不同菌株白僵菌代谢产物对大鼠肝线粒体单胺氧化酶的抑制作用研究

Study on monoamine oxidawe inhibition of extracts from eight strains of Beauveria sp

对8株白僵菌[Beauveriasp.]代谢产物的抑制单胺氧化酶的活性进行测定,发现菌株Ba02和Ba05的乙酸乙酯提取物在终浓度为55μg/mL时,对单胺氧化酶A型(MAO＿＿A)有较强的抑制活性,其抑制率分别为95.9%和83.4%;Ba02及Ba03菌株脂溶性成分在终浓度为55μg/mL时对单胺氧化酶B型(MAO＿B)有较强的抑制活性,其抑制率分别为94.8%和84.1%。浓度和抑制活性关系研究表明在一定浓度范围内Ba02菌株脂溶性成分对MAO的抑制活性呈量效关系,经计算得出其对MAO＿A、MAO＿B抑制的IC50分别为18.3μg/mL、28.2μg/mL;抑制特征曲线表明Ba02菌株脂溶性成分对MAO＿A呈竞争型抑制,对MAO＿B为混合型抑制,Km值分别为0.47×10-5mol/L,0.11×10-5mol/L。

The inhibitory effect of extracts from fermentation broth of 8 strains(Ba01_08) of Beauveria sp.On rate liver monoamine oxidase A and B was studied with the methods of MAO_A and MAO_B assay. The results revealed that ethylacetate extracts from fermentation broth of Ba02 and Ba05 have strong inhibitory activity on MAO_A, their inhibition rates are 95.9% and 83.4% respectively at the concentration of 55μg/ml. The ethylacetate extracts at 55μg/ml from fermentation broth of Ba02 and Ba03 show high inhibitory effect on MA0_B which inhibition rate are 94.8, 84.1% respectively. The inhibition on MAO_A and B of the ethylacetate extracts from Ba02 have a dose_dependent manner with IC50 of 18.3 μg/ml, 28.2 μg/ml. The inhibitory manner also showed that the ethylacetate extracts from Ba02 on MAO_A was competitive and on MAO_B competitive mixed with noncompetitive inhibition.