The Effects of Saposhnikovia divaricata Aqueous Extracts on the Inflammation and Intestinal Microflora in Allergic Rhinitis Mice

Allergic rhinitis (AR) is a type I allergic disease induced by IgE. Traditional Chinese medicine Saposhnikovia divaricata (Turcz.) Schischk (SD) has anti-inflammatory and antiallergic effects. Materials and

This study provides a possibility that the improvement effect of SD treatment on allergies and inflammation in AR mice may be related to the TLR4/TRAF6/NF-κB and IL-6/ROR-γt/STAT3 pathways and intestinal microflora modulation.

AR model mice were constructed with ovalbumin (OVA) sensitization to observe the improving effect of SD treatment on AR by counting the number of sneezing and rubbing the nose, hematoxylin-eosin, periodic acid-Schiff, and toluidine blue stains. In addition, the allergy and inflammatory cytokines levels and inflammatory cells were observed by ELISA and Wright's-Giemsa stain. The protein levels of the TLR4/TRAF6/NF-κB and IL-6/ROR-γt/STAT3 pathways were measured by immunohistochemistry, quantitative real-time PCR, and western blot. The intestinal microflora abundance in mice was observed by 16S rDNA high-throughput sequencing.

SD treatment inhibited the sneezing and rubbing times of the nose, decreased the degree of a dense arrangement of cells and mucosal swelling and the number of goblet and mast cells of nasal lavage fluid, reduced the levels of IgE, histamine, Leukotriene B4, IL-4, IL-5, TNF-α, IL-6, and IL-17, the eosinophils, neutrophils, and lymphocytes number, the LR4, TRAF6, IL-6, ROR-γt, and STAT3 mRNA levels, respectively, while, it increased the IL-2, IL-10, IFN-γ, and TGF-β1 proteins. SD treatment inhibited the NF-κB, p-STAT3, TLR4, TRAF6, and p-IκBα/IκBα proteins. Besides, the effects of OVA and SD treatments were significantly correlated with the abundance of intestinal microflora. The abundances of Cytophagales, Burkholderia, Alteromonadales, Lactococcus, and Clostridiaceae were changed in SD treatment on AR mice. Conclusions: This study provides a possibility that the improvement effect of SD treatment on allergies and inflammation in AR mice may be related to the TLR4/TRAF6/NF-κB and IL-6/ROR-γt/STAT3 pathways and intestinal microflora modulation.