半枝莲抗菌活性及其有效部位研究

目的研究半枝莲不同粗提物的体外抗菌活性,并初步确定其抗菌活性有效部位。方法采用甲醇冷浸法、乙醇热回流法及微波萃取法提取粗提物,96孔板培养法测定不同粗提物对的体外抑菌活性;将提取物分别用石油醚、乙酸乙酯和水萃取得到不同极性的萃取物组分,通过比较其抑菌活性初步确定半枝莲的抗菌有效部位。结果三种提取方法中,微波萃取法浸膏得出率最高;半枝莲的各粗提物对普通菌在2 mg/mL下未见抑制活性,但对耐甲氧西林金葡菌(ATCC33591和43300)半数抑制浓度(MIC值)达到2mg/mL;粗提物的萃取组分尤其是乙酸乙酯相,表现出广谱抗菌活性,其对各种菌株的半数抑制浓度大多在0.5～2 mg/mL范围,石油醚相对变异链球菌的抑菌活性较强,MIC值达到0.125 mg/mL。结论半枝莲具有广谱的抗菌活性,尤其是对耐药菌表现出较好的抗菌活性,并且初步确定抗菌有效部位为乙酸乙酯相,这为半枝莲抗菌应用的下一步研究奠定了基础。

ANTIBACTERIAL ACTIVITY AND ACTIVE FRACTION OF SCUTELLARIA BARBATA

Objective: To research the antibacterial activity of different crude extracts of Scutellaria barbata in vitro and determine its antibacterial fraction. Methods: The crude extracts were extracted by methanol cold leaching, ethanol thermal reflux and microwave extraction. The antibacterial activity of different crude extract pairs were determined by 96-well plate culture method. The extracts were suspended in water and extracted by petroleum ether and ethyl acetate in sequence. The extracts with different polarities were obtained and the antibacterial activity of these fractions was preliminarily determined to emerge the antibacterial fraction. Results: Among the three extraction methods, the extraction rate of microwave extraction was the highest; the crude extracts of S. barbata had no inhibitory activity against common bacteria at 2 mg/mL, but be effects against methicillin-resistant Staphylococcus aureus (ATCC 33591 and 43300) with a half inhibitory concentration (MIC value) of 2 mg/mL. The extract components of the crude extract, especially the ethyl acetate phase, exhibited a broad-spectrum antibacterial activity, and its MIC value against various strains were mostly ranged from 0.5 to 2 mg/mL. The petroleum ether fraction showed excellent antibacterial activity against Streptococcus mutans with the MIC value of 0.125 mg/mL. Conclusion: S. barbata has broad-spectrum antibacterial activity, especially against resistant bacteria, and it is preliminarily confirmed that the effective antibacterial fraction is ethyl acetate phase. This work lays a foundation for the next step of antibacterial application of S. barbata.