Abstract 23 — Ameliorative Effect of Biogenic Silver Nanoparticles Mediated with Naringin Against Collagen Induced Rheumatoid Arthritis in Rodents by Acting on Inflammation and Gut Microbiota

Background Rheumatoid arthritis (RA) hallmarked by functional impairment in joints due to inflammation, destruction and erosion of cartilages and bones. RA accounts as a major healthcare burden globally, hence there is a requirement of a novel therapeutic approach. Naringin is a flavanone glycoside possessing a variety of pharmacological activities in addition to anti-inflammatory and antioxidant properties. Among various metal oxide nanoparticles, silver nanoparticle drawing the attention of researchers as it possesses anti-inflammatory activity and utilized widely as a delivery vehicle for various natural anti-inflammatory drugs against RA. The study was designed to explore the effect of biogenic silver nanoparticles mediated with naringin (NAgNP) against RA induced by type II collagen, inflammation and gut microbiota in wistar rats. Methods NAgNPs were synthesized by co-precipitation method and characterized by various characterization techniques. Rats were employed for the study and randomized into five groups. Except control group, each group was treated with bovine type-II collagen (intradermal injection, 100 [Formula: see text] g) suspended in Freund’s complete adjuvant. On day 21 of the study, bovine type-II collagen and booster incomplete Freund’s adjuvant were again provided. Vehicle (Con), Methotrexate (Std, 3 mg/kg) and Test drugs, i.e., NAgNP, at three different dose levels (2, 4 and 8 mg/kg) were given in respective groups for consecutive 21 days. On the last day of study, various biochemical parameters including pro-inflammatory cytokine level in serum and the status of gut microbiome population were assessed with Illumina HiSeq. Results Characterization techniques confirmed the formation of spherical NAgNP with a size range of 80-100 nm. Data revealed that the groups administered with NAgNP exhibited a statistically significant decrease in (p < 0.01) rat paw swelling as well as arthritis scores than the control group. Different inflammatory markers such as IL-1[Formula: see text], IL-6, IL-7 and TNF-[Formula: see text] were found to be significantly reduced as compared to the control group. Significant improvement in the gut microbial population by alleviating the relative level of various microbes associated with inflammation was also observed. Conclusion NAgNP can be utilized as a beneficial candidate in the management of RA by the mechanism of amelioration of inflammation and gut microbiota.