Establishment of the dominant lethal test in the freshwater mollusk Biomphalaria glabrata (Say, 1818)

Abstract

Mutagens in the environment may represent a long-term risk for ecosystems. The reproductive potential of populations can be affected by alterations in the fecundity and offspring viability caused by germ cell mutations. Despite the ecological relevance of these effects, there are few studies on germ cell mutagenicity in natural populations. Biomphalaria glabrata was chosen for this study because of the scarcity of data on freshwater invertebrates and the ecological importance of this group. The aim of this study was to establish a germ cell mutagenicity test in B. glabrata by using a similar approach to that used in the dominant lethal test in rodents. Mitomycin C was used as a direct mutagen and cyclophosphamide as a mutagen that requires metabolic activation. Wild-type snails were exposed for 10 days to three concentrations of each agent and crossed with non-exposed albino snails at the end of the treatment. The total frequencies of malformations were analyzed in the offspring of wild-type snails; among the offspring of albino snails, only the heterozygous wild-type embryos were analyzed for malformations. Both agents induced germ cell mutations. The analysis of the offspring of the wild-type snails showed an effect of the exposure up to approximately 5 days after the end of the treatment with cyclophosphamide; the effect of mitomycin C was observed until 45 days after the end of the exposure. There was an increase in the frequencies of malformations in the wild-type offspring of the non-exposed albino snails crossed with the wild-type snails exposed to both agents. The dominant lethal test in B. glabrata proposed in this work is easy to perform, efficient, specific and sensitive in the evaluation of germ cell mutations induced by reference mutagens. The possibility of expanding its use to environmental biomonitoring studies seems very promising and worth trying.

Effects of varying concentrations of the crude aqueous and ethanolic extracts of <i>Dalbergia sissoo</i> plant parts on <i>Biomphalaria pfeifferi</i> egg masses.

“…In the tropics and subtropics, schistosomiasis is the second most important parasitic disease after malaria in terms of prevalence, public health and socio-economic importance (James and Colley, 1995 Five species; S. mansoni, S. haematobium, S. japonicum, S. intercalatum and S. mekongi are primarily adapted as human parasites and are endemic in different parts of the tropics where they cause significant morbidity. S. mansoni is transmitted by freshwater planorbid snails of the genus Biomphalaria which are amphimictic simultaneous hermaphrodites (WHO, 1965;Madsen, 1985;Rupp, 1996; Woodruff and Mulvey, 1997; Nakano et al, 2003). B. pfeifferi transmits S. mansoni in sub-saharan Africa including Nigeria (Rollinson and Simpson, 1987;WHO, 1993;Brown, 1994).…”

Obtenção e avaliação da atividade de compostos isolados de Piper em modelos biológicos para o controle da esquistossomose mansônica.

“…(KAWANO, 1983;KAWANO;SIMÕES, 1987;KAWANO;OKAZAKI;RÉ, 1992;NAKANO et al, 2003;TALLARICO et al, 2004). …”

“…O estudo fitoquímico de P. tuberculatum demonstrou a presença de amidas como piperina, piperidina, pelitorina e piperlonguminina todas com atividade fungicida e inseticida (CHAVES; SANTOS, 2003;LAGO et al, 2004;NAVICKIENE et al, 2000;da SILVA et al, 2002). O quadro 2 ilustra alguns constituintes químicos isolados de P. tuberculatum e suas atividades biológicas.…”

“…Os alcalóides e amidas são os mais representativos seguidos de lignanas e neolignanas, terpenos, propenilfenóis, flavonas, pironas, chalconas, cromenos e ácidos benzóicos (BALDOQUI et al, 1999;BENEVIDES et al, 1999;LAGO et al, 2004;MARQUES et al, 2007;NAVICKIENE et al, 2000;PARMAR, 1998;RAMOS et al, 1986). Devido a essa diversidade, os metabólitos oriundos dessa família têm apresentado atividade biológica em organismos diversos (Quadro 3).…”

“…Pesquisadores do laboratório de Química de Produtos Naturais da USP vem realizando estudos fitoquímicos em Piperaceae e identificaram espécies com diversas amidas em sua composição, em especial P. tuberculatum que possui em suas raízes majoritariamente a piplartina (NAVICKIENE et al, 2000;Da SILVA et al, 2002). Atualmente essa amida tem sido estudada por apresentar múltiplas atividades farmacológicas in vitro e in vivo (Quadro 4).…”