甘草黄酮类化合物对CDK1的抑制活性及体内外抗肝癌活性

Effect of licorice flavonoids as CDK1 inhibitors against liver cancer in vitro and in vivo

探讨甘草黄酮类化合物对细胞周期依赖性蛋白激酶(CDK1)的抑制活性及抑制肝肿瘤细胞Bel-7402活性。采用CDK1和CCK-8试剂盒分别测试甘草黄酮类化合物对CDK1的抑制活性和对肝癌Bel-7402细胞的体外增殖抑制活性。构建肝癌Bel-7402裸鼠皮下肿瘤模型,并将小鼠随机分为3组:灌胃给药组、阳性药物组和空白对照组,连续灌胃给药18 d,每隔1天记录实验小鼠的体重、肿瘤大小变化。结果表明,甘草黄酮类化合物对CDK1/cyclin B均展现出了抑制活性,尤其是异甘草素对CDK1/cyclin B的抑制活性(IC_(50)=0.05±0.005μmol/L)是阳性药物夫拉平度(IC_(50)=0.29±0.230μmol/L)的近6倍;通过分子对接研究发现,异甘草素在CDK1中能够与氨基酸残基K33、E81、L83、S84、D86、D149形成6个氢键,而阳性药物夫拉平度仅与氨基酸残基E81、L83、S84、Q132、D149形成5个氢键;体外抗肿瘤活性研究表明,甘草黄酮类化合物对Bel-7402有较强的抑制作用,其中异甘草素对Bel-7402(IC_(50)=0.7±0.11 mol/L)展现出了最强的抑制活性,是阳性药物夫拉平度(2.4±0.34)mol/L的3倍。动物体内研究表明,异甘草素的LD_(50)为4.38 mg/kg,并能够有效抑制肝癌Bel-7402细胞的增长。

This study aimed to study the inhibitory activities of flavonoids on cell cycle-dependent protein kinase(CDK1)and hepatoma cells BEL-7402.The CDK1inhibitory activity of licorice flavonoids was evaluated by CDK1reagent kit,and antiproliferaty activity in vitro was investgated by CCK-8assay.Subcutaneous tumor model of liver cancer Bel-7402was established in nude mice,which were then randomly divided into drug group,positive drug group and blank control group.The mice in drug group were orally administrated with licorice flavonoids for continuous18days.The body weight and tumor size of mice were recorded every other day.The results demonstrated that these licorice flavonoids displayed potent efficacy against CDK1,specifically,isoliquiritigenin exhibited the most potent CDK1inhibitory activity(IC50=0.05±0.005μmol/L),which was about6-fold more potent than positive control flavopiridol(IC50=0.29±0.230μmol/L).Molecular docking studies revealed that isoliquiritigenin engaged in six hydrogen bonds with K33,E81,L83,S84,D86,D149in CDK1,while flavopiridol only engaged in five hydrogen bonds with E81,L83,S84,Q132,D149.In vitro biological evaluation indicated that these licorice flavonoids displayed significant antiproliferative effects on Bel-7402cancer cells.Among them,isoliquiritigenin showed the greatest potency against Bel-7402(IC50=0.7±0.11mol/L),which was3-fold more potent than flavopiridol(2.4±0.34mol/L).In vivo biological evaluation showed that the LD50of isoliquiritigenin was4.38mg/kg,and could effectively inhibit the cell growth of liver cancer Bel-7402in mice.