HPLC Analysis of Bioactive Constituents and in vitro Antidiabetic Potential of Ethanolic Leaf Extract of Solanum aethiopicum

Abstract

Solanum aethiopicum (African garden egg) is a tropical vegetable commonly consumed in Nigeria and other parts of Africa, traditionally used not only as food but also in folk medicine for the management of chronic ailments such as diabetes. This study aimed to investigate the phytochemical constituents, nutritional composition, mineral content, and in-vitro antidiabetic potential of the ethanolic leaf extract of S. aethiopicum. The study utilized standard analytical techniques, including High-Performance Liquid Chromatography (HPLC) for profiling phenolic and flavonoid compounds, proximate and mineral analyses for nutritional assessment, Folin–Ciocalteu and aluminium chloride assays for total phenolic and flavonoid determination, and α-amylase inhibition assay to evaluate antidiabetic potential. HPLC profiling revealed caffeic acid (614.69 mg/L) as the most abundant compound, alongside kaempferol, naringin, gallic acid, salicylic acid, tannic acid, apigenin, rutin hydrate, quercetin, and p-coumaric acid. Proximate analysis indicated high carbohydrate content (83.83%) with appreciable levels of protein (3.16%) and ash (4.23%). Mineral evaluation showed magnesium (25.02 ppm) and calcium (13.04 ppm) as the dominant elements. The extract also exhibited significant levels of total phenolics (83.04 mg/g) and flavonoids (58.11 mg/g). In-vitro studies demonstrated a concentration-dependent α-amylase inhibitory effect, with maximum inhibition of 45.56% at 1000 µg/mL, compared to 89.90% for acarbose, the standard. These findings indicate that S. aethiopicum is a valuable source of nutrients and bioactive compounds and possesses moderate antidiabetic activity, thus supporting its ethnomedicinal use and potential role in diabetes management.