Birth control pill for men on the horizon?

Washington: Birth control pill for men could be on the horizon, say American scientists who claim to be working on the first non-steroidal male oral contraceptive.

A team at Columbia University says that tests of low doses of a compound that interferes with retinoic acid receptors (RARs), whose ligands are metabolites of dietary vitamin A, showed that it caused sterility in male mice.

The scientists found that low doses of the drug stopped sperm production with no apparent side effects. And crucial for a contraceptive, normal fertility was restored soon after drug administration was terminated, the latest edition of the `Endocrinology` journal reported.

In fact, earlier researches had led the investigators to the discovery that manipulating the retinoid receptor pathway could interfere with the process of spermatogenesis, which is necessary for sperm production.

It`s known for almost 100 years that depriving an animal of dietary vitamin A causes male sterility.

While investigating targeted loss of function of the gene encoding one of the RARs, RARalpha, which results in male infertility, the scientists came across a compound which was being tested for the treatment of skin disease.

To investigate whether the compound prevented conception at even lower levels than those cited in the company`s study, the scientists placed the treated male mice with females and found that reversible male sterility occurred with doses as low as 1.0mg/kg of body weight for a 4-week dosing period.

One advantage of using a non-steroidal approach, the scientists say, is avoiding the side effects commonly linked to steroidal hormone-based methods.