Effects of active components extracted from Dachuanxiong Decoction on the expressions of CGRP and its receptors in rats with migraine / 中成药

ABSTRACT

AIM To study the effects of active components extracted from Dachuanxiong Decoction (DCXD,Chuanxiong Rhizoma,Gastrodiae Rhizoma) on the expressions of calcitonin gene-related peptide (CGRP) and its receptors in hypothalamus and periaqueductal gray (PAG) of rats with migraine.METHODS Seventy-two rats were evenly assigned to six groups at random,normal group,model group,positive drug group,groups of highdose,middle-dose and low-dose DCXD.Each group was then divided into Subgroup A and Subgroup B.The migraine rat model was established by subcutaneous nitroglycerin injection.The expressions of CGRP in Subgroup B's rat hypothalamus and PAG were observed by immunohistochemical staining,while the levels of CGRP in rat plasma,hypothalamus and PAG in Subgroup A were detected by ELISA.All the gene expressions of CGRP and its receptors (CRLR,RCP,RAMP1) in Subgroup A's rat hypothalamus and PAG were assessed by real-time PCR.RESULTS There was a more significant CGRP level increase in plasma,hypothalamus and PAG in the model group than that in the normal group (P ＜ 0.01).The modelled rats found their up-regulated expressions of CGRP and RCP in hypothalamus (P ＜ 0.05),up-regulated expressions of CGRP and CRLR in PAG,and down-regulated expression of RCP (P ＜ 0.05).All low-dose,middle-dose,high-dose active components worked in decreasing the CGRP levels in plasma,hypothalamus and PAG.The middle-dose led to down-regulation of CGRP,RCP expressions in hypothalamus (P ＜0.05,P ＜0.01),down-regulation of CGRP,CRLR expressions in PAG (P ＜0.05),and up-regulation of RCP expression in PAG (P ＜ 0.05).CONCLUSION The mechanism of active components extracted from DCXD in migraine management may associate with its capability in down-regulating CGRP expressions in hypothalamus and PAG,reducing CGRP synthesis and inhibiting neurogenic inflammation.