Medicosnext
A new kind of non-hormonal, over-the-counter contraception is on the horizon, due to a discovery that blocks the transition of semen from a thick gel to a liquid. Researchers at the Washington State University recently showed that blocking a prostate-specific-antigen in human ejaculate caused the semen to remain as thick gel, thereby trapping most of the sperm. Under normal circumstances, the semen will turn liquid and allow sperm to swim through the female reproductive system to fertilize an egg.
Senior author Joy Winuthayanon, associate professor and director of WSU’s Center for Reproductive Biology, said that their goal is to develop an easily accessible female contraceptive that could also be used in combination with a condom to further lower the failure rate, which is an average of 13% to 21% with the currently available condoms and spermicides. Hormone-based contraceptives (IUDs and birth control pills) have lower failure rates, but they can have side-effects and are not always easily available.
In 2015, the researchers accidentally discovered that some female mice in a different reproductive study could not get pregnant; further investigation showed that the male’s semen was staying in solid form. They then purposely tried to stop the semen from liquefying using a non-specific protease inhibitor called AEBSF, which disrupted sperm movement. Then, they worked on translating the results to human sperm samples, targeting the prostate-specific antigen (PSA), because it is the primary active protein in liquefication and secreted from the prostate gland, which is present in humans but not in mice. The next step is to find more specific small molecule inhibitors that can prevent PSA’s ability to liquefy semen without any harmful side effects.
