Anthelmintic efficacy of ethanolic extracts from two Jatropha species against monogenean gill parasites and hematological and histopathological effects on Piaractus brachypomus

The present study evaluated the anthelmintic efficacy of ethanolic extracts from Jatropha gossypiifolia and Jatropha curcas leaves for the control of gill monogeneans, as well as their hematological and histopathological effects on Piaractus brachypomus. The dried and ground leaves were macerated in 96 % ethyl alcohol, and the extract was obtained through filtration followed by solvent evaporation. The chemical composition of the extract was analyzed using liquid chromatography coupled with mass spectrometry. In the in vitro assays, gills of P. brachypomus were exposed to extracts of J. gossypiifolia at concentrations of 500, 700, 1000, 1800, and 2000 mg L⁻¹ , and to J. curcas at 500, 700, 1000, 1500, and 2000 mg L⁻¹ . Two control groups were included: water and water with alcohol. For the treatment baths, five concentrations (50, 100, 500, 700 and 2000 mg L⁻¹) were tested. At the end of the exposure period, hematological and gill histological analyses were performed. The results indicated that the extracts contained phenolic compounds, peptides, and lipids. The in vitro assays demonstrated that all tested concentrations induced monogenean mortality, irrespective of dose or exposure time. Fish tolerated both 50 and 100 mg L⁻¹ concentrations of the extracts. J. gossypiifolia reduced the mean abundance of parasites after six days of treatment, whereas J. curcas achieved a reduction after only three days, with efficacy exceeding 87 %. The extract of J. curcas induced milder alterations in hematological and histological parameters. These findings suggest that species of the genus Jatropha possess therapeutic potential for controlling parasitic infections in fish.