Dados do Trabalho

Título

Toxic and genotoxic effects of ethereal extract of Cladonia substellata on Biomphalaria glabrata, cercariae of Schistosoma mansoni and ecotoxicity assay with Artemia salina

Introdução

The WHO recommends strategies for the control/prevention of schistosomiasis, among these, population control of intermediate hosts.

Objetivo (s)

We aimed to characterize the ethereal extract of the lichen Cladonia substellata (ECs) and its toxicity against Biomphalaria glabrata, hemocytes and DNA damage, as well as, action against cercariae of Schistosoma mansoni and ecotoxicity with Artemia salina.

Material e Métodos

ECs was analyzed by thin layer chromatography and high performance liquid chromatography. B. glabrata adults in groups (n=10) were exposed to ECs at 1.0 to 3.0 μg/mL for 24h and evaluated for another 7 consecutive days for parameters of fertility, fecundity and mortality. The ECs genotoxicity was evaluated through qualitative and quantitative analysis of the hemolymph and fragmentation of the hemocytic DNA through the comet assay, according to the damage index. One hundred cercariae were exposed to 1 to 10 μg/mL of ECs and evaluated after 15, 30, 60 and 120 min to determine morphological changes and motility. Ecotoxicity was done with Artemia salina exposed to 1 to 5.0 µg/mL of ECs for 24h.

Resultados e Conclusão

Chromatographic analysis of the ECs revealed the presence of stictic (4.12%), norstictic (2.14%) and usnic (92.58%) acids. B. glabrata exposed to 3.0, 2.5, 2.0, 1.5 and 1.0 ECs resulted in 100, 80, 40, 10 and 0.0% mortality, respectively, and lethal concentrations (LC) of 10, 50 and 90% were 1.59, 2.11 and 2.64 μg/mL, respectively. Mortality was followed by stretching and swelling of the cephalopod mass, increased mucus secretion, and hemolymph release. ECs caused hemocyte alteration with a high frequency of hemocytes in apoptosis and binucleation, in addition to increasing hemocyte DNA fragmentation. From 15min of exposure to ECs, alterations in the motility of cercariae were observed at 2.5μg/mL, a concentration that caused more than 50% of mortality after 120 min, and in that same time interval, the concentration of 5.0μg /mL of ECs caused total lethality of cercariae, which presented cercarial body with vacuoles and separated from the tail. ECs was non-toxic against A. salina. ECs was effective in controlling the population of B. glabrata, which caused hemocytic and genotoxic damage in adult snails, in addition to having a cercaricidal action, important factors for interrupting the biological cycle of S. mansoni. Furthermore, it was non-toxic against the environmental bioindicator.

Palavras-chave

Schistosoma mansoni; Lichen; Molluscicide; Cercaricide; Ecotoxicity.

Agradecimentos

CNPq, CAPES and FACEPE.