Dihydromyricetin Attenuates Inflammation through TLR4/NF-kappaB Pathway

Microglia plays a complex role in neuroinflammation, which has been implicated in neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease. This study aims to explore the effect and mechanism of Dihydromyricetin (DHM) on lipopolysaccharide (LPS)-induced inflammation in microglial BV-2 cells. Cell viability was measured by 3-[4,5-dimethylthiazol-2-yl]2,5-diphenyltetrazolium bromide (MTT) assay. The pro-inflammatory mediators and cytokines including interleukin (IL)-6, IL-1β, and tumor necrosis factor-α (TNF-α); inducible nitric oxide synthase (iNOS); and cyclooxygenase 2 (COX-2) were measured by enzyme-linked immunosorbent assay (ELISA) and/or quantitative real-time PCR (qRT-PCR). The expression of p-p65, p-IκBα, toll-like receptor 4 (TLR4), and myeloid differentiation primary response 88 (MyD88) were analyzed by western blot. The present study showed that DHM treatment alleviated LPS-induced viability reduction, suppressed the mRNA levels of IL-6, IL‐1β and TNF-α, inhibited the mRNA and protein expression of iNOS and COX-2, and attenuated the activation of NF-кB and TLR4 signaling in a concentration-dependent manner. In conclusion, DHM exerts an anti-inflammatory effect on LPS-induced BV-2 microglial cells, possibly through TRL4/NF-κB signaling pathway.