MATERIALS AND METHODS: In the initiation phase, the mice received a single dose of 100µl/100 µg DMBA (group I-V) or 100µl acetone (group VI) topically on the dorsal shaved skin area followed by the promotion phase involving treatment with the respective test solutions (100 µl of acetone, 10 mg/kg curcumin or MEMM (30, 100 and 300mg/kg)) for 30 min followed by the topical application of tumour promoter (100µl croton oil). Tumors were examined weekly and the experiment lasted for 15 weeks.
RESULTS: MEMM and curcumin significantly (p<0.05) reduced the tumour burden, tumour incidence and tumour volume, which were further supported by the histopathological findings.
CONCLUSION: MEMM demonstrated chemoprevention possibly via its antioxidant and anti-inflammatory activities, and the action of flavonoids like quercitrin.
OBJECTIVE: Quercetin-decorated liposomes of curcumin (QCunp) are perceived to be able to overcome these biopharmaceutical drawbacks.
METHODS: Curcumin liposomes with/without quercetin were prepared by lipid hydration technique. The liposomes were characterized for their particle size, zeta potential, surface morphology, drug loading and release characteristics. The toxicity of the liposomes were evaluated in-vitro and their invivo efficacy were tested against Dalton's ascites lymphoma in mice.
RESULTS: Liposomes designed showed particle size of 261.8 ± 2.1 nm with a negative zeta potential of -22.6±1.6 mV. Quercetin decorated liposomes were more effective in increasing the life span and body weight of lymphoma inflicted mice compared to those without quercetin. Similarly, the presence of quercetin also contributed to enhanced cytotoxicity of the liposomal formulation towards HT-29 cells and HCT-15 cells.
CONCLUSION: Newer liposomal design exhibited promising potential to emerge as alternative anticancer therapeutics.
HYPOTHESIS: Intracellular copper levels have been reported to correlate with tumor pathogenesis and affect the sensitivity of cancer cells to cytotoxic chemotherapy. We hypothesized that intracellular copper levels may affect the sensitivity of oral cancer cells to curcumin.
METHODS: We analysed the correlation between intracellular copper levels and response to curcumin treatment in a panel of OSCC cell lines derived from oral cancer patients. Exogenous copper was supplemented in curcumin insensitive cell lines to observe the effect of copper on curcumin-mediated inhibition of cell viability and migration, as well as induction of oxidative stress and apoptosis. Protein markers of cell migration and oxidative stress were also analysed using Western blotting.
RESULTS: Concentrations of curcumin which inhibited 50% OSCC cell viability (IC50) was reduced up to 5 times in the presence of 250 µM copper. Increased copper level in curcumin-treated OSCC cells was accompanied by the induction of intracellular ROS and increased level of Nrf2 which regulates oxidative stress responses in cells. Supplemental copper also inhibited migration of curcumin-treated cells with enhanced level of E-cadherin and decreased vimentin, indications of suppressed epithelial-mesenchymal transition. Early apoptosis was observed in combined treatment but not in treatment with curcumin or copper alone.
CONCLUSION: Supplement of copper significantly enhanced the inhibitory effect of curcumin treatment on migration and viability of oral cancer cells. Together, these findings provide molecular insight into the role of copper in overcoming insensitivity of oral cancer cells to curcumin treatment, suggesting a new strategy for cancer therapy.