Background: Several biological and medical benefits of Saffron, Crocus sativus
(Iridaceae), have been demonstrated. However, mechanisms of actions for purified
constituents are greatly unknown. Objective: To examine the effects of Safranal, a main
constituent of Saffron stigma, on cell viability and cytokine profile of peripheral blood
mononuclear cells (PBMC) were examined. Methods: Effects of Safranal at 0.1, 0.5
and 1 mM concentrations were evaluated on cell viability and production of interleukin
4 (IL-4), IL-10 and interferon-γ (IFN-γ) from non-stimulated and phytohemagglutinin
(PHA) stimulated PBMCs, compared to 0.1 mM dexamethasone and saline. Results: In
stimulated cells, different concentrations of Safranal caused significant decrease of
lymphocytes viability (p<0.001 for all concentrations). All concentrations of Safranal
inhibited IFN-γ and IL-10 secretion in stimulated cells (p<0.01). In addition, high
concentration of Safranal significantly decreased cell viability of non-stimulated
PBMCs (p<0.001). The effect of 1 mM Safranal on IL-4 secretion was less than
dexamethasone (p<0.05). Safranal showed a stimulatory effect on IFN-γ secretion in
non-stimulated cells. The IFN-γ/IL-4 ratio at the presence of two higher Safranal
concentrations both in non-stimulated and stimulated cells were significantly higher
than those of control and PHA stimulated groups, respectively (p<0.05). Conclusion:
The IFN-γ/IL-4 ratio increases in the presence of Safranal which indicates an effect on
Th1/Th2 balance. Therefore, Safranal may have therapeutic effects in inflammatory
diseases associated with Th1/Th2 imbalance.