Two compounds usually found in wild plants could create good alternatives to emergency contraceptives - if scientists find out where to get them in large amounts.
Chemicals from dandelion root and the "thunder god vine" plant have been used in traditional medicines for a long time.
Now, Californian researchers have found they can also be used to block fertilisation.
However the compounds existed at such low levels in plants that the cost of extraction was too high, the US team said.
In tests, chemicals called pristimerin and lupeol stopped fertilisation by stopping human sperm from whipping its tail and propelling itself into the woman's egg.
The chemicals acted like "molecular condoms", the study authors wrote in the journal Proceedings of the National Academy of Sciences.
That is, they successfully blocked progesterone - which triggers the sperm's forceful swimming - but didn't damage the sperm.
It doesn't kill sperm basal motility. It is not toxic to sperm cells; they still can move
Said Polina Lishko, assistant professor of molecular and cell biology from the University of California, Berkeley.
"But they cannot develop this powerful stroke, because this whole activation pathway is shut down."
Lupeol is found in plants such as dandelion root, mango and aloe vera, while pristimerin is from the tripterygium wilfordii plant (also known as "thunder god vine") and is used in traditional Chinese medicine.
The researchers discovered that the chemicals worked at very low doses and had no side-effects either, unlike hormone-based contraceptives.
They reached the conclusion that the compounds could possibly be used as an emergency contraceptive, before or after intercourse, or as a permanent contraceptive via a skin patch or vaginal ring.
Prof Lishko and her colleagues will now begin to test how well these chemicals work in primates, whose sperm cells work in a similar way to humans.
However further studies will be needed, and it might take years before this new contraceptive becomes available to humans.
Post a Comment