School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China; Division of Interdisciplinary Medicine and Biotechnology, Department of Medicine, Beth Israel Deaconess Medical Center/Harvard Medical School, Boston, MA, USA.
School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China; The Seventh Affiliated Hospital，Sun Yat-sen University, Guangzhou, China.
J Nutr Biochem. 2020 Oct;84:108454. doi: 10.1016/j.jnutbio.2020.108454. Epub 2020 Jun 20.
Rheumatoid arthritis (RA) is a prototypical autoimmune disorder mainly characterized by joint inflammation and cartilage destruction. Neutrophils actively take part in the initiation and progression of RA. Neutrophils express inflammatory mediators, including cytokines and chemokines. Aberrant formation of neutrophil extracellular traps (NETs) has been demonstrated in the pathogenesis of RA. Thus, neutrophils are regarded as important therapeutic targets in RA treatment. Quercetin is one of the major flavonoids found in fruits and vegetables. Previous studies have demonstrated that quercetin is a potential agent for the treatment of RA. However, the underlying antiarthritic mechanism of quercetin has not been investigated clearly. In this study, we analyzed the therapeutic mechanism of quercetin for RA. Our results showed that quercetin ameliorates inflammation in RA mice by inhibiting neutrophil activities. Quercetin inhibited neutrophil infiltration and reduced the plasma levels of inflammatory cytokines. Quercetin promoted the apoptosis of activated neutrophils. In addition, quercetin inhibited NET formation by suppressing autophagy. These findings suggest that quercetin may be an alternative agent for the treatment of RA by inhibiting neutrophil activities.
类风湿关节炎（RA）是一种典型的自身免疫性疾病，主要表现为关节炎症和软骨破坏。中性粒细胞积极参与 RA 的发生和发展。中性粒细胞表达炎症介质，包括细胞因子和趋化因子。RA 发病机制中已经证实了中性粒细胞胞外诱捕网（NETs）的异常形成。因此，中性粒细胞被认为是 RA 治疗的重要治疗靶点。槲皮素是水果和蔬菜中发现的主要类黄酮之一。先前的研究表明，槲皮素是治疗 RA 的潜在药物。然而，槲皮素的潜在抗关节炎机制尚未得到明确研究。在这项研究中，我们分析了槲皮素治疗 RA 的治疗机制。我们的结果表明，槲皮素通过抑制中性粒细胞活性改善 RA 小鼠的炎症。槲皮素抑制中性粒细胞浸润并降低炎症细胞因子的血浆水平。槲皮素促进活化中性粒细胞的凋亡。此外，槲皮素通过抑制自噬抑制 NET 形成。这些发现表明，槲皮素通过抑制中性粒细胞活性可能成为治疗 RA 的替代药物。
