Development of a natural molluscicide prototype kit (MoluSchall) for the control of schistosomiasis mansoni transmission

Abstract INTRODUCTION In Brazil, Biomphalaria glabrata, B. tenagophila, and B. straminea are intermediate hosts of Schistosoma mansoni, the etiological agent of schistosomiasis mansoni. Molluscicide use is recommended by the WHO for controlling the transmission of this parasite. Euphorbia milii latex has shown promising results as an alternative molluscicide. Thus, a natural molluscicide prototype kit based on freeze-dried E. milii latex was developed and evaluated against Biomphalaria spp. METHODS E. milii latex was collected, processed, and lyophilized. Two diluents were defined for freeze-dried latex rehydration, and a prototype kit, called MoluSchall, was produced. A stability test was conducted using prototype kits stored at different temperatures, and a toxicity assay was performed using Danio rerio. Additionally, MoluSchall was tested against B. glabrata under semi-natural conditions according to defined conditions in the laboratory. RESULTS MoluSchall was lethal to three Brazilian snail species while exhibiting low toxicity to D. rerio. Regardless of storage temperature, MoluSchall was stable for 24 months and was effective against B. glabrata under semi-natural conditions, with the same LD100 as observed under laboratory conditions. CONCLUSIONS MoluSchall is a natural, effective, and inexpensive molluscicide with lower environmental toxicity than existing molluscicides. Its production offers a possible alternative strategy for controlling S. mansoni transmission.

Insecticidal Efficacy and Chemical Composition of Hexane Oil Extracts from the Leaves of Euphorbia milii and Cassia occidentalis

Insecticidal efficacy of oils from the leaves of Cassia occidentalisand Euphorbia milii on selected insect pests was studied. The oils were extracted via Soxhletapparatus with hexane, and test insects exposed to the oils at 3 dose levels (0.2mg, 0.4mg and 0.6mg) for 24 hours. The results showed contact insecticidal activity of E. miliioil at LD50s and LD90s (mg/kg) as 0.583 and 1.108 for Periplaneta americana, 0.681 and 1.215 for Tettigonia viridissima0.488 and 0.893 for Anopheles gambaie,C. occidentalisoil gave LD50s and LD90s (mg/kg) of 0.889 and 1.689 for P. americana, 1.013 and 1.973 for T. virdissima, and 0.722 and 1.847 for Anopheles gambaie. The corresponding values for the conventional insecticide; SWAN were 0.417 and 1.017 for P. americana, 0.607 and 1.111 for T. viridissimaand 0.40 and 0.743 for A. gambaie,respectively. The GC-MS analysis of plant oils revealed for E.milii,the presenceof hexadecanoic acid, 2 hydroxy-1-(hydroxymethyl) ethyl ester; 6, 9,12,15-docosatetraenic acid methyl ester. For C. occidentalis,the presence of:phthalic acid isobutyl octyl ester; hexadecanoic acid methyl ester; 9,12-octadecadienoic acid methyl ester; 9-octadecenoic acid (z)-methyl ester; methyl stearate; phthalic acid,2-ethylhexyl isohexyl ester; decane; oleic acid; 4,7,-methano-1h-indene,3a,4,7,7a-tetrahydro and n-hexadecanoic acid were revealed. Overall, data from this study provides strong evidence that these oils possess bioactive metabolites with commendable degrees of insecticidal efficacy.

Estudo da atividade mutagênica das plantas, Euphorbia milii Des Moulins e Ricinus communis L através do teste de Allium cepa / Mutagenic activity study of the plants Euphorbia milii and Ricinus communis L. through the Allium cepa test

O objetivo deste trabalho foi avaliar a mutagenicidade e o grau de toxicidade de duas plantas tóxicas, a "mamona" (Ricinus communis) e a "coroa-de-cristo" (Euphorbia milii), utilizando infusões das sementes de mamona e o látex da coroa-de-cristo, em células meristemáticas de Allium cepa. Foram analisados: o índice mitótico (IM), as anomalias do ciclo mitótico (ACM), anomalias interfásicas, (AI) e o total de anomalias (TA). As soluções testes foram preparadas em três concentrações: MT1 - 0,5 g/l, MT2 - 1,0 g/l, MT3 - 2,0 g/l, e MT4 como controle. Da coroa-de-cristo extraiu-se o látex e dissolveu-se em água destilada nas concentrações CT1 -0,5 ml/l, CT2 - 1,0 ml/l, CT3 - 2,0 ml/l, e CT4 controle. Os resultados constataram que somente a mamona aumentou a freqüência de anomalias do ciclo mitótico, assim como, as anomalias interfásicas, demonstrando, dessa forma, uma ação tóxica para o material genético, através do teste de Allium cepa.

The aim of this work was to evaluate the mutagenicity and the degree of toxicity of two toxic plants, "castor bean" (Ricinus communis) and the "crown-of-thorns" (Euphorbia milii), using infusions of the seeds of Ricinus communis and the latex of the Euphorbia milii, in meristematic cells of Allium cepa, which were analyzed: the mitotic index (IM), the interphasics anomalies (AI), the mitotic cycle anomalies (ACM), and the total of anomalies (TA). The solutions tests were prepared in three concentrations: MT1 - 0.5 g/l, MT2 - 1.0 g/l, MT3 -2.0 g/l, and MT4 as control. From the Euphorbia milii the latex was extracted and was diluted in distilled water in concentrations: CT1 - 0.5 ml/l, CT2 - 1.0 ml/l, CT3 - 2.0 ml/l, and CT4 as control. The results evidenced that Ricinus communis increased the frequency of mitotic cycle anomalies, as well, the interphasics anomalies, demonstrating, a toxic action for the genetic material, through the test of Allium cepa.