Oral or parenteral administration of curcumin does not prevent the growth of high-risk t(4;11) acute lymphoblastic leukemia cells engrafted into a NOD/SCID mouse model

In this study, the efficacy of orally and parenter-ally administered curcumin was evaluated in non-obese diabetic/severe combined immunodeficient (NOD/SCID) mice (NOD.CB17-Prkdc(scid)/J mice) engrafted with the human t(4;11) acute lymphoblastic leukemia line, SEM. SEM cells were injected into the tail vein and engraftment was monitored by flow cytometry. Once engraftment was observed, the chemotherapeutic potential was examined by injecting mice intraperitoneally with curcumin (5 mg/kg body weight) dissolved in dimethylsulfoxide (DMSO) or DMSO alone (control) every other day, or vincristine (0.5 mg/kg body weight) 3 times per week for 4 weeks (n=16 per group). The intraperitoneal administration of curcumin did not inhibit the growth of the leukemia cells. To determine the efficacy of oral curcumin, mice were fed a control diet or a diet containing 0.5% w/w curcumin 3 weeks prior to the injection of the leukemia cells and throughout the experimental period (n=16 per group). To determine whether dietary curcumin can enhance the efficacy of a conventional chemotherapeutic agent, vincristine was injected intraperitoneally into leukemic mice fed the different diets. Dietary curcumin did not delay the engraftment or growth of leukemia cells, or sensitize the cells to vincristine. Liquid chromatography-tandem mass spectrometry analyses of mouse sera showed that curcumin rapidly metabolized to glucuronidated and sulfated forms within 1 h post-injection and these were the major curcumin metabolites found in the sera of the mice fed the curcumin diet. In contrast to the findings in previous in vitro models, the current data indicate that orally or parenterally administered curcumin is not a potent preventive agent against high-risk t(4;11) acute lymphoblastic leukemia.