Phytochemical Characterization and Evaluation of Anti-diabetic and Anti-inflammatory Potential of Indigofera nummulariifolia (L.) Livera ex Alston

Abstract

Background: Indigofera nummulariifolia is traditionally used in managing liver ailments, inflammation, and diabetes. However, scientific validation of its bioactive potential remains limited. Aims: The aim of this study was to isolate and characterise compounds with antidiabetic, anti-inflammatory, and antioxidant potential from Indigofera nummulariifolia. Methodology: Sampling was conducted at Gombe State University in June. The Indigofera nummulariifolia sample was identified at the Department of Plant Sciences, Gombe State University. The plant material was extracted using methanol. Free-radical-scavenging antioxidant activity of the extract was determined using the 2,2′-diphenyl-1-picrylhydrazyl (DPPH) method; the anti-inflammatory activity was assessed using the bovine albumin denaturation method, and the antidiabetic potential of the plant extract was determined using an α-glucosidase inhibition assay. Column chromatography was used to purify the extract, and ¹H and ¹³C NMR spectroscopy were used to identify and characterise the isolated compounds. Results: The methanolic extract showed concentration-dependent antioxidant activity, increasing from 17.62% inhibition at 100 µg/mL to 90.02% at 500 µg/mL. Anti-inflammatory activity increased from 52% inhibition at 100 µg/mL to 91% at 500 µg/mL. The extract also showed concentration-dependent α-glucosidase inhibitory activity, with 11% inhibition at 100 µg/mL. Two compounds were isolated from the dichloromethane fraction and identified as lupeol and myristic acid on the basis of spectroscopic data. Conclusion: These in vitro findings demonstrate antioxidant, anti-inflammatory, and α-glucosidase inhibitory activities in the methanolic extract and establish lupeol and myristic acid as isolated constituents of the investigated plant material.