A study recently published in the Journal of Medicinal Chemistry suggests a new and unusual source for a male birth control pill: ouabain, a plant extract that African warriors and hunters traditionally used as a heart-stopping poison on their arrows.
(First there was the god of thunder’s vine. Now, there’s arrow poison. Is it scientific marketing, or Nature’s inside joke that all of the potential sources of male birth control are phallus-themed? What’s in the lab next door — hardwood resin? lingam milk?)
Despite the fact that the study was performed on rats only (which means there’s a while before it’s applicable to humans) it seems like it’s worth learning a little more about this potential source of contraception.
Two types of African plants make ouabain. Mammals also produce it in their bodies, though at lower levels that are thought to help control blood pressure; doctors sometimes prescribe small doses of the compound to treat heart attack patients. Ouabain disrupts the passage of sodium and calcium ions through certain protein components of cell membranes. For the most part, these components are found in cardiac cells, but one type is found only in sperm cells, as part of a protein known to be critical in fertility (at least in male mice). The trick that the research team has been looking for is how to alter ouabain so that it binds only to the later, rather than to all — which would risk heart damage.
They seem to have achieved it (again — only in mice), with the result that the ouabain derivative interferes with sperm’s ability to swim. The most promising aspect is that it appears to be temporary and reversible, which has been one of the biggest hurdles in developing birth control pills for men; researchers say that the contraceptive effect should only apply to existing, mature sperm cells. Since men produce millions of new sperm cells a day, which take roughly three months to mature, the effect, in theory, would wear off once treatment ceased.
It will be a long time before any of this is proven in humans, and perhaps even longer, if it’s approved, to get past the strange stigma of a male contraceptive pill. Still, it’s exciting to hear there’s potentially some temporary poison for all of those arrows out there.
