The effect of safranal, a constituent of Crocus sativus (saffron), on tracheal responsiveness, serum levels of cytokines, total NO and nitrite in sensitized guinea pigs.

Background: The effect of safranal (one of the constituents of Crocus sativus) on ovalbumin (OVA) sensitized guinea pigs was examined.

Methods: One group of sensitized guinea pigs were given drinking water alone (group S), three groups drinking water containing three concentrations of safranal and one group contain dexamethasone (S + D). Tracheal responses (TR) of the animals to methacholine as effective concentration causing 50% of maximum response (EC(50) M), TR to 0.1% OVA, relative to contraction induced by 100 μM methacholine, IL-4, IFN-γ, total NO and nitrite levels in serum were measured.

Results: The TR to both methacholine and OVA, the level of total NO, nitrite and IL-4 significantly increased but IFN-γ and IFN-γ/IL-4 ratio was decreased in group S compared controls (p < 0.05 to p < 0.001). The TR to both methacholine and OVA in treated animals with dexamethasone and all concentrations of safranal were significantly decreased compared to S group (p < 0.01 to p < 0.001). The level of serum IL-4 in treated guinea pigs was significantly decreased but IFN-γ and IFN-γ/IL-4 ratio was increased compared to S group (p < 0.01 to p < 0.001). The levels of total NO and nitrite were significantly decreased in treated groups compared to sensitized group (p < 0.05 to p < 0.001).

Conclusions: These results showed a preventive effect for safranal on tracheal responses and serum cytokine, total NO and nitrite levels as well as increased Th1/Th2 balance in sensitized guinea pigs.