杜仲总黄酮对荷瘤小鼠的抗肿瘤作用

Antitumor effects of total flavonoids of Eucommia ulmoides in tumorbearing mice

目的:研究杜仲总黄酮对荷瘤小鼠的抗肿瘤作用,并探讨其可能的机制。方法:采用H22荷瘤小鼠模型,给予杜仲总黄酮12d后,观察荷瘤小鼠肿瘤生长情况,测定抑瘤率;检测血清中SOD、MDA变化;病理切片观察瘤细胞生长及病理形态变化情况;免疫组化检测肿瘤组织中Bcl-2、Bax蛋白的表达。结果:杜仲总黄酮对小鼠H22皮下移植瘤具有明显的抑制作用,小鼠成瘤时间普遍晚于空白对照组,肿瘤生长缓慢,低、中、高3个剂量组抑瘤率分别为35.90%、44.70%、47.60%;与空白对照组比较,杜仲总黄酮能提高小鼠SOD值,且具有一定的量效关系(P<0.05);病理切片显示杜仲总黄酮各组和环磷酰胺组坏死面积均比空白对照组大;免疫组化结果显示,小鼠经杜仲总黄酮作用后,肿瘤组织内Bcl-2蛋白的表达水平下降,Bax蛋白表达水平上升。结论:杜仲总黄酮具有很强的体内抗肿瘤作用,其作用机制可能与清除自由基和下调Bcl-2蛋白的表达水平、上调Bax蛋白的表达水平有关。

AIM：To evaluate the antitumor effects and its possible mechanisms of total flavonoids of Eucommia ulmoides on tumor-bearing mice.METHODS：H22 tumor-bearing mice were used as tumor model.Different doses of total flavonoids of Eucommia ulmoides were ig administered to the tumor-bearing mice once a day for continuous 12 d.Tumor growth was measured and tumor growth inhibition rate （IR） was calculated.Serum SOD and MDA concentrations were detected.The growth and pathomorphologic changes of tumor cell were observed through pathological sections.The protein expression level of Bcl-2 and Bax were detected by immunohistochemistry.RESULTS：Total flavonoids of Eucommia ulmoides inhibited the hepatocarcinoma H22 transplantation tumor.Compared with the control group,the tumor formation was significantly retarded and tumor growth was inhibited in total flavonoids of Eucommia ulmoides treated groups.The inhibitory rates were 35.90%,44.70% and 47.60% in three groups treated with low,middle,and high dosages of total flavonoids of Eucommia ulmoides,respectively.Compared with the control group,the levels of SOD were increased in total flavonoids of Eucommia ulmoides treated groups in a doesdependent manner （P 〈 0.05）.Pathology revealed that necrotic area of total flavonoids of Eucommia ulmoides treated groups and cyclophosphamide group was larger than the control group.Immunohistochemistry showed that the expression of Bax protein was increased and the expression of Bcl-2 protein was reduced in xenograft tumor tissues after total flavonoids of Eucommia ulmoides treatment.CONCLUSION：Total flavonoids of Eucommia ulmoides has significant inhibition on tumor growth in vivo,which is probably related to scanvenging oxygen free radicals and the down-regulation of Bcl-2 expression and up-regulation of Bax expression.