栝楼籽多糖提取纯化、结构表征及降血糖活性

Extraction and Purification, Structure Characterization and Hypoglycemic Activity of Polysaccharide from Trichosanthes kirilowii Maxim. Seed

摘要:

目的:探究栝楼籽多糖提取工艺、初级结构及降血糖活性。方法:采用热水浸提法对栝楼籽多糖的提取工艺进行优化。利用葡聚糖凝胶G-150进行纯化得均质多糖(WHP-I),并对多糖结构进行初步表征。通过体外和体内降血糖实验联合探究栝楼籽多糖降血糖活性。结果:栝楼籽多糖的最优提取条件为温度80℃、时间100 min、料液比1:25 (g/mL)、浸提次数2次。验证试验结果显示:多糖提取率17.54%,优化方案科学合理。WHP-I初级结构分析表明WHP-I重均分子量为47.65 kDa,并含有五种糖残基分别是→3)-Araf-(1→,→6)-Galp-(1→,→4)-Glcp-(1→, D-Glcp-(1→,和→4,6)-D-Glcp-(1→。WHP-I表面较为平整,表面有孔状结构,且附着有细小的颗粒。体外降血糖实验结果显示WHP-I抑制α-葡萄糖苷酶的IC50值为15.837 mg/mL。体内实验结果表明,WHP-I具有减缓T2DM引起脏器损伤的潜力,给药四周后,M-WHP-I组和H-WHP-I组小鼠的血糖值分别降低了32.13%和42.27%,且WHP-I对糖尿病小鼠的肾脏和肝脏具有修复作用。结论:优化的栝楼籽多糖工艺合理可行,多糖结构清晰,且具有明显的降血糖活性。

Abstract:

Objective: This study aimed to optimiz the extraction process of polysaccharide from the seeds of Trichosanthes Kirilowii Maxim and investigate the primary structure and hypoglycemic activity of polysaccharide. Methods: The extraction process of polysaccharide from seed of Trichosanthes Kirilowii Maxim was optimized by hot water extraction. The homogenous polysaccharide (WHP-I) was purified by dextran gel G-150, and its structure was characterized. The hypoglycemic activity of Trichosanthes Kirilowii seed polysaccharide was investigated by in vitro and in vivo experiments. Results: The optimal conditions for extracting polysaccharide from Trichosanthes Kirilowii seed by hot water extraction were 80℃, 100 min, 1:25 solid-liquid ratio (g/mL), and two times of extraction. Verification test results showed that the extraction rate of polysaccharide was 17.54%, and the optimal scheme was scientific and reasonable. The primary structure analysis showed that WHP-I had an average molecular weight of 47.65 kDa and contained five sugar residues: →3)-Araf-(1→,→6)-Galp-(1→,→4)-Glcp-(1→, D-Glcp-(1→,and →4,6)-D-Glcp-(1→. The surface of WHP-I was flat, with pore structure and fine particles attached to the surface. The results of in vitro hypoglycemic experiment showed that the IC50 value of WHP-I inhibited α-glucosidase was 16.837 mg/mL. In vivo experiments showed that WHP-I has the potential to slow the organ damage caused by T2DM. After 4 weeks of administration, the blood glucose levels of M-WHP-I group and H-WHP-I group were reduced by 32.13% and 42.27%, respectively. Moreover, WHP-I could repair the kidney and liver of diabetic mice. Conclusion: The optimized process of polysaccharide from the seeds of Trichosanthes Trichosanthes Kirilowii was reasonable and feasible, with clear structure and obvious hypoglycemic activity.