富锶茶多糖提取物的抗氧化活性及其对H_(2)O_(2)诱导LO2细胞氧化损伤保护研究

Antioxidant activity of strontium-rich tea polysaccharide extract and its protection against H_(2)O_(2)-induced oxidative damage in LO2 cells

目的 探明富锶茶多糖最佳提取工艺,并分析其体外抗氧化活性及对H_(2)O_(2)诱导LO2细胞氧化损伤的保护作用。方法 本研究采用热水超声辅助法从茶叶中提取富锶茶多糖,通过Box-Behnken响应面实验法对富锶茶多糖的提取工艺条件进行了优化;以1,1-二苯基-2-三硝基苯肼(1,1-diphenyl-2-picrylhydrazyl,DPPH)自由基、羟基自由基(·OH)、 2,2’-联氮-二(3-乙基-苯并噻唑啉-6-磺酸)二铵盐[2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) ammonium salt, ABTS]阳离子自由基的清除能力和Fe3+的还原能力为指标,分析富锶茶多糖的体外抗氧化活性;并以H_(2)O_(2)建立LO2细胞损伤模型,研究富锶茶多糖对LO2细胞氧化应激损伤的改善机制。结果 富锶茶多糖的最佳提取工艺条件为:提取温度67℃、浸提时间57 min、料液比1:25 (g:mL),富锶茶多糖得率为3.50%±0.12%。在体外抗氧化方面,富锶茶多糖对DPPH自由基、ABTS阳离子自由基、·OH和Fe3+的还原能力具有较好的清除能力;在改善LO2细胞氧化应激损伤方面,随着多糖质量浓度升高,细胞存活率也显著提高,当多糖质量浓度为50.0μg/mL时,细胞存活率达到99.5%;在清除机体过氧化机制上,相对于模型组,超氧化物歧化酶(superoxidedismutase,SOD)活力均有所增强,浓度越高处理的SOD活力越高,氧化氢酶(catalase, CAT)活力在中、高实验组中有显著提高,从细胞水平表明富锶茶多糖对LO2细胞氧化损伤具有明显的改善作用。结论 富锶茶多糖具有良好的抗氧化性以及对H_(2)O_(2)诱导LO2细胞氧化损伤有很好的保护作用,为富锶茶多糖功能性产品开发提供了理论基础。

Objective To explore the optimal extraction process of strontium-rich tea polysaccharides,and analyze their in vitro antioxidant activity and protective effect on H_(2)O_(2) induced oxidative damage in LO2 cells.Methods This study used hot water ultrasound assisted extraction of strontium-rich tea polysaccharides,and the extraction process conditions of strontium-rich tea polysaccharide were optimized by Box Behnken response surface methodology;the in vitro antioxidant activities of strontium-rich tea polysaccharides were analyzed by using the scavenging ability of 1,1-diphenyl-2-picrylhydrazyl(DPPH)radicals,hydroxyl radicals(ꞏOH),2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)ammonium salt(ABTS)cation radicals and the reducing energy of Fe3+as indicators;and a LO2 cell injury model was established by using H_(2)O_(2) to study the improvement mechanism of strontium-rich tea polysaccharides on oxidative stress damage in LO2 cells.Results The optimal extraction conditions were as follows:Extraction temperature was 67℃,extraction time was 57 min,solid-liquid ratio was 1:25(g:mL),and the extraction rates of strontium-rich tea polysaccharides were 3.50%±0.12%.In terms of antioxidants in vitro,strontium-rich tea polysaccharides had a good scavenging ability on DPPH radicals,ABTS cation radicals,ꞏOH and the reducing ability of Fe3+.In terms of improving oxidative stress damage of LO2 cells,the cell survival rate also increased significantly with the increase of polysaccharide mass concentration.When the polysaccharide mass concentration was 50.0μg/mL,the cell survival rate reached 99.5%.Compared with the model group,the activity of superoxide dismutase(SOD)was enhanced.The higher the concentration,the higher the SOD activity in the treatment.The activity of catalase(CAT)was significantly increased in the medium and high experimental groups,indicating that strontium rich tea polysaccharides had a significant improvement effect on oxidative damage in LO2 cells at the cellular level.Conclusion The strontium-rich tea polysaccharide has good antioxidant activity and protection against H_(2)O_(2)-induced oxidative damage of LO2 cells,which provides a theoretical basis for the development of functional products of strontium-rich tea polysaccharide.