Preventive and Therapeutic Effects of Krill Oil on Obesity and Obesity-Induced Metabolic Syndromes in High-Fat Diet-Fed Mice

Abstract

Obesity increases the risks of metabolic syndromes including nonalcoholic fatty liver disease (NAFLD), diabetic dyslipidemia, and chronic kidney disease. Dietary krill oil (KO) has shown antioxidant and anti-inflammatory properties, thereby being a therapeutic potential for obesity-induced metabolic syndromes. Thus, the effects of KO on lipid metabolic alteration were examined in a high-fat diet (HFD)-fed mice model. The HFD model (n = 10 per group) received an oral gavage with distilled water as a control, metformin at 250 mg/kg, and KO at 400, 200, and 100 mg/kg for 12 weeks. The HFD-induced weight gain and fat deposition were significantly reduced in the KO treatments compared with the control. Blood levels were lower in parameters for NAFLD (e.g., alanine aminotransferase, and triglyceride), type 2 diabetes (e.g., glucose and insulin), and renal dysfunction (e.g., blood urea nitrogen and creatinine) by the KO treatments. The KO inhibited lipid synthesis through the modification of gene expressions in the liver and adipose tissues and adipokine-mediated pathways. Furthermore, KO showed hepatic antioxidant activities and glucose lowering effects. Histopathological analyses revealed that the KO ameliorated the hepatic steatosis, pancreatic endocrine/exocrine alteration, adipose tissue hypertrophy, and renal steatosis. These analyses suggest that KO may be promising for inhibiting obesity and metabolic syndromes.

Krill oil attenuates obesity-induced skeletal muscle atrophy in mice

“…Additionally, it has been demonstrated that insulin resistance is associated with defects in PI3K/Akt pathway [48] . In the current study, KO treatment for 6 weeks did not ameliorate insulin resistance in HFD-induced obese mice notably, which is inconsistent with other studies [26,49] . This conflicting evidence might be due to the varying intervention time and doses of KO in our and other studies.…”

“…Furthermore, it has been demonstrated that the presence of astaxanthin in KO increases the stability of n-3 LCPUFAs and protects them against oxidation that may lead to better health outcomes [22] . In recent decades, several studies have shown that KO has therapeutic potential in several diseases such as inflammation, acute liver injury, hyperlipidemia, obesity and diabetic complications [23][24][25][26][27][28] . A recent study reported that KO supplementation improved muscle function and size in healthy older adults [29] .…”

Krill Oil’s Protective Benefits against Ultraviolet B-Induced Skin Photoaging in Hairless Mice and In Vitro Experiments

“…In our previous studies, KO has been recognized as a marine-derived natural substance with significant activation of nuclear factor E2-related factor 2 (Nrf2) transferase and potent antioxidant properties, making it a promising raw material for health functional foods with natural antioxidant benefits [ 16 , 17 ]. Although previous research on human immortalized keratinocyte lines and NC/Nga mice has suggested the potential benefits of KO in terms of antioxidants and anti-inflammatory effects [ 11 , 18 ], there is a lack of direct and detailed research on KO’s role in improving skin wrinkles and moisturization.…”

“…After centrifugation, a secondary evaporation and filtration were conducted to produce the final product, KO. The KO composition included 51.2% (wt/wt) phospholipids, comprising 44.9% phosphatidylcholine, 3.6% 1-palmitoyl-2-hydroxy-glycero-3-phosphocholine, 2.1% phosphatidylethanolamine, and 0.6% N-Acyl-phosphatidylethanolamine [ 17 ]. Additionally, EPA and DHA contents were analyzed in the KO.…”

Local Application of Krill Oil Accelerates the Healing of Artificially Created Wounds in Diabetic Mice

“…KO has been reported to have anti-inflammatory, anti-oxidative, and anti-fibrotic activities in mouse models of diabetic complications [ 11 , 12 , 27 ]. We previously found that KO could inhibit DM-induced cardiac and renal inflammation and fibrosis, preventing diabetic cardiomyopathy and nephropathy in a mouse model of T2DM [ 11 , 12 ].…”