Optimization and Metabolomic Profiling of Justicia spicigera Extracts: Response Surface Methodology for Solvent and Extraction Technique Evaluation.

Muicle (Justicia spicigera) is a traditional Mexican medicinal plant rich in phenolic compounds and pigments, yet its extraction conditions have not been systematically optimized. Using a 3² factorial response surface methodology (RSM) design, solvent type (water, ethanol, hexane) and extraction technique (stirring, decoction, sonication) were evaluated in leaves and flowers. Total phenolic content ranged from 2.77 to 97.39 mg GAE/100 g in leaves and reached up to 139.82 mg GAE/100 g in flowers, while ABTS antioxidant capacity was remarkably high in both tissues. RSM models (R² ≥ 0.70) identified water decoction as optimal for leaves and water decoction sonication for flowers, maximizing phenolic recovery and natural coloration. Metabolomic profiling putatively identified 27 metabolites including chalcones, flavonoids, stilbenes, secoiridoids, and omega phospholipids supporting the observed bioactivity. These results provide validated extraction protocols and a metabolomic baseline for muicle based functional foods, natural colorants, and nutraceuticals.