PHYTOCHEMICAL PROFILING AND ANTIOXIDANT POTENTIAL OF DIFFERENT EXTRACTS OF NIGELLA SATIVA SEEDS

Nigella sativa (black seed) is a medicinal plant renowned for its diverse phytochemical composition and therapeutic properties. This study aimed to evaluate the phytochemical profile and antioxidant potential of Nigella sativa seed extracts obtained using different solvents. Seeds were procured, authenticated, cleaned, dried, and ground into a fine powder. Extracts of Nigella sativa seeds, obtained using ethanol, methanol, acetone, n-hexane, and water via Soxhlet extraction, yielded both polar and non-polar compounds. Qualitative phytochemical screening revealed the presence of alkaloids, flavonoids, phenols, tannins, triterpenoids, proteins, steroids, carbohydrates, glycosides, quinones, and saponins, with methanol and ethanol extracts showing the highest concentrations. LC-MS analysis identified significant bioactive constituents, including thymoquinone, thymol, nigellidine, carvacrol, α-pinene, p-cymene, and α-hederin, compounds widely recognized for their antioxidant, anti-inflammatory, antimicrobial, and therapeutic potentials. Antioxidant activity was assessed using DPPH and FRAP assays, with the methanolic extract demonstrating the strongest activity (IC₅₀: 12.4±0.5 µg/mL; FRAP: 520±15 µM Fe(II) equivalents), comparable to ascorbic acid. The aqueous extract showed moderate activity, while acetone and n-hexane extracts exhibited lower antioxidant potential. These findings highlight the influence of solvent polarity on extraction efficiency, with methanol and ethanol being the most effective for extracting bioactive compounds. The results underscore the antioxidant potential of Nigella sativa seeds, supporting their traditional use in medicine and their potential application in functional foods and therapeutic formulations. Further research is recommended to explore the mechanisms of action and in-vivo efficacy of these bioactive compounds.