Dados do Trabalho

Título

Plumbagin: a promising molluscicidal agent with toxic, cytotoxic and genotoxic effect on the developmental stages of Biomphalaria glabrata and cercaricidal activity against schistosomiasis mansoni

Introdução

World Health Organization's strategy to eliminate schistosomiasis is the treatment of those infected with Praziquantel (the only drug available), sanitation, health education, and population control of snail vectors. Currently, the control of snails is carried out with Niclosamide, which, although effective, has low selectivity and high environmental and human toxicity.

Objetivo (s)

To evaluate the molluscicidal and antiparasitic activities of plumbagin (PLUM) against B. glabrata (embryos and adults), its genotoxic and cytotoxic effect, and the cercariae of S. mansoni.

Material e Métodos

One hundred embryos of B. glabrata in blastula, gastrula, trochophore, veliger, and hippo stage were exposed for 24 h to 0.3 to 2 μg/mL of PLUM and monitored for 7 days to observe death and malformations. Adult snails (n=10) were exposed to 2 to 4 μg/mL of PLUM for 24 hours and monitored for 7 days, with the mortality rate and non-viability recorded. After exposure, snail hemolymph was collected for morphological and quantitative analysis of hemocytes and evaluation of DNA fragmentation through the comet assay. The degree of DNA damage was calculated according to the damage index. One hundred cercariae of S. mansoni were exposed to PLUM at concentrations from 1 to 3 μg/mL. The cercaricidal evaluation was carried out at intervals of 15, 30, 60, and 120 minutes and the results were expressed according to morphological and motility alterations. Artemia salina larvae were exposed to 0.5 to 3 μg/mL of PLUM for 24 h for evaluation of environmental ecotoxicity.

Resultados e Conclusão

After 24 h of exposure, PLUM demonstrated molluscicidal activity at low concentrations against embryos (LC50 of 0.56, 0.93, 0.68, 0.51, and 0.74 μg/mL for blastula, gastrula, trochophore, veliger, and hippo stage, respectively) and adult snails (LC50 of 3.56 μg/mL). There were no changes in the fecundity or fertility of the exposed snails. However, PLUM caused hemocyte alteration with a high frequency of hemocytes in apoptosis and binucleation, in addition to increasing DNA fragmentation. Furthermore, PLUM caused the death of S. mansoni cercariae from 1.5 μg/mL after 60 min, while showing moderate toxicity to A. salina. PLUM showed promising activity in population control of embryos and adults of B. glabrata, as well as the cercariae of S. mansoni, being moderately toxic to A. salina.

Palavras-chave

Genotoxicity; Embryotoxicity; Hemocytes; Molluscicide, Naphthoquinone.

Agradecimentos

CAPES - Code 001, FACEPE (APQ-0498-4.03/19, APQ-1181-4.03/22) e UFPE.