In vitro and in vivo effects of xanthorrhizol on human breast cancer MCF-7 cells treated with tamoxifen

This study investigated the herb-drug interaction of xanthorrhizol and tamoxifen in human breast cancer cells. using mcf-7 cell line as an in vitro model,the herb-drug interaction between xanthorrhizol and tamoxifen was measured by mtt assay,luciferase reporter assay,and cell cycle analysis. the effects of xanthorrhizol on growth/autophagy related signaling were determined by immunostaining,western blotting,and real time rt-pcr. additionally,the in vivo effect of xanthorrhizol and tamoxifen on athymic nude mice implanted with mcf-7 cells was evaluated. when mcf-7 cells were co-treated with tamoxifen and xanthorrhizol,there were no significant changes in terms of cell number,luciferase activity,percentage s-phase cells and lc3-ii expression. however,using the mcf-7 implanted nude mice model,it was possible to detect significantly increased tumor volumes,a larger tumor size,and increased protein expression of p38 and p27(kip1) in the xanthorrhizol + tamoxifen group compared to the tamoxifen-alone group. it can be concluded that while there is no significant herb-drug interaction between xanthorrhizol and tamoxifen in vitro,there is such an interaction in tumor-bearing mice,which provides important information that affects breast cancer treatment translational research. © the japanese pharmacological society.