竹叶提取物的体外抑菌及抗氧化活性的研究

In vitro Antibacterial and Antioxidant Activity of Bamboo Leaves Extract

本文用水提取竹叶有效成分,将提取液浓缩至含生药量约1.0 g/mL,经醇沉后取清液浓缩,再经石油醚、三氯甲烷、乙酸乙酯、正丁醇分步萃取,得不同极性的各部分提取物。以金黄色葡萄球菌和大肠杆菌为供试菌,采用抑菌圈法(琼脂扩散法)和最低抑菌浓度(MIC)法测定其抑菌效果。结果显示,石油醚、三氯甲烷、乙酸乙酯部分均表现抑菌活性。各供试样对两种菌的抑菌圈直径达9.8～18.4 mm,最低抑菌浓度分别为1.25 mg/mL2,.50 mg/mL和5.00 mg/mL。最后采用亚硝基红盐-Co2+褪色法研究了竹叶提取物对.OH的清除作用,结果表明三氯甲烷和乙酸乙酯部分萃取物的抗氧化性明显优于水提物,其中乙酸乙酯部分萃取物的IC50值为1.06 mg/mL。

The bamboo leaves extract was obtained by decocting with water and then deposited with ethanol to remove the sample matrix.Water extract was further extracted by four different polarity solvents i.e.petroleum ether,chloroform,ethyl acetate and n-butanol,successively.Antibacterial activity on Staphylococcus aureus and Escherichia coli of the four fractions were studied by inhibition zone method（agar diffusion method） and minimal inhibitory concentration method（MIC） comparing with ethylparaben.The results indicated that the petroleum ether,chloroform,and ethyl acetate fractions exhibited significant inhibitory effects on both kinds of bacteria.The inhibition zones of samples for test were between 9.8 and 18.4 mm and minimal inhibitory concentration（MIC） were 1.25 mg/mL,2.50 mg/mL,and 5.00 mg/mL,respectively.Finally the scavenging effect on ·OH radical of bamboo leaves extract was studied by Nit-R-Co2＋ system,it was found that the chloroform and ethyl acetate fractions also possessed significant antioxidant activity,and IC50 of ethyl acetate extract was 1.06 mg/mL.