太行菊黄酮对α-葡萄糖苷酶活性的抑制作用

Inhibition of the α-Glucosidase Activity by the Flavonoids from Opisthopappus taihangensis (Ling) Shih

摘要:

为研究太行菊醇提物不同极性萃取相中黄酮对α-葡萄糖苷酶活性的影响及其抑制作用的动力学特征，采用萃取法制得太行菊黄酮的乙酸乙酯相、正丁醇相、残余水相和石油醚相，使用体外（PNPG） 法建立抑制α-葡萄糖苷酶活性的筛选模型，通过酶促反应动力学绘制Lineweaver-Burk曲线，分析太行菊黄酮对α-葡萄糖苷酶作用的抑制类型。太行菊不同极性萃取物对α-葡萄糖苷酶呈现不同程度的抑制作用，而且抑制活性与黄酮的质量浓度之间呈现明显的剂量效应关系。其中乙酸乙酯相和正丁醇相中黄酮质量分数及α-葡萄糖苷酶抑制活性均显著高于其他萃取相，且高于阿卡波糖，而残余水相和石油醚相中黄酮对α-葡萄糖苷酶的抑制活性低于阿卡波糖。酶抑制活性乙酸乙酯（IC₅₀=1.01 mg/mL）<正丁醇（IC₅₀=1.25 mg/mL）<阿卡波糖（IC₅₀=1.47 mg/mL）<残余水相（IC₅₀=1.77 mg/mL）<石油醚（IC₅₀=2.12 mg/mL）。酶抑制动力学研究发现，乙酸乙酯相和正丁醇相中太行菊黄酮对α-葡萄糖苷酶是混合型抑制类型中竞争与非竞争关系；残余水相和石油醚相中太行菊黄酮对α-葡萄糖苷酶是竞争与反竞争的混合抑制类型。太行菊醇提物不同极性萃取相黄酮均具有一定的α-葡萄糖苷酶的抑制活性，在开发成辅助降血糖的保健食品或药品方面具有良好的潜力，有望将太行菊醇提物乙酸乙酯相和正丁醇相黄酮开发为新型α-葡萄糖苷酶抑制剂。

Abstract:

To study the effects of flavonoids on the activity of α-glucosidase and their inhibitory kinetic characteristics in different polar extraction phases of the alcohol extract of Opisthopappus taihangensis (Ling) Shih, the ethyl acetate phase, n-butanol phase, residual water phase and petroleum ether phase of flavonoids from Opisthopappus taihangensis were extracted. A screening model of α-glucosidase activity inhibition was established by in vitro (PNPG) method. Lineweaver-Burk curves were drawn to analyze the type of inhibition of α-glucosidase by flavonoids from Opisthopappus taihangensis. Flavonoids from Opisthopappus taihangensis in different polar extraction phases showed different degrees of inhibition on α-glucosidase, and a significant dose-effect relationship was found between the inhibitory activity and the concentration of flavonoids. Among them, the flavonoid content and α-glucosidase inhibitory activity in the ethyl acetate phase and n-butanol phase were significantly higher than those in the other extraction phases and higher than that of the acarbose, while the inhibitory activity of glucosidase is lower than that of acarbose. The inhibitory activity was: ethyl acetate (IC₅₀=1.01 mg/mL) ＜n-butanol (IC₅₀=1.25 mg/mL) ＜acarbose (IC₅₀=1.47 mg/mL) ＜residual water (IC₅₀=1.77 mg/mL) ＜petroleum ether (IC₅₀=2.12 mg/mL). Enzyme inhibition kinetics studies found that α-glucosidase of flavonoids from Opisthopappus taihangensis in ethyl acetate phase and n-butanol phase is competitive and non-competitive mixed type; flavonoids from Opisthopappus taihangensis in residual water phase and petroleum ether phase α-glucosidase is a mixed type of competition and anti-competition. The flavonoids of different polar extraction phases of Opisthopappus taihangensis have α-glucosidase inhibitory activity, and have good potential in developing health foods or medicines that assist in lowering blood sugar. Ethyl acetate phase and n-butanol phase flavonoids can be developed as novel α-glucosidase inhibitors.