The Effect of Different Formulations of Praziquantel in Reducing Worms in the Prepatent Period of Schistosomiasis in Murine Models.

Schistosomiasis is a widely distributed parasitic disease and one of the most important neglected tropical diseases globally, for which Praziquantel® (PZQ) is the only available treatment. In this context, tests with new PZQ formulations become relevant for disease control. This study evaluated the effects of PZQ treatment in the prepatent phase of schistosomiasis using two formulations: nanoencapsulated (PZQ-NANO) and active pharmaceutical ingredient (PZQ-API). Five experimental groups were established, for which the following serological parameters were evaluated: ALT, AST, ALP, and TP. Animals treated with PZQ-API at 15 and 30 days post-infection showed decreased eggs per gram of feces (EPG) compared to untreated infected animals. The same animals showed reductions of 63.6 and 65.1%, respectively, at 60 days post-infection. Animals treated with PZQ-NANO experienced no significant changes in EPG at any time of observation. Animals treated with either PZQ-API or PZQ-NANO had higher ALT and AST levels in the patent period (60 and 90 days post-infection). Treatment with PZQ, either API or NANO, at 15 days post-infection reduced AST, ALT, and TP levels. It is concluded that prepatent treatment with PZQ-API can reduce the parasite load of infected animals and that treatment at 15 days post-infection can prevent increased serum levels of ALT, AST, and TP.

Destruction of Schistosoma mansoni sporocysts in Biomphalaria glabrata after phytochemical exposure.

Schistosomiasis is a neglected tropical disease and affects over 200 million people worldwide. The snail Biomphalaria glabrata is one of the intermediate hosts of S. mansoni. The aim of this work was to verify the action of Euphorbia milii var. hislopii latex in the hemocytes profile and histopathology of B. glabrata infected by S. mansoni. Uninfected and infected snails were exposed to sublethal concentration of E. milii latex for 24 hours (1.0 mg/L). The survival rate was 88.5% for the uninfected snails and 66.6% for the infected and exposed snails. In the snails infected by S. mansoni, the exposure to E. milii latex promoted proliferation of hemocytes in the tentacles, mantle, digestive gland and kidney. In the digestive gland and the kidney, granulomatous reactions occurred around the sporocysts and caused their destruction. The number of circulating hemocytes from the group infected and exposed to E. milii latex was significantly higher than in the other groups. Three types of hemocytes were found: hyalinocytes, granulocytes and blast-like cells. We conclude that the E. milii latex influenced the cellular immune response of the susceptible B. glabrata strain to infection by S. mansoni, promoting the destruction of parasites.

A rapid diagnostic test for schistosomiasis mansoni

This article presents an improvement to the Kato-Katz (KK) method, making it faster and more efficient for the visualisation of fertile eggs in stool samples. This modified KK method uses sodium acetate formalin as a fixative and reveals the intensity of infection in less than 1 h, reducing the diagnostic time without increasing the cost. This modified method may contribute to future epidemiological studies in both hospitals and the field due to its rapid and precise diagnostic, which allow for immediate treatment.

The influence of population density and food intake on the reproductive biology of Biomphalaria glabrata (Mollusca) and calcium proportion in snails experimentally infected with Schistosoma mansoni (Trematoda)

O presente trabalho teve por objetivo avaliar a influência da densidade populacional e da ingestão de alimento na sobrevivência e atividade reprodutiva de Biomphalaria glabrata não infectada e o efeito do carbonato de cálcio na emergência de cercárias de caramujos experimentalmente infectados, a fim de definir condições para maximizar a criação e a produção de cercárias em futuros estudos sobre esse modelo. Os resultados observados nesse estudo indicam que o aumento da densidade populacional tem efeito negativo sobre a sobrevivência e atividade reprodutiva de B. glabrata e aquantidade de alface fresca oferecida aos caramujos altera o número de ovos postos por molusco. Foi observada correlação significativa entre a quantidade de comida ingerida por dia e o número de ovos produzidos por molusco, bem como o número de massas ovígeras e ovos por massa ovígera.Além disso, a sobrevivência dos caramujos infectados foi diretamente associada a quantidade de carbonato de cálcio e a emergência de cercárias foi inversamente proporcional a quantidade de carbonato de cálcio. Esse estudo auxilia na compreensão da influência da densidade populacional e a ingestão de alimento na biologia reprodutiva de moluscos mantidos em colônias. Em relação à emergência de cercárias, suplementos de cálcio não devem ser adicionados nos criadouros decaramujos infectados com Schistosoma mansoni, tendo em vista que essa ação diminui a quantidade de cercárias eliminadas por caramujo.

