Protective Effect of Combined Melatonin and [alpha]-Tocopherol Administration in Spinal Cord Ischemia-Reperfusion Injury in Rat/Efecto Protector de la Administracion Combinada de Melatonina y [alpha]-Tocoferol en la Lesion por Isquemia-Reperfusion de la Medula Espinal en Ratas

Oxidative stress and inflammation are the key players in the development of motor dysfunction post-spinal cord ischemic reperfusion injury (SC-IRI). This study investigated the protective effect of concomitant pre-administration of melatonin and alpha-tocopherol on the early complications (after 48 hours) of spinal cord IRI injury in rats. Melatonin or [alpha]-tocopherol were pre-administered either individually or in combination for 2 weeks, then rats were exposed SC-IRI. Neurological examinations of the hind limbs and various biochemical markers of oxidative stress and inflammation in the SC tissue were assessed. Solely pre-administration of either melanin or [alpha]-tocopherol significantly but partially improved motor and sensory function of the hind limbs mediated by partial decreases in SC levels of MDA, AOPP and PGE2 levels and activities of SOD, partial significant decreases in plasma levels of total nitrate/nitrite and significant increases in AC activity of GSH-Px. However, combination therapy of both drugs resulted in the maximum improvements in all neurological assessments tested and biochemical endpoints. In conclusion, by their synergistic antioxidant and anti-inflammatory actions, the combination therapy of melatonin and [alpha]-tocopherol alleviates SC-IRI induced paraplegia. KEY WORDS: Spinal cord ischemic reperfusion injury; Melatonin; alpha-tocopherol, Oxidative stress; Paraplegia.