Atividade acaricida, inibição da acetilcolinesterase e análise química de resíduos agroindustriais

Abstract

The aim of this study was to analyze the in vitro efficacy of crude extracts of agroindustrial residues obtained from fruits against engorged females of Rhipicephalus microplus, using the adult immersion test. The first chapter gathers studies about the fruits used in this study and the bovine ectoparasites of economic importance. In the second chapter, the fruit residues of Spondias mombin, Tamarindus indica, Genipa americana and Citrus latifolia were submitted to maceration with ethanol to obtain the extracts. Engorged females were collected for acaricidal evaluation. The treatments consisted of six groups with extracts at 50 mg mL-1 concentration and two control groups (positive: fipronil and negative: 70 % ethanol). The extract of S. mombin fruit peel showed an acaricidal efficiency of 96.37 %. In order to investigate the mechanism of acaricide action, the in vitro effect of the extracts against acetylcholinesterase was evaluated and only the extract of the bagasse of C. latifolia showed a correlation with the acaricide effect. The extracts were monitored by high performance liquid chromatography and identified derivatives of phenolic compounds. In the third chapter, the fruit extract of S. mombin presented an acaricidal efficacy of 98.4 % at a concentration of 12.5 mg mL-1 and larvicidal efficacy of 84.8 % at a concentration of 25 mg mL-1. After fractionation of the S. mombin extract, the fraction with the major inhibition potential of the acetylcholinesterase enzyme was identified. The active fraction was analyzed by gas chromatography and a mixture of unsaturated fatty acids and terpenoids were identified, which act synergistically in the acaricidal action