Rheumatoid arthritis; Anti-arthritic activity; Protein denaturation; Membrane stabilization; Diclofenac sodium ,

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disorder characterized by synovial joint inflammation, cartilage destruction, and progressive disability. Protein denaturation and lysosomal membrane destabilization are key pathological events that drive auto antigen generation and perpetuate the inflammatory cascade in RA. The present study investigated the in vitro anti-arthritic potential of the test sample SU using two well-established biochemical models: inhibition of heat-induced albumin denaturation and stabilization of human red blood cell (RBC) membranes against hypotonic-induced hemolysis, both of which are recognized surrogates for mechanisms operative in rheumatoid arthritis. Diclofenac sodium was used as the reference standard. Both assays were performed at concentrations of 50 to 1600 µg/mL. In the protein denaturation assay, SU exhibited concentration-dependent inhibitory activity ranging from 16.35 ± 0.29% at 50 µg/mL to 69.78 ± 0.20% at 1600 µg/mL, compared to 32.81 ± 0.33% and 96.33 ± 0.16% for diclofenac sodium. In the membrane stabilization assay, SU demonstrated inhibition of hemolysis from 3.35 ± 0.16% to 79.49 ± 0.50%, while diclofenac sodium showed values between 34.26 ± 0.56% and 96.61 ± 0.35%. The IC50 values of the given test sample (SU) and reference standard (Diclofenac sodium) were found to be (406.55 µg/ml, and 86.28 µg/ml) for protein denaturation and 526.43µg/ml and 99µg/ml for membrane stabilization assay respectively. SU displayed a clear dose-response relationship in both assays, indicating pharmacological specificity relevant to RA pathology. These findings suggest that SU may suppress key mechanisms of arthritic inflammation and warrants further in vivo and mechanistic investigation in rheumatoid arthritis models

16 , 1 , 2026