ABSTRACT
Aim To investigate the mechanism of inhibition on the proliferation of human cervical carcinoma HeLa cells by quercetin.Methods Cell proliferation was detected by CCK-8 method.Flow cytometry was used to detect the cell cycle changes.OD480 values which reflected the metabolism of tryptophan and the production of kynurenine were measured by UV-Vis spectrophotometer.The mRNA levels of IDO1 were detected by qPCR.The expression and purification of IDO1 protein were detected by Western blot.Enzyme activity reaction was performed in vitro,and the content changes of tryptophan and kynurenine were detected by HPLC.Results Quercetin inhibited the proliferation of HeLa cells and led to cell cycle arrest.Quercetin inhibited the metabolism of tryptophan.Quercetin significantly inhibited the enzymatic activity of IDO1 in vitro,but did not affect the expression of IDO1.The addition of kynurenine could reverse the inhibition of cell proliferation induced by quercetin.Conclusion Quercetin affects tryptophan metabolism through inhibiting the enzymatic activity of IDO1.This may be one of the mechanisms by which quercetin exerts its effect on the proliferation of HeLa cells.