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

Abstract

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. The AR mice model was established using ovalbumin (OVA). AR mice were treated with bufotalin started on Day 22 with various doses (1, 10, 100μg or 1mg 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. 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. Bufotalin ameliorated allergic rhinitis symptoms in AR mice by restoring Tregs in lymph node.