Determinação da CL50 de fases dos extratos Erythroxylum caatingae Plowman e Erythroxylum revelutum Mart como paramêtro de bioatividade.

Abstract

The aim of this study was to evaluate the bioactivity and / or toxicity of substances and extracts of Erythroxylum caatingae and Erythroxylum revolutum, for their use in subsequent pharmacological studies. For this, the toxicity tests were conducted with the methanol extract of the species E. caatingae, extract the basic aqueous phase E. caatingae and extract Erythroxylum revolutum. The method of Meyer et al (1982) was adopted. The Artemia was used as nauplii and concentration of each extract / substance was tested in triplicate and repeated at least three experiments. The median lethal concentration (LC50) was analyzed in non-linear regression, with a confidence interval of 95%. After completion of the toxicity tests, it was observed that in A. saline trials which used methanol extract of the E. caatingae at concentrations of 10, 20, 60, 120, 240, 480, 960 and 1920 μL, the results obtained had an average of 0; 4.4; 8.8; 32.2; 56.6; 75.5; 83.3 and 98.9% of dead artemias respectively. In tests conducted with the second to A. salina extract (aqueous basic phase of the E. caatingae), it was observed that concentrations 60, 120, 240, 480, 960, 1920, 3840 μL averaged 0; 2,2; 5,5; 28,8; 35,5; 82,2 and 98,8% of dead artemias respectively. In A. salina tests performed with the extract of Erythroxylum revolutum, at concentrations of 30, 60, 120, 240, 480, 960, 1920, 3840 μL , the results had an average of 0; 3,3; 12,2; 34,4; 73,3; 83,3; 95,5 and 100% of artemias dead. The LC50 value for methanol and aqueous phase species E. caatingae extracts and extract of Erythroxylum revolutum were 203.7 (190.1 to 218.2) mg / mL, 1,074.0 (949.6 - 1,214.0) / mL and 308,1 (241,1 - 393,6) μg/mL respectively. Thus, it is concluded that there is a toxic dose of the extract E.caatingae and E. revolutum for saline A., as well as a directly proportional relationship between the concentration of the extract and the mortality rate of artemias. The methanol extract of the species E. caatingae presented more toxic compared to the aqueous extract of this species.