Deciphering the impact of essential elements on spermatozoa quality and seminal protein integrity- an in vitro and in silico study

Abstract

Background

Essential Elements (EEs) such as calcium, zinc, selenium, magnesium, copper, sodium, and potassium are essential for spermatogenesis. They maintain seminal proteins, especially semenogelin and sperm morphology, which are followed by spermatozoa ejaculation to reach the egg for successful conception. In addition, these elements serve as nutrients/cofactors during ejaculation and enhance spermatogenic rapid progressive motility with sustained sperm integrity.

Aim

The current study sought to determine the relationship of essential elements (calcium, zinc, selenium, magnesium, copper, sodium, and potassium) between these three major components of sperm morphology, quality, and integrity via seminal proteins, as an in vitro and in silico study.

Methodology

With appropriate institutional approval, 116 individuals aged 25–39 were divided into normozoospermic (N = 58) and teratozoospermic (N = 58). The study volunteers were selected based on their andrology profile using Computer-Assisted Semen Analysis. This was followed by an atomic absorption spectrometer for essential element quantification, Enzyme Linked Immune Sorbent Assay (ELISA) for testosterone measurement, lipid peroxidation by malondialdehyde (MDA) analysis, sperm chromatin structure assay (SCSA) and acridine orange (AO) staining procedures were used for sperm DNA fragmentation index (DFI). In addition, computational analysis was done to predict ion binding sites on the seminal protein semenogelin.

Results

Our results showed the concentration of essential elements to be comparatively lower in teratozoospermic subjects than in normozoospermic (zinc> calcium >magnesium> selenium) individuals with a significant (p < 0.001 &p < 0.05) correlation. Morphological analysis revealed that teratozoospermia subjects have sperms with altered morphology, directly correlated (p < 0.001& p < 0.05) with reduced zinc, calcium, and selenium due to fragmented DNA and reduced motility. The correlation of semen parameters and essential elements revealed a direct impact of these elements on sperm motility, DNA profile, total antioxidant capacity (TAC), and testosterone levels. In addition, an in silico study confirms the presence of metal binding motifs like D-H-D, C-X-C, and G-K-[TS]-T for Zn, Mg, and Se ions in the seminal protein semenogelin in normozoospermic than teratozoospermic.

Conclusion

Our study's findings have significant implications for male reproductive health. We propose that the presence and adequate concentration of essential elements, notably zinc, calcium, magnesium, and selenium, are crucial for maintaining sperm morphology. The computational discovery of semenogelin sequences such as D-H-D, C-X-C, and G-K-[TS]-T, which promote robust sperm integrity, further supports this. These findings could guide future research and clinical practice, highlighting the importance of essential elements in the seminal profile for successful male reproduction.