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.