Kaempferol attenuates experimental autoimmune neuritis through TNFR1/JNK/p38 signaling pathway inhibition

Kaempferol (Kae) is a flavonoid that has antioxidant, anti-inflammatory and neuroprotective effects. In recent years, there have been increasing reports on viral infection-induced Guillain-Barré syndrome (GBS) with high rates of disability and fatality. Therefore, in order to search for effective peripheral nerve injury repair drugs, we used rats with experimental autoimmune neuritis (EAN) as the typical animal model for GBS, and implemented Kae treatment intervention on EAN rats. Real-time quantitative polymerase chain reaction (qPCR), western blotting (WB) and immunofluorescence (IF) were utilized to detect the changes of inflammatory factors and signaling pathway proteins in peripheral nerve of rats. The impact of Kae on peripheral nerve damage in EAN rats was evaluated in multiple dimensions by clinical symptom score and neuroelectrophysiology examination, and the protective impact and mechanism of Kae on peripheral nerve injury were revealed. Our results showed that Kae increased the expression of sciatic myelin basic protein (MBP), decreased the expression of peripheral nerve macrophage infiltration and inflammatory cytokines, including TNF-α, IL-1β and IL-6, and down-regulated the expression levels of TNFR1. Additionally, it suppressed the activation of the JNK and p38 pathways. It can alleviate sciatic nerve symptoms and pathological injury in EAN rats. Therefore, we believe that Kae can be used as an adjunct drug in the treatment of GBS.