Baicalin inhibits TLR7/MYD88 signaling pathway activation to suppress lung inflammation in mice infected with influenza A virus

Abstract

The present study aimed to investigate the protective effects and underlying mechanisms of baicalin on imprinting control region mice infected with influenza A/FM/1/47 (H1N1) virus. Oral administration of baicalin into mice infected with H1N1 prevented death, increased the mean time to death and inhibited lung index and lung consolidation. Subsequently, fluorescence quantitative polymerase chain reaction was used to assess the mRNA expression of toll-like receptor 7 (TLR7) and myeloid differentiation primary response gene 88 (MYD88), and western blot analysis was used to determine the expression of phosphorylated nuclear factor κB (NF-κB)-P65 and c-jun/activator protein 1 (AP-1). An enzyme-linked immunosorbent assay was applied to test for the inflammatory cytokines, tumor necrosis factor (TNF)-α and interleukin (IL)-1β and IL-6, in the lung tissue. The findings indicated that baicalin downregulated the mRNA expression of TLR7 and MYD88, significantly downregulated the protein expression of NF-κB-P65 and AP-1 and also inhibited the secretion of TNF-α, IL-1β and IL-6. In conclusion, baicalin effectively reduced the pathological damage and inflammation of the lungs by downregulating the TLR7/MYD88-mediated signaling pathway.

Dioscin prevents LPS‑induced acute lung injury through inhibiting the TLR4/MyD88 signaling pathway via upregulation of HSP70

“…MyD88 was originally identified as the members of the 12 myeloid differentiation initial response genes. MyD88, as the adaptor protein, can mediate the signal transduction of 10 TLRs families (23). MyD88-dependent signaling pathway may be involved in the injury caused by ischemia reperfusion, aggravating the organ damage.…”

Baicalin from Scutellaria baicalensis blocks respiratory syncytial virus (RSV) infection and reduces inflammatory cell infiltration and lung injury in mice

“…We found that baicalin blocked RSV infection through inhibition of cell attachment and intracellular replication, a mechanism that is also shared against influenza and dengue infection 13 15 . Other mechanisms include baicalin inhibition of autophagy activity and innate immune responses 19 44 . Baicalin is a potent immune modulator in other disease models 35 .…”

Protective effects of baicalin on LPS-induced injury in intestinal epithelial cells and intercellular tight junctions

“…Baicalin is a flavonoid extracted from the root of S. baicalensis, which demonstrates a variety of biological activities, such as antiplatelet, anticoagulant, and profibrinolytic activities (Lee et al 2014), anti-Chlamydia activity (Hao et al 2009), antiadipogenic activity , and anti-inflammatory activity (Wan et al 2014). A recent study by Wu et al has shown that baicalin attenuates LPS-induced injury in mouse intestinal mucosa ).…”