青钱柳为我国特有植物,以其叶制成的茶叶具有较好的降血糖效果。为了进一步研究其降糖作用,以超声辅助法提取青钱柳叶总三萜,经萃取、大孔树脂吸附、脱色等纯化后纯度达86.3%,其中熊果酸、齐墩果酸、山楂酸、科罗索酸和白桦脂酸的含量分别为19.35%、17.38%、7.53%、4.59%和1.42%。对于3T3-L1前脂肪细胞,纯化后的青钱柳叶总三萜(CPTT)在基础状态下对葡萄糖消耗没有明显的影响,但在同时添加10nM胰岛素进行刺激时能显著提高葡萄糖消耗;对于成熟的脂肪细胞,无论是在基础状态下还是胰岛素刺激状态下,CPTT均能显著促进其葡萄糖消耗;对于由地塞米松诱导的胰岛素抵抗3T3-L1脂肪细胞,CPTT能有效地改善其胰岛素敏感性,提高葡萄糖消耗,且呈剂量.效应关系,以25μg/mL的效果最佳。以上研究结果表明,CPTT能促进脂肪细胞的葡萄糖消耗,在食品和药品领域有很好的应用前景。
Cyclocarya paliurus is a unique plant native to China, tea made from the leaves of this plant known for its hypoglycaemic effects. To further explore its hypoglycaemic property, total triterpenoids from Cyclocarya paliurus leaves (CPTT) were extracted by an ultrasound-assisted method and successively purified by extraction, macroporous resin adsorption, and decolorization. The total lriterpenoid content of CPTT was as high as 86.3%. The content of ursolic acid, oleanolic acid, maslinic acid, corosolic acid, and betulinic acid in CPTT were 19.35%, 17.38%, 7.53%, 4.59%, and 1.42%, respectively. No obvious change in glucose consumption was observed when 3T3-L1 pre-adipocytes were treated with CPTT in the basal condition, but the consumption significantly increased after simultaneous stimulation with 10 nM insulin. For mature adipocytes, CPTT increased glucose consumption significantly in both basal and insulin-stimulated conditions. For dexamethasone-induced insulin-resistant 3T3-L1 adipocytes, CPTT effectively improved insulin sensitivity and enhanced glucose consumption in a dose-dependent maimer, with the optimal effect observed at 25 μg/mL. These results suggest that triterpenoids from Cyclocarya paliurus leaves can effectively increase glucose consumption in adipocytes and therefore have a potential application in both the food and pharmaceutical industries.