Effect of Melatonin on the Malondialdehyde Level of Neutrophils in Cyclosporine-Treated Rats

Abstract

Introduction

Cyclosporine (CsA) may contribute to oxygen free radical metabolism in neutrophils, thus resulting in the damage to these cells. This damage may be mitigated by antioxidants such as melatonin. In this study, we measured the malondialdehyde level, which was used as a marker of free radical–induced tissue damage from neutrophils in rats treated with CsA and melatonin.

Methods

The experiments included the following: (1) normal controls (group 1) that received Cremophor EL and 0.5 mL of 5% ethanol-saline solution; (2) CsA alone–treated (group 2) rats that received 15 mg/kg of body weight per day for 14 days by subcutaneous injection; and (3) melatonin-treated (group 3) rats received CsA as for group 2 plus melatonin (715 μg).

Results

Malondialdehyde level was significantly higher among group 2 (13.34 ± 7.54 nmol/107 neutrophils) than group 1 animals (7.33 ± 2.63 nmol/107 neutrophils; P < .05). The level was significantly lower in group 3 (5.58 ± 1.59 nmol/107 neutrophils) than group 2 (P < .01). CsA levels were not significantly different between group 2 (6.25 ± 1.60 μg/mL) and group 3 (6.09 ± 2.01 μg/mL).

Conclusions

In this experiment, the malondialdehyde level in neutrophils was increased after CsA treatment, suggesting that damage resulted from oxygen free radicals by CsA. This damage was reduced by melatonin. Thus, CsA-induced neutrophils oxidative damage may be protected by melatonin in transplant recipients.