RESUMEN
BACKGROUND: Multidrug resistance (MDR) is a major obstacle in the chemotherapeutic treatment of many human cancers. 2',4'-Dihydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC) isolated from the buds of Cleistocalyx operculatus (Roxb.) Merr. et Perry (Myrtaceae), was investigated for its reversal effects on cancer cell MDR. RESULTS: A human hepatocellular tumor xenograft model was established with the BEL-7402/5-FU cell line. Combined 5-fluorouracil (5-FU) and DMC (40 mg kg(-1) ) treatment significantly elevated tumor inhibition rate to 72.2%. DMC could also increase 5-FU concentrations in tumor tissues and increase caspase-3 activity. Also, combined therapy resulted in enhanced tumor apoptotic and reduced proliferative activities relative to 5-FU alone. Examining body weight and other signs of unwanted toxicity of the different treatment groups revealed no significant signs of adverse effects. CONCLUSION: All results suggested that DMC reverses 5-FU resistance, with a benign side effects profile.
Asunto(s)
Chalconas/farmacología , Resistencia a Múltiples Medicamentos/efectos de los fármacos , Fluorouracilo/uso terapéutico , Neoplasias Hepáticas/tratamiento farmacológico , Myrtaceae/química , Fitoterapia , Extractos Vegetales/uso terapéutico , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica , Apoptosis/efectos de los fármacos , Caspasa 3/metabolismo , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Chalconas/uso terapéutico , Modelos Animales de Enfermedad , Femenino , Fluorouracilo/metabolismo , Fluorouracilo/farmacología , Humanos , Neoplasias Hepáticas/metabolismo , Meristema , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Extractos Vegetales/farmacología , Trasplante Heterólogo , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Multi drug resistance (MDR) is a major obstacle in the chemotherapeutic treatment of many human cancers. 2',4'-Dihydroxy-6'-methoxy-3',5'-dimethylchalcone (DMC), a chalcone, isolated from the buds of Cleistocalyx operculatus, has been shown to have antitumor effects on human carcinoma SMMC-7721 cells in vitro and in vivo. In this paper, we studied the reversal effect and the mechanism of DMC on human hepatocellular carcinoma drug-resistant cells BEL-7402/5-FU in vitro. Administration of DMC reversed the multi-drug resistance of human hepatocellular carcinoma BEL-7402/5-FU cells significantly. DMC enhanced the sensitivity of BEL-7402/5-FU cells to 5-fluorouracil (5-FU) and doxorubicin (DOX). Staining with Hoechst 33258 and flow cytometric analysis showed that DMC has apoptosis-inducing effect on BEL-7402/5-FU cells. It could also increase the concentration of 5-FU in the resistant multi-drug-resistant cells. We also observed that over-expression of the multi-drug resistance-associated protein (MRP1) and of the glutathione S-transferase π (GST-π) contributed to MDR in BEL-7402/5-FU cells. The mRNA expressions of MRP1 and GST-π and the protein expression of MRP1 were decreased by DMC. These data demonstrated that DMC could effectively reverse MDR in BEL-7402/5-FU cells.