In a breakthrough that almost sounds too good to be true, researchers have found a potential new form of birth control that could solve numerous problems. It offers the possibility of being effective for both sexes, no hormonal side effects, and might even be a Plan B that doesn’t piss off anti-abortion advocates.
In a newly published study, scientists from UC Berkeley show how two chemicals that are found in plants can cause sperm to be unable to drill itself into an egg. Traditionally, birth control has attempted to stop the sperm from ever reaching an egg.
Human sperm have to travel 24,000 times their own body length to reach an egg and they do this by wagging their tail from side to side. Once a sperm reaches the egg it switches over to a corkscrew technique, pushing its head through the egg’s protective zona pellucida layer. This final push towards fertilisation is accomplished by pushing a tonne of calcium ions into the sperm’s tail.
Sperm has a unique ion channel that is called Catsper. When the sperm gets close to an egg, that ion channel kicks in due to its proximity to progesterone. The researchers behind this study made their finding by testing chemical compounds that could sabotage the corkscrewing climax of the sperm’s journey. They found that lupeol and pristimerin have shown the most promising results.
These herbal chemicals are found in plants that humans have consumed for a long time. Lupeol is found in aloe as well as fruits and vegetables like grapes, olives, and cabbage. Pristimerin is a bit less common and comes from a vine that is technically known as Tripterygium wilfordii but it’s more often called “thunder god vine.” Chinese herbal medicine has used the vine frequently.
The researchers found these chemicals were able to nullify the sperm’s natural response to progesterone and they say that this method is 10 times more effective than other forms of birth control currently on the market. The researchers refer to it as a “molecular condom.”
According to Wired, Professor Polina Lishko, one of the three researchers on the team, plans to start a company that will offer what she calls “a universal contraceptive”—meaning it’s suitable for men or women. It could be delivered through a skin patch or a vaginal ring and it could even be an emergency contraceptive. Critics of Plan B (aka the morning after pill) take issue with the belief that it sometimes prevents a fertilised egg from attaching to the uterus, though the science on that has been up for debate. The beauty of this new method is that the egg would never become fertilised at all.
The biggest hurdle in this method’s development could be the manufacturing costs. The team is looking for cheaper ways to acquire the necessary chemicals which are present at very low levels in plants.
Trials on primates have already begun and results are expected by the end of the year. If all goes well, human trials could be completed in a matter of a few years. And then the debate around how much of the birth control burden should be shouldered by men will begin. [PNAS via BBC, Wired]