Biomphalaria glabrata: exposure to different amounts of calcium carbonate influencing growth, sexual maturation and pearls formation

O cálcio desempenha um papel fundamental na vida dos caramujos, regulando diferentes processoscomo motilidade, crescimento e divisão celular. O cálcio influencia diretamente o crescimento da concha, fecundidade, oviposição, mortalidade, metabolismo interno e homeostase. O objetivo deste trabalho foi descrever a formação de pérolas em Biomphalaria glabrata expostos a diferentes quantidades de carbonato de cálcio em condições de laboratório. As pérolas foram observadas na glândula digestiva e no intestino no grupo de caramujos expostos a 20 e 60 mg /L de carbonatode cálcio após 45 dias. Os resultados mostram que os caramujos produzem pérolas como um reservatório de cálcio antes de atingirem a maturidade sexual.

Carbohydrate metabolism alterations in Biomphalaria glabrata infected with Schistosoma mansoni and exposed to Euphorbia splendens var. hislopii latex

This paper evaluates the alterations in the glycogen content of tissues (digestive gland and cephalopedal mass) and glucose in the haemolymph of Biomphalaria glabrata BH strain infected with Schistosoma mansoni BH strain and exposed to the latex of Euphorbia splendens var. hislopii. A reduction in the glycogen deposits was observed in infected snails exposed and not exposed to latex. However, the exposure to latex caused a greater depletion of the glycogen levels in both sites analysed, especially from the third week onward. The utilisation of latex as a molluscicide to control the population of infected B. glabrata selectively is proposed.

Reproductive activity alterations on the Biomphalaria glabrata exposed to Euphorbia splendens var. hislopii latex

The reproductive activity of Biomphalaria glabrata exposed to Euphorbia splendens var. hislopii latex was evaluated. Parameters related to fecundity and fertility were observed. The snails were exposed to the LD50 (1 mg/l) of crude latex. At the first week post exposure (p.e.), the egg laying was reduced. After the fourth week p.e., an increase of the number of eggs/snail occurred. The results showed a marked reduction in the hatching of the snails, revealing an interference of latex exposure with the reproductive process of B. glabrata of E. splendens var. hislopii. The LD50 of the latex may be used as an alternative method to control the size of the populations of B. glabrata in field.

Physiological changes in Biomphalaria glabrata say, 1818 (Pulmonata: Planorbidae) caused by sub-lethal concentrations of the latex of Euphorbia splendens var. hislopii N.E.B (Euphorbiaceae)

Molluscides have been used as one of the strategies to control schistosomiasis. Many plant extracts with molluscidal effects have been tested, but the action of the latex of Euphorbia splendens var. hislopii is considered the most promising because it meets the recommendations of the World Health Organization (WHO). The objective of this study was to determine the lethal dose and identify the effects of the different doses of latex of E. splendens var. hislopii on the physiology of Biomphalaria glabrata submitted to treatment for 24 h. The concentrations of glucose, uric acid and total proteins in the hemolymph and of glycogen in the digestive gland and cephalopodal mass were determined. The LD50 value was 1 mg/l. The highest escape index was found to be at a concentration of 0.6 mg/l. The results showed that the latex of E. splendens var. hislopii caused a sharp reduction in the reserves of glycogen in the digestive gland and elevation of the protein content in the hemolymph of B. glabrata.