Phytochemical, Cytoprotective Profiling, and Anti-Inflammatory Potential of Colchicum luteum in Rheumatoid Arthritis:...

Rheumatoid arthritis (RA) is a chronic autoimmune disorder characterized by severe pain, inflammation, and joint deformity. Currently, it affects 1% of the population, with a projection to exceed 23 million cases by 2030. Despite significant advancements, non-steroidal anti-inflammatory drugs (NSAIDs), the first line of treatment, are associated with a range of adverse effects. Consequently, plant-based derivatives are being utilized as an effective alternative. This study evaluates the anti-inflammatory and safety profile of Colchicum luteum hydroethanolic extract (CLHE) in comparison to NSAIDs, with a focus on COX-2 and TNFα inhibition.

CLHE potential was evaluated by phytochemical screening and in vitro bioactivity assays. Toxicity profile was conducted in Human Colon Epithelial Cells (HCEC) and Balb/c mice. Anti-inflammatory potential was explored in a collagen-induced arthritic (CIA) mice model. Bioactive compounds were identified computationally from GCMS data and subjected to docking and simulation studies against COX2 and TNFα.

CLHE demonstrated significant antioxidant (IC-50 = 6.78 µg/mL) and anti-inflammatory (IC-50 = 97.39 µg/mL) activity. It maintained 50% cell viability at 78.5 μg/µL in HCEC cells and exhibited no toxicity at a dose of 5000 mg/kg in mice. In the CIA model, CLHE significantly reduced paw swelling, arthritic scoring, C-reactive protein levels, and spleen indices, outperforming ibuprofen. Expression analysis confirmed the downregulation of COX-2, TNFα, and MMP-9. Histopathological analysis indicated the superior efficacy of CLHE compared to ibuprofen in reducing inflammation, synovial hyperplasia, and bone erosion. Computational studies identified compound-15 (CL15), (4-(4,7-dimethoxy-1,3-benzodioxol-5-yl)-2-oxo pyrrolidine-3-carboxylic acid), a non-toxic compound with strong binding affinities to COX-2 (-12.9 KJ/mol), and TNF-α (-5.8 KJ/mol).

The findings suggest the potential of Colchicum luteum as a safer, anti-inflammatory, and multi-targeted alternative to NSAIDs for RA treatment.