Galangin Suppresses Pro-Inflammatory Gene Expression in Polyinosinic-Polycytidylic Acid-Stimulated Microglial Cells

• Published in: Biomolecules & therapeutics Vol. 25; no. 6; pp. 641 - 647
• Main Authors: Choi, Min-Ji, Park, Jin-Sun, Park, Jung-Eun, Kim, Han Su, Kim, Hee-Sun
• Format: Journal Article
• Language: English
• Published: Korea (South) The Korean Society of Applied Pharmacology 01.11.2017; 한국응용약물학회
• Subjects: Original; 약학; NF-κB; signaling; Poly(I:C); Galangin; PPAR-γ; Microglia; PI3K/Akt
• ISSN: 2005-4483; 1976-9148; 1976-9148; 2005-4483
• DOI: 10.4062/biomolther.2017.173

Galangin (3,5,7-trihydroxyflavone) is a polyphenolic compound abundant in honey and medicinal herbs, such as . In this study, we investigated the anti-inflammatory effects of galangin under and neuroinflammatory conditions caused by polyinosinic-polycytidylic acid (poly(I:C)), a viral mimic dsRNA analog. Galangin suppressed the production of nitric oxide, reactive oxygen species, and pro-inflammatory cytokines in poly(I:C)-stimulated BV2 microglia. On the other hand, galangin enhanced anti-inflammatory interleukin (IL)-10 production. Galangin also suppressed the expression of pro-inflammatory markers in poly(I:C)-injected mouse brains. Further mechanistic studies showed that galangin inhibited poly(I:C)-induced nuclear factor (NF)-κB activity and phosphorylation of Akt without affecting MAP kinases. Interestingly, galangin increased the expression and transcriptional activity of peroxisome proliferator-activated receptor (PPAR)-γ, known to play an anti-inflammatory role. To investigate whether PPAR-γ is involved in the anti-inflammatory function of galangin, BV2 cells were pre-treated with PPAR-γ antagonist before treatment of galangin. We found that PPAR-γ antagonist significantly blocked galangin-mediated upregulation of IL-10 and attenuated the inhibition of tumor necrosis factor (TNF)-α and IL-6 in poly(I:C)-stimulated microglia. In conclusion, our data suggest that PI3K/Akt, NF-κB, and PPAR-γ play a pivotal role in mediating the anti-inflammatory effects of galangin in poly(I:C)-stimulated microglia.