title: The protective effects of melatonin against cryopreservation-induced oxidative stress in human sperm.
abstract: Reactive oxygen species (ROS) production and lipid peroxidation during cryopreservation harm sperm membrane and as a result reduce the recovery of motile sperm. The antioxidant effects of melatonin on different cells have been widely reported. This study was aimed to evaluate changes in post-thaw motility, viability, and intracellular ROS and malondialdehyde (MDA) in response to the addition of melatonin to human sperm freezing extender. Semen of 43 fertile men was collected and each sample was divided into eight equal aliquots. An aliquot was analyzed freshly for viability, motility, and intracellular ROS and MDA. Melatonin was added to the recommended human freezing extender to yield six different final concentrations: 0.001, 0.005, 0.01, 0.05, 0.1, and 1 mM. A control group without melatonin was also included. Two weeks after cryopreservation, samples were thawed and pre-freeze analyses repeated. Obtained results showed that cryopreservation significantly (P <0.05) reduces viability and motility, but increases intracellular ROS and MDA of human sperm. The semen extender supplemented with various doses of melatonin (except for 0.001 mM) significantly (P <0.05) increased motility and viability, but decreased intracellular ROS and MDA levels of cryopreserved sperm after the thawing process, as compared with the control group. We also found that the most effective concentration of melatonin in protecting human spermatozoa from cryopreservation injuries was 0.01 mM. These findings suggest that melatonin exerts its cryoprotective effects on spermatozoa possibly by counteracting intracellular ROS, and thereby reduces MDA generation. This finally leads to increase of post-thaw viability and motility of cryopreserved spermatozoa.
authors: Department of Anatomical Sciences, School of Medicine, Ilam University of Medical Sciences, Ilam, Iran Department of Anatomical Sciences, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran.
authors: M H
authors: MH
authors: Karimfar
authors: Student Research Committee, Ilam University of Medical Sciences, Ilam, Iran.
authors: F
authors: F
authors: Niazvand
authors: Department of Clinical Biochemistry, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran.
authors: K
authors: K
authors: Haghani
authors: Clinical Microbiology Research Center, Ilam University of Medical Sciences, Iran.
authors: S
authors: S
authors: Ghafourian
authors: Department of Anatomical Sciences, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
authors: R
authors: R
authors: Shirazi
authors: Student Research Committee, Ilam University of Medical Sciences, Ilam, Iran Department of Clinical Biochemistry, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran bakhtiyaribio@gmail.com.
authors: Salar
authors: S
authors: Bakhtiyari
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000494:pharmacology; D015925:Cryopreservation / Q000379:methods; D003451:Cryoprotective Agents / Q000494:pharmacology*; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D008550:Melatonin / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism; D012661:Semen / Q000187:drug effects / Q000378:metabolism; D013081:Sperm Motility / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects* / Q000378:metabolism
chemical_list: D000975:Antioxidants; D003451:Cryoprotective Agents; D017382:Reactive Oxygen Species; D008315:Malondialdehyde; D008550:Melatonin
keywords: cryopreservation; malondialdehyde; melatonin; motility; oxygen reactive species