Effect of Usuhiratake (Pleurotus pulmonarius) on sneezing and nasal rubbing in BALB/c mice.

The anti-rhinitis properties of Pleurotus pulmonarius were investigated in BALB/c mice. A single administration of Pleurotus Pulmonarius caused no significant effect on antigen-induced nasal rubbing and sneezing at a dose of 500 mg/kg, but a significant inhibition was observed after 2 weeks of repeated treatment at this dose, and at a dose of 200 mg/kg, it also caused a significant inhibition after repeated administration for 4 weeks. Pleurotus pulmonarius showed no significant inhibitory effect on the production of IgE. In addition, Pleurotus pulmonarius caused no inhibition of histamine-induced nasal rubbing and sneezing at a dose of 500 mg/kg, but in vitro study, it inhibited histamine release from rat mast cells induced by compound 48/80 at the soluble supernatant solution of 30 and 100 microg/ml of Pleurotus pulmonarius suspended in PBS. These results demonstrated that Pleurotus pulmonarius may be effective in the relief of symptoms of allergic rhinitis through inhibition of histamine release.