OVICIDAL EFFECT OF PIPERACEAE SPECIES ON Biomphalaria glabrata, Schistosoma mansoni HOST

SUMMARY Schistosomiasis is a neglected disease with public health importance in tropical and subtropical regions. An alternative to the disease control is the use of molluscicides to eliminate or reduce the intermediate host snail population causing a reduction of transmission in endemic regions. In this study nine extracts from eight Piperaceae species were evaluated against Biomphalaria glabrata embryos at blastula stage. The extracts were evaluated in concentrations ranging from 100 to 10 mg/L. Piper crassinervium and Piper tuberculatum extracts were the most active (100% of mortality at 20 mg/L and 30 mg/L respectively).RESUMO A esquistossomose é uma doença negligenciada de importância para a saúde pública em regiões tropicais e subtropicais. Uma alternativa para o controle da doença é o uso de moluscicidas para eliminar ou reduzir a população de caramujo hospedeiro, acarretando uma redução da transmissão da doença nas regiões endemicas. Neste estudo, nove extratos vegetais provenientes de oito espécies de Piperaceae foram expostos a embriões de Biomphalaria glabrata no estágio de blástula. Os extratos foram avaliados em concentrações que variaram entre 100 e 10 mg/L, sendo Piper crassinervium e Piper tuberculatum os extratos mais ativos (100% de mortalidade a 20 mg/L e 30 mg/L respectivamente)

Morphological changes in <i>D. rerio</i> during the 48 hours of exposure to piplartine.

<p><b>A</b>) Leakage of the ocular pigment caused by 1.8 ppm piplartine, <b>B</b>) tissue alterations on the head and mouth caused by 1.6 µg/ml piplartine, <b>C</b>) exophthalmia and hemorrhage caused by 1.4 µg/ml piplartine and D) control group.</p

Toxicity of piplartine and niclosamide to the freshwater microcrustacean <i>D. similis</i> and the fish <i>D. rerio</i>.

<p>Data are presented as EC₅₀ or LC₅₀ (µg/ml) with the respective 95% confidence limits in brackets.</p><p>Toxicity classification: Cat. 1 - acute toxicity ≤1.00 µg/ml; Cat. 2 - acute toxicity >1.00 but ≤10.0 µg/ml; Cat. 3 - acute toxicity >10.0 but <100 µg/ml <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002251#pntd.0002251-Abiquim1" target="_blank">[28]</a>.</p

Mortality of <i>B. glabrata</i> adults exposed to methanolic extracts of different organs of <i>Piper tuberculatum</i>.

<p>n = 30 adult snails.</p><p>Values were obtained at the end of the 7^th day of observation.</p

Calculated (squares) and predicted (circles) PLS data.

<p>These data were generated from ESIMS data, versus measured and autoscaled LC₅₀ values of <i>P. tuberculatum</i> extracts for <i>B. glabrata</i>.</p

<i>B. glabrata</i> embryos exposed to piplartine at the blastula stage.

<p><b>A</b>) Immediately following exposure to 1.2 µg/ml piplartine, <b>B</b>) during the 7 day observation period after exposure to 1.0 µg/ml piplartine (1- dead, 2 - normal, 3 – malformed).</p

LC₅₀ and LC₉₀ for <i>B. glabrata</i> embryos and adults exposed to piplartine.

<p>[ ] 95% confidence interval.</p><p>nc – not calculated.</p

Mortality of <i>B. glabrata</i> adults and embryos exposed to amides (20 µg/ml).

<p>n = 10 snails for the adult stage; total embryo number for the other stages.</p><p>0^* = negative control (1% DMSO).</p><p>Values were obtained at the end of the 7^th day of observation.</p