铁钉菜水提醇沉上清液部分的抗氧化、抗酪氨酸酶活性及其冲剂的降糖作用

Antioxidant and Anti-Tyrosinase Activities of Supernatants from Water Extracting-Alcohol Precipitation of Ishige okamurai and Hypoglycemic Effect of Its Granules

为探讨海藻铁钉菜提取物的抗氧化、抗酪氨酸酶活性与降糖作用,作者采用DPPH、羟基自由基清除体系测定铁钉菜水提醇沉上清液部分(SWEAPI)的抗氧化活性,采用多巴色素法测定其抗酪氨酸酶活性,并以可溶性淀粉、甜蜜素、β-环状糊精为辅料,采用正交实验设计的优化条件制备铁钉菜固体冲剂;通过体外α-葡萄糖苷酶活性抑制实验与体内四氧嘧啶致糖尿病小鼠模型,研究该冲剂的降血糖作用。结果表明:SWEAPI具有较强的自由基清除能力与抗酪氨酸酶活性,其DPPH自由基清除的半效应质量浓度EC50为1.19 mg/mL,羟基自由基清除的EC50为5.08 mg/mL,酪氨酸酶活性抑制的半效应质量浓度IC50为1.27 mg/mL;这可能与其较高的多酚含量(8.30%)有关。采用SWEAPI:可溶性淀粉:甜蜜素:β-环状糊精为30∶60∶1∶7.5的配比进行铁钉菜冲剂制备可获得较好的产品质量,冲剂的水分质量分数≤10%、总糖质量分数约为18.74%、蛋白质质量分数16.60%、多酚质量分数2.53%。该冲剂具有较强的α-葡萄糖苷酶抑制活性,半效应质量浓度IC50为0.37 mg/mL。口服冲剂14 d后,与模型组比较,350 mg/kg的使用剂量时可极显着降低糖尿病小鼠血糖,糖耐量实验进一步证实其可以在短时间内降低餐后血糖,总体上,其降糖效果与阳性药物二甲双胍处理组(500 mg/kg)相近。可见,SWEAPI具有较强的抗氧化活性、抗酪氨酸酶活性与降糖作用,具有开发成海藻源护肤品、降糖功能产品的潜在应用价值。

The study aimed to investigate the antioxidant,anti-tyrosinase,and hypoglycemic activities of the extracts from Ishige okamurai.The antioxidant activities of the supernatants from water extracting-alcohol precipitation of Ishige okamurai(hereafter,referred to as simply SWEAPI)were determined by the DPPH and hydroxyl radical scavenging system,its anti-tyrosinase activity was determined by the dopachrome method.Using SWEAPI as basic material and soluble starch,sodium cyclamate,andβ-cyclodextrine as auxiliary materials,the granules were prepared by the optimization conditions from orthogonal experiment.The hypoglycemic effects of granules were studied by in vitroα-glycosidase enzyme activity inhibition experiment and in vivo alloxan-induced diabetic mice.The results show that EC50 of DPPH scavenging is 1.19 mg/mL,EC50 of hydroxyl radical scavenging is 5.08 mg/mL,and IC50 of tyrosinase inhibition is 1.27 mg/mL.These phenomena are related to its higher polyphenol content(8.30%).When the granules are made by the optimization conditions with the 30∶60∶1∶7.5 ratio of SWEAPI:soluble starch:sodium cyclamate:β-cyclodextrine,it has the best product quality with content of water(≤10%),total sugar(18.74%),protein(16.60%),and polyphenol(2.53%).The granules have strong inhibitory activity againstα-glycosidase enzyme with IC50 of 0.37 mg/mL.Compared with the model control group,the granules could significantly reduce the blood glucose level of diabetes mice after 14 days of treatment with oral dose of 350 mg/kg.The granules also could reduce postprandial blood glucose level in a short time by the results of glucose tolerance experiment,which are similar to positive drug metformin at dose of 500 mg/kg.In conclusion,SWEAPI has strong antioxidant,anti-tyrosinase,and hypoglycemic activities with potential applications in skin care products and hypoglycemic functional products.