Friable Calluses of a Brazilian Peanut Cultivar Increased Cytotoxic Activity against K562 Human Leukemia Cells

Cancer is considered the leading cause of death worldwide, and the number of new cases is expected to rise over the next few years. In this context, plant materials are increasingly studied in the search for substances to prevent and/or treat this disease. In this work, the cytotoxic activity of extracts from plants and friable calluses of five Brazilian peanut cultivars (IAC 886, IAC Caiapo, IAC Tatu ST, IAC 8112 and BR1) against a leukemic cell line (K562) was compared. Inhibition of K562 cells viability (79.8%) was significantly higher in response to extracts from calluses of cultivar IAC 886 as compared to extracts of aerial parts of in vivo and in vitro plants from the same cultivar. Callus extracts displayed low toxicity on non-tumor cells (NIH-3T3 fibroblasts and peripheral blood mononuclear cells). Trans-resveratrol was found in extracts from aerial parts of cultivar IAC Tatu ST and from calluses of cultivar IAC 886. In addition, three compounds with UV spectrum compatible with phenolic compounds were detected in the samples. Calluses from cultivar IAC 886 displayed higher relative contents of these compounds, which can be contributing to their cytotoxic activity.