Phytochemical profile of Anacardium occidentale L. (cashew tree) and the cytotoxic and toxicological evaluation of its bark and leaf extracts

Abstract Anacardium occidentale (Anacardiaceae), popularly known as cashews, is a vegetable native to South America, consumed worldwide in the food sector. Its leaves and bark are used in the preparation of teas for health maintenance, being indicated in ethnobotanical studies for the treatment of cancer, which is considered a serious public health problem worldwide. The objective of this study was to evaluate the cytotoxicity of the A. occidentale leaf and bark extracts over tumor and normal cells, as well as their in vivo toxicity using the Drosophila melanogaster fruit fly. Cytotoxicity was evaluated using the MTT method [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazol bromide] in five cell lines (HL-60, NCI-H292, HCT-116, P815 and L929). Toxicity was evaluated by fly mortality rate and negative geotaxis, as well as by oxidative stress markers (Fe2+ quantification, protein and non-protein thiols) in the D. melanogaster model. The chromatographic study was performed by UPLC-QTOF/MS. As a result, 11 compounds present in the A. occidentale leaf extract (LEAo) and 6 compounds in the bark extract (BEAo) were identified, with gallic acid and galloyl hexoside being present in both samples. The bark extract presented a greater cytotoxic activity for HCT-116, HL60 and P815 tumor cells. The extracts also presented a low cytotoxicity with the normal cell line, L929. No changes in the levels of protein and non-protein thiols (NPSH) were observed, whereas a considerable increase in Fe2+ levels was observed in the Fe2+ quantification assays from homogenized flies exposed to the leaf extract in the D. melanogaster assays. However, further in-depth studies need to be carried out to elucidate the mechanisms of action of the extracts and to assess their pharmacological safety.