Determination of Total Flavonoid Content and Phenolic Content, Antioxidant Assay, and Antiepileptic Activity of <i>Achillea millefolium</i> Extract

Objectives This study aimed to evaluate the antioxidant and antiepileptic potential of the ethanolic extract of Achillea millefolium aerial parts. Antioxidant activity was measured using DPPH photometric assay, and flavonoid content was quantified via the aluminum chloride method. The extract's neuroprotective effect was assessed using the pentylenetetrazole (PTZ)-induced seizure model, along with immunohistochemical (IHC) analysis and hematoxylin &amp; eosin (H&amp;E) staining. Methods The antioxidant potential of the extract was determined through DPPH radical scavenging activity, while flavonoid content was assessed as quercetin equivalents (QE). The in vivo antiepileptic activity was evaluated in mice using the PTZ-induced seizure model. Key biomarkers of oxidative stress, including glutathione (GSH), glutathione-S-transferase (GST), catalase, and lipid peroxidation (LPO), were measured to evaluate the extract's ability to ameliorate PTZ-induced oxidative stress. Results The extract demonstrated notable antioxidant activity, with 72% scavenging activity observed at 900 µg/mL. Flavonoid content was determined to be 39.45 ± 1.84 µg QE/mg. In the PTZ-induced seizure model, Achillea millefolium extract at 400 mg/kg and 600 mg/kg significantly reduced neuroinflammatory markers and oxidative stress, as evidenced by decreased LPO and increased levels of GSH, GST, and catalase. IHC and H&amp;E staining revealed neuroprotective effects, including reduced neuroinflammation and enhanced neuronal survival. Conclusion The ethanolic extract of Achillea millefolium exhibited strong antioxidant and neuroprotective properties, effectively mitigating PTZ-induced seizures, oxidative stress, and inflammatory responses. These findings suggest its potential as a natural alternative for epilepsy treatment.