Evaluation of anti-inflammatory activity of EGCG-loaded nanostructured lipid carriers on CFA-induced rheumatoid arthritis in experimental animals

Background The current study was designed to assess the in vivo anti-rheumatoid arthritis activity of Epigallocatechin gallate (EGCG)-loaded nanostructured lipid carriers (NLCs) topical gel against the Complete Freund’s Adjuvant (CFA) arthritis model in rats. Methods EGCG-NLCs were developed via hot homogenization followed by the ultrasonication method and characterized for particle size, polydispersity index, zeta potential, and encapsulation efficiency. The CFA-induced rheumatoid arthritis model in Wistar albino rats (both sexes, 150–180 g) was utilized to assess the anti-rheumatoid arthritis activity. EGCG gel, EGCG-NLC gel, and Diclofenac gel were tested against the arthritic control group. Paw edema, inflammatory score, serum proinflammatory markers (TNF-α, IL-6, and IL-β), and oxidative stress markers (CAT, SOD, GSH, and MDA) were observed to evaluate therapeutic efficacy. Results The optimized EGCG-NLCs exhibited a mean particle size of ~ 140 nm with high encapsulation efficiency (87.4 ± 2.3%). EGCG-NLCs were found to significantly reduce paw edema compared to the arthritic control group and showed better effectiveness than conventional EGCG gel. In the EGCG-NLC group, there was an inhibition of inflammation, which reached a maximum value of 54.05% after 28 days, compared with free EGCG (inhibition = 31.53%). Moreover, EGCG-NLCs treatment significantly reduced serum concentrations of pro-inflammatory and oxidative stress markers, suggesting improved anti-inflammatory and antioxidant effects. Conclusion NLC delivery systems significantly up-regulated the anti-inflammatory efficacy of EGCG in experimental animals and could therefore serve as a promising strategy to potentiate the therapeutic effectiveness of natural polyphenolic compounds.