Effects of extraction methods on antibacterial activity of Chinese herbal medicine | 不同提取方法对中草药抑菌效果的影响

Chinese. 采用水煎法、半仿生法、乙醇回流法、超声-微波协同萃取法、微波萃取法、水提醇沉法6种方法制备五倍子、多梅、生地榆、生黄芪、大黄等6种中草药原液，以9种畜禽肠道病原菌为试验菌株进行体外抑菌试验。结果表明：6种中草药的提取液对供试菌株均有不同程度的抑菌活性；不同提取方法对不同中草药抑菌作用的影响不同，其中，五倍子、诃子以乙醇回流提取法制备的提取液的抑菌效果最好（P0.01），水提醇沉法次之（P0.05）；乌梅以乙醇回流提取法制备的提取液的抑菌效果最好（P0.01），超声-微波协同萃取法及微波萃取法次之（P0.05）；黄芩、大黄各提取液抑菌效果差异不显著（P0.05），6种方法无明显的区别；地榆各提取液抑菌效果差异显著（P0.05），其中，微波萃取法、超声-微波协同萃取法、水提醇沉法和乙醇回流法等方法制备的提取液的抑菌效果优于水煎法和半仿生法。说明乙醇回流法对6种中草药抗菌成分的提取效果最佳。

English. In this study, the effective extraction methods on antibacterial activity of Chinese herbal medicine were validated for the determination. Extractions were prepared from six Chinese herbal medicines with water decoction, semi-bionic extraction, ethanol refluxing process, ultrasonic and microwave co-assisted extraction, microwave extraction, ethanol subsiding method. Antimicrobial activities of each extraction were validated by in vitro bacteriostasis test. The antimicrobial assay by agar diffusion method showed that extractions of six Chinese herbal medicines effectively inhibited the growth of pathogenic bacteria, and each extracts with different extraction method have different effects on antibacterial activity. Extractions with ethanol refluxing process from Galla chinensis and Fructus chebulae most effectively inhibited the growth of pathogenic bacteria (P0.01), and ethanol subsiding method was determined as the second way for extracting (P0.05). For Fructus Mume, ethanol refluxing process was the best way for extracting (P0.01), and ultrasonic and microwave co-assisted extraction was lower (P0.05). For Scutellariae baicalensis and Rheum officinale, extraction method didn’t have significant effects on their antibacterial activity (P0.05). Extractions with ultrasonic, microwave co-assisted, ethanol subsiding method and extraction from Radix Sanguisorbae most effectively inhibited the growth of pathogenic bacteria. As a whole, ethanol refluxing process was the best way for extracting of antibacterial component from six Chinese herbal medicines.