Chang Shuaishuai, Lei Xiao, Xie Qiang, Zhang Mingjin, Zhang Yuangai, Xi Jiaxin, Duan Jiyou, Ge Jian, Nian Fuzhao
China Jiliang University School of Life Sciences, Hangzhou, 310018, China.
Luzhou Branch of Sichuan Tobacco Company, Luzhou, 646000, China.
Bioresour Bioprocess. 2024 Jan 23;11(1):15. doi: 10.1186/s40643-024-00729-9.
Tobacco polysaccharides were extracted by hot water extraction, and purified and separated using DEAE-52 cellulose chromatography columns, and three purified polysaccharide fractions, YCT-1, YCT-2, and YCT-3, were finally obtained. The physicochemical properties of the three fractions were analyzed by ultraviolet spectroscopy, high-performance liquid chromatography and high-performance gel chromatography. The in vitro antioxidant activity of tobacco polysaccharides was compared among different fractions by using DPPH radical, hydroxyl radical scavenging assay and potassium ferricyanide method. The in vitro hypoglycemic activity was compared using α-amylase and α-glucosidase activity inhibition assay. And the in vitro hypolipidemic activity were investigated by using pancreatic lipase activity inhibition assay and HepG-2 intracellular lipid accumulation assay. All the results showed that the constituent monosaccharides of the three tobacco polysaccharide fractions were similar, but the molar percentages of each monosaccharide were different. The average molecular weights of the three components were 27,727 Da, 27,587 Da, and 66,517 Da, respectively, and the scavenging activities on DPPH radicals and hydroxyl radicals were at a high level with good quantitative-effect relationships. The reducing power were much lower than that of the positive control VC, and the three polysaccharide fractions had a weak inhibitory ability on α-amylase activity, but showed excellent inhibitory ability on α-glucosidase and pancreatic lipase activity. In addition, the results of cellular experiments showed that all three fractions were able to inhibit lipid over-accumulation in HepG-2 cells by increasing the mRNA expression levels of PPAR-α, CPT-1A, and CYP7A1 genes, and the tobacco polysaccharide YCT-3 showed the best effect. The mechanism by which YCT-3 ameliorated the over-accumulation of intracellular lipids in HepG-2 cells was found to be related to its influence on the expression of miR-155-3p and miR-17-3p in the exosomes of HepG-2 cells.
采用热水提取法提取烟草多糖，并用DEAE - 52纤维素色谱柱进行纯化分离，最终得到3种纯化的多糖组分YCT - 1、YCT - 2和YCT - 3。采用紫外光谱、高效液相色谱和高效凝胶色谱对这3种组分的理化性质进行分析。通过DPPH自由基、羟自由基清除试验和铁氰化钾法比较不同组分烟草多糖的体外抗氧化活性。采用α -淀粉酶和α -葡萄糖苷酶活性抑制试验比较体外降血糖活性。通过胰脂肪酶活性抑制试验和HepG - 2细胞内脂质积累试验研究体外降血脂活性。所有结果表明，3种烟草多糖组分的组成单糖相似，但各单糖的摩尔百分比不同。3种组分的平均分子量分别为27727 Da、27587 Da和66517 Da，对DPPH自由基和羟自由基的清除活性处于较高水平，具有良好的量效关系。还原力远低于阳性对照VC，3种多糖组分对α -淀粉酶活性的抑制能力较弱，但对α -葡萄糖苷酶和胰脂肪酶活性表现出优异的抑制能力。此外，细胞实验结果表明，3种组分均能通过提高PPAR -α、CPT - 1A和CYP7A1基因的mRNA表达水平来抑制HepG - 2细胞内脂质的过度积累，其中烟草多糖YCT - 3的效果最佳。发现YCT - 3改善HepG - 2细胞内脂质过度积累的机制与其对HepG - 2细胞外泌体中miR - 155 - 3p和miR - 17 - 3p表达的影响有关。
