Atividade larvicida de Anacardium occidentale como alternativa ao controle de Aedes aegypti e sua toxicidade em Rattus norvegicus

Abstract

The search for substitutes for synthetic pesticides has been the subject of many scientific publications, including considering the use of oils, extracts and active constituents from plants. This demand can be justified by the insecticide potential associated with an easy degradation of its constituents, lower toxicity to humans and, consequently, a safer alternative for the environment. After collecting and heating the Anacardium occidentale (Anacardiaceae) fruits at 40°C, they were tested to confirm their larvicidal activity. Then, it was fractionated in a silica gel column. The fractionation resulted in eight fractions, which were coded as AO 1 to AO 8 . In this paper, the cashew nut shell liquid (CNSL) and its fractions were evaluated as to their biological activity in the third instar larvae of Aedes aegypti. The acute oral toxicity in Rattus norvegicus also was evaluated. CNSL and the AO 2 and AO 3 fractions presented larvicidal activity. The lethal concentrations, LC 50 and LC 90 , of CNSL were, respectively, 6.55 and 10.98 ppm. The active fractions, AO 2 and AO 3 , presented LC 50 and LC 90 of 3.18 and of 7.80 ppm, and 3.57 and 10.47 ppm, respectively. The LCC and the fractions were orally administered at a dose of 2000 mg/kg. These products showed larvicidal potential against Ae. aegypti and no sign of toxicity was evident in the parameters analyzed.