Anti-inflammatory efficacy of brown seaweed (Padina tetrastromatica) in 3T3-L1 adipocytes and low-dose LPS induced inflammation in C57BL6 mice

Abstract

Chronic systemic inflammation is a central indicator of numerous diseases. Regulation of inflammation in adipose and liver is essential in mitigating obesity. SIRT1 is known to modulate inflammation and metabolic pathways. Brown algae Padina tetrastromatica possesses anti-oxidant and anti-inflammatory properties. However, the synergistic effects of P. tetrastromatica bioactives Fucoxanthin (Fx) and Total lipids (TL) to inhibit inflammation in SIRT1 silenced 3T3-L1 adipocytes remain unknown. Furthermore, the role of anti-inflammatory food supplements in mitigating systemic inflammation stays elusive. Therefore, here we studied the effects of P.tetrastromatica bioactives on cytokine production and activation of cell signals in SIRT1 silenced and LPS-induced inflammation in 3T3-L1 adipocytes and mice models. Preliminary in silico screening of Fx and its metabolites with target inflammatory markers was performed. The effects of Fx and TL on adipogenesis and reactive oxygen species (ROS) in silenced cells were detected by Oil Red O and DCFH-DA assay. Cytokine production and protein expression of NF-κB, COX-2, IL-10 and SIRT1 were determined by ELISA and western blotting. Fx and TL significantly inhibited adipogenesis, ROS, and Nitric oxide (NO), pro-inflammatory cytokine production (IL-6, IL-1ß, MCP-1, TNF-α) in SIRT1 silenced and LPS-challenged inflamed cells. Inflammatory marker (NF-κB, COX-2) expression was downregulated in Fx and TL treated cells compared to LPS and SIRT1 silenced cells indicating their modulating mechanistic ability to mitigate inflammation. Whereas, the expression of anti-inflammatory cytokine IL-10, adiponectin and NAD+ were upregulated significantly in Fx and TL treated cells compared to silenced and LPS insulted cells. These results were further validated by feeding seaweed and barley blended anti-inflammatory food (AIF) to LPS-treated mice. Results showed that AIF supplementation inhibited ROS generation, and pro-inflammatory cytokine, COX-2 and NF-κB expression. Whereas, feeding AIF upregulated adiponectin, NAD+, IL-10, and SIRT1 levels. Results suggest potential therapeutic food applications of P. tetrastromatica to manage inflammation and obesity.