不同月份香椿不同部位叶片提取物中α-葡萄糖苷酶抑制剂的分布规律及其降血糖活性

Distribution Patternsand Hypoglycemic Activities of α-Glucosidase Inhibitors in Extracts from Different Parts of Toona sinensis Leaves Collected in Different Months

摘要:

为探究不同月份香椿不同部位叶片提取物中α-葡萄糖苷酶抑制剂的分布规律和降血糖效果，2020年8~11月，从3棵香椿树中采集36个样本，φ=50%乙醇提取α-葡萄糖苷酶抑制剂。分析香椿叶提取物对α-葡萄糖苷酶的抑制活性、酶抑制动力学和荧光光谱特征。进而将不同浓度香椿叶提取物与质量分数为3%葡萄糖共暴露斑马鱼，研究在斑马鱼体内的降血糖效果。结果表明：香椿叶中α-葡萄糖苷酶抑制剂的时间分布规律为8月、11月抑制率较高，可达99%；空间分布规律为从上层到下层抑制率依次递减， α-葡萄糖苷酶的抑制活性在时间和空间呈现显著性差异。香椿叶提取物对α-葡萄糖苷酶抑制的IC50为0.45 mg/mL，远低于阳性对照阿卡波糖5.05 mg/mL。香椿叶提取物的酶抑制类型为竞争性抑制，香椿叶提取物与酶的相互作用模式属于动态荧光猝灭。当香椿叶提取物暴露浓度为4 mg/L时，斑马鱼体内血糖浓度与高糖组有显著性差异。该研究为从香椿叶中大量提取α-葡萄糖苷酶抑制的采样方法设计及开发一种新型降血糖药物提供理论支持。

Abstract:

In order to explore the distribution patterns and hypoglycemic effect of α-glucosidase inhibitors in the extracts from different parts of Toona sinensis collected in different months. From August to November of 2020, 36 samples were collected from three Toona sinensis trees respectively, and 50% ethanol was used to extract the inhibitors against α-glucosidase. The inhibitory activity, enzyme inhibition kinetics and fluorescence spectral characteristics of Toona sinensis leaf extract against α-glucosidase were analyzed. Furthermore, zebrafish was exposed to different concentrations of Toona sinensis leaf extract along with 3% glucose to study the hypoglycemic effect. The results showed that the temporal distribution pattern of α-glucosidase inhibitors in Toona sinensis leaves was: the inhibitory rate was higher in August and November (up to 99%); the spatial distribution pattern was: the inhibitory rate decreased from the upper layer to the lower layer. The inhibitory activity against α-glucosidase showed significant differences in time and space. The half inhibitory concentration (IC50) of Toona sinensis leaf extract against α-glucosidase was 0.45 mg/mL, which was much lower than the positive control acarbose (5.05 mg/mL). The enzyme inhibitory type of Toona sinensis leaf extract was competitive inhibition, and the interaction mode between the Toona sinensis extract and enzyme belonged to dynamic fluorescence quenching. When the exposure concentration of Toona sinensis leaf extract was 4 mg/L, the concentration of blood glucosein zebrafish was significantly different from that forhigh glucose group. This study providesa theoretical support for sampling method design for massive extraction of α-glucosidase inhibitors from Toona sinensis leaves and development of a new hypoglycemic drug.