The Effect of L-Carnitine and Melatonin on Sperm Quality Parameters, DNA Fragmentation and Membrane Lipid Peroxidation during Sperm Freezing Process

Abstract

Background and Objective: During sperm freezing, its functional indices, including survival and motility, are damaged and lead to a decrease in sperm quality and fertility. Studies have been performed to lower these damages, including adding antioxidants to the freezing environment. This study was conducted to investigate the effects of antioxidants melatonin and L-carnitine on the quality of sperm parameters after freezing and thawing. Methods: In this interventional study, 40 sperm samples were divided into 4 groups including: control group (no antioxidant), melatonin group (0.01 mmol melatonin), L-carnitine group (100 μmol L-carnitine) and combined group (0.01 mmol melatonin and 100 μmol L-carnitine). The samples were thawed two weeks after freezing, then the motility, survival and morphology parameters were evaluated by Eosin-nigrosin staining and were counted. Lipid peroxidation was evaluated by measuring MDA with thiobarbituric acid reaction and DNA fragmentation through Tunnel kit. Findings: The results showed that the combined use of melatonin and L-carnitine in the freezing medium had a significant effect on the rate of motility and survival (increase from 15% to 25%), DNA fragmentation (decrease from 32% to 23%) and MDA level (decrease from 10 to 6.5 µm/dl). However, the examination of sperm morphology did not show any significant difference between the studied groups. Conclusion: The results of the study showed that melatonin and L-carnitine can reduce the damage caused by sperm manipulation during the freezing and thawing process.

Keywords

• melatonin
• l-carnitine
• sperm freezing
• apoptosis.