21种中药的体外抗菌活性筛选

Screening of the antimicrobial activities of 21 Chinese herbal medicines

目的 测定21种中药醇提取物的体外抗菌活性,筛选出抑菌活性强的药材,并进一步追踪其有效成分.方法 制备21种药材的80％乙醇冷、热提取物和其中2种药材的90％甲醇热提取物,采用常规琼脂扩散法对金黄色葡萄球菌、大肠埃希菌、白色念珠菌、铜绿假单胞菌等4种标准菌及临床分离得到的耐甲氧西林金黄色葡萄球菌（MRSA）的菌株进行体外抑菌试验,倍比稀释法测定最小抑菌浓度（MIC）、最低杀菌浓度（MBC）.结果 21种中药的醇提取物中有14种对4种标准菌有不同程度的抑制作用,其中12种对耐药MRSA菌有抑制作用,尤以两面针的醇提物体外抗菌活性最高,其MIC和MBC分别为16 ～128、64～512 μg·mL-1.结论 两面针醇提物呈广谱抗菌特性,且对MRSA菌株有良好的抑制作用;热提取物的效果稍优于冷提取物,且甲醇热提的效果优于乙醇.

OBJECTIVE To determine the antibacterial activity in vitro of ethanol extracts from 21 Chinese herbal medicines, and to screen the active extracts against methicillin resistant Staphylococcus aureus （MRSA）. METHODS The 80% ethanol （both hot and cold） extracts were prepared from 21 Chinese herbs and two of them were additionally extracted with 90% hot methanol. Their antibacterial activity in vitro was determined by agar - diffusion method, and the minimum inhibitory concentration （MIC） and minimum bactericidal concentration （MBC） was measured by double - dilution method. RESULTS 14 of the 21 ethanol extracts showed inhibitory effects on Staphylococcus aureus, Escherichia coli,Pseudomonas aeruginosa and Candida albicans with different potency, and 12 extracts showed better inhibition against MRSA. Among them,the extracts from Zanthoxylum nitidum showed the highest with the MIC at 16 - 128 μg·mL-1 and the MBC at 64 -512 μg·mL-1. CONCLUSION The alcoholic extracts of Zanthoxylum nitidum showed promising broad spectrum of antirnicrobial activity, including the effect on drug resistance bacteria MRSA. The antibacterial activity of the hot methanol extract is better than that of the extract by ethanol.