Indonesian medicinal plants as potential candidates for alpha-glucosidase inhibitor : A comprehensive literature review for anti-diabetic therapy

Diabetes mellitus is a chronic metabolic disorder characterized by elevated blood glucose levels due to impaired insulin activity. One therapeutic strategy to manage postprandial hyperglycemia is the inhibition of the ?-glucosidase enzyme, which plays a key role in carbohydrate digestion. This literature review aimed to identify Indonesian medicinal plants with potential ?-glucosidase inhibitory activity based on in vitro studies. Articles were systematically retrieved from Google Scholar using specific keywords, covering publications from the last ten years (2014–2024) in English or Indonesian and accessible in full text. Inclusion criteria focused on studies evaluating in vitro ?-glucosidase inhibition from Indonesian plant extracts; non-Indonesian or non-in vitro studies were excluded. Of the 200 screened articles, 34 met the criteria. Most studies employed spectrophotometric colorimetric assays using p-nitrophenyl-?-D-glucopyranoside (pNPG) as the substrate to assess inhibitory activity. In total, 40 plant species were identified as having ?-glucosidase inhibitory potential, with active compounds primarily including flavonoids, polyphenols, alkaloids, saponins, and tannins. The most commonly observed mechanism was competitive inhibition, wherein active compounds, especially flavonoids, blocked carbohydrate hydrolysis and reduced glucose absorption. Some studies also reported mixed and non-competitive inhibition through allosteric binding or conformational changes in the enzyme. This review supports the potential of various Indonesian medicinal plants as sources of natural ?-glucosidase inhibitors, highlighting their relevance for the development of safer, plant-based antidiabetic therapies.