TLR4 and inflammation: In the present study, PCA or Que suppressed mRNA and protein abundance of pro-inflammatory cytokines such as TNF-α, IL-8 and IL-6, which was associated with inhibiting TLR4 and its downstream signals such as LBP, MD2, CD14, TLR4, IRAK1 and NF-κB, indicating a protective role in preventing intestinal inflammation via TLR4 signaling pathway.