Estudo do potencial biológico de Ricinus communis L. (EUPHORBIACEAE) como proposta de combate à esquistossomose

Abstract

Schistosomiasis is a waterborne parasitosis of great public health importance, prevalent in tropical and subtropical regions, in communities without access to drinking water and services such as basic sanitation and garbage collection. The disease has been reported in 78 countries, affecting an estimated 240 million people worldwide. Thus, studies that aim to circumvent the expansion of the parasitosis by combating the intermediate host have grown, among them, those that evaluate the molluscicidal activity of plants. Molluscicides derived from extracts are usually more accessible and less toxic to non-target organisms compared to synthetic molluscicides, which demostrating their importance. This work is divided into two parts, where the first includes the review study and the second, the experimental study. In the review, the studies that analyzed the molluscicidal action of plants of the Euphorbiaceae family were gathered. Therefore, 5 databases were selected to carry out the article searches. The descriptors used were “schistosomiasis”, “Euphorbiaceae” and molluscicide, which were crossed using the Boolean operators “OR” and “AND”. 39 articles were found that evaluated the molluscicidal action of 4 genera of the Euphorbiaceae family: Euphorbia, Jatropha, Croton and Synadenium. The snail genera where the molluscicide tests were carried out were Biomphalaria, Bulinus and Oncomelania. The lethal concentrations and doses that killed 50, 90 or 100% of the mollusks ranged from less than 1 to more than 100 ppm. In the experimental work, the molluscicide potential of the hydroalcoholic extract of Ricinus communis (EUPHORBIACEAE) leaves was investigated. Thus, 5 groups of snails with 10 animals each, one being the negative control group, were subjected to treatments with 4 concentrations of 25, 50, 75 and 100 ppm of the hydroalcoholic extract of R. communis, in 5 repetitions. The phytochemical characterization of the extract was carried out by means of high performance liquid chromatography coupled with mass spectrometry. The toxicity test was performed with Artemia salina Leach. The phytochemical characterization revealed the presence of tannins, flavonoids and alkaloids (ricinin), but there was no presence of saponins. There was no expressive molluscicidal activity of the extract, but alterations were observed in the feeding, motility and physiological state of the snails (alteration of the cephalopodal mass and oviposition) and there was no toxicity against A. salina. The results found in the two works contribute to the state of knowledge about the molluscicidal activity of plants of the Euphorbiaceae family, with emphasis on R. communis. It is hoped that these results will encourage more in-depth studies that focus not only on mortality, but also on the problem of the proliferation of snails.