Introduction: Pervious studies indicated that the mesenchymal stem cells (MSCs) produce adenosine and express adenosine receptors. Moreover, produced adenosine has biological effect on these cells. On the other hand, MSCs have a wide relationship with macrophages in tissues and bone marrow. The aim of the present study was to determine the effects of the MSCs treated with caffeine, as an adenosine antagonist, on the peritoneal macrophages isolated from rats.
 
Materials & methods: After isolation of mesenchymal stem cells from bone marrow of rats, these cells pulsed with different concentration of caffeine (0, 0.1, 0.5 and 1 mM) for 48h. Then, MSCs were co-cultured with macrophages for 1 day. Then, the level of nitric oxide production and respiratory burst of macrophages after challenge with N-formylmethionine-leucyl-phenylalanine (f-MLP) or opsonized yeast were evaluated.
Findings: It seems that MSCs pulsed with caffeine or without it could significantly decrease the respiratory burst and nitric oxide production of co-cultured macrophages more prominent than macrophages alone after unspecific challenged with fMLP. Although, pervious treatment of MSCs with caffeine could decrease the respiratory burst and nitric oxide production of macrophages challenged with f-MLP more prominent than MSCs without treatment. However, the potential of nitric oxide production and respiratory burst of various group after challenge with opsonized yeast didn’t show any significant differences.
 
Discussion & conclusions: Collectively, these data may offer new insight into the potential mechanisms underlying the immunomodulatory and anti-inflammatory effects of caffeine.