Antiallergic effect of Ostericum koreanum root extract on ovalbumin-induced allergic rhinitis mouse model and mast cells

Objective: In the present study, the anti-allergic effect of OR extract was evaluated on an ovalbumin (OVA)-induced allergic rhinitis in mice and rat peritoneal mast cells (RPMC). Methods: Balb/c mice were systemically sensitized to OVA followed by intraperitoneal and nasal allergen challenges. We investigated the effect of OR extract on allergic symptoms, serological marker production and histological changes of the nasal mucosa in a mouse model of allergic rhinitis. We observed mast cell degranulation and detected the production of histamine and inflammatory cytokines by ELISA. Results: Compared to the OVA-control group, oral administration of OR extract at doses of 50 and 100 mg/kg significantly (p <0.001) decreased the serum levels of histamine, OVA-specific IgE and Th2 cytokine, IL-4 as well as increasing Th1 cytokine, IFN-gamma. Oral administration of OR extract also attenuated disease progression as determined by nasal symptoms and histological changes of the nasal mucosa in OVA-sensitized mice. Furthermore, treatment with OR extract at doses of 0.2, 0.5 ad 1 mg/ml, in RPMC significantly (p <0.01, p <0.001 and p <0.001, respectively) decreased compound 48/80-induced histamine release and suppressed mast cell degranulation. Treatment with OR extract in RPMC also inhibited PMA/A23187-induced production of inflammatory cytokines such as TNF-alpha and IL-6. The mechanism of action underlying OR extract in allergic inflammation appears to be inhibition of the phosphorylation of ERK1/2 and p38 MAPK, in addition to blocking of the NF kappa B pathway. Conclusions: These results indicate that OR extract has the potential to be a source of anti-allergic agents for use in allergen and/or mast cell-mediated diseases including allergic rhinitis. (Asian Pac J Allergy Immunol 2011;29:338-48)