Chemical fingerprinting of Peganum harmala seeds via UV–Vis, XRD, TGA, FTIR, and GC-MS techniques; In vitro assessment of cytotoxic properties

Peganum harmala L., a perennial herb traditionally valued for medicinal and ritual uses, was comprehensively profiled to elucidate its chemical composition and cytotoxic potential. Methanolic seed extracts contained diverse primary and secondary metabolites, including alkaloids, flavonoids, saponins, glycosides, steroids, proteins, and carbohydrates. Proximate analysis revealed high moisture (45.88 %) and crude fibre (18.39 %) with moderate fat (14.74 %) and protein (7.67 %) levels. Spectroscopic studies supported the presence of β-carboline alkaloids: FTIR spectra showed characteristic functional group vibrations, UV–Vis displayed a strong absorption at 440 nm, and X-ray diffraction revealed semi-crystalline patterns enriched in harmine and harmaline. GC–MS provided definitive chemical identification, detecting harmine (53.13 %) and harmaline (39.12 %) as major constituents. Thermal analyses (TGA–DTA and DTG) indicated multiphase decomposition typical of complex organic matrices. Cytotoxicity assessment using the MTT assay on L929 fibroblast cells demonstrated a dose-dependent decline in cell viability, with an LC₅₀ of 243.9 μg/mL, signifying moderate–high cytotoxic potential. These findings validate the ethnomedicinal significance of P. harmala and underscore its promise for phytomedicine, nutraceutical applications, and pharmaceutical research, while highlighting the necessity of standardized and regulated use to ensure efficacy and safety.