Is resveratrol therapeutic when used to treat allergic rhinitis in rats?

Purpose: Resveratrol has anti-infective, anti-inflammatory and antioxidant activities. The purpose of this study was to determine the effect of resveratrol in a rat experimental model of allergic rhinitis (AR). Methods: Wistar albino rats were divided into three groups: control (n=7), AR with no treatment (AR+NoTr, n=7) and AR with resveratrol treatment (AR+Res, n=7). For AR+Res, AR was induced and resveratrol given on days 21-28. On day 28, the total blood IgE levels were measured. Allergic symptoms (sneezing, nose-rubbing, eye lacrimation and nasal congestion) were scored on a 0-3 point scale, and histopathological changes in the nasal mucosa were evaluated. Results: Allergic symptom score of AR+NoTr was higher than the other two groups and the score of AR+Res was higher than the control group. Histopathologically, neither ciliary loss nor chondrocyte hypertrophy differed among the three groups; however, vascular congestion, inflammatory and plasma cell numbers, eosinophil and mast cell infiltration and goblet cell numbers were higher and mast cell infiltration was more prominent in AR+NoTr than in AR+Res and control. AR+Res and control did not differ significantly in any histological parameter. In AR+NoTr, nasal mucosa exhibited ciliary loss, squamous epithelial metaplasia, inflammatory cell infiltration, vascular congestion of the lamina propria and goblet cell epithelial metaplasia. In AR+Res, goblet cell metaplasia was focal or absent and infiltration of the lamina propria by inflammatory cells, eosinophils, and plasma cells was reduced relative to AR+NoTr. Conclusion: Allergic symptoms and tissue reactions were reduced by resveratrol treatment in rats with experimentally-induced AR