双歧杆菌的抗癌效应及其机制的初步研究

双歧杆菌是一种重要的革兰氏阳性无芽胞厌氧杆菌，是人类肠道正常菌群中的优势菌种。本文观察了在改变栖生环境的情况下，双歧杆菌作为生物反应调节剂发挥抗肿瘤作用及其对单核巨噬细胞的激活作用。６１５小鼠在腹腔或皮下接种肝癌Ｈ２２／Ｆ２３后，从第１天起每隔３天腹腔或皮下两种途径注射双歧杆菌进行治疗，结果表明在瘤内注射给药时显示显著的抑瘤作用。双歧杆菌激活的腹腔渗出细胞（ＰＥＣ）在形态学上表现为细胞表面积增大，细胞皱褶增多；在功能上则表现为杀瘤活性增强，激活的ＰＥＣ经Ｗｉｎｎａｓｓａｙ证明对肿瘤生长的早期或中期有明显的抑制作用，用ＭＴＴ比色法测定细胞毒进一步证实激活的ＰＥＣ在体外具有直接杀瘤作用。实验结果提示双歧杆菌激活单核一巨噬细胞是其发挥抗肿瘤作用的重要机制。由于该菌为生理性细菌，对宿主无致病性，所以其较目前已在临床上广泛应用的其它非特异性生物反应调节剂如ＯＫ４３２、卡介苗等可能更具优越性，值得深入研究。

THE STUDY OF BIFIDOBACTERIUM ON THE INHIBITION OF TUMOR AND ITS PRIMARY ANTITUMOR MECHANISMS

Bifidobacterium (Bif)is a gram-positive non-spore anaerobic orga-nism. which is a normal microobial flora in human intestine,In thisOstudy,we investigated the effects of Bif,in inhibition of tumor and itspotential of activation of monocytes/macrophages. 615 strain mice were subcutaneously or intraperitoneally inoculatedwith H22/F3 hepatomacells,the mice were then treated by administrationof Bif,for 4 times at 3 day interval begening one day after tumor inje-ction. When Bif.Was administrated at the same placf3 of tumor inocula-tion,the growth of tumor could be markedly inhibited.The morpholo-gical study shoxved the increase of cell surface folds in Bif.Activatedperitoneal effusion cell(PEC)as comparison with non-activated PEC.Winn assay demonstrated that activated PEC could markedlv inhibite thegrowth of early and middle stage tumor.MTT colorimetric assay furtherproved the cytotoxic effect of PEC increased significantly after Bif.Sti-mulation. Our results demonstrated that the activation of monocytes/ma-crophages plays a very important role for Bif,in its antitumor mechan-isms