Phytochemical Characterization and Antioxidant Potential of Peganum harmala L. Seeds: A Natural Source of Bioactive Compounds.

This study investigated the antioxidant potential and biochemical composition of Peganum harmala (üzerlik) using ethanol (ETOH) and water (AQUA) as extraction solvents. Antioxidant capacity was assessed via ABTS, DPPH, and FRAP assays, alongside total protein quantification and chromatographic analysis of phenolic compounds. The ethanol extract demonstrated markedly higher ABTS (782 μM TE/gDW) and DPPH (150 μM TE/gDW) activities compared to the aqueous extract (160.25 and 60.94 μM TE/gDW, respectively), indicating ethanol’s greater efficiency in extracting lipophilic antioxidants. Conversely, FRAP activity was higher in the aqueous extract (684.69 μM TE/gDW) than in ethanol (520.69 μM TE/gDW), suggesting better recovery of hydrophilic antioxidants. Protein content was also higher in ethanol extracts (54.41 µg/gDW) than in aqueous (39.37 µg/gDW). Phenolic profiling revealed that aqueous extracts were richer in 3-hydroxybenzoic, 4-hydroxybenzoic, ferulic, and p-coumaric acids, while ethanol extracts contained gallic and chlorogenic acids absent in aqueous samples. Flavonoids such as hesperidin and hyperoside were detected only in the aqueous extract. Overall, ethanol favored the extraction of proteins, lipophilic antioxidants, and certain phenolic acids, while water was more effective for hydrophilic phenolics and some flavonoids. These findings underscore the solvent-dependent selectivity in bioactive compound recovery from P. harmala, providing a comprehensive insight into its functional potential.