Antidiabetic Effects of Ethanolic Extract of Macrothelypteris Torresiana : In Vitro Enzyme Inhibition and In Vivo Evaluation in Streptozotocin-Induced Sprague-Dawley Rats

Abstract

Background: Diabetes mellitus is a chronic metabolic disorder characterized by persistent hyperglycemia and associated long-term complications. Plant-based therapies possessing enzyme inhibitory and antioxidant properties have gained attention as complementary approaches for diabetes management. Macrothelypteris torresiana (M. torresiana) (Family: Thelypteridaceae) is a medicinal fern traditionally used in folklore medicine; however, its antidiabetic potential remains inadequately explored. 

Methods: The present study evaluated the antidiabetic activity of the ethanolic extract of M. torresiana using both in vitro and in vivo approaches. In vitro assays included α-amylase and α-glucosidase inhibition, along with hydrogen peroxide (H₂O₂) radical scavenging activity. The extract exhibited IC₅₀ values of 424.08 µg/ml (α-amylase), 238.30 µg/ml (α-glucosidase), and 662.16 µg/ml (H₂O₂ scavenging). In vivo studies were conducted in normal and streptozotocin-induced diabetic Sprague–Dawley rats treated with the extract for 28 days. Fasting blood glucose, serum insulin, glycated hemoglobin (HbA1c), lipid profile, and body weight were evaluated. One-way ANOVA and Dunnett's test were used as statistical analysis, and the findings were reported as mean ± SEM. 

Results: The extract demonstrated dose-dependent inhibition of α-amylase and α-glucosidase enzymes and significant antioxidant activity in vitro. In diabetic rats, treatment significantly (p<0.05) reduced fasting blood glucose, HbA1c, total cholesterol, triglycerides, and LDL levels, while increasing serum insulin, HDL levels, and body weight compared to diabetic control. The observed effects were comparable to the standard drug Glibenclamide. 

Conclusion: The findings of this study demonstrate that M. torresiana possesses significant antidiabetic activity, likely mediated through enzyme inhibition, antioxidant action, and improvement of metabolic disturbances. These results provide scientific support for the therapeutic potential of this fern as a natural candidate for the management of diabetes mellitus. However, further studies involving phytochemical standardization and molecular-level investigations are required to confirm its therapeutic potential.