Protective effects of sulfated polysaccharides from Enteromorpha intestinalis on oxidative stress, liver iron overload and Ferroptosis in Zebra fish exposed to ethanol

The study investigates the protective effects of sulfated polysaccharides extracted from Enteromorpha intestinalis (EIP) against oxidative stress, liver iron overload, and ferroptosis in zebrafish exposed to ethanol, a model for alcohol-related liver disease (ALD). The extracted polysaccharides were characterized for sulfate and sugar content, molecular weight, and functional groups. Adult male zebrafish were divided into three groups: control, ethanol-exposed (EE) (0.2 % ethanol (v/v) in the water), and ethanol-exposed with EIP supplementation (1 % EIP incorporated into the basal diet) (EE+EIP) for 30 days. The study measured liver oxidative stress indexes, serum enzymological indexes, liver and serum lipid profiles, liver iron ion content, and expression of ferroptosis-related genes. Histological analysis was conducted to assess lipid accumulation and iron deposition in liver tissues. The findings indicate that EIP supplementation significantly mitigates ethanol-induced liver damage. Specifically, EIP reduced malondialdehyde levels, increased antioxidant enzyme and non-enzymatic antioxidant activity, and decreased iron ion accumulation and the area of iron granules in the liver tissue. Additionally, EIP treatment lowered lipids levels and aminotransferase enzyme activity in the serum. In the ALD model, EIP inhibited ethanol-induced ferroptosis by modulating the expression of key genes: it decreased the expression of transferrin (tf), transferrin receptor (tfr), ferroportin (fpn), and ferritin heavy chain (fth), while increasing the expression of glutathione peroxidase 4 (gpx4) and solute carrier family 7 member 11 (slc7a11). EIP has protective effects against ethanol-induced liver injury in zebrafish, offering a foundation for further research into its hepatoprotective action and potential application in preventing and treating ALD.