4-amino-3-(phenylselanyl) benzenesulfonamide attenuates intermittent cold stress-induced fibromyalgia in mice: Targeting to the Nrf2-NFκB axis.

Stress is widely recognized as the primary environmental factor associated with chronic pain conditions, including fibromyalgia. A recent study demonstrated the potential antinociceptive effects of 4-amino-3-(phenylselanyl) benzenesulfonamide (4-APSB) in acute nociceptive animal models due to its antioxidant and anti-inflammatory properties. However, the efficacy of 4-APSB in managing chronic painful conditions, such as fibromyalgia, has not been explored so far. This study investigated the pharmacological effects of 4-APSB in an experimental model of fibromyalgia induced by intermittent cold stress (ICS). Male and female mice were divided into Control, ICS, 4-APSB, and ICS + 4-APSB. After the ICS, the animals were treated with 4-APSB (1 mg kg-1) or vehicle by the intragastric route until the tenth day. The behavioral tasks were performed on days 5, 8, and 10. The findings showed a negative correlation between paw withdrawal threshold and Nrf2 or NFκB mRNA expression levels caused by ICS exposure. The 4-APSB suppressed the nociceptive signs and a depressive like-phenotype in male and female mice exposed to ICS. 4-APBS normalized the elevated levels of TBARS and the up-regulation of Nrf2 and NFκB expression in the cerebral cortex of ICS-exposed mice. This compound also modulated the oxidative stress in the spinal cord of female mice. The 4-APSB attenuated the inhibition of Na+, K+ - ATPase activity in the central nervous system (CNS) of female mice exposed to ICS. 4-APSB attenuated behavioral and redox imbalance triggered by the ICS model in male and female mice, suggesting its beneficial effects for treating fibromyalgia in both sexes.