Washington: A plant extract, traditionally used by African warriors as a heart-stopping poison on their arrows, may be used to develop birth control pill for men, a study in mice suggests.
Ouabain disrupts the passage of sodium and calcium ions through the membrane protein, which is found in cell membranes and is made up of protein subunits.Prior clinical studies have shown that ouabain curbs fertility in men. However, ouabain itself is not an option as a contraceptive because of the risk of heart damage.
Researchers, including those from University of Minnesota in the US, set out to design ouabain analogues that are far more likely to bind to the alpha4 protein in sperm than to subunits found in heart tissue.
By removing a sugar group from ouabain and also replacing its lactone group with a triazole group, researchers created a derivative that is particularly good at zeroing in on alpha4 in sperm cells in rats.
Once bound, it interferes with the cells’ ability to swim, which is essential to its role in fertilising an egg, researchers said. The compound had no toxicity in rats.
The contraceptive effect should be reversible because alpha4 is only found on mature sperm cells.
That means sperm cells produced after stopping treatment with the ouabain derivative should not be affected, researchers said.