Partial Reversal of Obesity-Induced Insulin Resistance Owing to Anti-Inflammatory Immunomodulatory Potential of Flaxseed Oil

Abstract

The present study was designed to assess the potential of supplementation of diet with Flaxseed (Linum usitatissimum, L.) oil (FXO), on obesity-related inflammation and reversal of obesity-induced insulin resistance. Swiss Albino mice, C57bl/6 mice and co-culture of 3T3-L1 adipocytes – RAW 264.7 macrophages to mimick obese adipose tissue environment were used for the study. Oral gavage of FXO at concentrations of 4, 8 or 16 mg/kg body weight (bwt) for 4 weeks or high-fat diet (HFD, 60% energy as fat) supplemented with dietary FXO (4, 8 or 16 mg/kg bwt) was given to the mice. FXO was characterised using gas chromatography – mass spectrometry. FXO supplemented HFD-fed mice (4 mg/kg bwt exhibited reduced adiposity index, serum glucose levels and triglycerides (8 and 16 mg/kg bwt) and improvement in insulin sensitisation (4, 8 and 16 mg/kg bwt) when compared with HFD mice. The co-culture showed a dose-dependent shift in cytokines towards anti-inflammatory (IL-4) state, with a decrease in pro-inflammatory TNF-α (p < 0.05). For immunomodulatory studies a dose-dependent increase (p < 0.05) was observed in antigen-specific levels of Th2 (IL-4) cytokine, serum anti-ova IgG1 and IgE levels. Suppression in anti-ova IgG2a_, IgG2b, and IgG3 and antigen-specific Th1 cytokines like TNF-α and IFN-γ significantly (p < 0.05) was observed at 16 mg/kg bwt dosage. The results indicate that FXO exhibits an anti-inflammatory immunomodulatory potential and may partially relieve symptoms of obesity-associated insulin resistance.

• Anti-inflammatory
• cell-mediated immune response
• co-culture
• humoral immune response
• immunomodulation
• obesity

Acknowledgements

We thank the Advance instrumentation research facility (AIRF) of Jawaharlal Nehru University for performing GC/MS analysis. Dr Ambrish Tiwari, veterinary pathologist is duly acknowledged for histopathological analysis.

Declaration of interest

Jawaharlal Nehru fellowships for doctoral studies granted to Samina Bashir is acknowledged. The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.