Wang Chao, Sun Danni, Liu Chunfang, Zhu Chunyan, Jing Xianghong, Chen Shuping, Liu Cuiling, Zhi Kai, Xu Tengfei, Wang Hui, Liu Junling, Xu Ying, Liu Zhiqiang, Lin Na
Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, No. 16, Nanxiaojie, Dongzhimennei, Beijing, 100700, China.
Institute Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, 100700, China.
J Transl Med. 2015 Aug 30;13:284. doi: 10.1186/s12967-015-0636-4.
Processed Chuanwu (PCW), the mother root of Aconitum carmichaelii Debeauxv, has been widely used as a classic Traditional Chinese Medicine for pain relieve for over two millennia clinically. However, its action on chronic inflammatory pain has not been clarified. Here, we investigated the antinociceptive effect of PCW in complete freund's adjuvant (CFA)-induced mice and its possible mechanisms associated with opioid system and TRPV1 ion channel.
Male ICR mice were intraplantarly injected with CFA. PCW (0.34, 0.68 and 1.35 g/kg) was orally given to mice once a day for 7 days. Von frey hairs and planter test were assessed to evaluate the antinociceptive effect of PCW. To investigate the participation of dynorphin/opioid system in PCW antinociception, subtype-specific opioid receptor antagonists or anti-dynorphin A antiserum were used. To eliminate other central mechanisms that contribute to PCW antinociception, hot plate (50 °C) test were performed. Further, involvements of TRPV1 in PCW antinociception were evaluated in CFA-induced TRPV1(-/-) and TRPV1(+/+) C57BL/6 male mice, and in capsaicin-induced nociception ICR naive mice pretreated with nor-BNI. Meanwhile, calcium imaging was performed in HEK293T-TRPV1 cells. Finally, rotarod, open-field tests and body temperature measurement were carried out to assess side effects of PCW.
PCW dose-dependently attenuated mechanical and heat hypersensitivities with no tolerance, which could be partially attenuated by coadministration of k-opioid receptor antagonist nor-binaltorphimine (nor-BNI) or anti-dynorphin A (1-13) antiserum. And PCW antinociception was totally erased by pretreatment with nor-BNI in the hot plate test. In addition, PCW antinociception was decreased in TRPV1(-/-) mice compared to TRPV1(+/+) group. And PCW still manifested inhibitory effects in capsaicin-induced nociception with nor-BNI pretreatment. PCW significantly inhibited capsaicin-induced calcium influx in HEK293T-TRPV1 cells. Finally, no detectable side effects were found in naive mice treated with PCW.
This study shows PCW's potent antinociceptive effect in inflammatory conditions without obvious side effects. This effect may result from the activation of κ-opioid receptor via dynorpin release and the inhibition of TRPV1. These findings indicate that PCW might be a potential agent for the management of chronic inflammatory pain.
制川乌，即乌头的母根，作为一种经典的传统中药，在临床上用于缓解疼痛已有两千多年的历史。然而，其对慢性炎性疼痛的作用尚未阐明。在此，我们研究了制川乌在完全弗氏佐剂（CFA）诱导的小鼠中的镇痛作用及其与阿片系统和TRPV1离子通道相关的可能机制。
雄性ICR小鼠足底注射CFA。制川乌（0.34、0.68和1.35 g/kg）每天口服给药小鼠1次，共7天。采用von frey毛发试验和足底试验评估制川乌的镇痛作用。为研究强啡肽/阿片系统在制川乌镇痛中的作用，使用亚型特异性阿片受体拮抗剂或抗强啡肽A抗血清。为消除其他导致制川乌镇痛的中枢机制，进行热板（50℃）试验。此外，在CFA诱导的TRPV1（-/-）和TRPV1（+/+）C57BL/6雄性小鼠以及用去甲BNI预处理的辣椒素诱导的伤害感受的ICR未处理小鼠中评估TRPV1在制川乌镇痛中的作用。同时，在HEK293T-TRPV1细胞中进行钙成像。最后，进行转棒试验、旷场试验和体温测量以评估制川乌的副作用。
制川乌剂量依赖性地减轻机械性和热超敏反应且无耐受性，联合给予κ-阿片受体拮抗剂去甲纳曲酮（nor-BNI）或抗强啡肽A（1-13）抗血清可部分减弱其作用。在热板试验中，用nor-BNI预处理可完全消除制川乌的镇痛作用。此外，与TRPV1（+/+）组相比，TRPV1（-/-）小鼠中制川乌的镇痛作用降低。在用nor-BNI预处理的情况下，制川乌在辣椒素诱导的伤害感受中仍表现出抑制作用。制川乌显著抑制辣椒素诱导的HEK293T-TRPV1细胞中的钙内流。最后，在用制川乌处理的未处理小鼠中未发现可检测到的副作用。
本研究表明制川乌在炎性条件下具有强大的镇痛作用且无明显副作用。这种作用可能是由于通过强啡肽释放激活κ-阿片受体以及抑制TRPV1所致。这些发现表明制川乌可能是一种治疗慢性炎性疼痛的潜在药物。
