Analgesic and antioxidant potential of tulathromycin: evidence from molecular docking, in vitro assay, and in vivo model.

Tulathromycin is a macrolide antibiotic widely used in veterinary medicine; however, its potential analgesic and antioxidant properties remain insufficiently explored. This study investigated the analgesic and antioxidant effects of tulathromycin using an integrative approach combining molecular docking, in vitro antioxidant assessment, and in vivo analgesic models. Molecular docking against cyclooxygenase-2 (COX-2; PDB ID: 5F19) demonstrated favorable binding affinity (- 11.22 kcal/mol) with stable hydrogen-bond interactions, suggesting possible inhibition of prostaglandin synthesis. Antioxidant activity was evaluated using the DPPH radical scavenging assay, where tulathromycin exhibited concentration-dependent activity, achieving 41.5% inhibition at 100 µg/mL. Analgesic effects were assessed in Swiss albino mice using hot-plate, formalin, and acetic acid-induced writhing tests. Tulathromycin significantly increased response latency and reduced nociceptive behavior compared with the control group (p < 0.05), although its effect was less potent than dipyrone. These findings indicate that tulathromycin possesses moderate antioxidant and analgesic properties in addition to its antimicrobial activity. The results support the concept of drug repurposing and suggest that tulathromycin may have therapeutic potential in veterinary conditions associated with inflammation and pain.