Evaluation of Nutritional, Phytochemicals and Antioxidant Capacity of Telfairia Occidentalis F. and Vernonia Amygdalina Delile Leaves

Abstract

This study assessed the nutritional composition, phytochemical constituents, and antioxidant activities of Telfairia occidentalis and Vernonia amygdalina leaves. Standard analytical methods were employed to evaluate the powdered and aqueous extracts of both plants. Findings indicated that T. occidentalis exhibited higher levels of moisture (11.43%), crude fiber (9.11%), protein (8.19%), and crude lipid (3.67%) compared to V. amygdalina. No significant difference was observed in total ash content between the two species. Qualitative phytochemical analysis identified the presence of saponins, cardiac glycosides, terpenoids, triterpenoids, flavonoids, and tannins in both plants, while anthraquinones and steroids were absent. Quantitatively, V. amygdalina contained higher concentrations of phenolics (25.17 ± 1.03 mg/g), flavonoids (25.86 ± 0.09 mg/g), saponins (7.61 ± 0.07 mg/g), and alkaloids (6.42 ± 0.07 mg/g). In contrast, T. occidentalis had greater amounts of tannins (12.47 ± 0.06 mg/g) and cardiac glycosides (2.46 ± 0.03 mg/g). The antioxidant capacity, measured by DPPH radical scavenging activity, revealed that both plants possess significant antioxidant properties. V. amygdalina demonstrated a higher scavenging ability with an IC₅₀ of 10.37 ± 1.61 μg/mL, compared to T. occidentalis at 22.99 ± 0.61 μg/mL. However, both were less potent than standard ascorbic acid (0.49 ± 0.001 μg/mL). Total antioxidant capacity (TAC) analysis showed V. amygdalina had a significantly higher TAC (0.941 ± 0.001 mg/g ascorbic acid equivalent) than T. occidentalis (0.830 ± 0.002 mg/g). These results suggest that T. occidentalis and V. amygdalina leaves are valuable vegetable sources capable of meeting human nutritional needs and providing defense against oxidative stress-related diseases.