Dietary lecithin attenuates adverse effects of high fat diet on antioxidant activity, inflammation and fibrotic damage in the kidney of blunt snout bream (Megalobrama amblycephala).

This research aimed to explore how different levels of dietary lipids and lecithin influenced the antioxidant capacity, inflammatory response, and fibrotic damage in the kidney tissues of blunt snout bream (Megalobrama amblycephala). The five experimental diets were formulated to include the control (5.49% lipid), lecithin diet (5.63% lipid, 0.10% lecithin), high-fat diet (HFD, 11.80% lipid without additional lecithin), HFD + 0.10% lecithin (11.69% lipid + 0.10% lecithin) and HFD + 0.20% lecithin (11.41% lipid + 0.20% lecithin). The blunt snout bream was reared on these diets for 12 weeks. Lecithin lessened kidney damage and weight loss caused by an HFD. Lecithin mitigated the reduction in the activities of antioxidant enzymes, including T-AOC, GSH-Px, T-SOD, and CAT. It also alleviated the decrease in the mRNA expression of antioxidant-related genes such as sod1, gpx1, cat, nrf2, and ho-1, as well as the protein expression of Nrf2. Moreover, it counteracted the up-regulation of MDA content, the mRNA expression of the antioxidant-related gene keap1, and the protein expression of Keap1 caused by HFD. Lecithin addition mitigated the up-regulation of mRNA expression of inflammatory-related genes (tnf-α, mcp-1, nlrp3, il-1β and caspase-3) and proteins (Nlrp3 and Il-1β), serum Il-1β content induced by HFD, and the down-regulation of mRNA expression of inflammatory-related gene il-10. Dietary lecithin addition mitigated the up-regulation of mRNA expression of fibrosis-related genes (tgf-β1, acta-2, actn-4, pdgf, fgfr-2, col1a2 and smad3), serum CRE and BUN content induced by HFD. These findings suggested that dietary lecithin supplementation could significantly improve the growth performance and antioxidant ability of blunt snout bream. It also mitigated inflammatory damage and alleviated kidney fibrosis. As a result, it lessened the adverse impacts of HFD on the functionality and well-being of the kidney tissue in blunt snout bream.