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

Objective: Astilbe chinensis, is a traditional Chinese medicine commonly employed for pain management. However, its primary active ingredient remains a subject of debate.

Methods: 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.

Results: 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 E_max 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).

Conclusions: In summary, this study provides evidence that astilbin alleviates pain by modulating neuronal metabolic processes and synaptic homeostasis.