Anti-inflammatory and anti-diabetic effects of brown seaweeds in high-fat diet-induced obese mice

BACKGROUND/OBJECTIVES: Seaweeds have been reported to have various health beneficial effects. In this study, we investigated the potential anti-obesity and anti-inflammatory effects of four types of domestic brown seaweeds in a high-fat diet-induced obese mouse model and bone marrow-derived macrophages (BMDM). MATERIALS/METHODS: Male C57BL/6N mice were fed low-fat diet (LFD), high-fat diet (HFD) or HFD containing Undaria Pinnatifida, HFD containing Laminaria Japonica (LJ), HFD containing Sargassum Fulvellum, or HFD containing Hizikia Fusiforme (HF) for 16 weeks. RESULTS: Brown seaweed supplementation did not affect long-term HFD-associated changes in body weight or adiposity, although mice fed HFD + LJ or HFD + HF gained slightly less body weight compared with those fed HFD at the beginning of feeding. Despite being obese, mice fed HFD + LJ appeared to show improved insulin sensitivity compared to mice fed HFD. Consistently, we observed significantly reduced blood glucose concentrations in mice fed HFD + LJ compared with those of mice fed HFD. Although no significant differences in adipocyte size were detected among the HFD-fed groups, consumption of seaweeds decreased formation of HFD-induced crown-like structures in gonadal adipose tissue as well as plasma inflammatory cytokines. BMDM from mice fed HFDs with seaweeds showed differential regulation of pro-inflammatory cytokines such as IL-1beta and IL-6 compared with BMDM from mice fed HFD by LPS stimulation. CONCLUSION: Although seaweed consumption did not prevent long-term HFD-induced obesity in C57BL/6N mice, it reduced insulin resistance (IR) and circulation of pro-inflammatory cytokines. Therefore, seaweeds may ameliorate systemic inflammation and IR in obesity partially due to inhibition of inflammatory signaling in adipose tissue cells as well as bone marrow-derived immune cells.

Role of AMPK signaling pathway in regulating antibacterial autophagy in murine bone marrow derived macro-phages / 局解手术学杂志

Objective To investigate the regulatory effects and possible mechanisms of autophagy induction and bactericidal activity in muring bone marrow derived macrophages ( BMDMs) . Methods Murine BMDMs were isolated and cultured in vitro. Then standard strain of E. coli was used to infect BMDMs and cellular autophagy levels and AMPK activation were detected. We next modulated functions of AMPK by pretreating cells with the specific agonist or antagonist of AMPK. Then cellular AMPK activation, autophagy levels and bactericidal activity were observed after E. coli infection. Results In E. coli infected BMDMs,autophagy related molecules like LC3B and Beclin1 were upregu-lated,accompanied with elevated LC3Ⅱ/Ⅰratio. Phosphorylation of AMPK was also upregulated by E. coli treatment. Enhanced AMPK activi-ty by its agonist leads to increased cellular autophagy and bactericidal activity,whereas inhibition of AMPK by its suppressor downregulated autophagy and dampened bactericidal activity. Conclusion AMPK and its related signaling pathway is required for anti-bacterial response in macrophage,which is dependent on its function in upregulating autophagy related molecules and inducing autophagy.