In vitro Antidiabetic Activity of Aqueous Leaf Extract of Coccinia Grandis L. Encapsulated Alginate Nanoformulation

Abstract

Background: Development of alginate nanoparticles loaded with extract of Coccinia grandis L. (Ivy Gourd, Family: Cucurbitaceae) is a prospective approach to enhance the antidiabetic activity of the aqueous leaf extract of C. grandis. Objective: To assess in vitro antidiabetic activity of aqueous leaf extract of C. grandis encapsulated alginate nanoformulation (CNF). Methods: Aqueous leaf extract of C. grandis (0.06 mg/mL) was prepared using ultrasonication (40oC, 30 min, 40 kHz) followed by refluxing (100oC, 2 ½ h). CNF was synthesized via ionic gelation method. The encapsulation efficiency (EE) and loading capacity (LC) of the nanoformulation was calculated with respect to the total phenol content in the supernatant. Resultant pellet was subjected to the analysis of particle size and zeta potential. CNF was evaluated for α - amylase and α - glucosidase inhibitory activities with the reference compound of acarbose. Glucose uptake and glucose adsorption assays were performed on CNF using metronidazole as the reference compound. Results: The optimum concentration of aqueous leaf extract of C. grandis for encapsulation was determined as 4 mg/mL with the highest EE (56.7 ± 0.6%), LC (3.1), lowest particle size (298.9 nm) and agreeable zeta potential ((–) 21.0 mV). Both α - amylase and α - glucosidase inhibitory activity of CNF was improved as 60.8% and 19.1 % with respect to the crude C. grandis leaf extract. CNF gained higher glucose adsorption capacity of 16.6% (200 mM)) than the crude extract. Glucose uptake percentage of CNF was increased by 48.28% in 5 mM and 1.6% in 25 mM glucose concentration when compared to the crude C. grandis leaf extract. Conclusion: The in vitro antidiabetic activity in terms of α - amylase, α - glucosidase inhibitory potential, glucose uptake and glucose adsorption capacity of CNF was enhanced compared to the crude aqueous leaf extract of C. grandis.