Phytochemical Study and Evaluation of Toxicity and Antioxidant Properties of Allium ascalonicum Leaf Extracts on Cell Line HepG2

Abstract

Allium ascalonicum, a leafy vegetable belonging to the Liliaceae family, is widely cultivated and consumed in several West African countries, including Ghana, Benin, and Nigeria. The leaves of this plant are utilized both as a fresh salad ingredient and as a cooked component in sauces. In addition to its culinary uses, Allium ascalonicum is traditionally consumed in concoctions for managing various health conditions, including diabetes and hypertension. While numerous global studies have explored the medicinal properties of this plant, there is a notable lack of research specifically addressing its therapeutic potential within Nigeria. This study investigates the phytochemical composition, antioxidant activities, and cytotoxic properties of Allium ascalonicum leaf extracts, with a focus on methanol and aqueous preparations. Phytochemical analysis identified key bioactive constituents such as phenolics, flavonoids, alkaloids, and tannins, with the methanol extract demonstrating higher concentrations of phenolics (82.4 mg GAE/g) and flavonoids (54.7 mg QE/g) compared to the aqueous extract. Antioxidant efficacy was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) assay, and total antioxidant capacity (TAC) assays, wherein the methanol extract exhibited superior performance. The methanol extract showed a lower 2,2-diphenyl-1-picrylhydrazyl (DPPH) IC₅₀ value (42.8 µg/mL) and a higher FRAP value (310.5 µM ascorbic acid equivalents), indicating robust free radical scavenging and reducing capabilities. Cytotoxicity was assessed against HepG2 liver cancer cells, revealing an IC₅₀ of 72.4 µg/mL for the methanol extract, indicative of significant anticancer potential. Conversely, the aqueous extract demonstrated comparatively lower cytotoxicity, with an IC₅₀ value of 145.6 µg/mL. These findings underscore the potential of Allium ascalonicum leaf extracts, particularly the methanol preparation, as a promising natural source of antioxidants and anticancer agents. Further research is warranted to elucidate the molecular mechanisms underpinning these bioactivities and to evaluate the plant’s potential applications in pharmaceutical and therapeutic contexts.