Avaliação da atividade citotóxica de compostos de Picrasma crenata

Abstract

Medicinal plants are made up of various substances that can be extracted and have therapeutic use and/or alternative medicine. The increasing number of diagnoses of chronic diseases, such as cancer and, consequently, the high death rate, stimulated the search for cure and/or for new and less aggressive treatments. Thus, the objective of the present study was to discover the cytotoxic/antitumor activity of the crude extract of Pau Tenente and its isolated compounds, quassin and parain, in culture of rat hepatic tumor cells (HTC), and to obtain adjustments of polynomials that describe the results using empirical equations. The cytotoxicity/antitumor activity of MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] was performed by exposing the HTC cells for 24, 48 and 72 hours to treatments: negative control (100 μL culture medium); positive control (treatment with 500 μM cytotoxic agent methyl methane sulfonate); solvent control (25 μL DMSO (dimethylsulfoxide)/mL culture medium for quassin and 20 μL DMSO/mL culture medium for parain); and treatments with the crude extract of Pau Tenente (5, 10, 50, 100, 200, 300, 400, 500, 1000 and 1000 μg/mL culture medium) and the quassin and parain compounds (1, 5, 10, 15, 20, 40, 60, 80 and 100 μg/mL culture medium). After the exposure period of the treatments, the reading was performed in a spectrophotometer at 492 nm to determine the cytotoxic activity of the compounds studied. The results of the obtained absorbance averages show that the crude extract showed low cytotoxicity for the HTC cells at all concentrations tested. For quassin, concentrations of 80 and 100 μg/mL were cytotoxic after 72 hours of treatment. On the other hand, the test with parain showed that the concentrations of 1, 5, 20, 40, 60, 80 and 100 μg/mL, at 72 hours, were cytotoxic, revealing a new activity for this compound. Thus, in the experimental conditions, the results proved the antitumor activity of quassin and parain, adding an important social and economic value to these compounds, and may also be applied in future research and in the pharmaceutical industry.