In -vitro Anti-inflammatory Activity, Release of Polyphenols and Accelerated Stability of Aegle marmelos L. Fruit Extracts Encapsulated Alginate Nanoparticles

Abstract

Background: Nanoencapsulation of Aegle marmelos L. (Family: Rutaceae) fruit extracts, is a timely approach to enhance its anti-inflammatory activity, controlled release of polyphenols, and preserve stability. The synthesized A. marmelos fruit extracts encapsulated alginate nanoparticles (ANs) were characterized by several characterization techniques previously by our research group. Objectives: To evaluate in-vitro anti-inflammatory activity of aqueous, ethanol, 50% ethanol, and 50% acetone extracts of A. marmelos encapsulated ANs and their controlled release of polyphenols and accelerated stability Methods: ANs were prepared using the ionic gelation method. Anti-inflammatory activity was evaluated by xanthine oxidase (XO) inhibitory activity, heat-induced and hypotonicity-induced hemolysis. Allopurinol and diclofenac were used as the reference compounds, respectively. The in-vitro release of polyphenols was studied at both pH 1.2 and pH 6.8. Accelerated stability was assessed using thin layer chromatography fingerprints and based on total polyphenol content over a month period at 27 °C and 4 °C. Data of anti-inflammatory assays were analysed using one-way ANOVA, followed by Tukey’s post-hoc test. Results: Of the four nanoformulations, 50% acetone extract of A. marmelos encapsulated ANs was most effective in inhibiting XO enzyme (68.8%) compared to its free extract. However, 50% ethanol extract of A. marmelos encapsulated ANs showed the highest significant (p<0.05) increase in the inhibitory activity of 93.3% for heat-induced hemolysis, and aqueous extract of A. marmelos encapsulated ANs exhibited 95.8% for hypotonicity-induced hemolysis. The cumulative release of polyphenols from the alginate matrix was controlled by encapsulation, accounting for approximately 16-69% (aqueous), 25-69% (ethanol), 20-58% (50% ethanol), 43-100% (50% acetone) in both pH 1.2 and 6.8 within 48 h. The results of the accelerated stability revealed that phytoconstituents were preserved upon encapsulation over the period of one month at 27 °C and 4 °C. Conclusions: Results proved that nanoencapsulation of aqueous, ethanol, 50% ethanol, and 50% acetone extracts of A. marmelos enhanced its anti-inflammatory activity, prolonged controlled release, and preserved the stability of phytoconstituents. Therefore, they could be promising anti inflammatory agents with a controlled release profile.