Editor-in-Chief İlkay Küçükgüzel Associate Editor Aslı Türe Online ISSN 2630-6344 Publisher Marmara University Frequency Bimonthly (Six issues / year) Abbreviation J.Res.Pharm. Former Name Marmara Pharmaceutical Journal
Journal of Research in Pharmacy 2020 , Vol 24 , Issue 6
Crocin suppressed cold allodynia and anxiety through α2-adrenoceptors in the anterior cingulate cortex following chronic constriction injury of sciatic nerve in rats
Mohammad Reza ZOHREHVAND1,Reza KAZEMI1,Mohammad Hassan MIRASHEH1,Farideh BAHRAMI2,Mohammad Ali ZABIHIAN1, Gholam Hossein MEFTAHI3,Mehdi RAHIMI-Nasrabadi4,Zahra BAHARI2
1Students research committee, Baqiyatallah University of Medical Sciences, Tehran, Iran
2Department of Physiology and Medical Physics, Faculty of Medicine, Baqiyatallah University of Medical Sciences, Tehran, Iran
3Neuroscience Research Center, Baqiyatallah University of Medical Sciences, Tehran, Iran
4Faculty of Pharmacy, Baqiyatallah University of Medical Sciences, Tehran, Iran
DOI : 10.35333/jrp.2020.242 It is believed that α-adrenoceptors have critical contribution in the process of pain information. Anterior cingulate of cortex (ACC) is a key area of brain associated with pain perception. Pharmacological studies demonstrated that crocin, as a potent antioxidant, has analgesic effects. The underlying analgesic mechanism of the crocin is far from clear. Therefore, the present study was design to examine the interaction of anti-nociceptive effects of crocin with α1- and α2-adrenoceptors of ACC in chronic constriction injury (CCI) model of neuropathic pain. Intra-ACC injection of crocin significantly decreased cold allodynia (using acetone test) and anxiety (using elevated plus maze test) in neuropathic rats from 2 days to 6 days’ post-surgery. Co-injection of crocin and prazosin (α1-adrenoceptors antagonist, 30 μg/5μl) had no effect on the allodynia. However, co-injection of crocin and yohimbine (α2-adrenoceptors antagonist, 30 μg/5μl) significantly increased the allodynia on days 4 and 6 post-surgery as compared with CCI+crocin rats. Moreover, our data identified that neuropathy decreased open arm entries and locomotor activity. Additionally, crocin increased entries to open arms; but this increase was not significant as compared to CCI group. There was no significant difference between CCI+Crocin and CCI+crocin+prazosin groups. However, co-injection of crocin and yohimbine significantly decreased entries to open arms as compared with CCI+crocin group. Furthermore, co-injection of crocin with prazosin or yohimbine did not cause significant changes in locomotor activity. The present study suggested that the anti-nociceptive and anxiolytic effects of crocin appear to be mediated through α2-, and not α1-adrenoceptors in the ACC. Keywords : Neuropathic pain; anterior cingulate cortex; crocin; prazosin; yohimbine
Marmara University