RESUMEN
Calotropin (M11), an active compound isolated from Asclepias curasavica L., was found to exert strong inhibitory and pro-apoptotic activity specifically against cisplatin-induced resistant non-small cell lung cancer (NSCLC) cells (A549/CDDP). Molecular mechanism study revealed that M11 induced cell cycle arrest at the G2/M phase through down-regulating cyclins, CDK1, CDK2 and up-regulating p53 and p21. Furthermore, M11 accelerated apoptosis through the mitochondrial apoptotic pathway which was accompanied by increase Bax/Bcl-2 ratio, decrease in mitochondrial membrane potential, increase in reactive oxygen species production, activations of caspases 3 and 9 as well as cleavage of poly ADP-ribose polymerase (PARP). The activation and phosphorylation of JNK was also found to be involved in M11-induced apoptosis, and SP610025 (specific JNK inhibitor) partially prevented apoptosis induced by M11. In contrast, all of the effects that M11 induce cell cycle arrest and apoptosis in A549/CDDP cells were not significant in A549 cells. Drugs with higher sensitivity against resistant tumor cells than the parent cells are rather rare. Results of this study supported the potential application of M11 on the non-small lung cancer (NSCLC) with cisplatin resistance.
Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Apoptosis/efectos de los fármacos , Asclepias/química , Cardenólidos/farmacología , Resistencia a Antineoplásicos/efectos de los fármacos , Puntos de Control de la Fase G2 del Ciclo Celular/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Células A549 , Antineoplásicos Fitogénicos/aislamiento & purificación , Apoptosis/genética , Proteína Quinasa CDC2 , Cardenólidos/aislamiento & purificación , Caspasa 3/genética , Caspasa 3/metabolismo , Caspasa 9/genética , Caspasa 9/metabolismo , Cisplatino/farmacología , Quinasa 2 Dependiente de la Ciclina/antagonistas & inhibidores , Quinasa 2 Dependiente de la Ciclina/genética , Quinasa 2 Dependiente de la Ciclina/metabolismo , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/agonistas , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/genética , Inhibidor p21 de las Quinasas Dependientes de la Ciclina/metabolismo , Quinasas Ciclina-Dependientes/antagonistas & inhibidores , Quinasas Ciclina-Dependientes/genética , Quinasas Ciclina-Dependientes/metabolismo , Resistencia a Antineoplásicos/genética , Humanos , MAP Quinasa Quinasa 4/genética , MAP Quinasa Quinasa 4/metabolismo , Potencial de la Membrana Mitocondrial/efectos de los fármacos , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Extractos Vegetales/química , Poli(ADP-Ribosa) Polimerasas/genética , Poli(ADP-Ribosa) Polimerasas/metabolismo , Proteolisis , Proteínas Proto-Oncogénicas c-bcl-2/agonistas , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal , Proteína p53 Supresora de Tumor/agonistas , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Proteína X Asociada a bcl-2/agonistas , Proteína X Asociada a bcl-2/genética , Proteína X Asociada a bcl-2/metabolismoRESUMEN
Four new xanthones, 3,5,6,8-tetrahydroxyxanthone-1-C-ß-D-glucoside (1), 7-hydroxy-3,4,8-trimethoxyxanthone-1-O-(ß-D-glucoside) (2), 6-hydroxy-3,5-dimethoxyxanthone-1-O-(ß-D-glucoside) (3), 3,4,7,8-tetramethoxyxanthone-1-O-(ß-D-glucoside) (4), together with twenty-one known xanthones (5-25) were isolated from the ethanol aqueous extract of Swertia mussotii. Their structures were elucidated via spectroscopic analyses. Oxygen radical absorbance capacity of all the isolated xanthones was systematically evaluated by ORAC(FL) assay. Results disclose that all the tested xanthones display moderate to excellent antioxidant activity, where 1 is the most active compound and 13 is the least one. A preliminary structure-activity relationship is also discussed.