The Protective Effects of Astaxanthin (AST) in the Liver of Weaned Piglets

SIMPLE SUMMARY: Weaning is a period when young animals are exposed to a number of stressors caused by the separation from the sow, transport and handling, different food sources, a new social hierarchy, and different physical environments. This situation contributes to the generation of free radicals that cause oxidative stress. In weaned piglets, the most prominent disorders occur in the intestines, and their increased permeability can compromise liver function as metabolites migrate to the liver. Oxidative stress can lead to liver necrosis. Astaxanthin (AST) is a powerful carotenoid and antioxidant that can scavenge free radicals and protect cells from oxidative damage. Findings show that AST has a protective effect on the liver, reducing inflammation, lipid accumulation and markers of liver damage. It also inhibits insulin resistance and lipotoxicity-induced steatohepatitis and regulates fatty acid metabolism pathways. This study investigated the liver-protective properties of AST in weaned piglets. The study showed that AST reduces collagen content in liver tissue and affects the expression of specific genes related to liver function. Expression of CREB, NOTCH1 and NR1H3 genes decreased, while expression of the CYP7A1 gene increased. These findings underscore the beneficial effects of AST on liver health and suggest its potential as a protective agent against liver damage. ABSTRACT: During the weaning period, piglets are exposed to high levels of stress, which often causes problems with the digestive system. This stress also promotes the production of free radicals, resulting in oxidative stress. Astaxanthin (AST) stands out as one of the most potent antioxidants. Its resistance to light and heat makes it particularly valuable in compound feed production. This study was to determine the effect of AST impact on liver histology and gene expression in piglets. For our experiment, we used 16 weaned piglets of the PL breed, which we divided into two groups: Group I (control group with no AST supplementation) and Group II (supplemented with AST at 0.025 g/kg). Both feed mixtures were iso-proteins and iso-energetic, meeting the nutritional requirements of the piglets. The experiment lasted from day 35 to day 70 of the piglets’ age, during which they had ad libitum access. The results indicate that the addition of AST prevents liver fibrosis due to reduced collagen deposition in the tissue. Analysis of gene expression supported these results. In the AST-supplemented group, we noted a decrease in NR1H3 expression, an increase in CYP7A1 expression, and reductions in the expression of NOTCH1 and CREB genes.