Evaluation of the Effect of the 47 kDa Protein Isolated from Aged Garlic Extract on Dendritic Cells

Objective(s)  Garlic (Allium sativum) is known as a potent spice and a medicine with broad therapeutic properties ranging from antibacterial to anticancer, and anticoagulant. One of the major purified garlic protein components is the 47 kDa protein. In this study, the effect of 47 kDa protein extracted from aged garlic (AGE) was evaluated on mouse dendritic cell (DC) maturation in vitro. Materials and Methods Forty seven kDa protein was purified from AGE by ammonium sulfate precipitation and gel filtration. SDS-PAGE was used to determine the molecular weight and purity of the isolated protein. DCs were purified from spleen of BALB/c mice by Nycodenz centrifugation and their adhesiveness to the plastic dish. The 47 kDa protein isolated from AGE was added to DCs medium during the overnight culture and the expression of DC surface markers was assessed via flowcytometry. Results The 47 kDa protein-treated DCs lowered the expression of DC maturation markers including: CD40, CD86 and MHC-II in comparison with non-treated DCs; (median of 41% versus 47%, 84% versus 91% and 83% versus 90%, respectively) but we observed no statistical difference between the two groups. Conclusion Upon treatment with DCs with 47 kDa protein, DCs down regulated the expression of costimulatory and MHC-II surface molecules, which is similar to tolerogenic DC phenotype. According to the results of the present study, we found that 47 kDa protein purified from AGE can be considered as a potential candidate to generate tolerogenic DCs in vitro.