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 H₂O₂ was measured with DCFH-DA, a fluorescent dye; Intracellular free Ca²⁺ 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 H₂O₂ induced by angiotensin II, significantly inhibited the increase in intracellular free Ca²⁺ induced by H₂O₂, 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.