Article Title: Evaluating the Effect of Eugenol on the Expression of Genes Involved in the Immunomodulatoty Potency of Mouse Mesenchymal Stem Cells In Vitro XML

The immunomodulation ability of mesenchymal stem cells (MSCs) has attracted interest as a unique property that makes them interesting tools for the treatment of inflammatory and autoimmune diseases. Eugenol is a volatile compound from the phenylpropanoids class of chemical compounds. Despite extensive investigations on the biological and pharmacological properties of Eugenol, its effect on the MSCs characteristics remains to be clarified. Therefore, this study was designed to evaluate the effect of Eugenol on the expression of genes (Tlr3, Tlr4, Ccl2, and Ccl3) involved in immunomodulation potency of MSCs by quantitative real-time PCR (qRT-PCR). To do so, MSCs were isolated from 4-8 weeks old mouse bone marrow (BM). The effect of Eugenol on the viability of BM-MSCs was evaluated by MTT assay at 24, 48, and 72h after treatment. The results showed that Eugenol reduced the number of BM-MSCs in a dose- and time-dependent manner. In addition, the half maximum inhibitory concentration of Eugenol on MSCs was 400μg/ml at 24 and 48h and 200μg/ml at 72h after treatment. Moreover, about 90% of MSCs were alive at the concentration of 12.5μg/ml 24h after treatment. The qRT-PCR results indicated that Tlr3, Tlr4, Ccl2, and Ccl3 genes up-regulated 1.6-, 1.8-, 1.3-, 2.2-fold, respectively, in Eugenol-treated BM-MSCs compared to untreated controls. In conclusion, we declare that Eugenol may somewhat regulate the immunomodulation potency of MSCs and this study provides a background for further studies on the effect of Eugenol on MSCs characteristics and functions, which may finally improve their potency for cell-based therapy applications