Biological Evaluation of in vitro Cytotoxicity of Extracts of Lafoensia glyptocarpa Koehne (Lythraceae)

Secondary metabolites, organic compounds produced by plants, are currently studied in relation to their medicinal potential, such as antioxidant, anti-inflammatory, antibiotic and antiviral effects. Among the plants of clinical interest is Lafoensia glyptocarpa Koehne, an arboreal species of the Lythraceae family widely used in Brazilian urban landscaping. This plant has scientific data indicative of medicinal potential and its genus presents studies related to the therapeutic potential. Considering the importance of new studies that aim to expand the scientific knowledge of species of native flora, this work has the objective to test the safety of the use of different L. glyptocarpa extracts through an in vitro cytotoxicity assay in Vero cells. They were exposed to concentrations (25, 50, 100 and 1000 μg/mL) of aqueous and ethanolic extracts of L. glyptocarpa leaves for 24h and then a solution of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromid) was added for 2 h. The method is indicative of mitochondrial activity related to cellular viability and the absorbance is read at 570 nm. In addition, photomicrographs were observed in phase contrast microscopy for cell culture evaluation of cytotoxicity at different concentrations. Cytotoxicity assays were performed using positive (cells with DMSO 50%) and negative controls (only growth medium with cells). The results showed that the extracts of Lafoensia glyptocarpa (aqueous and ethanolic) do not present cytotoxicity in the range of 25 to 100 μg/mL. This work reinforces the importance of the study with medicinal plants and demonstrates a high sensitivity and reliability in in vitro cytotoxicity studies.