Abstract
AIM OF THE STUDY: To evaluate the toxicological potential between açaí extracts and two widely used anticancer drugs - methotrexate and tamoxifen. MATERIALS AND METHODS: Euterpe oleracea Mart. fruit powder extracts obtained from a name brand company in Brazil and two açaí dietary supplement brands were tested on two cancer cell lines, MCF-7 and MDA-MB-231, and one normal epithelial breast cell line, MCF-10A. Cell viability was measured using MTT assay. The data was analyzed using SynergyFinder Plus and Compusyn to determine the potential synergism, antagonism, or additive effect of the açaí extract when combined with the selected anticancer drugs, tamoxifen and methotrexate. RESULTS: When combined with methotrexate, the methanol extract of the açaí powder and the acidic methanol extract of the açaí dietary supplements caused significant synergy (potentiation), thus increasing toxicity, of the combination to the normal cell line, MCF-10A. The combination of the acidic methanol extract of the açaí dietary supplements also induced apoptosis with the MCF-10A cells. Methotrexate was potentiated by the aqueous extract of the açaí powder when tested with the MCF-7 cells. Tamoxifen toxicity was increased only with the MCF-7 cells. Pre-exposure of the MCF-10A cells to the methanol extract of the açaí powder caused increased tamoxifen toxicity for the normal cell line but decreased toxicity for methotrexate combination. There were no significant indications of the açaí extracts causing an antagonistic relationship with either anticancer drug. CONCLUSION: The açaí extracts evaluated here potentiated both anticancer drugs, increasing their toxicity for all cell lines with the most significant increase in toxicity occurring with normal cell line, MCF-10A. The toxicity was further confirmed to be through induction of apoptosis. This calls for further investigation of the chemical constituents of açaí that are the cause of the toxicity of the combination of anticancer drug and açaí extract.