蒲公英提取优化及其对大肠杆菌致小鼠腹泻的保护作用研究

Study on extraction optimization of dandelion and its protective effect on mice diarrhea induced by E. coli

试验旨在优化蒲公英水提条件及其对大肠杆菌体内外的抑菌作用。试验对提取时间、提取次数、加水倍数3个因素进行正交设计,筛选最优提取工艺条件;利用最小抑菌浓度试验(MIC)、抑菌曲线试验测定水提液对大肠杆菌的体外抑制作用;利用BALB/C小鼠研究水提液对大肠杆菌致小鼠腹泻的保护作用。结果显示:蒲公英水提的最优条件为提取时间1.5 h、提取次数3次、提取液料比20 mL/g。水提液对大肠杆菌的MIC为0.25 g/mL,0.5 MIC、1.0 MIC、2 MIC均能够抑制大肠杆菌生长。模型组小鼠的脏器系数均显著高于空白组小鼠和给药组小鼠(P<0.05)。模型组小鼠脾脏出血、充血现象明显,肠绒毛结构被破坏、上皮细胞数量减少,用药组小鼠的脾脏和十二指肠的损伤明显减轻。与空白组和药物组小鼠相比,模型组小鼠血清谷草转氨酶(AST)、谷丙转氨酶(ALT)活性和谷胱甘肽(GSH)含量显著升高(P<0.05)。研究表明,蒲公英提取液具有体内、体外抑制大肠杆菌的作用。

The experiment was to optimize the water extraction conditions of dandelion and studied its antibacterial effect on E. coli in vitro and in vivo. Orthogonal design was carried out for three factors of extraction time, extraction times and water addition multiple. The inhibitory effect of water extract on E. coli in vitro was determined by MIC, inhibition curve test and protective effect of water extract on diarrhea induced by E. coli in BALB/C mice was studied. The results showed that the optimal conditions for water extraction of dandelion was extraction time of 1.5 h, extraction of 3 times and extraction liquid material ratio of 20 mL/g. The MIC of water extract to E. coli was 0.25 g/mL, and inhibited the growth of E. coli under the conditions of 0.5 MIC, 1.0 MIC and 2 MIC. The organ coefficients of model group mice were significantly higher than those of blank group mice and drug group mice(P<0.05), the spleen hemorrhage and congestion were obvious, the structure of intestinal villi was destroyed and the number was reduced in model group, and the damage of spleen and duodenum in drug group was significantly reduced. Compared with mice in blank group and drug group, the activity of serum AST, ALT and the content of GSH in model group were significantly increased(P<0.05). The experiment indicates that the dandelion extract can inhibit E. coli in vivo and in vitro.