<i>In vitro</i> anti-diabetic potential of medicinal herbs commonly used in the Ayurvedic system of Sri Lanka with comprehensive metabolite profiling of <i>Phyllanthus emblica</i> using GC-MS and LC-HRMS

This study assessed the <i>in vitro</i> anti-diabetic potential and bioactive constituents of ten Sri Lankan medicinal herbs. Initial screening of aqueous extracts for starch-digesting enzyme inhibition prioritised three plants with notable activity (<i>p</i> ≤ 0.05), for further assessment using methanolic extracts: <i>Phyllanthus emblica</i> (PE), <i>Cassia auriculata</i> (CA), and <i>Hemidesmus indicus</i> (HI). The selected plants were tested for starch-digesting enzyme inhibition, cytotoxicity, and bioactive metabolite identification, with PE subjected to GC-MS and LC-HRMS analyses. All three extracts contained alkaloids, flavonoids, tannins, and terpenoids, except saponins and steroids in PE. GC-MS analysis of PE annotated ten compounds, eight with anti-diabetic properties, while LC-HRMS annotated thirty metabolites, including fourteen anti-diabetic compounds. Cell viability assessments confirmed the non-toxic nature of PE, CA, and HI. The significant enzyme inhibition and non-toxic nature of PE highlight its potential to treat type 2 diabetes. Further <i>in vivo</i> and clinical studies are essential to determining effective dosage and toxicity levels.