As single agents , curcumin and metformin are reported to exhibit chemopreventive properties , in vitro as well as in patients with oral cancer .
Curcumin and metformin-mediated chemoprevention of oral cancer is associated with inhibition of cancer stem cells. Effective chemoprevention is critical for improving outcomes of oral cancer. As single agents , curcumin and metformin are reported to exhibit chemopreventive properties , in vitro as well as in patients with oral cancer . In this study, the chemopreventive efficacy of this drug combination was tested in a 4-nitro quinoline-1-oxide (4NQO) induced mice oral carcinogenesis model. Molecular analysis revealed a cancer stem cell (CSC)-driven oral carcinogenic progression in this model, wherein a progressive increase in the expression of CSC-specific markers (CD44 and CD133) was observed from 8th to 25th week, at transcript (40-100-fold) and protein levels (P ≤ 0.0001). Chemopreventive treatment of the animals at 17th week with curcumin and metformin indicated that the combination regimen decreased tumor volume when compared to the control arm (0.69+0.03 vs 6.66+2.4 mm
### Instruction:
            Given the context about compound efficacy for the given treatment mentioned within the input, mentioned the compounds 
            that can co-occur for the mentioned treatment

            ### Input:
            Curcumin and metformin-mediated chemoprevention of oral cancer is associated with inhibition of cancer stem cells. Effective chemoprevention is critical for improving outcomes of oral cancer. As single agents , curcumin and metformin are reported to exhibit chemopreventive properties , in vitro as well as in patients with oral cancer . In this study, the chemopreventive efficacy of this drug combination was tested in a 4-nitro quinoline-1-oxide (4NQO) induced mice oral carcinogenesis model. Molecular analysis revealed a cancer stem cell (CSC)-driven oral carcinogenic progression in this model, wherein a progressive increase in the expression of CSC-specific markers (CD44 and CD133) was observed from 8th to 25th week, at transcript (40-100-fold) and protein levels (P ≤ 0.0001). Chemopreventive treatment of the animals at 17th week with curcumin and metformin indicated that the combination regimen decreased tumor volume when compared to the control arm (0.69+0.03 vs 6.66+2.4 mm

            ### Response:
            curcumin, metformin
            