Oral administration of polyphenol-rich Sargassum horneri suppresses particulate matter exacerbated airway inflammation in murine allergic asthma: Relevance to the TLR mediated NF-κB pathway inhibition

Particulate matter (PM) is known to exacerbate airway inflammatory responses in asthma patients and to worsen asthma symptoms. Hypothesizing that attenuating airway inflammation might delay the exacerbation of PM-induced asthma symptoms, we investigated polyphenol-containing Sargassum horneri extract's (SHE's) anti-inflammatory efficacy and its underlying mechanism against PM-exacerbated inflammatory response using an asthma mouse model. SHE attenuated the PM-aggravated granulocytes infiltration into the airway and suppressed the PM-exacerbated mRNA expression of TLRs (TLR2/4/7), leading to the reduction of MyD88 dependent NF-kappa B activation in lungs of asthmatic mice. This resulted in attenuated PM-exacerbated mRNA expression of pro-inflammatory cytokines (IL-1 beta, TNF-alpha, TGF-beta, IL-6), pro-allergic cytokines (TSLP, IL-25, IL-33), and a chemokine (IL-8) in lungs of asthmatic mice. Taken together, we conclude that SHE mitigates the PM-exacerbated airway inflammatory response of asthmatic mice via modulating TLR2/4/7 mediated MyD88 dependent NF-kappa B pathway and might make a natural candidate against the PM exacerbated severe asthma.