ABSTRACT. Oreochromis niloticus (Nile tilapia) is one of the most produced fish for human consumption globally; however, these fish are susceptible to exposure to toxic chemicals in the water. Pyriproxyfen is a pesticide widely used to control mosquitoes in drinking water supplies and pests in crops. The present study aimed to examine pyriproxyfen's effects on fish O. niloticus fingerlings exposed using an acute 96 h and subchronic tests for 28 days. The lethal concentration LC50−96 h for O. niloticus was 2.77 mg L−1, no observed effect concentration (NOEC), and the lowest observed effect concentration (LOEC) was 1.0 and 2.5 mg L−1, respectively. The hepatic catalase activity was significantly changed after exposure to pyriproxyfen above 0.4 mg L−1. Pyriproxyfen also induced histopathological lesions in the hepatic tissue at 28 days in a dose-dependent pattern at concentrations above 0.4 mg L−1. Pyriproxyfen above 1.2 mg L−1 reduced the locomotor behavior, distance traveled inside the tank, mean speed, and angular variation. This pesticide also decreased weight gain, food conversion, and specific growth rate at concentrations above 1.2 mg L−1. In conclusion, exposure to pyriproxyfen in water from 0.4 mg L−1 may impair O. niloticus development; consequently, pyriproxyfen may affect this fish's production and quality at higher concentrations than commonly used in water (0.01 mg L−1).

Existem poucos estudos sobre as alterações da função hepática em camundongos com esquistossomose associada à desnutrição. Neste trabalho, os animais foram divididos em quatro grupos, de acordo com as dietas (normal ou hipoprotéica) e infectados ou não pelo Schistosoma mansoni. Todos os grupos desenvolveram-se menos que o grupo controle (p<0,0001). A mortalidade nos animais foi devida à infecção. Níveis altos de aminotransferases nos animais nutridos e infectados sugerem um processo inflamatório intenso (p<0,0001). Todos os grupos apresentaram elevação da fosfatase alcalina. Houve aumento da aspartato transferase e da fosfatase alcalina em animais nutridos infectados. As dietas modificaram os níveis de albumina (p>0,001), e das proteínas séricas. Os grupos, comparados ao controle, mostraram baixos níveis de glicose (p<0,001). Este estudo verificou que ambas, infecção e/ou desnutrição, interferiram nos níveis dos indicadores bioquímicos, mas as alterações mais importantes da função hepática ocorreram durante a inflamação intensa causada pela esquistossomose.

There are few studies on liver function abnormalities in mice with schistosomiasis associated with malnutrition. In this study, animals were divided into four groups, according to their diet (normal or low protein) and whether they were infected with Schistosoma mansoni or not. All the groups grew slower than the control did (p < 0.0001). Mortality among the animals occurred because of the infection. High levels of aminotransferases in well-fed animals with infection suggested that there was an intensive inflammatory process (p < 0.0001). All the groups presented high levels of alkaline phosphatase. There were increases in aspartate transferase and alkaline phosphatase in infected well-fed animals. The diets modified the albumin levels (p > 0.001) and the serum proteins. Compared with the controls, the groups showed low levels of glucose (p < 0.001). This study found that both infection and malnutrition interfered with the biochemical indicator levels, but the most important liver function abnormalities occurred during the intense inflammation caused by schistosomiasis.