Ameliorative impacts of carvacrol on DNA integrity, oxidative stress, and sperm quality in asthenozoospermic infertile individuals during cryopreservation

Nowadays, the cryopreservation process can produce reactive oxygen species (ROS), which cause damage to the motility, cell membrane, and DNA integrity of sperm. This study is aimed at evaluating the impact of carvacrol, as a powerful antioxidant, on sperm features and improving oxidative stress throughout the cryopreservation procedure. In this prospective study, semen samples from 25 patients with asthenozoospermia were separated into three groups: fresh, freezing, and freezing + carvacrol (a dose of 100 µM). The subsequent parameters were evaluated using standard methods in all three groups: sperm motility according to WHO criteria, sperm morphology using Papanicolaou staining, sperm viability with eosin-nigrosin staining, DNA integrity with acridine orange staining, levels of antioxidant enzymes (catalase, glutathione, and superoxide dismutase), total antioxidant capacity (TAC), and malondialdehyde (MDA) using ELISA. Also, DNA fragmentation was analyzed by the SDFA kit, and mitochondrial membrane potential (MMP) was assessed by rhodamine staining. Average sperm viability, motility, mitochondrial membrane potentiality, integrity of sperm membrane, and antioxidant enzyme levels are meaningfully reduced in the freezing group in contrast to the control group. The freezing group showed a meaningful rise in the mean MDA levels and DNA fragmentation compared to the control group. In the freezing group supplemented with carvacrol, a meaningful rise could be visible in mean percentages of viability, motility, and antioxidant enzyme levels, whereas mean levels of MDA and DNA fragmentation meaningfully declined in contrast to the freezing group. The results demonstrate that carvacrol, a potent antioxidant, offers significant protection against the loss generated by the freeze–thaw procedure, thereby improving sperm quality.