Background: In infertility clinics, long-time preserving high-quality spermatozoa is a challenging problem.

Objective: The present study aimed to prolong preserving of the human spermatozoa by adding pentoxifylline (PT) and L-carnitine (LC) without using high-cost freezing techniques. Materials and Methods: In this experimental study, semen samples of 26 normozoospermia men aged between 28–34 yr, were firstly prepared using the swim-up technique, and each sample was divided into the following 3 aliquots: untreated control group, the LC, and PT-treated groups. The samples were stored for up to 12 days at 4–6°C, and sperm motility was assessed. The percentages of the sperms with double-stranded DNA, apoptotic, and acrosomal interacted sperms were evaluated by sperm chromatin structure assay, AnnexinV-PI staining, and peanut agglutinin, respectively.

Results: On day 7, 26.83% ± 4.26 of sperms were motile in the PT group which was significantly more than LC (6.67% ± 0.61) and control (0.83 ± 0.17) groups (p < 0.001). At day 12, while all sperms lost their motility in LC and control groups, adding PT led to 3.17% ± 0.47 sperms remaining motile (p < 0.001). Moreover, on day 12, the percent of apoptotic sperms in the PT-treated group (8% ± 0.20) was significantly lower than in LC-treated group (5.9% ± 0.28, p = 0.03). None of the additives positively affected the number of sperms with double-stranded DNA (p > 0.05). LC could also maintain acrosomal integrity over a storage time of up to 12 days.

Conclusion: Despite PT’s improved sperm motility, LC was more efficient in preventing apoptosis and acrosomal reactions. However, DNA was resistant to denaturation regardless of the treatments.

Keywords: Apoptosis, Sperm motility, L-carnitine, Pentoxifylline, Semen preservation.

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