Effect of polysaccharide from the root of Bupleurum Chinese DC and Bupleurum scorzonerifolium Willd on hydrogen peroxide-induced myocardial apoptosis

Abstract

Purpose: To investigate the protective effect of polysaccharide (BRP) from the root of Bupleurum Chinese DC. and Bupleurum scorzonerifolium Willd. on cardiomyocyte cells. Methods: Response surface methodology (RSM) based on Box-Behnken Design (BBD) was performed to optimize the extraction conditions for BRP. The effect of BRP on cardiomyocyte cell apoptosis was evaluated in H9c2 cells treated with hydrogen peroxide (H2O2). Cell viability was determined by CCK-8 assay, while oxidative stress levels in H9c2 cells, including lactate dehydrogenase (LDH), superoxide dismutase (SOD), catalase (CAT) and creatine kinase (CK) were determined using commercial kits following the manufacture’s instruction. mRNA expressions (caspase-3, caspase-8, caspase-9 and Fas) were determined by quantitative real time-polymerase chain reaction (RT-qPCR). Results: The obtained optimal extraction conditions for BRP was as follows: extraction time (1.43 h), ratio of water to the raw material (30 mL/g) and extraction times (2 times). BRP (200, 400, 600 and 800 μg/mL) significantly increased the cell viability of H2O2 induced H9c2 cells (p < 0.05, p < 0.01, p < 0.01, p < 0.01, respectively). BRP (200, 400 and 800 μg/mL) significantly decreased LDH and CK levels (p < 0.01, p < 0.01, p < 0.01, respectively). However, BRP increased levels of SOD (200, 400 and 800 μg/mL, p < 0.05) and CAT (400 and 800 μg/mL, p < 0.05) in H9c2 cells. BRP significantly downregulated mRNA expressions of Caspase-3, Caspase-8, Caspase-9 and Fas (200, 400 and 800 μg/mL, p < 0.01) in H9c2 cells induced by H2O2. Conclusion: BRP protects cardiomyocyte against apoptosis via inhibition of oxidative stress and mitochondria-mediated intrinsic apoptosis, and thus, may be potential therapeutic agent for the management of cardiovascular diseases. Keywords: Bupleurum Chinese, Bupleurum scorzonerifolium Willd., Polysaccharide, Cardiomyocyte, Apoptosis, H9c2 cell, Biochemical parameters