Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022;23(3):196-203.
doi: 10.22099/IJVR.2022.41489.6042.

The effects of cysteine and L-carnitine on the DNA integrity of post-thaw sperm of frozen buck semen

Y H Altyeb  1 , G Absy  1 , M S Medan  1 , Sh T Hassan  1 , D H Elsayed  1
Affiliations

The effects of cysteine and L-carnitine on the DNA integrity of post-thaw sperm of frozen buck semen

Y H Altyeb et al. Iran J Vet Res. 2022.

Abstract

Background: The addition of antioxidants to semen extenders is fundamental to limit oxidative changes resulting from cryopreservation.

Aims: This experiment was designed to clarify the effects of cysteine and L-carnitine (LC) on post-thaw sperm criteria.

Methods: Semen samples were collected once weekly from five mature Zaraibi bucks for 10 successive weeks. Fresh semen samples were evaluated for basic semen characteristics, and the accepted samples were pooled and divided into seven aliquots: control (Tris egg yolk extender), cysteine (2.5, 5 and 10 mM) and LC (2.5, 5 and 7.5 mM). Aliquots were diluted and subjected to cryopreservation procedures. After thawing, sperm criteria were evaluated regarding motility, viability, plasma membrane (hypo-osmotic swelling test, HOST) and acrosome integrity, total antioxidant capacity (TAC), level of malondialdehyde (MDA), and DNA comet assay.

Results: Addition of both 10 mM cysteine and 7.5 mM LC significantly increased post-thaw sperm motility, viability, HOST, and acrosome integrity. Comet assay revealed significant decreases in DNA damage with best results at 2.5 mM cysteine and 7.5 mM LC. Besides, 10 mM cysteine and 7.5 mM LC exhibited significant diminish in MDA levels. Cysteine was positively correlated with sperm viability, acrosome integrity, and comet, but negatively correlated with MDA and tail length. Positive correlations were declared between LC and progressive motility, viability, HOST and TAC, while negative correlations were found with MDA, comet, tail DNA, tail moment, and olive tail moment.

Conclusion: Supplementing cysteine and LC to frozen buck semen improved sperm criteria and decreased DNA damage, possibly due to their effectiveness in the suppression of MDA formation.

Keywords: Buck; Cysteine; Frozen semen; L-carnitine.

PubMed Disclaimer

Conflict of interest statement

The authors confirmed the absence of conflict of interest.

Figures

Fig. 1
Fig. 1
Comet assay shows DNA damage in extended buck sperms (A) Intact DNA without comet tail B) Damaged DNA with B) Damaged DNA with long comet tail
See this image and copyright information in PMC

References

    1. Abd-Allah M, El Kelawy H, Ibrahim H, El-Gaafary N, El-Ela A. Effect of treatment with L-carnitine, co-enzyme q10 and zinc-methionine as stimulants on semen quality and some blood parameters of Damascus goat bucks during summer season of Egypt. J. Product. Dev. 2021;26:671–688.
    1. Adekunle E, Iyanda O, Majekodunmi B, Akosile A, Ojo S, Odeyemi A, Logunleko M, Oderinwale O, Sorongbe T, Daramola J. Preservative effects of cysteine on sperm viability of West African dwarf goat bucks chilled at 4oC. Niger. J. Anim. Prod. 2022;49:49–59.
    1. Alahmar AT. Role of oxidative stress in male infertility: An updated review. J. Hum. Reprod. Sci. 2019;12:4–18. - PMC - PubMed
    1. Alcay S, Gokce E, Toker MB, Onder NT, Ustuner B, Uzabacı E, Gul Z, Cavus S. Freeze-dried egg yolk based extenders containing various antioxidants improve post-thawing quality and incubation resilience of goat spermatozoa. Cryobiology. 2016;72:269–273. - PubMed
    1. Alomar M. Effects of oxidized glutathione, cysteine and taurine supplementations on motility charateristics of different goat spermatozoa types. Iran. J. Vet. Sci. Technol. 2021;13:84–92.

LinkOut - more resources