我们已证实黄酮山奈酚因肠道循环，可高浓度、长滞留于肠细胞。前期发现：中药山奈及山奈酚可显著抑制结肠癌(抑瘤率各为86.94%和73.52%)；山奈酚与核内DNA甲基转移酶(DNMTs)直接结合，使抑癌基因DACT2启动区42.8%CpG岛去甲基化，阻碍β-catenin入核，抑制肿瘤；预实验又发现，山奈酚在细胞核中被葡萄糖醛酸化酶代谢，抑制核膜外排转运蛋白(ETs)外排代谢物，可显著增加山奈酚核内分布与浓度。因此，推测山奈酚入核处置直接调控DNMTs；山奈中有成分可抑制ETs外排，增加山奈酚核内浓度与滞留，是山奈/山奈酚抑制结肠癌的关键机制。为此，拟采用分子药代与生物学方法，揭示山奈酚核处置对DNMTs的调控及机制；筛查山奈中抑制ETs外排的活性成分；研究山奈酚核内处置对山奈整体药效的影响。课题创新地从核内PK-PD及调控，阐明山奈/山奈酚作用方式与药效机制，是中药药效研究的新思路和新方法

Our group has proved that flavonoids in traditional Chinese medicines (TCMs) may subject to intestinal triple recycling, which resulted in their specific high concentration and long-term exposure in the intestine. Our previous studies found that Kaempferia galanga Linn.(KGL), one of TCMs used for gastrointestinal treatments, and its corresponding biological flavonoid kaempferol could both significantly suppress colon cancer with respective inhibition rate of 86.94% and 73.52%. Further mechanism study revealed that kaempferol in KGL directly bound with DNA methyltransferases (DNMTs) and decreased 42.8% of CpG methylation in DACT2 promoter, subsequently inhibited β-catenin translocating into nucleus, ultimately suppressed colon cancer initiation. On the other hand, our preliminary data also showed that kaempferol in the nucleus could be metabolized by glucuronidation enzymes, and inhibition of efflux transporters (ETs) contrarily increased the nuclear distribution of kaempferol. Therefore, we hypothesized that the nuclear disposition of kaempferol may directly regulate DNMTs to exert anti-tumor efficacy. While some other components in KGL may serve as ETs inhibitors to markedly enhance the cancer prevention efficacy of kaempferol itself by increasing the concentration and retention of kaempferol in the nucleus. Thus, in this proposal, molecular pharmacokinetics and biological methodologies were employed in nucleus to find out 1) the regulatory mechanisms between nuclear pharmacokinetics of kaempferol and DNMTs catalytic activity; 2) screening the promising ETs inhibitors from KGL; 3) determining the effect of kaempferol nuclear disposition on its anti-colon cancer efficacy. By studying PK-PD correlation of kaempferol and KGL in nucleus, our study may provide novel strategy and experimental evidence for understanding the specific anti-cancer efficacy of TCMs.