Comparative assessment of phenolic and flavonoid contents and antioxidant activities in methanol extracts of spices from Jigjiga market, Ethiopia

Abstract

This study examined the phytochemical composition and antioxidant potential of four medicinal plants: Amomum subulatum, Lippia adoensis, Coriandrum sativum, and Ruta chalepensis. Total phenolic and flavonoid contents were determined using the Folin-Ciocalteu and aluminum chloride methods, respectively. Antioxidant activity was assessed by DPPH, ABTS, and FRAP assays. Lippia adoensis demonstrated the highest levels of both phenolics (50 ± 0.23 mg GAE/g) and flavonoids (20.5 ± 1.2 mg QE/g), followed by Ruta chalepensis. Lippia adoensis also exhibited the strongest antioxidant activity across all assays, with the lowest IC₅₀ values in DPPH and ABTS assays and the highest FRAP value. A significant correlation was found between phenolic and flavonoid content and antioxidant activity, suggesting that these compounds contribute significantly to the antioxidant properties of these plants. These findings highlight Lippia adoensis as a promising source of natural antioxidants with potential applications in various fields, including food, pharmaceutical, and cosmetic industries.