Novel Benzenesulfonamide Derivatives of 5'-Aminospirotriazolotriazine Exhibit Anti-Inflammatory Activity by Suppressing Pro-Inflammatory Mediators: In Vitro and In Vivo Evaluation Using a Rat Model of Carrageenan-Induced Paw Edema.

Background/Objectives: Inflammation is a crucial and complex mechanism that protects the body against infections. In our study, we propose to provide scientific evidence for the anti-inflammatory properties of 1,3,5-triazine derivatives. Methods: Initially, we ensured the safety of the three synthesized derivatives by administering graded doses of up to 2000 mg/kg intraperitoneally in Wistar rats. Thus, the three derivatives were considered generally safe. We also evaluated their ability to reduce carrageenan-induced rat paw edema. Results: Compounds 1, 2, and 3 demonstrated stronger anti-inflammatory activity than indomethacin (10 mg/kg), achieving maximum inhibition at the fourth hour with percentages of 96.31%, 72.08%, and 99.69%, respectively, at a dose of 200 mg/kg, compared to 57.66% for the standard drug. To explore the mechanism, levels of pro-inflammatory cytokines (TNF-α, IL-1α, IL-1β, IL-6, CRP) and oxidative stress markers were measured in paw tissue. All three compounds significantly reduced these markers more effectively than indomethacin and enhanced antioxidant levels (SOD and GSH) beyond those achieved by the standard treatment. Additionally, the compounds reduced COX-1 and COX-2 levels to values comparable to those in the normal (non-inflamed) control group. Conclusions: Compounds 1, 2, and 3 at doses of 200 mg/kg significantly (p  < 0.05) inhibited the heat-induced hemolysis of red blood cell (RBC) membranes by 94.6%, 93.9%, and 95.2%, respectively, compared to 94.5% produced by indomethacin. Consequently, we concluded that 1,3,5-triazine derivatives are a safe antioxidant agent with significant anti-inflammatory activity.