Curcumin – A Potent Inhibitor of Galectin-3 Expression

The expression of galectin-3, a b-galactoside binding lectin, was found to be affected by different kinds of stressors, and is strongly modified in numerous physiological and pathophysiological conditions. Although no precise regulatory mechanisms of galectin-3 expression are unraveled, transcription factors AP-1 (activator protein 1) and NF-kB (nuclear factor kappa B) play an important role in these processes. Activities of both transcription factors are affected by curcumin, a biologically active compound extracted from rhizomes of Curcuma species. We have analyzed the impact of curcumin on the expression of galectin-3 in glioblastoma cells under basal conditions and under stress invoked by the cell exposure to alkylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and ultraviolet C (UV-C) light. Galectin-3 level was measured by western-blot technique using M3/38 monoclonal antibody. Curcumin has decreased the basal level of galectin-3, while the pretreatment of cells with curcumin has considerably reduced the inducible effect of UV-C radiation and abolished the inducible effect of alkylating agent. Thus, curcumin has been identified as a potent inhibitor of galectin-3 expression