RESUMO
Natural products and their biological activities are currently a subject of great interest to the industrial and scientific sector, due to society's awareness of the proper use of biodiversity and economic and sustainability. To promote the sustainable use of biomass the extract of the by-product of the shell seed of Lecythis pisonis was applied to develop a natural cosmetic emulsion. To ensure safety for its topical use the cytotoxic activity of its crude extract was evaluated by the colorimetric method of 3- bromide (4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium, MTT, in cell culture of fibroblasts L929, human keratinocytes HaCat, and human endothelium EA.hy926 cell lines. The triplicate of the cosmetic formulation containing the extract was obtained regarding stability according to the procedures of the Brazilian Health Regulatory Agency (Anvisa). The irritability tests were performed using alternative methods, in vitro, chorioallantoic membrane assay (HET-CAM and CAM-TBS), and hemolysis test (RBC). The crude extract was not cytotoxic, IC50 index >780 mg/mL. The preservative system was effective against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, and Aspergillus niger. The emulsion was classified as non-irritable. The crude extract of the by-product of sapucaia seeds can be incorporated into a natural emulsion, safe for topical use.