Comparison of the effects of crocin, safranal and diclofenac on local inflammation and inflammatory pain responses induced by carrageenan in rats.

BACKGROUND Crocin and safranal are the active substances of saffron and have many biological properties. In the present study, we compared the effects of crocin, safranal and diclofenac on local inflammation and its induced pain in rats. METHODS Local inflammation was induced by intraplantar (ipl) injection of carrageenan (100 μl, 2%). Paw thickness was measured before and after carrageenan injection. Inflammatory pain responses including cold allodynia, mechanical allodynia and hyperalgesia were assessed using acetone spray and von Frey filament tests, respectively. The number of neutrophils in inflammatory zone was counted 6.5 h after injection of carrageenan. RESULTS Carrageenan produced edema, cold allodynia, mechanical allodynia and hyperalgesia and caused neutrophil infiltration in paw tissues. Crocin at doses of 25, 50 and 100 mg/kg, safranal at doses of 0.5, 1 and 2 mg/kg and diclofenac (as a reference drug) at a dose of 10 mg/kg attenuated edema, suppressed inflammatory pain responses and decreased the number of neutrophils. CONCLUSION The present study showed anti-inflammatory and antinociceptive activities for crocin, safranal and diclofenac in carrageenan model of local inflammation and inflammatory pain.