Nonalcoholic steatohepatitis (NASH) can progress into liver cirrhosis; however, no definite treatment is available. Omega-3 polyunsaturated fatty acid (omega-3) has been reported to alleviate experimental NASH, although its beneficial effect was not evident when tested clinically. Thus, this study aimed to investigate the additive effect of omega-3 and ursodeoxycholic acid (UDCA) on diet-induced NASH in mice. C57BL/6 mice were given a high-fat diet (HFD) for 24 weeks, at which point the mice were divided into three groups and fed HFD alone, HFD with omega-3 or HFD with omega-3 in combination with UDCA for another 24 weeks. Feeding mice an HFD and administering omega-3 improved histologically assessed liver fibrosis, and UDCA in combination with omega-3 further attenuated this disease. The assessment of collagen alpha1(I) expression agreed with the histological evaluation. Omega-3 in combination with UDCA resulted in a significant attenuation of inflammation whereas administering omega-3 alone failed to improve histologically assessed liver inflammation. Quantitative analysis of tumor necrosis factor alpha showed an additive effect of omega-3 and UDCA on liver inflammation. HFD-induced hepatic triglyceride accumulation was attenuated by omega-3 and adding UDCA accentuated this effect. In accordance with this result, the expression of sterol regulatory binding protein-1c decreased after omega-3 administration and adding UDCA further diminished SREBP-1c expression. The expression of inducible nitric oxide synthase (iNOS), which may reflect oxidative stress-induced tissue damage, was suppressed by omega-3 administration and adding UDCA further attenuated iNOS expression. These results demonstrated an additive effect of omega-3 and UDCA for alleviating fibrosis, inflammation and steatosis in diet-induced NASH.
Animals ; Cholagogues and Choleretics/pharmacology/*therapeutic use ; Diet, High-Fat/adverse effects ; Drug Synergism ; Fatty Acids, Omega-3/pharmacology/*therapeutic use ; Fibrosis/drug therapy/etiology/immunology/pathology ; Inflammation/drug therapy/etiology/immunology/pathology ; Liver/*drug effects/immunology/pathology ; Male ; Mice, Inbred C57BL ; Non-alcoholic Fatty Liver Disease/*drug therapy/etiology/immunology/pathology ; Ursodeoxycholic Acid/pharmacology/*therapeutic use

INTRODUCTIONConsumption of omega-3 fatty acids can alter the inflammatory response in diabetic patients. This study aimed to determine the effects of omega-3 fatty acid supplementation on the serum levels of C-reactive protein (CRP), interleukin (IL)-2 and tumour necrosis factor-alpha (TNF-α) in type 2 diabetes mellitus patients.

METHODSA randomised, double-blind, placebo-controlled clinical trial was conducted on 84 subjects aged 45-85 years with at least a two-year history of type 2 diabetes mellitus. Participants were randomly assigned to the treatment or control group. Each subject in the treatment group received three omega-3 capsules per day (eicosapentaenoic acid 1,548 mg; docosahexaenoic acid 828 mg; other omega-3 fatty acids 338 mg), while each subject in the control group received three placebo capsules (sunflower oil 2,100 mg) for a period of eight weeks. At the beginning of the study and post intervention, fasting blood samples were taken and serum concentrations of IL-2, TNF-α and CRP were assessed and compared.

RESULTSSerum IL-2 and TNF-α levels were significantly reduced in the treatment group compared to the controls (p < 0.01). There was no significant change in serum CRP levels.

CONCLUSIONShort-term omega-3 fatty acid supplementation (3 g/day for eight weeks) can decrease the serum levels of TNF-α and IL-2 in diabetic patients, with no change in CRP levels. Consumption of omega-3 fatty acid supplements is highly recommended to alleviate inflammation caused by type 2 diabetes mellitus.

Aged ; Aged, 80 and over ; Biomarkers ; blood ; C-Reactive Protein ; drug effects ; metabolism ; Diabetes Mellitus, Type 2 ; blood ; drug therapy ; immunology ; Dietary Supplements ; Double-Blind Method ; Fatty Acids, Omega-3 ; pharmacology ; therapeutic use ; Female ; Humans ; Inflammation ; blood ; prevention & control ; Interleukin-2 ; blood ; Male ; Middle Aged ; Tumor Necrosis Factor-alpha ; blood ; drug effects