TY - JOUR ID - 4547 TI - Effects of intra-fourth ventricle injection of crocin on capsaicin-induced orofacial pain in rats JO - Avicenna Journal of Phytomedicine JA - AJP LA - en SN - 2228-7930 AU - Tamaddonfard, Esmaeal AU - Tamaddonfard, Sina AU - Pourbaba, Salar AD - Division of Physiology, Department of Basic Sciences, Faculty of Veterinary Medicine, Urmia University, Urmia, I.R. Iran AD - Faculty of Veterinary Medicine, Urmia Azad University, Urmia, I.R. Iran Y1 - 2015 PY - 2015 VL - 5 IS - 5 SP - 450 EP - 457 KW - Crocin KW - Morphine KW - Naloxone KW - Orofacial pain KW - Rats DO - 10.22038/ajp.2015.4547 N2 - Objectives: Crocin, a constituent of saffron and yellow gardenia, possesses anti-nociceptive effects. In the present study, we investigated the effects of intra-fourth ventricle injection of crocin in a rat model of orofacial pain. The contribution of opioid system was assessed using intra-fourth ventricle injection of naloxone, an opioid receptor antagonist. Materials and Methods: A guide cannula was implanted into the fourth ventricle of brain in anesthetized rats. Orofacial pain was induced by subcutaneous (s.c.) injection of capsaicin (1.5 µg/20 µl) into the right vibrissa pad. The time spent face rubbing/grooming was recorded for a period of 20 min. Locomotor activity was measured using an open-field test. Results: Intra-fourth ventricle injection of crocin (10 and 40 µg/rat) and morphine (10 and 40 µg/rat) and their co-administration (2.5 and 10 µg/rat of each) suppressed capsaicin-induced orofacial pain. The analgesic effect induced by 10 µg/rat of morphine, but not crocin (10 µg/rat), was prevented by 20 µg/rat of naloxone pretreatment. The above-mentioned chemical compounds did not affect locomotor activity. Conclusion: The results of this study showed that the injection of crocin into the cerebral fourth ventricle attenuates capsaicin-induced orofacial pain in rats. The anti-nociceptive effect of crocin was not attributed to the central opioid receptors. UR - https://ajp.mums.ac.ir/article_4547.html L1 - https://ajp.mums.ac.ir/article_4547_7331a79e51fccf9e1d54be72802c8754.pdf ER -