Ursolic Acid Alleviates Mucus Secretion and Tissue Remodeling in Rat Model of Allergic Rhinitis After PM2.5 Exposure

Abstract

Background According to recent epidemiologic studies, exposure to fine particulate matter (particulate matter 2.5 ≤ µm [PM2.5]) in the air increases the incidence and severity of allergic rhinitis (AR). Ursolic acid (UA) has activities in immune regulation and anti-inflammatory. However, the role of UA intervention on PM2.5-exposed AR remains unknown. In this study, we investigated the effects of UA on tissue remodeling and mucus hypersecretion in a rat model of AR after PM2.5 exposure. Methods AR was induced in rats with ovalbumin (OVA) and they were exposed to ambient PM2.5(200 µg/m3) via a PM2.5 inhalation exposure system for 30 days(ARE group). Ursolic acid intervention was administrated in the AR model after PM2.5 exposure (UA group). Hyperplasia of goblet cells was detected by periodic acid-Schiff (PAS) staining and collagen deposition in the nasal mucosa was detected by Masson trichrome (MT) staining.MUC5AC expression was measured by immunohistochemistry. Results UA group showed reduced goblet cell hyperplasia and collagen deposition in the nasal mucosa which exacerbated after PM2.5 exposure, as reflected by PAS and MT staining when compared with the ARE group. Immunohistochemical results showed that the expression of MUC5AC in the UA group was lower than that in the ARE group. Conclusion Analysis of our data indicated that UA could attenuate nasal remodeling and mucus hypersecretion in aggravation of AR after PM2.5 exposure, which may be the pathophysiologic mechanisms for the prevention of AR exacerbated by exposure to PM2.5.

BMAL1/p53 mediating bronchial epithelial cell autophagy contributes to PM2.5-aggravated asthma

“…A high concentration of PM2.5 in the atmosphere was significantly correlated to the remodeling of the coronary artery [ 29 ]. Nasal remodeling and mucus hypersecretion in an allergic rhinitis rat model was also found after PM2.5 treatment [ 30 ]. PM2.5 increased some epidermal growth factor receptor ligands in airway epithelial cells, which elicited and sustained a pro-inflammatory response and contributed to airway remodeling [ 31 ].…”

Nasal Epithelial Barrier Integrity and Tight Junctions Disruption in Allergic Rhinitis: Overview and Pathogenic Insights

“…AR rat exposed to PM2.5 had significantly increased AR symptoms (i.e. number of sneezes and nasal rubs) and exhibited disorderedly arrangement of nasal mucosa epithelium (42), and a substantial increase in goblet cell hyperplasia and collagen deposition were also observed compared with control rats (43).…”

“…Through Akt inhibition, it decreased UPM-induced ROS formation and p38 and p65 protein phosphorylation, and restored the expression of ZO-1 and Ecadherin (44). Meanwhile, the mucosal epithelium was observed to be arranged in a more orderly manner when treated with ursolic acid (UA) (a pentacyclic triterpene extract from natural plants) in AR model exposed to PM2.5 (42), and decrease in number and size of goblet cells in epithelial layer, expression of MUC5AC and proportion of collagen deposition areas (43). UA possesses anti-inflammatory, antioxidant and anti-fibrotic properties where it is capable of modulating the MAPK and NF-kB signaling pathways (47).…”

Interdisciplinary Teamwork within the Medical Profession: The Way of the Future

“…While further studies are needed to determine the effects of GO and MGO on the lower airway, the results in this study suggest that these compounds in electronic cigarettes may play a role in mucus hypersecretion related airway diseases. Sun et al 3 investigated the potential impact of Ursolic acid (UA) in allergic rhinitis (AR) on a rat model. UA is a compound that can be found in apple peels and herbal medicines, amongst others and has been shown to have anti-inflammatory, antioxidant and antifibrotic effects.…”

“…Sun et al. 3 investigated the potential impact of Ursolic acid (UA) in allergic rhinitis (AR) on a rat model. UA is a compound that can be found in apple peels and herbal medicines, amongst others and has been shown to have anti-inflammatory, antioxidant and anti-fibrotic effects.…”