Wu Hui-Qing, Ma Zhi-Li, Zhang De-Xin, Wu Ping, Guo Yuan-Hua, Yang Fang, Li De-Yuan
Wuhan Functional Food Engineering and Technology Research Center, School of Laboratory Medicine, Hubei University of Chinese Medicine, Wuhan, China.
Front Nutr. 2021 Nov 3;8:769181. doi: 10.3389/fnut.2021.769181. eCollection 2021.
This study aimed to extract polysaccharides from pumpkin, characterize the structures of four of them, and evaluate their antioxidant and hypoglycemic activities. Additionally, an animal model of type 2 diabetes mellitus (T2DM) was established and used to determine their hypoglycemic and hypolipidemic effects , and the underlying mechanisms related to the regulation of gut microbiota. Water-extracted crude pumpkin polysaccharides (W-CPPs), water extraction and alcohol precipitation crude pumpkin polysaccharides (WA-CPPs), deproteinized pumpkin polysaccharides (DPPs), and refined pumpkin polysaccharides (RPPs) were sequentially extracted and purified from pumpkin powder by hot water extraction, water extraction, and alcohol precipitation, deproteinization and DEAE-52 cellulose gel column, respectively. The extraction and purification methods had significant influence on the extraction yield, physicochemical properties, and antioxidant and hypoglycemic activities. W-CCP and RPPs had a significant positive free radical-scavenging capacities and inhibitory activities on α-glucosidase and α-amylase. RPP-3 not only inhibited the uptake of glucose in Caco-2 monolayer but also promoted the excretion of glucose, while RPP-2 had no inhibitory effect. Animal experiment results showed that W-CPP treatment significantly improved the T2DM symptoms in mice, which included lowering of fasting blood glucose (FBG), reducing insulin resistance (IR), and lowering of blood lipid levels. It increased the diversity of intestinal flora and reduced the harmful flora of model mice, which included , and . At the family level, W-CPP (1,200 mg/kg) treatment significantly reduced the abundance of , and the of became a biomarker. Pumpkin polysaccharides reshaped the intestinal flora by reducing and increasing abundance, thereby improving blood glucose and lipid metabolism in the T2DM mice. Our results suggest that W-CCP and RPP-3 possess strong antioxidant and hypoglycemic activities, and are potential candidates for food additives or natural medicines.
本研究旨在从南瓜中提取多糖，对其中四种多糖的结构进行表征，并评估它们的抗氧化和降血糖活性。此外，建立了2型糖尿病（T2DM）动物模型，用于确定它们的降血糖和降血脂作用以及与肠道微生物群调节相关的潜在机制。通过热水提取、水提取和乙醇沉淀、脱蛋白以及DEAE-52纤维素凝胶柱，依次从南瓜粉中提取并纯化了水提取粗南瓜多糖（W-CPPs）、水提取乙醇沉淀粗南瓜多糖（WA-CPPs）、脱蛋白南瓜多糖（DPPs）和精制南瓜多糖（RPPs）。提取和纯化方法对提取率、理化性质以及抗氧化和降血糖活性有显著影响。W-CCP和RPPs具有显著的自由基清除能力以及对α-葡萄糖苷酶和α-淀粉酶的抑制活性。RPP-3不仅抑制Caco-2单层细胞对葡萄糖的摄取，还促进葡萄糖的排泄，而RPP-2没有抑制作用。动物实验结果表明，W-CPP处理显著改善了小鼠的T2DM症状，包括降低空腹血糖（FBG）、降低胰岛素抵抗（IR）以及降低血脂水平。它增加了肠道菌群的多样性，减少了模型小鼠的有害菌群，其中包括[具体有害菌群1]、[具体有害菌群2]和[具体有害菌群3]。在科水平上，W-CPP（1200mg/kg）处理显著降低了[具体有害菌科1]、[具体有害菌科2]和[具体有害菌科3]的丰度，[具体有益菌科]的[具体有益菌属]成为生物标志物。南瓜多糖通过降低[具体有害菌属1]和增加[具体有益菌属1]丰度重塑肠道菌群，从而改善T2DM小鼠的血糖和脂质代谢。我们的结果表明，W-CCP和RPP-3具有强大的抗氧化和降血糖活性，是食品添加剂或天然药物的潜在候选物。
