Mina Taati - Division of Physiology, Department of Basic Sciences, Faculty of Veterinary Medicine, Urmia University, Urmia ۵۷۱۵۳-۱۱۷۷, Iran
Amir Erfanparast - Division of Physiology, Department of Basic Sciences, Faculty of Veterinary Medicine, Urmia University, Urmia ۵۷۱۵۳-۱۱۷۷, Iran
Esmaeal Tamaddonfard - Division of Physiology, Department of Basic Sciences, Faculty of Veterinary Medicine, Urmia University, Urmia ۵۷۱۵۳-۱۱۷۷, Iran
Hamid Ghasemi - Division of Physiology, Department of Basic Sciences, Faculty of Veterinary Medicine, Urmia University, Urmia ۵۷۱۵۳-۱۱۷۷, Iran

Objective: Crocin and safranal, as the major constituents of saffron, have many biological activities. This study investigated the effects of crocin and safranal on yawning response induced by intracerebroventricular (i.c.v.) injection of histamine in rats. Materials and Methods: In ketamine/xylazine-anesthetized rats, a guide cannula was implanted in the right ventricle of the brain and yawning induced by i.c.v. injection of histamine. Crocin and safranal were intraperitoneally (i.p.) injected alone and before i.c.v. injection of histamine. Results: Histamine at the doses of 10 and 20 µg/rat produced yawning. Mepyramine (a histamine H1 receptor antagonist) 40 µg/rat significantly (p<0.05) prevented histamine (20 µg/rat)-induced yawning.  Crocin (30 mg/kg) and safranal (1 mg/kg) significantly (p<0.05) increased histamine (10 µg/rat)-induced yawning. Crocin and safranal also induced yawning when injected before mepyramine plus histamine administration.    Conclusion: The results of the present study showed a yawning-inducing effect for central histamine, which was inhibited by mepyramine. Crocin and safranal increased histamine-induced yawning, and also produced yawning when the histamine action is blocked.

Crocin, Histamine, Safranal, Yawning