The power strokes sperm use to drill an egg get dashed by herbal remediesEnlarge / Human Spermatozoa, Scanning Electron Micrograph. (credit: Enver Kerem Dirican )
For the final stretch of their fertilization journey, sperm rev up their whip-like tails to ludicrous egg-boring speed.

But amid chemicals from old herbal remedies, sperm may be left feebly treading water a few strokes from the finish line.
Two steroid-like chemicals from plants used in traditional medicines can power-down sperms’ tail engines to prevent the propelling power needed to penetrate their target, Berkeley researchers report in PNAS.

The chemicals work by blocking the activation of a calcium ion channel in the sperm, which charge up their tails for final turbo thrusts. Normally, progesterone, a hormone involved in pregnancy that is secreted by cells surrounding eggs, activates this ion channel during sperms’ final approach, the researchers report.
Because the herbal chemicals—called pristimerin and lupeol—are already used in traditional remedies (though not necessarily for anti-fertility purposes), the researchers are hopeful that they’ll easily pass safety tests and offer an effective alternative form of contraception.

And, because the chemicals aren’t hormones, unlike other forms of birth control, they may dodge the unpleasant side-effects that arise from messing with complicated and delicate hormone balances in the body, such as changes in mood, weight, and libido.

For now, though, the chemicals are just in early lab testing—years away from marketable products even if tests in primates and clinical trials go well.
Read 5 remaining paragraphs

Leave a Reply