Alsubaie_2025_Comp.Biochem.Physiol.B.Biochem.Mol.Biol__111086

This study examined the effects of supplementing the Nile tilapia (Oreochromis niloticus) diet with purslane (Portulaca oleracea L.) leaf powder (PLNP, 10 g/kg) on neurobehavioral performance, brain oxidative status, tight junction mRNA expression, and brain histology in fish exposed to waterborne cadmium (Cd, 50 microg /L) for 60 days. Adding PLNP to the diet ameliorated the Cd-induced decline in ingestive behavior and swimming behavior, and reversed the Cd-induced increase in aggressive behavior. The significant decrease in the non-enzymatic (reduced glutathione) and enzymatic (catalase and superoxide dismutase) brain antioxidants detected in Cd-exposed fish was eliminated by dietary PLNP. PLNP supplementation also led to a decrease in brain malondialdehyde content, which was elevated by Cd exposure. In addition, dietary PLNP increased brain acetylcholinesterase content, and upregulated mRNA expression of tight junction (zo-2, claudin-4, and zo-1), apoptotic (p53, caspase-9, caspase-8, and caspase-3), and oxidative stress (sod-2, gpx, and nrf-2) genes in the brain, relative to decreases in these parameters caused by Cd exposure. Furthermore, the Cd-induced histological changes in the Nile tilapia brain were ameliorated by PLNP dietary supplementation. In light of these findings, PLNP may be a useful dietary supplement for reducing the harmful effects of Cd on the brain and behavior of Nile tilapia.