Green-synthesized Matricaria chamomilla silver nanoparticles enhance anticonvulsant and neuroprotective effects through GABAergic and antioxidant pathways in an acute seizure rat model

Abstract

Epilepsy is a major chronic neurological disorder with significant treatment limitations, particularly in drug-resistant cases, highlighting the need for novel and affordable neuroprotective strategies. This study investigates the anticonvulsant and neuroprotective effects of ethanolic extract of Matricaria chamomilla (German chamomile) and its green-synthesized silver nanoparticles (MC-AgNPs) in a pentylenetetrazole (PTZ)-induced rat model. The phytochemical analysis (TPC, TFC, GC-MS) showed high phenolic (18.64 mg GAE per g) and flavonoid (17.04 mg QE per g) content with apigenin and quercetin identified as major constituents. Green-synthesized MC-AgNPs exhibit significant characteristics such as an SPR peak at 420 nm and a hydrodynamic diameter of 273.9 nm, indicating their stability and potential for neuroprotective applications. The administration of crude extract or MC-AgNPs (25 or 50 mg kg⁻¹ p.o) for three days prior to PTZ induction results in substantial improvements. The high dose of MC-AgNPs notably increased seizure latency (69.33 ± 1.08 s), decreased seizure frequency (1.16 ± 0.16), and reduced seizure duration (9.5 ± 0.17 s), far exceeding the crude extract's effects (p < 0.0001). Furthermore, motor performance and memory retention were significantly enhanced, with GABA levels restored (5.1 ± 0.14 µmol g⁻¹ tissue) and oxidative stress parameters improved. The histopathological assessments revealed minimal neuronal damage. Overall, MC-AgNPs demonstrated superior efficacy compared to the crude extract, indicating that nano-formulation could enhance the therapeutic potential of plant-derived agents in epilepsy management, suggesting a cost-effective adjunct therapy deserving further research studies.