Melatonin and tadalafil treatment improves erectile dysfunction after spinal cord injury in rats

Abstract

Oxidative stress plays an important role both in spinal cord injury (SCI) and erectile dysfunction (ED). The present study investigated the effects of melatonin and tadalafil treatment alone or in combination on SCI-induced ED. Male Wistar albino rats (n = 40) were divided into five groups: sham-operated control and SCI-injured rats given either vehicle, melatonin (10 mg/kg, i.p.), tadalafil (10 mg/kg, p.o.) or a combination of melatonin and tadalafil. Spinal cord injury was induced using a standard weight-drop method. On Day 7 after SCI, intracavernosal pressure (ICP) was measured and all rats were decapitated. Cavernosal tissues were obtained to examine caspase 3, nitric oxide synthase (NOS), myeloperoxidase (MPO) and superoxide dismutase (SOD) activities, as well as cGMP, nerve growth factor (NGF), malondialdehyde (MDA) and glutathione (GSH) levels. Spinal cord injury caused oxidative damage, as evidenced by increases in MDA and cGMP levels. In addition, MPO and caspase 3 activites were increased after SCI, whereas GSH and NGF levels and SOD activity were reduced. Melatonin effectively reversed these oxidative changes. Furthermore, in rats treated with both melatonin and tadalafil, the recoveries were more pronounced than in rats given either melatonin or tadalafil alone. The ICP/mean arterial pressure value in vehicle-treated SCI rats was significantly higher than in the control group, whereas in the tadalafil- and tadalafil + melatonin-treated groups have returned this value had returned to control levels. As an individual treatment, and especially when combined with tadalafil, a well-known agent in the treatment of ED, melatonin prevented SCI-induced oxidative damage to cavernosal tissues and restored ED, most likely due to its anti-oxidant effects.

Riboflavin Treatment Reduces Apoptosis and Oxidative DNA Damage in a Rat Spinal Cord Injury Model

“…In our previous studies with SCI-induced bladder and erectile dysfunction, we demonstrated that the damage was due inflammatory and oxidative stress mechanisms (21,27). Similarly, the results of this study also showed that SCI-induced multi-organ damage is the result of inflammation and free radicals.…”

“…Various studies have shown that irrespective of whether it is ischemia/reperfusion or trauma-related injuries on neural tissue or multiple organs, apoptosis has vigorously increased (32)(33)(34)(35). In our previous studies, we have shown an increase in caspase-3 activity and protein expression in SCI-induced spinal cord, bladder, and corpus cavernosum injuries (21,27,36). Moreover, an increase in renal caspase-3 activity caused by SCI demonstrated an increase in apoptosis of injured tissue while tadalafil blocked these effects (37).…”

Evaluation of the colo-protective effects of tadalafil in an experimental model of ulcerative colitis in rats

“…The current study results showed that tadalafil pretreatment by 1, 5 or 10 mg/kg reduced caspase 3 protein expression. Similarly, Tavukçu et al (2014) in their study found that tadalafil is able to reduce caspase 3 activity, as an index of apoptosis.…”

Protective and Therapeutic Effects of Polygonum cognatum Meissn Aqueous Extract in Experimental Colitis

“…Analysis of MPO, MDA and GSH was performed by a previously described method (10,11). The activity of tissueassociated MPO, a natural constituent of primary granules of neutrophils, was determined in the colonic samples homogenized in 50 mM potassium phosphate buffer.…”

“…SOD activity in the colon samples was measured according to the previously described method at 460 nm (11,12). The result was expressed in SOD activity U/mg protein.…”