Antioxidant Activity and Alpha-glucosidase Inhibition of 70% Ethanol Extracts from Fig Leaves and Figs (Ficus racemosa L.)

Abstract

This study highlights the therapeutic potential of fig leaves and fruits (Ficus racemosa L.) in Vietnam. Phytochemical analyses identified key bioactive compounds, including polyphenols, flavonoids, tannins, triterpenoids, and reducing agents. Ripe fruits exhibited elevated levels of anthocyanosides, proanthocyanidins, and cardiac glycosides, while fig leaves contained additional polyuronic compounds. Antioxidant activity and α-glucosidase inhibition were evaluated using 70% ethanol extracts. The extracts from leaves demonstrated the strongest activity, with IC₅₀ values of 26.02 µg/mL for DPPH and 27.64 µg/mL for α-glucosidase inhibition. In contrast, ripe and unripe fruit extracts showed lower efficacy, with IC₅₀ values of 48.36 µg/mL and 102.44 µg/mL (ripe) and 51.03 µg/mL and 197.89 µg/mL (unripe), respectively. Compared with ascorbic acid (vitamin C), a strong antioxidant control, vitamin C demonstrated an IC₅₀ value of 2.63 µg/mL in the DPPH assay, which was significantly more potent than fig leaves and fruits. However, in the α-glucosidase inhibition assay, leaf extract (IC₅₀ = 27.64 µg/mL) exhibited stronger activity than acarbose (IC₅₀ = 126 µg/mL), as a positive control. These results highlight the potential of F. racemosa L. as a source for developing therapeutic products to combat oxidative stress and diabetes.