Multidrug resistance reversal effect of DMC derived from buds of Cleistocalyx operculatus in human hepatocellular tumor xenograft model.

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.

CONCLUSIONS

All results suggested that DMC reverses 5-FU resistance, with a benign side effects profile.