The effects of prophylactic zinc and melatonin application on experimental spinal cord ischemia–reperfusion injury in rabbits: experimental study

Abstract

Study design: Experimental study. Objectives: To determine the neuroprotective effects of zinc and melatonin on spinal cord ischemia-reperfusion (I/R) injuries of rabbits. Setting: The Experimental Research Centre of Selc¸uk University, Konya, Turkey. Methods: Twenty-four male rabbits underwent spinal cord ischemia by clamping the thoracoabdominal aorta for 20 min. Twenty minutes before the aortic clamping, animals received zinc, melatonin or a combination of both. Neurological examination of the animals was performed three times during reperfusion period. The animals were killed 24 h after reperfusion. Spinal cord samples were taken for biochemical and histopathological evaluation. Results: Pre-treated animals with zinc, melatonin or combination displayed better neurological outcomes than the I/R group (Po0.05). Zinc, melatonin and combined treatment prevented spinal cord injury by reducing apoptosis rate (Po0.05) and preserving intact ganglion cell numbers (Po0.05). Zinc pre-treatment protected spinal cord by preventing malondialdehyde (MDA) formation (P ¼ 0.002), increasing glutathione peroxidase (GPx) activity (P ¼ 0.002) and decreasing xanthine oxidase enzyme activity (P ¼ 0.026) at molecular level. Melatonin treatment also resulted with MDA formation (P ¼ 0.002), increased GPx activity (P ¼ 0.002) and decreased xanthine oxidase activity (P ¼ 0.026). Conclusion:The results of the study showed that prophylactic zinc and melatonin use in spinal cord I/R not only suppressed lipid peroxidation by activating antioxidant systems but also had significant neuroprotective effects by specifically improving the neurological and histopathological situation.

Melatonin regulates matrix metalloproteinases after traumatic experimental spinal cord injury

“…It was previously demonstrated that melatonin and its metabolites exert beneficial effects in different experimental model of SCI in rodents [33,37,38]. The present study documents that melatonin exerts protective effects reducing SCI-induced MMP-9 and MMP-2 activity and expression.…”

Effects of Ketamine on the Balance of Ions Ca2+, Mg2+, Cu2+ and Zn2+ in the Ischemia-reperfusion Affected Spinal Cord Tissues in Rabbits

“…Spinal cord ischemia/reperfusion injury induces stress response and consequently releases glucocorticoid and adrenocorticotropic hormone to speed up tissue repair, which consume a large amount of zinc, leading to decreased serum Zn 2? [25]. During repairing of spinal cord injury, enhanced synthesis of enzymes can lead to an increase in Cu 2?…”

Current Developments in Antioxidant Therapies for Spinal Cord Injury

“…In a model with lesion with vascular clips, the administration of 30 mg/kg alleviated post-traumatic injury associated with SCI by binding the PPARα-receptor; the administration of 50 mg/kg in moderate lesion decreased the BSCB permeability modulating the expression of brainderived neurotrophic factor (BDNF), growth-associated protein 43 (GAP-43), and caspase-3 [33][34][35]. In combination therapy with dexamethasone (10-0.025 mg/kg), it showed significant anti-inflammatory effects, attenuating the synthesis of tumor necrosis factor alpha (TNF-α) and iNOS and the nitration of tyrosine residues, increasing tissue recovery and motor capacity in an experimental SCI model of mouse [36], while the combination with methylprednisolone favored neurological recovery and decreased LP; its administration with zinc activated the internal antioxidant system and also decreased the LP [37][38][39].…”