Antidiabetic Potential of Nypa fruticans Fronds: Inhibition of α-Amylase, α-Glucosidase, and Glucose Absorption In Vivo

Abstract

Background: Diabetes mellitus (DM) results from insulin resistance or impaired insulin secretion, leading to hyperglycemia, which, in advanced stages, causes macrovascular and microvascular complications. Effective management of postprandial hyperglycemia is critical to reducing these complications. Inhibition of carbohydrate hydrolyzing enzymes such as α-amylase and α-glucosidase offers a therapeutic approach for controlling postprandial glucose levels. While acarbose is a known inhibitor of these enzymes, its long-term use can cause gastrointestinal side effects. Therefore, alternative treatments, such as medicinal plants, are being explored. This study focuses on the antidiabetic potential of the Nipah frond (Nypa fruticans Wurmb), a traditional remedy, which is believed to inhibit glucose absorption and carbohydrate degradation. Methods; Nipah frond powder was extracted using ethanol through maceration. Phytochemical screening was conducted to detect bioactive compounds, and in vivo and in vitro assays were performed to evaluate antidiabetic properties. The inverted intestinal pouch technique assessed glucose absorption, while the Oral Glucose Tolerance Test (OGTT) was conducted on male Wistar rats. Enzyme inhibition assays for α-amylase and α-glucosidase were carried out to measure the extract's effectiveness in inhibiting carbohydrate degradation. Results: In vitro tests demonstrated that the ethanol extract exhibited inhibitory activity against both α-amylase and α-glucosidase enzymes, with IC50 values of 38.493 ± 0.900 ppm and 40.401 ± 0.558 ppm, respectively. In vivo studies using the everted sac technique showed that the extract reduced glucose absorption by 74.10% compared to the control group, similar to acarbose. In the OGTT, administration of 1000 mg/kg BW of Nipah frond extract significantly reduced postprandial glucose levels, with an area under the curve (AUC) comparable to glibenclamide. Conclusion: The ethanol extract of Nypa fruticans fronds demonstrated significant antidiabetic activity by inhibiting α-amylase and α-glucosidase, reducing glucose absorption, and suppressing postprandial hyperglycemia in vivo.