Search

The aim of this study was to investigate the effects of the dietary supplementation of levamisole hydrochloride on Oreochromis niloticus lipid and protein profiles through matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) and possible tissue lesions by histopathological analyzes. A total of 320 fingerlings were distributed into the following groups: fish fed supplemented diets with 100, 150 and 200 mg of levamisole kg−1 and fish fed a diet receiving no supplementation. After 8 days of feeding, stomach histopathology showed that fish fed the 100 and 150 mg kg−1 levamisole supplemented diets had a significantly lower intensity in the degeneration of columnar epithelial cells when compared to the control group (p < 0.05), possibly a result of a generalized superior health status caused by the supplementation. Liver analysis showed no significant alterations (p ≥ 0.05), while histopathology of gills showed significant alterations in the fusion of secondary lamellae, in which only fish fed the highest dose showed a significant higher value when compared to the control group (p < 0.05). In the protein analysis, a total of 106 m/z peaks were observed, where 28 peaks showed significant changes in their intensity (p < 0.05). In general, fish supplemented with 100 mg kg−1 of levamisole showed an increase in the intensity in the peaks within the m/z ranges 2814–3337, 3732–6998 and 9045–13,505, while fish fed with 150 mg kg−1 dose showed a reduction in the intensity at most of the peaks found within those intervals. Immune system related proteins occurring within those ranges suggest a positive modulation of the protein profile. There were also marked alterations in the lipid profiles. Levamisole supplemented fish showed a significant positive modulation in the glycerophosphocholines group (p < 0.05), whose function in improving fish resistance to cold water suggests an additional health benefit of this feed additive. Judging on the histopathological analyses and MALDI-TOF MS lipid and protein profiling, the 100 mg kg−1 levamisole supplementation dose provided the greatest benefits to Nile tilapia fingerlings. • 100 and 150 mg kg−1 fed levamisole did not negatively affect Nile tilapia histology. • MALDI-TOF protein and lipid profiles were significantly altered by levamisole. • Glicerophosphocholin lipid peaks were positively modulated in levamisole fed fish. • 100 mg kg−1 levamisole supplementation provided the best benefits to Nile tilapia. [ABSTRACT FROM AUTHOR]