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Abstract
Improved sperm motility is necessary for successful sperm passage through the female genital system, efficacious fertilization, and a greater probability of pregnancy. By stimulating the mitochondrial respiratory chain, low-level laser photobiomodulation has been shown to increase sperm motility and velocity. The respiratory chain in mitochondria is the primary site of action for cytochrome c oxidase because it can absorb light in the visible and infrared ranges. The present study aimed to investigate the effects of red laser 650 nm, near infrared laser (NIR) 980 nm, and combination of both on human spermatozoa motility and DNA integrity at different doses. An in-vitro controlled trial was performed in Al Zahraa university hospital laboratory using thirty fresh human semen specimens. Samples were exposed to red laser 650 nm, near infrared laser (NIR) 980 nm, and combination of both for various irradiation times. Sperm motility for the test and control aliquots was assessed as recommended in the manual of WHO-2021. Sperm chromatin integrity was evaluated using the Sperm Chromatin Structure Assay. Results revealed almost 70%, 80% and 100% increase in the total motility after 3 min of the 650-nm, 980-nm and the combined laser irradiation, respectively. Additionally, the Sperm Chromatin Dispersion assay was carried out on sperm heads utilizing human sperm DNA fragmentation, demonstrating that none of the three laser types had any discernible effects.
Safian F et al., 2020·Photobiomodulation, photomedicine, and laser surgery
Enhanced sperm motility is necessary for the successful journey of sperm inside the female genital tract, successful fertilization, and the increased chance of pregnancy. We investigated the impact of red and near-infrared (NIR) ranges of photobiomodulation (PBM) alone and together on fresh human sperm to validate an optimized PBM protocol that would maximize sperm motility and viability in vitro. We randomly divided 30 normal human semen samples into 3 different PBM protocols (red, NIR, and red+NIR lasers). Each sample was divided into four subparts, one control group sample and three experimental group samples. Each experimental group received one of the PBM protocols (red, NIR, or red+NIR). Each protocol was adjusted to three energy densities (0.6, 1.2, and 2.4 J/cm2). After exposure to the selected protocol, we determined the percentage of either viable or progressive sperm motility (PSM) and measured the DNA Fragmentation Index (DFI). The NIR and red+NIR lasers at 2.4 J/cm2 energy density significantly increased PSM after 60 min compared with the control groups [least significant difference (LSD) test, p = 0.023 and p = 0.04, respectively]. Samples treated with the red laser at 0.6 J/cm2 had significantly decreased viability compared with the control group (LSD test, p = 0.003). Samples treated with the red+NIR lasers had significantly decreased viability at 0.6 J/cm2 (p = 0.003), 1.2 J/cm2 (p = 0.001), and 2.4 J/cm2 (p = 0.04) energy densities when compared with the control groups. The NIR laser resulted in no significant difference in sperm viability between the control and experimental groups. At 120 min after exposure, treatment with the red+NIR and red lasers at 2.4 J/cm2 density significantly increased DFI compared to the control groups (LSD test, p = 0.000, p = 0.007). In this study, sperm motility, viability, and DFI data confirmed the superiority of the NIR laser at 0.6 J/cm2 energy density compared with the red and red+NIR PBM protocols.
Sperm motility is a crucial factor in male fertility. Photobiomodulation (PBM) has been reported to increase sperm motility, but a consistent approach suitable for identifying standardizable protocols is lacking. We collected asthenozoospermic (n = 70) and normozoospermic (n = 20) semen. The asthenozoospermic samples were irradiated with an 810 nm diode laser, in continuous wave mode, at 0.25 W, 0.5 W, 1 W and 2 W for 60 s on a circular area of 1 cm2 through a novel handpiece with an innovative flat-top profile. Sperm motility was assessed immediately, after 30 and 60 min. A sample size calculator, unpaired t-test and one-way ANOVA with post-hoc Tukey HSD tests were used for statistics. One and 2 W were the most effective outputs in increasing progressive motility compared to control (p < 0.001). The maximum effect was immediately after 1 W-PBM (p < 0.001) and decreased after 60 min (p < 0.001). Time physiologically decreased vitality (p < 0.001), but less in the 1 W-PBM samples (p < 0.05). 1 W-PBM did not affect chromatin condensation. Asthenozoospermic samples displayed an impairment of 80% in oxygen consumption and ATP production and a slight inefficiency of oxidative phosphorylation compared to normozoospermic samples (p < 0.001). 1 W-PBM partially restored the functionality of aerobic metabolism (p < 0.001) by recovery of oxidative phosphorylation efficiency. PBM did not affect lactate dehydrogenase (glycolysis pathway). No irradiated samples increased accumulated malondialdehyde, a marker of lipidic peroxidation. In conclusion, PBM improves progressive motility in asthenozoospermia through increased mitochondrial energetic metabolism without harmful oxidative stress.
Preece D et al., 2017·Sci Rep·Free full text on PubMed Central
The ability to successfully fertilize ova relies upon the swimming ability of spermatozoa. Both in humans and in animals, sperm motility has been used as a metric for the viability of semen samples. Recently, several studies have examined the efficacy of low dosage red light exposure for cellular repair and increasing sperm motility. Of prime importance to the practical application of this technique is the absence of DNA damage caused by radiation exposure. In this study, we examine the effect of 633 nm coherent, red laser light on sperm motility using a novel wavelet-based algorithm that allows for direct measurement of curvilinear velocity under red light illumination. This new algorithm gives results comparable to the standard computer-assisted sperm analysis (CASA) system. We then assess the safety of red light treatment of sperm by analyzing, (1) the levels of double-strand breaks in the DNA, and (2) oxidative damage in the sperm DNA. The results demonstrate that for the parameters used there are insignificant differences in oxidative DNA damage as a result of irradiation.
Salman Yazdi R et al., 2014·Lasers in medical science
Sperm motility is known as an effective parameter in male fertility, and it depends on energy consumption. Low-level laser irradiation could increase energy supply to the cell by producing adenosine triphosphate. The purpose of this study is to evaluate how the low-level laser irradiation affects the human sperm motility. Fresh human semen specimens of asthenospermic patients were divided into four equal portions and irradiated by 830-nm GaAlAs laser irradiation with varying doses as: 0 (control), 4, 6 and 10 J/cm(2). At the times of 0, 30, 45 and 60 min following irradiation, sperm motilities are assessed by means of computer-aided sperm analysis in all samples. Two additional tests [HOS and sperm chromatin dispersion (SCD) tests] were also performed on the control and high irradiated groups as well. Sperm motility of the control groups significantly decreased after 30, 45 and 60 min of irradiation, while those of irradiated groups remained constant or slightly increased by passing of time. Significant increases have been observed in doses of 4 and 6 J/cm(2) at the times of 60 and 45 min, respectively. SCD test also revealed a non-significant difference. Our results showed that irradiating human sperms with low-level 830-nm diode laser can improve their progressive motility depending on both laser density and post-exposure time.
Male Fertility › Male Factor Treatment › Medical Management · Therapeutics › Emerging Therapies › Light Therapy
Rasha Ahmed, Omnia Hamdy, Shaimaa Elattar, Amany Ahmed Soliman
R Ahmed, O Hamdy, S Elattar, A Soliman
PMID 38280133 38280133 DOI 10.1007/s43630-023-00525-y 10.1007/s43630-023-00525-y Ahmed et al. 2024, Ahmed 2024