Microwave-assisted extraction optimization and bioactivity assessment of flavonoid-rich extract from Lantana camara L. leaves in zebrafish epilepsy model

Background: Lantana camara L. (Verbanaceae) is known for its bioactive compounds and has been reported for its potential therapeutic applications. Flavonoids from natural sources are acknowledged for their antioxidant and neuroprotective properties, suggesting a possible role in seizure management.Objectives: This study intended to optimize the microwaveassisted extraction (MAE) of flavonoid-rich extract from L. camara L. leaves utilizing a designof- experiment approach and evaluate its antiepileptic property using the zebrafish model. Materials and Methods: Four solvents (ethyl acetate, acetone, ethanol, and water) were initially used, with ethanol yielding the highest total flavonoid content (TFC). A central composite design was employed to optimize MAE parameters, including temperature, extraction time, microwave power, and solvent-to-leaf ratio. The optimized extract was evaluated for its antioxidant property using 2,2-diphenyl-1-picrylhydrazyl and reducing power assays. Moreover, the antiepileptic activity was evaluated in zebrafish exposed to pentylenetetrazole-induced seizures, with pre-treatment using the optimized extract at various concentrations compared to diazepam, the standard drug. Results: Optimal extraction conditions were determined to be 60°C, 1 min, 50 W power, and a 1:20 solvent-leaf ratio, achieving a TFC of 240.66 ± 2.25 mg QE/g with minimal deviation among predicted and experimental values. The extract demonstrated concentration-dependent antioxidant activity in the evaluated assay models. Acute toxicity study in zebrafish revealed no signs of toxicity or mortality throughout the 96-h exposure duration. The extract exhibited a moderate reduction in seizure scores, an increase in seizure latency, besides improving the locomotor behavior. The observed protective effect might be attributed to the TFC and the potential antioxidant property of the optimized extract.Conclusion: The optimized ethanol extract of L. camara L. leaves exhibits strong in vitro antioxidant properties and moderate antiepileptic effects in zebrafish. These findings support its potential as a natural therapeutic alternative for seizure management.