Investigation of the Effect of Krill Oil on Sortilin in Liver and Adipose Tissue in Obese Rats

Sortilin regulates lipid metabolism, adipogenesis, and inflammation in obesity. While the anti-inflammatory and lipid-modulating effects of krill oil (KO) on obesity are well known, its effects on sortilin remain insufficiently investigated. This study investigates the potential effects of KO supplementation on sortilin and pro-inflammatory cytokine levels in rats fed a high-fat diet (HFD). Twenty-four male Sprague Dawley rats were randomly assigned to three groups: standard diet (SD), HFD, and HFD + KO (600 mg/kg/day KO via oral gavage for 12 weeks). Body weights were monitored weekly. Serum total cholesterol (TC), triglyceride, glucose, insulin, and HOMA-IR were measured. Sortilin, TNF-α, IL-1β, and IL-6 levels were assessed in liver and retroperitoneal (RP) adipose tissues. The HFD group showed significant increases in weight, TC, glucose, and HOMA-IR, with decreased hepatic and increased RP adipose sortilin and TNF-α levels. KO reduced serum TC, increased hepatic sortilin and TNF-α, and decreased their levels in RP adipose tissue. These findings indicate that KO exerts a protective effect against HFD-induced obesity and inflammation by modulating lipid metabolism, reducing TNF-α and sortilin levels. Therefore, KO may serve as a promising dietary intervention for mitigating obesity-related metabolic and inflammatory complications.