Bufotalin ameliorates ovalbumin-induced allergic rhinitis by restoring the Tregs.

Abstract

BACKGROUND: Allergic rhinitis (AR) is one of the most common inflammatory diseases. IgE, inflammatory cytokine production and Th17/Tregs imbalance have been implicated in AR pathogenesis. Bufotalin, a component extracted from toad venom skin secretions and auricular glands, has anti-inflammatory activity and regulates Th17/Tregs balance. Here, the effects of bufotalin on AR were explored. METHODS: The AR mice model was established using ovalbumin (OVA). AR mice were treated with bufotalin started on Day 22 with various doses (1, 10, 100 μg or 1 mg per mouse) every day to Day 30. The sneezing and rubbing frequencies were counted. Serum levels of IL-1β, IL-10 and OVA-specific IgE were measured. The superficial cervical lymph nodes were harvested and the percentage of Tregs in lymph node was determined using CD4 and Foxp3 markers. RESULTS: OVA treatment successfully induced AR model in mice with significantly increased sneezing and rubbing frequency, elevated levels of serum histamine, IL-1β, IL-10 and OVA-specific IgE. Bufotalin treatment significantly ameliorated AR symptoms, with reduced histamine, IgE and IL-1β levels, as well as sneezing and rubbing frequency. Moreover, bufotalin treatment decreased the serum levels of IL-1β, IL-10 and OVA-specific IgE in AR mice. CONLCUSION: Bufotalin ameliorated allergic rhinitis symptoms in AR mice by restoring Tregs in lymph node.