Cytotoxic effect of antioxidants found in food from plant origin on human osteosarcoma U2OS Cells

Plants are a major source of natural products with antioxidant properties. Some of these phytochemicals have been used in effort to prevent and treat several human diseases, including cancer. Several studies support the effects of dietary antioxidants as chemopreventive agents, while other reports suggest potential pharmacological anticancer activity. However, the available studies were conducted under different experimental conditions, precluding a comparative analysis of the anticancer properties of the compounds. Although osteosarcoma has a low overall incidence, it is the third most common cancer in adolescence. These cancers are generally locally aggressive and tend to produce early systemic metastases, justifying the search for novel therapeutic approaches. This work assessed the cytotoxic profile of ten antioxidants from food from plant origin on human osteosarcoma cells (U2OS): catechin, kaempferol, quercetin, resveratrol, gallic acid, ferulic acid, ascorbic acid, melatonin, lycopene, and β-carotene. Cell viability was determined using the crystal violet assay (24 h). β-carotene and gallic acid considerably reduced cell viability, with IC50 values of 18.8 μM and 184.5 μM, respectively. The remaining compounds did not markedly reduce cell viability. These results might contribute to the rational and evidence-based selection of natural antioxidants to be included in anticancer strategies and to further explore possible food-inspired drugs.