Investigation of Possible Immunomodulatory Effects of Resveratrol as an Add-on Therapy in a Murine Model of Ovalbumin-Induced Bronchial Asthma
Rania Hamed Shalaby *1, 2, Waleed Barakat Al Bahoty1 , Amany Abd El-Rahim Abdin1 and Mohamed Nabih Abd Al – Rahman1
Journal Title:Medical & Clinical Research
Background: Bronchial asthma is a cause of significant morbidity and mortality with increasing prevalence worldwide. Although corticosteroids are routinely used in management of bronchial asthma either for long term therapy or control of acute attacks, but unfortunately they have limitations due to their diverse side effects. Resveratrol, a natural polyphenol, exhibits a wide range of biological and pharmacological activities, such as anticarcinogenesis, cardiovascular protection, and anti-inflammatory effects. Thus it is of much interest to investigate possible immunomodulatory effects of resveratrol in bronchial asthma representing a new mechanism that has not yet been fully elucidated. Methods: This experiment was performed on 50 albino mice divided in 5 equal groups. The normal control group (group I) received a veheicle of saline. The Ova-untreated group (group II); received ovalbumin (OVA) via two I.P. injections in days 0 and 14 in a dose of 100 µg and challenged with an intranasal (I.N.) dose of 50 µg OVA in days 14, 25, 26&27. The OVA- challenged group treated by Resveratrol (group III) in a dose of 30 mg/kg given by oral gavage 1 h. before challenge in days 14, 25, 26 & 27. The OVA- challenged group treated by Dexamethasone (group IV) in a dose of 2.5 mg/kg by intraperitoneal injection (I.P) 1 h. before challenge in days 14, 25, 26&27. OVA- challenged group treated by dexamethasone and resveratrol (group V) in the same dose regimen. At the end of experiment in the 28th day (24 hours after the last challenge in the 27thday), serum was analyzed for total IgE (TIgE) levels and bronchoalveolar lavage (BAL) was investigated for inflammatory cell count. The lung tissues were examined for histopathology score and immunohistochemistry for TLR2, CD4 and CD8. Results: The untreated group of asthma model showed a significant increase in serum level of TIgE, the number of total inflammatory cells, inflammatory score and the number of positive TLR2, CD4+ and CD8+ when compared to normal group. The treatment by both of resveratrol and dexamethasone was better than treatment with resveratrol alone as it showed significant decrease in the whole studied parameters. Conclusion:We demonstrated the immunomodulatory effect of resveratrol preclinical in bronchial asthma induced model via suppression of TLR2, CD4 and CD8 expression. We could suggest using resveratrol as add- on therapy with dexamethasone to achieve more efficacies in management of bronchial asthma. However, this should be verified in further clinical studies.