Baicalin attenuates lipopolysaccharide-induced pro-inflammatory cytokine expression in murine macrophage cell line RAW264.7 through miR-124-STAT3 axis

Abstract

Baicalin, a flavonoid isolated from Scutellaria baicalensis Georgi, has shown a wide range of anti-inflammatory, antioxidative, antiviral, and antitumor properties. However, the molecular mechanism of how baicalin exerts its effects, especially on inflammation regulation, has not been fully investigated. In this article, we report the effects of baicalin on the mouse macrophage cell line RAW264.7. Our results demonstrate that baicalin inhibits the production of inflammatory factors interleukin-6 and tumor necrosis factor-alpha upon lipopolysaccharide stimulation of macrophages. We observed that baicalin inhibits STAT3 activation through retarding its expression and phosphorylation. Interestingly, baicalin treatment promotes the elevation of miR-124 in lipopolysaccharide-treated macrophages. Overexpression of the miR-124 mimic in RAW264.7 reduced STAT3 expression and phosphorylation. Furthermore, inhibition of miR-124 attenuated the dysregulation of STAT3 and reduction of inflammatory factors upon baicalin treatment. Our results revealed the molecular mechanism that baicalin attenuates pro-inflammatory cytokine production through miR-124-STAT3 signaling pathway, suggesting that miR-124 is an important modulator in regulating anti-inflammation by baicalin in macrophages.

Baicalin improves the survival in endotoxic mice and inhibits the inflammatory responses in LPS-treated RAW 264.7 macrophages

“…The results of the present study indicated that baicalin significantly inhibited the formation of TNF-α, IL-1β, and IL-6 both in LPS-stimulated macrophages and septic mice, which was the same as the reports by others. 33,34…”

“…The results of the present study indicated that baicalin significantly inhibited the formation of TNF-α, IL-1β, and IL-6 both in LPS-stimulated macrophages and septic mice, which was the same as the reports by others. 33,34 NF-κB located in the cytoplasm is an inactive complex bound to IκB-α. In the presence of inflammatory stimuli such as LPS, IκB-α is phosphorylated and degraded, leading to dissociation with NF-κB and release of activated NF-κB that then translocates into nucleus, where it activates the transcription of downstream target genes, including iNOS, COX-2, and pro-inflammatory cytokines.…”