Panax notoginseng Flower Extract Attenuates Pentylenetetrazole-Induced Epilepsy by Restoring Glutamate Homeostasis

Objectives: One-third of patients experience inadequate seizure control with antiseizure medications. Therefore, safer and more effective therapeutic strategies remain urgently needed. Research evidence indicates that Panax notoginseng flower may exhibit potential antiepileptic properties. The study aimed to investigate the neuroprotective and antiepileptic effects of Panax notoginseng flower (PNF) extract in a chronic pentylenetetrazole (PTZ)-kindled mouse model and explore its potential mechanisms, focusing on glutamate homeostasis. Methods: Chronic epilepsy was induced in ICR mice via repeated subconvulsive PTZ intraperitoneal injections. Following successful kindling, mice were orally treated with PNF (1.5 g/kg or 3 g/kg) for 30 days. Seizure behaviors were scored using Racines scale. Neuronal survival, systemic and cerebral cytokines, hippocampal glutamate levels (in vivo microdialysis with LC-MS/MS analysis), glutamate homeostasis related proteins glutamate transporter-2 (GLT-1), glutamate-aspartate transporter-1 (GLAST), and glutamine synthetase (GS) were investigated. Results: PNF treatment significantly reduced seizure severity and restored neuronal nuclei (NeuN+) cell neurons in the cortex and hippocampal CA1 region of PTZ kindled mice. PNF attenuated systemic and neuroinflammation by lowering interleukin-1ß (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-a (TNF-α) levels and increasing interleukin-10 (IL-10) in serum and brain of PTZ mice. PNF reduced hippocampal glutamate accumulation and upregulated GLT-1, GLAST, and GS expression, which were altered by PTZ stimulation. Conclusions: The PNF extract exhibits significant neuroprotective and antiepileptic effects in PTZ-kindled mice, likely through restoring glutamate homeostasis, and suppressing inflammation. These findings, with further clinical development, support the therapeutic potential of PNF as a complementary approach for epilepsy management.