thiazolyl tetrazolium (MTT); Intracellular H 2 O 2 was measured with DCFH-DA, a fluorescent dye; Intracellular free Ca 2+ was measured with a confocal laser scanning microscopy; Genes expression was measured with gene array and real-time quantitative polymerase chain reaction (RT-PCR); Phosphorylation of extracellular signal-regulated kinase 1/2 (phospho-ERK1/2) was measured with cell-based enzyme-linked immunosorbent assay (ELISA) and western blotting. Results: TSETT significantly suppressed the increase in cells proliferation induced by angiotensin II, significantly suppressed the increase in the intracellular production of H 2 O 2 induced by angiotensin II, significantly inhibited the increase in intracellular free Ca 2+ induced by H 2 O 2 , significantly inhibited the increase in phospho-ERK1/2 induced by angiotensin II; significantly inhibited the increase in mRNA expression of c-fos, c-jun and pkc-α induced by angiotensin II. Conclusion: These findings provide a new insight into the antiatherosclerotic properties of TSETT and provide a pharmacological basis for the clinical application of TSETT in anti-atherosclerosis. © 2013 S. Karger AG, Basel.