Prevalent Cultural Conditions => Herbs as Contraceptives => Topic started by: ―λlτεrηιτγ- on July 05, 2017, 09:35:58 pm

Title: Thunder God Vine (Tripterygium wilfordii )
Post by: ―λlτεrηιτγ- on July 05, 2017, 09:35:58 pm
Folk Contraceptive “Thunder God Vine” Contains Chemicals That Really Prevent Conception




The head of a human sperm is just five puny microns long. To get through the 30-micron-deep zona pellucida, it has to turn its tail into a powerful drill. Instead of beating side to side, it starts to turn in only one direction, corkscrewing the head forward, through the dense, viscous environment of the egg’s outer layers. Scientists call this maneuver the “power kick.

And what powers the power kick? A massive dump of calcium ions into the sperm’s tail. (Ion transfer across membranes is how cells generate the electricity they need to power motor function.)

While there are thousands of different kinds of ion channels in every cell in the human body, the power kick relies on just one, found only in sperm. Its name is Catsper. And it only activates to let calcium in when it gets close to an egg and encounters progesterone. Scientists have known about Catsper (the friendly, sperm-specific ion channel) since 2001, when they stumbled across it while studying male infertility. The patients, it turned out, had a mutation in at least one of the nine genes that code for Catsper.

In a paper published today in PNAS, researchers at UC Berkeley screened more than 50 chemical compounds to find a few that could tightly bind with Catsper, gumming up its channel and preventing the calcium dump needed for a power kick. The two most promising ones both come from plants that humans have been consuming for millennia: lupeol, a compound found in mangos, grapes, and olives, and pristimerin, which comes from an ancient medicinal herb known as the “Thunder God Vine.