Chemicals found in Chinese folk medicines may be used to make next generation of ‘molecular condoms’ that may serve as a safe alternative to today’s hormone-based contraceptives, scientists say.
The chemicals, extracted from two plants, thunder god vine and aloe, are effective at low doses and have no adverse effect on egg or sperm, other than preventing a key step in fertilisation – the meeting of egg and sperm.
They work by stopping sperm’s power kick, which is normally stimulated by the hormone progesterone secreted by cells surrounding the egg and makes the sperm’s tail whip forcefully to propel it toward and into the egg.
According to researchers from the University of California (UC) Berkeley in the US, the chemicals may serve as an emergency contraceptive taken either before or after intercourse, or as a permanent contraceptive via a skin patch or vaginal ring.
Human sperm take about five to six hours to mature once they enter the female reproductive system, which is enough time for the drug to enter the system and block the kick.