Effect of 5-aminosalicylate on allergic rhinitis model in mice.

Previous studies have shown that peroxisome proliferator-activated receptor gamma (PPARgamma) is involved in allergic rhinitis. It has been reported that 5-aminosalicylate (5-ASA) has an affinity for PPARgamma, but the effects of 5-ASA on the nasal symptoms of allergic rhinitis are unclear. This study aimed to clarify the effects of 5-ASA on nasal symptoms in an allergic rhinitis model in mice. Female BALB/c mice were sensitized by intraperitoneal injection of ovalbumin (OVA) and aluminium hydroxide hydrate gel (alum) on days 0, 5, 14 and 21. Seven days later, mice were sensitized by the intranasal application of OVA thrice a week. 5-ASA was also administered orally after instillation of the antigen from day 28. The severity of allergic rhinitis was assessed by determining the extent of 2 nasal allergic symptoms-sneezing and nasal rubbing. In addition, serum OVA-specific immunoglobulin E (IgE) antibody, interleukin (IL)-4, and IL-10 levels in nasal lavage fluid and histamine sensitivity were determined. Repeated oral administration of 5-ASA attenuated the progression of nasal symptoms in sensitized mice in a dose-dependent manner. Additionally, 5-ASA prevented an increase in histamine sensitivity. Finally, 5-ASA inhibited both OVA-specific IgE antibody and IL-4 production; however, it had no effect on IL-10 levels. These results indicate that 5-ASA has a prophylactic effect on allergic rhinitis.