Tibolone Improves Motor Recovery and Regulates Neuroinflammation and Gliosis in a Model of Traumatic Spinal Cord Injury

Spinal cord injury (SCI) results in significant motor, sensory, and autonomic dysfunction. The pathophysiology of SCI develops during the primary and secondary phases. Inflammation contributes to the secondary phase through the non-specific activation of the innate immune response. Glial scar formation (gliosis), a reactive cellular mechanism facilitated by astrocytes, also occurs during this phase. Synthetic steroids such as tibolone (Tib) have been proposed as a treatment for SCI since they exert neuroprotective effects in various models of central nervous system (CNS) injury. We studied the effect of Tib on locomotor functional recovery and the regulation of neuroinflammation and gliosis in an SCI model. We performed an SCI at the thoracic vertebrae nine in male Sprague Dawley rats. The animals received daily doses of Tib (1 or 2.5 mg per kg of body weight) administered orally. We quantified pro- and anti-inflammatory cytokine levels at the injury site and determined motor recovery using the Basso, Beattie, and Bresnahan (BBB) scale. Finally, we investigated the effect of Tib on the expression of glial fibrillary acidic protein (GFAP) and ionized calcium-binding adaptor molecule 1 (Iba-1), two markers of gliosis, using an immunohistochemistry assay. Our findings showed that Tib regulated pro- and anti-inflammatory cytokine levels at 3 h and 3, 7, and 14 days post-SCI. Furthermore, Tib administered orally for 15 days reduced gliosis markers and favored tissue preservation and motor function recovery after SCI.