Anti-allergic effects of total bakkenolides from Petasites tricholobus in ovalbumin-sensitized rats.

The anti-allergic effect of total bakkenolides from the rhizome of Petasites tricholobus (BAPT) was evaluated in an ovalbumin-induced allergic rhinitis model in male Wistar rats. The major components of the bakkenolide fraction are bakkenolide-D, bakkenolide-B, bakkenolide-IIIa and bakkenolide-IVa, which account for 60.04% of the total. The rats were treated with 40 mg/kg, 20 mg/kg, 10 mg/kg or 5 mg/kg BAPT, and 0.942 mg/kg loratadine and 0.5% gum tragacanth were used as positive and negative controls, respectively. The frequency of nose rubbing and sneezing was observed, the number of eosinophils infiltrating into the nasal tissue was counted, and serum levels of IL-4 and histamine were determined by ELISA. The results showed that BAPT had a beneficial effect on allergic rhinitis in ovalbumin-sensitized Wistar rats, which was evidenced by a significant decrease in the frequency of sneezing, the number of eosinophils infiltrating into the nasal tissue, and the serum levels of IL-4 and histamine. BAPT may therefore be a potential antiallergic drug.