Astilbin exerts anti-hypersensitivity by regulating metabolic demand and neuronal activity in rodent model of neuropathic pain

Astilbe chinensis, is a traditional Chinese medicine commonly employed for pain management. However, its primary active ingredient remains a subject of debate. Spinal nerve ligation (SNL) and formalin-induced pain models were employed. Network pharmacology and bioinformatics were utilized to identify targets. Verification was performed through spinal cord double immunofluorescence staining, quantitative PCR and whole-cell recording techniques. In experiments conducted on neuropathic rats, both systemic and intrathecal administration of astilbin, an essential constituent, exhibited a noteworthy and dose-dependently decrease in chronic and acute pain behaviours. The ED50 value, which represents the dose at which 50% effectiveness is achieved, was measure at 7.59 μg, while the Emax value, indicating the maximum attainable effect, was found to be 60% of the maximal possible effect (% MPE). Forty-two shared targets were identified, enriching the metabolic and synaptic pathways in the network pharmacology analysis, as confirmed by transcriptomic analysis. Weighted gene co-expression network analysis (WGCNA) revealed a strong correlation between the anti-nociceptive effects of astilbin and neuronal metabolic processes. Spinal functional ultrasound (FUS) analysis indicated increased spinal blood flow intensity and changes in metabolism-related enzyme activity, including stearoyl-CoA desaturase (Scd), 17beta-hydroxysteroid dehydrogenase (Hsd17b7) and sterol 14alpha-demethylase (Cyp51) in neuropathic rats, pretreatment with astilbin decreased formalin-induced blood flow in acute pain. Bath application of astilbin dose-dependently inhibited neuronal activity by reducing the frequency and amplitude of miniature excitatory postsynaptic currents (mEPSCs) without affecting miniature inhibitory postsynaptic currents (mIPSCs). In summary, this study provides evidence that astilbin alleviates pain by modulating neuronal metabolic processes and synaptic homeostasis.落新妇（Astilbe chinensis）是一种常用于镇痛治疗的传统中药，但其核心活性成分仍存在争议。本研究采用脊髓神经结扎（spinal nerve ligation, SNL）及福尔马林致痛模型，借助网络药理学与生物信息学手段筛选潜在靶点，并通过脊髓双免疫荧光染色、定量PCR及全细胞膜片钳记录技术进行验证。在神经病理性疼痛大鼠模型实验中，落新妇苷（astilbin）——该中药的关键活性组分——经全身给药与鞘内给药后，均可显著且呈剂量依赖性地抑制慢性与急性疼痛行为反应。其半数有效剂量（ED50）测得为7.59 μg，最大效应值（Emax）可达最大可能效应的60%（% MPE）。研究共筛选得到42个共有靶点，网络药理学分析显示这些靶点显著富集于代谢与突触通路，该结果经转录组学分析得以验证。加权基因共表达网络分析（WGCNA, Weighted gene co-expression network analysis）结果表明，落新妇苷的抗伤害感受作用与神经元代谢过程密切相关。脊髓功能超声（FUS, functional ultrasound）分析显示，神经病理性疼痛大鼠的脊髓血流强度升高，且硬脂酰辅酶A去饱和酶（Scd, stearoyl-CoA desaturase）、17β-羟类固醇脱氢酶（Hsd17b7, 17beta-hydroxysteroid dehydrogenase）及固醇14α-去甲基化酶（Cyp51, sterol 14alpha-demethylase）等代谢相关酶的活性发生改变；预先给予落新妇苷可降低福尔马林诱导的急性疼痛模型中的脊髓血流升高。体外实验证实，落新妇苷可通过降低微小兴奋性突触后电流（mEPSCs, miniature excitatory postsynaptic currents）的频率与振幅，呈剂量依赖性地抑制神经元活动，而对微小抑制性突触后电流（mIPSCs, miniature inhibitory postsynaptic currents）无显著影响。综上，本研究证实落新妇苷可通过调控神经元代谢过程与突触稳态发挥镇痛作用。