RESUMO
Colon cancer, one of the leading causes of cancer-associated deaths, is the target of choice for nutrition-based-prevention approaches because of the direct and early contact between the active compounds and the cancerous tissues. We previously reported alkylresorcinols (ARs) as the major active components in wheat bran against human colon cancer. Here, we further investigate the anticancer mechanisms of action of ARs. Our mechanistic studies indicated that AR C15 and AR C17 exert their anticancer activities in colon-cancer cells by inducing apoptosis through PUMA upregulation and mitochondrial-pathway activation, inducing cell-cycle arrest through p21 upregulation, and inhibiting proteasome activity and Mdm2 expression. This cascade of distinct mechanisms was linked to the consequent activation and accumulation of p53. The results of treatment with p53 inhibitor further confirmed that the p53 pathway might play a very important role in AR-induced apoptosis in colon-cancer cells. Altogether these results show that AR C15 and AR C17 can specifically activate the mitochondrial pathway of apoptosis and cause cell-cycle arrest and that inhibition of p53 greatly reduces the activation of this pathway.
Assuntos
Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Neoplasias do Colo/fisiopatologia , Extratos Vegetais/farmacologia , Resorcinóis/farmacologia , Proteína Supressora de Tumor p53/metabolismo , Grãos Integrais/química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Extratos Vegetais/química , Proteólise/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Resorcinóis/química , Proteína Supressora de Tumor p53/genéticaRESUMO
Gingerols are a series of major constituents in fresh ginger with the most abundant being [6]-, [8]-, and [10]-gingerols (6G, 8G, and 10G). We previously found that ginger extract and its purified components, especially 10G, potentially stimulate both the primitive and definitive waves of hematopoiesis (blood cell formation) in zebrafish embryos. However, it is still unclear if the metabolites of 10G retain the efficacy of the parent compound toward pathological anemia treatment. In the present study, we first investigated the metabolism of 10G in zebrafish embryos and then explored the biotransformation of 10G in humans. Our results show that 10G was extensively metabolized in both zebrafish embryos and humans, in which two major metabolites, (3S,5S)-[10]-gingerdiol and (3R,5S)-[10]-gingerdiol, were identified by analysis of the MS(n) spectra and comparison to authentic standards that we synthesized. After 24 h of treatment of zebrafish embryos, 10G was mostly converted to its metabolites. Our results clearly indicate that the reductive pathway is a major metabolic route for 10G in both zebrafish embryos and humans. Furthermore, we investigated the hematopoietic effect of 10G and its two metabolites, which show similar hematopoietic effects as 10G in zebrafish embryos.