混菌发酵豆豉中异黄酮含量及对小鼠肺癌细胞的抑制作用

选用高产蛋白酶菌株枯草芽孢杆菌D2和β-葡萄糖苷酶产生菌枯草芽孢杆菌U35进行单菌种、混合菌种发酵生产豆豉,测定大豆异黄酮含量及其抗肿瘤能力,分析异黄酮含量和抗肿瘤能力的关系。用HPLC法测定豆豉提取物异黄酮含量,采用MTT比色法检测异黄酮含量对细胞增殖的影响,并在荧光显微镜下观察小鼠肺癌(LLC)细胞形态变化。结果表明,D2U35混菌豆豉苷元型异黄酮含量分别比D2、U35单菌豆豉高101.95μg/mL(2.38倍)和35.48μg/mL(1.25倍),D2U35混菌豆豉对肿瘤细胞的抑制率分别比D2、U35单菌豆豉高15.79%和7.02%,说明混菌发酵不仅提高了苷元型异黄酮含量,还提高了豆豉提取物的抗肿瘤能力。对肿瘤抑制作用,苷元苷型异黄酮>总异黄酮>糖苷型异黄酮。

Influence of isoflavone content in mixed fermentation douchi on proliferation of LLC cells

In order to increase the isoflavone content in fermented soya beans and improve the antitumor properties,soya beans were fermented by protease-producing strains Bacillus subtili D2 and β-glucosidase producing strain Bacillus subtili U35 through single and multi-strain fermentation.The contents of isoflavone were measured by HPLC.The relationship between isoflavone content and the antitumor properties was also analyzed.LLC cells were cultured to logarithmic growth time,and the isoflavone with different concentrations were added into the media.After the culture of 24h,48h,72h and 96h,the inhibiting rates of isoflavone to LLC cells were measured by MTT method.The morphological changes of the LLC cells were observed by fluorescence microscope.The results showed that isoflavone aglycones content of D2U35 multi-strain fermented soya beans were enhanced greatly,with 2.38 times(101.95 μg/mL) and 1.25 times(35.48 μg/mL) higher than that of D2 and U35 fermented soya beans,respectively.D2U35 fermented soya beans could also inhibit LLC cells,with 15.79% and 7.02% higher than that of D2 and U35 feimented soya beans,respectively.The multi-strain fermentation D2U35 not only improved the isoflavone aglycones content,but also improved the antitumor properties.The inhibition capacity of Isoflavone aglycones to LLC cells was higher than those of total isoflavones content and glycoside isoflavone.