Background
Microglial inflammation is considered to be an important process in the pathogenesis of many neurodegenerative diseases, and modulation of inflammatory responses may represent a potential therapeutic strategy for these diseases. The root of the licorice (Glycyrrhiza glabra L.) plant contains glycyrrhizin, a compound reported to possess anti-inflammatory and antioxidant properties.
Objectives
The aim of this study is to determine the effects of glycyrrhizin on inflammatory cytokines in BV-2 microglial cells stimulated with LPS.
Methods
BV-2 cells were stimulated with LPS and subsequently treated with glycyrrhizin at concentrations of 0.2, 0.4, 1.2, and 4 μg/mL, except in the IL-12 assay, in which concentrations of 0.5, 1, 3, and 10 μg/mL were used. One group of BV-2 cells received LPS alone and served as the control group. The levels of TNF-α, IL-1β, IL-6, IL-12, and HMGB-1 were measured at 24, 48, and 72 h.
Results
Glycyrrhizin reduced the levels of inflammatory mediators in LPS-stimulated BV-2 cells, with the magnitude of the effects varying among the mediators and experimental conditions. Glycyrrhizin significantly reduced TNF-α and IL-1β levels at 72 h, particularly at higher concentrations (P<0.05). IL-6 was also significantly reduced at 72 h at higher concentrations (P<0.01), while HMGB-1 was significantly reduced at all tested time points (P<0.01). IL-12 showed a decreasing trend, particularly at later time points (P<0.05).
Conclusions
Overall, the findings of this study showed that glycyrrhizin reduced selected inflammatory mediators in LPS-stimulated BV-2 cells, with more pronounced effects observed for some mediators at later time points and higher concentrations.
These findings support further investigation of glycyrrhizin as a potential modulator of inflammatory responses in experimental models of neuroinflammation.