Quercetin alleviates high-fat diet-induced inflammation in brown adipose tissue

Inflammation in brown adipose tissue (BAT) causes BAT to lose its ability to regulate energy metabolism, which exacerbates obesity development. This study investigated the anti-inflammatory and antioxidant effects of quercetin on BAT in high-fat diet (HFD)-induced obese mice. Quercetin reduced proinflammatory and macrophage genes and increased antioxidant genes in the BAT of HFD-fed mice and in TNF alpha-induced brown adipocytes. In addition to increasing silent mating type information regulation 2 homolog 1 (SIRT1) levels, quercetin suppressed nuclear translocation and increased deacetylation of the nuclear factor kappa B (NF kappa B) subunit p65. The effects of quercetin on SIRT1 and NF kappa B p65 deacetylation disappeared in SIRT1-knockdown brown adipocytes. MicroRNAs that negatively regulate SIRT1 were downregulated in the BAT of HFDQ-fed mice. Taken together, these results suggest that quercetin improves obesity-induced inflammation in BAT by suppressing the NF kappa B pathway through activation of SIRT1.