Abstract / Summary
Background: Rheumatoid arthritis (RA) is a chronic systemic autoimmune disorder characterized by persistent synovitis, progressive joint destruction, and significant morbidity. Despite advances in targeted therapies, achieving sustained remission remains challenging, necessitating the exploration of novel, multi-targeted therapeutic strategies. This study investigates the therapeutic potential of a self-emulsifying nanoformulation, quercetin-loaded pumpkin seed oil nanoemulsion (Qu-PSONE), in a complete Freund’s adjuvant (CFA)-induced RA rat model, focusing on elucidating its integrated molecular mechanisms. Methods: Adult male Wistar rats (n = 50) were divided into a normal control group (n = 10) and an RA-induced rat model (n = 40), with the latter being further subdivided into four experimental groups: RA control, free quercetin (Qu), pumpkin seed oil nanoemulsion (PSONE), and Qu-PSONE-treated groups. We performed comprehensive analyses, including physicochemical characterization of the nanoformulations and quantification of synovial protein levels of key mediators (IL-17, TLR-4, NF-κBp65, Nrf2, OPG, RANKL, JAK1, and STAT3) via ELISA. In parallel, synovial gene expression of GSDMD and miRNA-146a was assessed using RT-qPCR. Treatment efficacy was further evaluated through paw thickness measurements, clinical arthritis scoring, radiographic assessment of joint erosion, and histopathological examination, alongside immunohistochemical staining for TNF-α and MMP-9. Results: Our findings demonstrate that Qu-PSONE exerts a superior nutrigenomic inhibitory effect on the inflammatory cascade and joint deformity associated with CFA-induced adjuvant arthritis. The Qu-PSONE significantly modulated miRNA-146a expression, serving as a sensitive indicator of attenuated synoviocyte activation. This treatment concurrently increased Nrf2 synovial level, suppressed synovial NF-κBp65, TLR-4, and IL-17 levels, which in turn downstream-inhibited the JAK/STAT pathway, balanced RANKL/OPG signaling, and downregulated transcriptional priming of the pyroptotic marker GSDMD. Together, these findings demonstrate that Qu-PSONE effectively breaks the inflammatory cascade in adjuvant arthritis. These palliative effects of Qu-PSONE were robustly correlated with reduced paw edema, improved arthritis scores, mitigated radiographic joint damage, and diminished synovial infiltration and MMP-9 expression, as confirmed by histological and immunohistochemical analyses. Conclusions: Qu-PSONE halts arthritic progression and curtails joint damage through multitarget suppression of the NF-κBp65/TLR-4/IL-17 inflammatory axis at the synovial level. This response is accompanied by reduced JAK1 and STAT3 protein expression, re-established RANKL/OPG homeostasis to mitigate bone destruction, and attenuated GSDMD transcript levels, with miRNA-146a serving as a responsive biomarker of disease resolution.