生姜姜辣素的分离及对HepG2细胞胰岛素抵抗的预防作用

目的:本文通过提取和分离生姜姜辣素，探究姜辣素对HepG2细胞胰岛素抵抗的预防作用。方法:采用乙醇作为溶剂，水浴振荡提取得到姜辣素粗提物，通过乙酸乙酯萃取和石油醚对姜辣素粗提物进行纯化。测定姜辣素对1,1-二苯基-2-苦肼基（DPPH）和2,2'-联氮-双-3-乙基苯并噻唑啉-6-磺酸（ABTS）自由基清除率进行抗氧化活性分析。构建HepG2细胞胰岛素抵抗模型，测定姜辣素对细胞的葡萄糖消耗量、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）活力和PI3K/AKT通路有关基因表达量的影响。结果:采用正交试验确定乙醇提取姜辣素的最佳条件为:料液比1:50 g/mL、提取时间80 min、乙醇体积分数60%、提取温度50 ℃。在此条件下，姜辣素的得率为 1.885%±0.071%。乙酸乙酯和石油醚萃取后姜辣素含量大于34.55%。抗氧化分析结果表明，姜辣素对DPPH和ABTS+自由基半数清除浓度（EC₅₀）分别为0.501和0.111 mg·mL?1。使用25 μg·mL?1胰岛素处理HepG2细胞48 h后，细胞的葡萄糖消耗量显著降低（P<0.05）。姜辣素显著提高了细胞的葡萄糖消耗量、SOD和CAT活力（P<0.05），并呈现剂量依赖性。此外，姜辣素处理组均显著上调PI3K、IRS-2和AKT基因的表达量（P<0.05），并能显著下调GSK-3β、FoxOI和PEPCK的表达量。结论:生姜姜辣素具有良好的抗氧化活性，且通过激活PI3K/AKT通路预防HepG2细胞的胰岛素抵抗作用。

Isolation of Gingerols and Its Preventive Effect on Insulin Resistance of HepG2 Cells

Objective: To investigate the prevention effect of gingerols on insulin resistance of HepG2 cells, extraction and isolation of ginger gingerols were carried out. Methods: The crude extract of gingerols were extracted by using ethanol and water bath oscillation. The crude extract of gingerols were separated and purified by ethyl acetate extraction and petroleum ether. The antioxidant activity of gingerols were determined using 1,1-diphenyl-2-picrhydrazyl (DPPH) and 2,2'-biazo-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS). Insulin resistance model of HepG2 cells were constructed, and the effects of gingerols on glucose consumption, superoxide dismutase (SOD), catalase (CAT) activity and PI3K/AKT pathway related gene expression were determined. Results: The optimum extraction conditions determined by orthogonal experiment were as follows: Solid-liquid ratio of 1:50 g/mL, extraction time of 80 min, ethanol volume fraction of 60%, extraction temperature of 50 ℃. Under these conditions, the yield of gingerols was 1.885%±0.071%. After extraction with ethyl acetate and petroleum ether, gingerols content was more than 34.55%. Antioxidant analysis showed that the semi-scavenging concentrations (EC₅₀) of gingerols on DPPH and ABTS+ were 0.501 and 0.111 mg·mL?1, respectively. After treating with 25 μg·mL?1 insulin for 48 h, cells exhibited reduced glucose consumption (P<0.05). Gingerols treatment significantly increased glucose consumption, SOD and CAT activities in a dose-dependent manner (P<0.05). In addition, the expressions of PI3K, IRS-2 and AKT genes were significantly up-regulated in gingerols treatment group (P<0.05), and the expressions of GSK-3β, FoxOI and PEPCK were significantly down-regulated in gingerols treatment group. Conclusion: Gingerols had desirable antioxidant activity, and also prevented insulin resistance through PI3K/AKT pathway.