The impact of Zataria multiflora Boiss extract on in vitro and in vivo Th1/Th2 cytokine (IFN-γ/IL4) balance

Ethnopharmacological relevance: Anti-inflammatory, anti-oxidant and effect of Zataria multiflora on Th-1/Th-2 balance were previously described. Different therapeutic effects of this plant have been described in Iranian traditional medicine. To evaluate the immune modulatory effects of Zataria multiflora on Th1/Th2 balance, which may be implicated in inflammatory disorders, in vitro and in vivo studies were carried out. Materials and methods: The effects of three concentrations of the extract, dexamethasone, and saline on interleukin 4 (IL-4) and interferon gamma (IFN-gamma) gene expression were evaluated in phytohemagglutinin (PHA) stimulated and non-stimulated human peripheral blood mononuclear cells (hPBMCs). RNA was extracted from the hPBMCs to make cDNA for real time PCR relative quantification. Furthermore, the effect of the extract on serum level of IL-4 and IFN-gamma was assessed in ovalbumin (OA) sensitized guinea pigs (n=6 for each group). Results: Dexamethasone showed significant inhibitory effect on both IFN-gamma and IL-4 gene expression and serum level of the cytokines and significantly enhanced IFN-gamma/IL-4 ratio (p < 0.05-p < 0.001). The extract inhibited IL-4 and enhance IFN-y gene expression and IFN-gamma/IL-4 ratio too (p < 0.05-p < 0.001). In sensitized animals also serum level of IL-4 were significantly decreased after treatment with both dexamethasone and extract, but serum level of IFN-gamma and IFN-gamma/IL-4 ratio were significantly increased due to extract treatment (p < 0.01 for medium and p < 0.001 for high concentration). Conclusions: These results indicated consistent in vitro and in vivo data for selective immune modulatory effect of the extract of Zataria multiflora which increased IFN-gamma, decreased IL-4, and enhanced the ratio of IFN-gamma to IL-4 (Th-1/Th-2 balance). Therefore, the extract of Zataria multiflora may have therapeutic value in inflammatory responses such as allergy, autoimmunity and infectious diseases associated with Th-1/Th-2 imbalance. (C) 2013 Elsevier Ireland Ltd. All rights reserved.