Enhancement of in vitro anti-inflammatory activity of aqueous leaf extract of Xanthium strumarium L. through encapsulation in chitosan nanoparticles

Xanthium strumarium L. (Asteraceae) is a medicinally important plant widely documented for its anti-inflammatory, antirheumatic and anti-rhinitis activities. Chitosan is a noteworthy versatile, biopolymer in drug delivery due to its biocompatibility and efficacy in controlled drug release. The aim of the present investigation was to encapsulate aqueous leaf extract of X. strumarium (XS-ALE) using chitosan nanoparticles (CSNPs), determine the in vitro drug release kinetics and to evaluate the anti-inflammatory activity using various in vitro assays. The XS-ALE encapsulated CSNPs (XS-ALE CSNPs) were synthesized and their entrapment efficiency, drug release percentage, drug release kinetics, various characterization studies such as UV-Vis spectroscopy, FTIR, SEM, zetapotential and anti-inflammatory activity were assessed. The concentration (5µg/mL) with maximum entrapment efficiency percentage (64.80%) was selected for further drug release, characterization and anti-inflammatory assays. In vitro drug release studies demonstrated a controlled and sustained drug release of 70.96% within 3.5 hours. The drug release kinetics fit in to the Higuchi model, exhibiting a high correlation coefficient (R² = 0.97), which suggests a diffusion-regulated release mechanism. Fourier transform infrared (FTIR) spectral analysis confirmed the presence of characteristic functional groups accountable to both chitosan and the plant extract. XS-ALE CSNPs showed irregular morphology with a positive charge of +32.7 mV. XS-ALE CSNPs showed the highest percentage inhibition for both protein denaturation (79%) and proteinase inhibitory (82.46%) compared to CSNPs and the reference drugs. The outcomes of the study suggested the efficacy of using XS-ALE CSNPs at minimal concentrations as a potent biocompatible and eco-friendly anti-inflammatory agent.