Effects of Pulsed‐Wave Photobiomodulation Therapy on Human Spermatozoa

Abstract

Background and Objectives: Previous studies reported that photobiomodulation (PBM) positively affects the mitochondrial respiratory chain in sperm, resulting in improved motility and velocity. As laser settings are not yet fully established, the present study aimed at optimizing PBM on human sperm. In addition, possible side-effects of PBM on sperm DNA fragmentation level and acrosomal integrity have been analyzed. Study Design/Materials and Methods: A pulsed laserprobe (wavelength 655 nm, output power 25 mW/cm², impulse duration 200 nanoseconds) was used. Native fresh liquefied semen samples underwent radiation with energy doses of 0 (control), 4, 6, and 10 J/cm². Sperm parameters were assessed at 0, 30, 60, 90, and 120 minutes after radiation using a computer-assisted sperm analysis system. Motility and velocity of sperm from asthenozoospermic patients (n = 42) and normozoospermic controls (n = 22) were measured. The amount of DNA strand breaks was analyzed using ligation-mediated quantitative polymerase chain reaction in patients with asthenozoospermia (n = 18) and normozoospermia (n = 13). Postirradiance acrosomal integrity was investigated using flow cytometry based on CD46 protein expression (n = 7). Results: Exposure to laser energy-doses of 4 and 6 J/cm² improved sperm motility and velocity in asthenozoospermic patients. PBM exhibited no significant effect on DNA fragmentation level and expression of CD46 serving as a biomarker for acrosome integrity. Conclusion: PBM improves sperm motility parameters by maintaining DNA and acrosome integrity and, therefore, represents a promising new tool for assisted reproductive therapy. In particular, improving sperm motility in asthenozoospermic patients by PBM in future may contribute to increasing the chance for successful intrauterine insemination. The present trial has no clinical registration number, as only in vitro studies were performed. The study was approved by the local ethics committee and performed according to the Declaration of Helsinki. Lasers Surg. Med.

A pilot study on the effects of far-infrared-emitting fabric on neuromuscular performance of knee extensor and male fertility

“…Fragmentation greater than 30% is incompatible with the initiation and/or maintenance of pregnancy [ 27 ]. We did not identify effects of far-IR on sperm DNA fragmentation rate in agreement with studies that used other wavelengths [ 23 – 25 ]. Taking into account that sperm are susceptible to damage caused by ROS and other spermatogenesis processes [ 41 ], which can damage sperm DNA and consequently its viability, the far-IR irradiation by the FIR of our study shows that this therapeutic modality is safe in terms of damage to sperm DNA.…”

“…It is expected that mitochondrial function and pathways modulated by ATP availability are preserved in normal semen samples, consequently sperm motility as well, since flagellum movement is highly dependent on mitochondrial energy metabolism and intracellular calcium modulation [ 25 , 38 ]. Thus, if we consider that one of the main effects observed under PBMT is the improvement of mitochondrial energy metabolism [ 39 ], the absence of effects of FIR on participant semen quality is reasonable.…”

“…Thus, although they accumulated 113.1 ± 10.2 h of use over five consecutive days, the effective accumulated energy dose on the sample spermatozoa (FIR) could be lower, despite the epididymis not being completely emptied in one ejaculation. Therefore, if spermatozoa show a dose–response curve equal to neuromuscular performance, it is plausible that the energy dose accumulated in our study is below the minimum threshold of the therapeutic window since normal samples may also show improvements in motility and energy metabolism, although the effects in abnormal samples are more evident [ 23 – 25 ].…”

“…Thus, the aim of this study was twofold: first, to evaluate the time course of the effects of far-IR-emitting fabric (FIR) on neuromuscular performance of knee extensor in voluntary contractions over 120 h in healthy resistance-trained males and, second, to investigate whether the use of FIR affects semen parameters since the genital region would be being irradiated, and traditional PBMT has been used in the treatment of male infertility [ 22 ] and presents promising results [ 23 – 25 ].…”

Medical Applications of Diode Lasers: Pulsed versus Continuous Wave (cw) Regime

“…The radiation can improve corneal surface, alleviate inflammation through decreasing of the neutrophils levels, etc. Espey et al [ 9 ] demonstrated that PBM using 665 nm pulsed (200 ns) radiation from a DL with fluence 4 and 6 J/cm 2 results in a significant increase in sperm motility and velocity within 120 min post-irradiation.…”