Antitumor effect and mechanism of action of polysaccharides extracted from &lt;i&gt;Polygonum perfoliatum&lt;/i&gt; L whole plant in human lung carcinoma A549 cell line

Xi-Xi Lai,Yu-Ping Li

doi:10.4314/tjpr.v15i6.17

Abstract

Purpose: To optimize the extraction conditions of polysaccharides from Polygonum perfoliatum L. (PSDP) and to evaluate their anti-tumor activities on A549 cell line.Methods: Extraction of PSDP was optimized using Box-Behnken design (BBD). Three factors of response surface methodology (RSM) including extraction time, ratio of water to raw material and number of extractions were employed to optimize the yield of PSDP. The cytotoxic effect of PSDP on human lung carcinoma A549 cell line was evaluated in vivo, while its effects on expressions of caspase- 3, caspase-9, Bcl-2 and Bax were determined by western blot assay.Result: BBD was significant and applicable to PSDP extraction. Based on the contour plots, response surface plots and variance analysis, it predicted that the optimum conditions for PSDP extraction were: 1.58 h (extraction time); 30.18 mL/g (ratio of water to raw material); and 2.02 (number of extractions). PSDP had significant inhibitory effect on the growth of A549 cells in a concentration- and timedependent manner (p < 0.05). After treatment with PSDP, caspase-3, caspase-9 and Bax were significantly up-regulated (p < 0.05), whereas Bcl-2 was down-regulated, all concentration-dependently.Conclusion: RSM analysis is an appropriate method to optimize PSDP extraction. The results also indicate that PSDP has significant anti-tumor effect against A549 cells, most likely via inducing mitochondria-mediated apoptosis.Keywords: Polygonum perfoliatum, Polysaccharides, Anti-tumor effect, Human lung carcinoma, Mitochondria-mediated apoptosis

Highlights

It is well-known that lung cancers still remain one of the leading causes of cancer related death all over the world, especially in men aged more than 40 years [1]
Based on Box-Behnken design (BBD) design, 17 experiments were performed for different combinations of the extraction parameters to study the independent variables on the extraction yield of PSDP (Table 1)
The expression of Bcl-2 was down-regulated, whereas Bax, caspase-3 and caspase-9 were increased after treatment with PSDP, in a concentration-dependent manner. These results indicated that the mechanism underlying the anti-tumor activity of PSDP on A549 cells is related to the induction of mitochondria-mediated apoptosis pathway

Summary

Introduction

It is well-known that lung cancers still remain one of the leading causes of cancer related death all over the world, especially in men aged more than 40 years [1]. It is important to explore newer and more effective approaches for the treatment of this disease

Methods

Results

Conclusion