LAUSR

Abstract The aim of this study is to evaluate the mechanism of actions involved in the anticancer effect of hesperidin against cell proliferation and inducing apoptosis in human lung cancer A549 cells. MTT assay were performed, by treating the cells with different concentrations of hesperidin ranges from 0, 6.25, 12.5, 25, 50 and 100  μM for 0, 6, 12, 24, and 48 h. Hesperidin treatment significantly inhibited the cell viability based on concentration and time dependent manner, which shows optimal LC 50 effective, dose as 12.5 and 25  μM for 24 h and this LC50 doses and optimized time point used for further studies. Hesperidin treated cells significantly inhibited the cell proliferation through down regulation of c-myc, β-catenin, PCNA protein expressions. An additional studies also shows that hesperidin significantly increased the p53 and p21 tumor suppressor proteins which subsequently inhibited the cyclin dependent kinase 4 (cdk4) and cyclin D protein expressions. Further studies supported that restoring of tumor suppressor proteins by hesperidin treatment directly affects the Bcl-2/Bax ratio, which limits the Bcl-2 levels and increased the pro-apoptotic Bax protein levels. Mitochondrial transmembrane potential studies, increased levels of cytochrome c, APAF-1, caspase-3 and DNA fragmentation was observed in hesperidin treated cells which clearly indicates apoptosis induction. Taken together, these findings suggest the anticancer effect of hesperidin in human lung cancer A549 cells through up regulation of p53, which triggers the proliferation arrest and mitochondrial dependent apoptosis activation.