Long Lina, Zhong Wenwei, Guo Liwei, Ji Jing, Nie Hong
Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, College of Pharmacy, Jinan University, Guangzhou, China.
International Cooperative Laboratory of Traditional Chinese Medicine Modernization and Innovative Drug Development of Chinese Ministry of Education (MOE), College of Pharmacy, Jinan University, Guangzhou, China.
Front Pharmacol. 2022 Jun 13;13:910885. doi: 10.3389/fphar.2022.910885. eCollection 2022.
The treatment of neuropathic pain (NPP) is considered challenging, while the search for alternative medication is striving. NPP pathology is related with the expression of both the purinergic 2X7 (P2X7) receptor and the transient receptor potential vanilloid 1 receptor (TRPV1). Bufalin is a traditional Chinese medication derived from toad venom with pronounced antitumor, analgesic, and anti-inflammatory properties. However, poor solubility, rapid metabolism, and the knowledge gap on its pain alleviation mechanism have limited the clinical application of bufalin. Hence, the purpose of this study is to illustrate the NPP alleviation mechanism of bufalin chronic constriction injury (CCI). To address the concern on fast metabolism, bufalin-PLGA microspheres (MS) were prepared membrane emulsification to achieve prolonged pain-relieving effects. Western blot, real-time PCR, immunofluorescence, and molecular docking were employed to demonstrate the therapeutic action of bufalin on NPP. The results showed enhanced thermal withdrawal latency (TWL) and mechanical withdrawal threshold (MWT) after the administration of both bufalin and bufalin-PLGA MS in the CCI rats. Prolonged pain-relieving effects for up to 3 days with reduced dose frequency was achieved bufalin-PLGA MS. In the CCI rats treated with bufalin-PLGA MS, the expression levels of protein and mRNA in TRPV1 and P2X7, both localized in the dorsal root ganglion (DRG), were reduced. Moreover, bufalin-PLGA MS effectively reduced the levels of IL-1β, IL-18, IL-6, and TNF-α in the CCI group. The results from molecular docking suggested a possible mechanism of NPP alleviation of bufalin through binding to P2X7 receptors directly. The administration of bufalin-PLGA MS prepared by membrane emulsification demonstrated promising applications for sustained effect on the alleviation of NPP.
神经病理性疼痛（NPP）的治疗颇具挑战性，而对替代药物的探索一直在进行。NPP的病理与嘌呤能2X7（P2X7）受体和瞬时受体电位香草酸亚型1受体（TRPV1）的表达均有关联。蟾毒灵是一种源自蟾蜍毒液的传统中药，具有显著的抗肿瘤、镇痛和抗炎特性。然而，其溶解度差、代谢快以及在疼痛缓解机制方面的知识空白限制了蟾毒灵的临床应用。因此，本研究的目的是阐明蟾毒灵对慢性压迫性损伤（CCI）所致NPP的缓解机制。为了解决对快速代谢的担忧，采用膜乳化法制备了蟾毒灵-聚乳酸-羟基乙酸共聚物微球（MS）以实现延长的止痛效果。运用蛋白质免疫印迹法、实时聚合酶链反应、免疫荧光法和分子对接技术来证明蟾毒灵对NPP的治疗作用。结果显示，在CCI大鼠中给予蟾毒灵和蟾毒灵-聚乳酸-羟基乙酸共聚物微球后，热缩足潜伏期（TWL）和机械缩足阈值（MWT）均增强。蟾毒灵-聚乳酸-羟基乙酸共聚物微球以降低的给药频率实现了长达3天的延长止痛效果。在用蟾毒灵-聚乳酸-羟基乙酸共聚物微球治疗的CCI大鼠中，位于背根神经节（DRG）的TRPV1和P2X7的蛋白质和mRNA表达水平均降低。此外，蟾毒灵-聚乳酸-羟基乙酸共聚物微球有效降低了CCI组中白细胞介素-1β、白细胞介素-18、白细胞介素-6和肿瘤坏死因子-α的水平。分子对接结果提示蟾毒灵通过直接与P2X7受体结合来缓解NPP的可能机制。通过膜乳化法制备的蟾毒灵-聚乳酸-羟基乙酸共聚物微球给药显示出在缓解NPP方面持续有效的应用前景。
