Objective: To determine the effect of medicated serum of Chinese herbal compound Naofucong (, NFC) on the microglia BV-2 cells viability and the transcription and expression of interleukin-6 (IL-6) and tumor necrosis factor α (TNF-α) in microglia BV-2 cells to further explore the mechanisms underlying the protective effect of NFC on inflammatory process induced by high glucose.
Methods: The microglia BV-2 cells incubated in vitro were divided into different groups: the control group (25 mmol/L glucose), the model group (75 mmol/L glucose), high glucose media containing different dose medicated serum of NFC. After being cultured for 24 h, changes in IL-6 and TNF-α were measured by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay. The expression of surface marker CD11b of activated microglia was measured by confocal laser scanning microscope and Western blot. Nuclear factor-κB (NF-κB) p-p65 expression was analyzed by Western blot.
Results: The model group obviously increased the expression of microglial surface marker CD11b and NF-κB p-p65 (all P<0.01), induced a signifificant up-regulation of release and the mRNA expression of IL-6 and TNF-α (P<0.01 or P<0.05). The medicated serum of NFC could obviously down-regulate the transcription and expression of surface marker CD11 b and NF-κB p-p65 (all P<0.01), and inhibit the mRNA and protein expression (P<0.01 or P<0.05) of inflflammatory cytokines, such as IL-6 and TNF-α, in microglia BV-2 cells cultured with high glucose for 24 h.
Conclusions: The inhibition of microglial activation and IL-6 and TNF-α expression induced by high glucose may at least partly explain NFC therapeutic effects on diabetes-associated cognitive decline diseases. Its underlying mechanism could probably be related to the inhibition of NFC on NF-κB phosphorylation.
Keywords: Chinese herbal compound Naofucong; high glucose; inflflammatory cytokine; microglia.