Avaliação do bloqueio de transmissão de Plasmodium vivax para Anopheles aquasalis por extratos e substâncias de plantas amazônicas.

Abstract

Due to the resistance that has been occurring in Pasmodium falciparum and Plasmodium vivax to the drugs in use and the increasing number of malaria cases, there is a need to look for new disease control strategies and one of them may be the blockage of malaria transmission (Transmission Blocking Strategies - TBS) which in recent years has increased interest in it. In this study we used the laboratory model Anopheles aquasalis - Plasmodium vivax against the action of extracts and substances extracted from plants of the Amazon region. In P. vivax there is a lack of continuous in vitro culture, so in this study we used the experimental model of mosquito feeding through artificial membrane, with blood from malarial patients and cis-cajucarina B extracted from 'sacaca' Croton cajucara and 7 -epi-gedunine synthesized from limoids extracted from oil and 'andiroba' Carapa guianensis residual cake. In addition to the substances, aqueous extracts of the bark and twig of 'acariquara-white' Geissospermum argenteum. Concentrations of extracts and substances were prepared, diluted and offered along with parasitized blood to mosquitoes by means of glass feeders. For dilution of the substances, it was necessary to standardize 0 to 5% of the dimethylsulfoxide-DMSO diluent because the substances used in this study do not dissolve in water. Among those concentrations that best fit the tests was 1%. Lower numbers of eggs retained and laid were observed at concentrations of 1% DMSOPv- and 1% DMSOPv +, respectively. Highest mosquito infection at 1% DMSOPv +. In addition, ivermectin was used as a reference drug, which at the concentration of 200ng / mL presented high mortality of A. aquasalis. The number of P. vivax oocysts varied significantly against cis-cajucarin DMSO / 1ppmPV + action when compared to the 1% DMSO / 0ppmPV + control. The number of oocysts at 100ppm / PV + concentration of the aqueous extract of the G. argenteum branch and 1000ppm / PV + of the same extract differed significantly from each other and 1000ppm / PV + differed when compared to 0% ppm of the same extract.