Protocatechualdehyde ameliorates temporal lobe epilepsy via synergistic regulation of HMGB1-TLR4-NF-κB pathway and metabolic reprogramming

Ethnopharmacological relevance Temporal lobe epilepsy (TLE) is the most prevalent subtype of epilepsy, characterized by recurrent spontaneous seizures. Gastrodia elata Blume, a classic traditional Chinese medicinal herb, has long been clinically applied for the intervention of neurological disorders including epilepsy. However, its key bioactive components and definite pharmacological mechanisms against TLE remain poorly clarified.Aim of the study This study was designed to screen effective anticonvulsant active ingredients from G. elata Blume, and further explore the therapeutic efficacy and potential molecular mechanisms of protocatechualdehyde against TLE.Material and methods Maximal electroshock seizure (MES) and pentylenetetrazole (PTZ)-induced acute seizure models were adopted to screen six phenolic active constituents from G. elata Blume. A lithium-pilocarpine-induced chronic TLE mouse model was established to assess the in vivo antiepileptic efficacy of protocatechualdehyde. Behavioral tests were carried out to monitor seizure manifestations and cognitive alterations. Furthermore, a combined strategy integrating network pharmacology, molecular docking, proteomics, serum metabolomics, and molecular biology experiments was applied to explore the underlying pharmacological mechanisms of protocatechualdehyde against TLE.Results Protocatechualdehyde was screened out as the component with the strongest anticonvulsant activity. After 28 days of continuous intraperitoneal injection intervention, different doses of protocatechualdehyde significantly reduced seizure frequency and duration in TLE mice, ameliorated cognitive impairment, and effectively corrected hippocampal disorders in neurotransmitter and amino acid metabolism as well as cerebral energy and glucose metabolism. In addition, protocatechualdehyde inhibited the abnormal activation of microglia and astrocytes in a dose-dependent manner. Mechanically, it blocked HMGB1 nuclear export, and further inhibited the excessive activation of downstream TLR4-NF-κB inflammatory signaling pathway.Conclusions Protocatechualdehyde alleviates TLE-induced neuroinflammation and metabolic dysfunction via indirect modulation of the HMGB1-TLR4-NF-κB signaling cascade, accompanied by suppression of glial overactivation and restoration of brain metabolic homeostasis, which is expected to become a promising candidate agent for the treatment of TLE.