Antidiabetic Potential of Arcangelisia flava Merr. from Southeast Sulawesi: In vitro a-Glucosidase Inhibition and in vivo Evaluation.

<b>Background and Objective:</b> The stem of <i>Arcangelisia flava</i> Merr., a medicinal plant from Southeast Sulawesi, has shown potential as a natural source of antidiabetic agents, but its activity requires further validation through <i>in vitro</i> and <i>in vivo</i> approaches. This study aimed to evaluate the antidiabetic activity of the stem extract and fractions of <i>A. flava</i> using <i>in vitro</i> and <i>in vivo</i> approaches. <b>Materials and Methods:</b> The <i>in vitro</i> assay was performed using a colorimetric α-glucosidase inhibition method with p-nitrophenyl-D-glucopyranoside (pNPG) as the substrate. The <i>in vivo</i> study was conducted using streptozotocin/nicotinamide-induced diabetic mice divided into 15 groups (n = 4), including normal control, negative control, positive control, ethanol extract groups, n-hexane fraction groups, ethyl acetate fraction groups and butanol fraction groups. The extract was administered at doses of 250, 500 and 750 mg/kg bw, while each fraction was administered at doses of 28, 56 and 112 mg/kg bw. Data was analyzed using two-way repeated measures ANOVA. Result: The extract and fractions of <i>A. flava</i> stem exhibited α-glucosidase inhibitory activity and reduced fasting blood glucose levels in diabetic mice. Among the samples, the ethyl acetate fraction showed the strongest <i>in vitro</i> activity, with an IC<sub>50</sub> value of 95.35 μg/mL. <i>In vivo</i> evaluation also showed that the ethyl acetate fraction at 112 mg/kg bw produced the highest reduction in fasting blood glucose levels. The effects of the ethanol extract and ethyl acetate fractions at 56 and 112 mg/kg bw were comparable statistically (p>0.05) to glibenclamide. <b>Conclusion:</b> These findings suggest that Southeast Sulawesi yellow wood has promising antidiabetic potential and warrants further investigation for active compound identification and mechanism elucidation.