Potential O-Acyl-Substituted (−)-Epicatechin Gallate Prodrugs as Inhibitors of DMBA/TPA-Induced Squamous Cell Carcinoma of Skin in Swiss Albino Mice
作者:Sandeep Vyas、Benu Manon、Tej Vir Singh、Pritam Dev Sharma、Manu Sharma
DOI:10.1002/cbdv.201000219
日期:2011.4
Moreover, significant increases in the protein levels analyzed by ELISA of c-Jun, p65, and p53 were observed in the skin of DMBA/TPA treated mice, whereas mice treated with 2 and DMBA/TPA had a similar expression of these transcription factors than the control mice. The prodrug potential of the O-acyl derivatives 2-6 showed that they were adequately stable to be absorbed intact from the intestine, more
(-)-Epicatechin-3-gallate(1)是绿茶的主要儿茶素之一,在各种动物模型中均具有预防癌症的作用。但是,该化合物在中性或碱性介质中不稳定,因此生物利用度差。为了提高其稳定性,通过从绿茶提取物中分离出部分纯化的茶儿茶素级分并用各种酰化剂处理来制备1的O-酰基衍生物。筛选所得的化合物2-6的化合物对小鼠7,12-二甲基苯并[a]蒽(DMBA)/ 12-O-十四烷酰佛波醇13-乙酸盐(TPA)诱导的小鼠皮肤鳞状细胞癌的抗肿瘤潜力。结果表明,抗肿瘤活性随酰基链长度的增加而降低,即由化合物2(带有Ac基团的衍生物)化合物6具有戊酰基。此外,具有支链酰基链5的C(4)衍生物的活性低于线性C(4)衍生物4的活性。这种抑制活性的降低可能是由于两个Me基的空间位阻。此外,在DMBA / TPA处理的小鼠皮肤中观察到通过c-Jun,p65和p53的ELISA分析的蛋白质水平显着增加,而用2和DMBA