Pterostilbene and tamoxifen show an additive effect against breast cancer in vitro

BACKGROUND Tamoxifen is widely used for the treatment of breast cancer Pterostilbene a bioavailable stilbenoid found in blueberries has been found to inhibit breast cancer growth in vitro It was hypothesized that combining pterostilbene with tamoxifen would produce additive effects on estrogen receptor positive breast cancer cells METHODS Two estrogen receptor positive breast cancer cell lines, MCF7 and ZR-751 were pretreated with graduated doses of pterostilbene for 24 hours followed by 5 mu mol/L tamoxifen MTT proliferation assays and Cell Death Detection ELISA(PLUS) us tests evaluated cell viability and apoptosis RESULTS MCF7 cells showed inhibition (10 and 20 mu mol/L P < 001, 30 mu mol/L, P < 05) at all time points when combined with tamoxifen ZR-751 cells showed additive reductions in cell viability (P < 001) Cell Death Detection ELISA(PLUS) indicated increased apoptosis (P < 01) CONCLUSIONS Pterostilbene shows an additive inhibitory effect on breast cancer cells when combined with tamoxifen, most likely from augmented cancer cell apoptosis (C) 2010 Elsevier Inc All rights reserved