In vitro Experimental Study of Aqueous and Ethanolic Extracts of Selected Medicinal Plants for Free Radical Scavenging and Hypoglycemic Activity

Abstract

Diabetes mellitus (DM) is a metabolic disorder characterized by persistent hyperglycemia, which results from either insufficient insulin production by pancreatic β-cells (Type I diabetes) or impaired cellular insulin responsiveness (Type II diabetes). This study aimed to qualitatively and quantitatively assess the phytochemical constituents, antioxidant potential, and both in vitro and in vivo hypoglycemic effects of specific parts of four medicinal plants, employing solvents of differing polarity; ethanol and water. The selected species included Artocarpus heterophyllus Lam., Dendrocalamus hamiltoni, Fagopyrum megacarpum H. Hara., and Urtica parviflora Roxb. Results indicated that A. heterophyllus and F. megacarpum exhibited superior total phenolic content (TPC) and total flavonoid content (TFC), correlating with significant free radical scavenging activity. In vitro analysis revealed potent α-amylase inhibitory activity of the ethanolic and aqueous extracts of F. megacarpum, with half-maximal inhibitory concentrations (IC50) of 0.136 mg/ml and 0.168 mg/ml, respectively. These findings suggest that the bioactivity of these extracts, particularly those of F. megacarpum, may be largely ascribed to their rich phenolic profiles, which confer both antioxidant and hypoglycemic properties. Given that diabetes management primarily focuses on hyperglycemia control, the concurrent mitigation of oxidative stress induced by reactive oxygen species (ROS) and reactive nitrogen species (RNS) is critical in preserving β-cell function and limiting disease progression. Thus, the present study demonstrates that plant-derived antioxidants with robust free radical scavenging activity can also serve as effective hypoglycemic agents. Moreover, the potent α-amylase inhibition observed in F. megacarpum extracts may be mediated through both antioxidant-dependent and other mechanistic pathways, underscoring their potential as natural therapeutic agents for diabetes management. Further research, including the isolation and characterization of bioactive compounds and molecular docking analyses, is warranted to develop efficacious plant-based antidiabetic therapeutics.

Keywords

• Diabetes mellitus
• total phenolic content
• total flavonoid content
• free radical scavenging property
• alpha-amylase

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