Abstract: This study aimed to investigate the inhibitory effects of different concentrations of loganin on microglia activation and its molecular mechanisms. In this study, primary mouse microglia were isolated and cultured. The cells were pretreated with different concentrations of loganin(50, 100, and 200 μmol/L), and then activated by lipopolysaccharide (LPS), to observe the effects of loganin on LPS-induced microglia activation, inflammatory factor release, and NF-κB signaling pathway. The results showed that, compared with the control group, the body of microglia in LPS group expanded, microglia secreted inflammatory cytokines in abundance, and the degree of nuclear transfer of NF-κB increased (P<0.05). Microglia showed obvious M1 activation state. After intervention with low, medium, and high concentrations of loganin glucoside, the total cell and nuclear areas of the microglia decreased significantly (P<0.05). In addition, low, medium, and high concentrations of loganin could inhibit iNOS expression and activation of NF-κB signaling pathway in microglia. These results suggest that loganin can significantly inhibit the activation of microglia and reduce the release of inflammatory factors, which may be related to the inhibition of NF-κB signaling pathway. This provides a theoretical basis for the application of loganin in the prevention and treatment of neuroinflammation.

Key words: loganin, microglia, inflammatory factor;lipopolysaccharide, NF-κB