Evaluation of the analgesic effects of resveratrol in a chronic acidic saline induced muscle pain model

Fibromyalgia (FM) is a chronic pain disorder of multifactorial origin, in which central sensitization, neuroimmune alterations, and gut-brain interactions have been proposed to contribute to symptom development. In this context, resveratrol (RESV) emerges as a potential therapeutic agent with neuromodulatory properties. In the present study, we employed a mouse model of chronic muscular hyperalgesia that mimics key features of FM to investigate the analgesic effects of RESV (50 mg/kg). To induce FM-like syndrome two acidic saline (pH 4.0) injections were administrated four days apart into the left gastrocnemius muscle of female BALB/c mice. Von Frey and Choi tests revealed increased mechanical and thermal sensitivity, indicating reduced pain thresholds and enhanced cold responses, which were partially attenuated by RESV. Locomotor parameters, including distance travelled and immobility time, were unaffected. Molecular analyses included RT-PCR assessment of spinal cord P2X4, P2X7, S1PR1 and S1PR3 expression. Spinal cord connexin 36 immunoreactivity, associated with trigeminal mechanical and cold allodynia, remained unchanged. These findings suggest that RESV may exert antinociceptive effects in a mouse model of FM-like pain and may represent a promising adjunct strategy for the management of chronic pain conditions. Supported by Universidad Austral, CONICET and FONCYT.