Strategies to Develop Na,K-ATPase-α4 Inhibitors as Male Contraceptives
Shameem S Syeda1, Gladis Sánchez2, Jeffrey P McDermott2
1Department of Medicinal Chemistry, Institute for Therapeutics Discovery and Development, College of Pharmacy, University of Minnesota, Minneapolis, MN 55414, USA.
International Journal of Molecular Sciences
|June 26, 2025
Summary
Developing novel male contraceptives is crucial. Researchers simplified complex molecules to create new NKAα4 inhibitors, with compound 45 showing promise for non-hormonal male contraception by reducing sperm motility and blocking fertilization.
Area of Science:
- Biochemistry
- Reproductive Biology
- Medicinal Chemistry
Background:
- Male contraception faces unmet needs, with limited options available.
- Na,K-ATPase α4 (NKA α4) in sperm flagella is a validated target for male contraceptives due to its role in motility and fertility.
- Previous NKAα4 inhibitors had complex structures hindering optimization.
Purpose of the Study:
- To develop novel, simplified steroidal and non-steroidal NKAα4 inhibitors.
- To evaluate these compounds for NKAα4 inhibition, sperm motility reduction, and contraceptive potential.
- To identify promising lead compounds for non-hormonal male contraceptive development.
Main Methods:
- Structure-activity relationship (SAR) studies were used to simplify existing cardenolide scaffolds.
- Novel steroidal and non-steroidal analogs were synthesized.
- In vitro assays assessed NKAα4 inhibition, sperm motility, viability, and reversibility.
- In vivo and fertilization assays were performed for promising candidates.
Main Results:
- Synthesized compounds effectively inhibited NKAα4 with picomolar IC50 values.
- Both steroidal and non-steroidal series reduced sperm motility by up to 50%.
- Compounds 13 and 45 showed high specificity for NKAα4 over NKAα1, without affecting sperm viability or reversibility.
- Compound 45 demonstrated potent NKAα4 inhibition, reduced sperm motility in vitro and in vivo, and blocked fertilization in vitro.
Conclusions:
- Structural simplification yielded potent NKAα4 inhibitors with contraceptive potential.
- Compound 45 is a promising lead candidate for non-hormonal male contraception.
- The newly generated compound series possess key characteristics for further development as male contraceptive agents.
Keywords:
and simplified small moleculesmale contraceptionmale fertilityouabainsimplified steroidal analogssperm capacitationsperm motilityMore Related Videos
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