Inhibitory effects and molecular mechanisms of tetrahydrocurcumin against human breast cancer MCF-7 cells

Background : Tetrahydrocurcumin (THC), an active metabolite of curcumin, has been reported to have similar biological effects to curcumin, but the mechanism of the antitumor activity of THC is still unclear. Methods : The present study was to investigate the antitumor effects and mechanism of THC in human breast cancer MCF-7 cells using the methods of MTT assay, LDH assay, flow cytometry analysis, and western blot assay. Results : THC was found to have markedly cytotoxic effect and antiproliferative activity against MCF-7 cells in a dose-dependent manner with the IC 50 for 24 h of 107.8 μM. Flow cytometry analysis revealed that THC mediated the cell-cycle arrest at G0/G1 phase, and 32.8% of MCF-7 cells entered the early phase of apoptosis at 100 μM for 24 h. THC also dose-dependently led to apoptosis in MCF-7 cells via the mitochondrial pathway, as evidenced by the activation of caspase-3 and caspase-9, the elevation of intracellular ROS, a decrease in Bcl-2 and PARP expression, and an increase in Bax expression. Meanwhile, cytochrome C was released to cytosol and the loss of mitochondria membrane potential (Δψm) was observed after THC treatment. Conclusion : THC is an excellent source of chemopreventive agents in the treatment of breast cancer and has excellent potential to be explored as antitumor precursor compound. Keywords: tetrahydrocurcumin; antitumor effect; cell cycle; apoptosis; mitochondria (Published: 17 February 2016) Citation: Food & Nutrition Research 2016, 60: 30616 - http://dx.doi.org/10.3402/fnr.v60.30616