玉米须抗糖尿病活性成分的分离及其作用机制研究

Separation of anti-diabetic constituents from corn stigma and their mechanism of action

目的研究玉米须抗糖尿病的活性成分。方法 65%乙醇玉米须提取物分别经硅胶、凝胶及制备液相色谱进行分离,并根据理化性质和波谱技术来鉴定所得化合物的结构。然后,对以上化合物进行3T3-L1成熟脂肪细胞葡萄糖消耗量测试,用以筛选活性化合物,Western blot法检测AMPK蛋白,油红O染色法检测活性化合物对前脂肪细胞3T3-L1分化的影响,RT-PCR法检测PPARγ、c/EBPα的相对表达量。结果从玉米须中分离鉴定了7个化合物,分别为柯伊利素-6-C-β-波伊文糖-7-O-β-葡萄糖苷(1)、柯伊利素(2)、香草酸(3)、木犀草素(4)、胡萝卜苷(5)、棕榈酸(6)、土槿戊酸(7)。其中,化合物1能有效提高3T3-L1成熟脂肪细胞的葡萄糖消耗量和其AMPK的磷酸化水平,并且该作用能够被AMPK特异性抑制剂化合物C所阻断。另外,它还能显著抑制前脂肪细胞3T3-L1分化及PPARγ、c/EBPα相对基因表达。结论化合物1显示出较好的抗糖尿病活性,而且化合物4为首次从该植物中分离得到。

AIM To study the chemical constituents from corn stigma and their anti-diabetic activity. METHODS Extracted with 65% ethyl alcohol,the constituents from corn stigma were isolated by chromatography of silica gel,gel and preparative HPLC,and their structures were identified on the basis of the physical and chemical properties and spectral analysis. Glucose consumption assays and Western blot were used to assay their anti-diabetic activity,while Oil red O and RT-PCR were used to assay their effects on 3T3-L1 differentiation. RESULTS Seven compounds were isolated from corn stigma and identified as chrysoeriol-6-C-β-boivinopyranosyl-7-O-β-glucopyranoside（ 1）,chrysoeriol（ 2）,vanillic acid（ 3）,luteolin（ 4）,daucosterol（ 5）,palmitic acid（ 6）,pesudolario acid（ 7）. Among them,compound 1 significantly stimulated glucose consumption and phosphorylation of AMPK in3T3-L1 adipocytes,and this function was blocked by compound C. Furthermore,it could still inhibit 3T3-L1 differentiation and the mRNA level of PPARγ,c / EBPα. CONCLUSION Compound 1 significantly exhibits antidiabetic activity,and compound 4 is isolated from this plant for the first time.