Poison arrows African hunters suggested to use for contraception

© Photo : Brian WoodОхотники in Africa. Archive photoPoison arrows African hunters suggested to use for contraception© Photo : Brian Wood

American scientists from the universities of Minnesota and Kansas have established that the substance ouabain, which African hunters smeared arrowheads, can serve as a basis for pharmacological male contraception. About the study says Science Alert.

Ouabain is found in the roots, stems, and leaves of a shrub of the dogbane family that grows in East Africa and in Yemen. It is believed that its toxic properties were known to the Ethiopian hunters two thousand years ago — ouabain stopped the heart of a wounded animal.

In the eighteenth century was revealed the medicinal property of a substance in small doses, ouabain was used to treat hypotension and arrhythmias. In 2014, scientists found that the toxin causing asthenozoospermia which reduces the activity of sperm and prevents the possibility of fertilization. Then the substance is considered too dangerous for use as a contraceptive due to its effects on the heart.

In a new study of American chemists claimed that they were able to modify the toxin so that it ceased to affect the cardiovascular system. For this, the researchers removed a group of sugars of the molecule ouabain and replaced it lactone group on the triazole. Obtained modification of a substance only affects the flagella of sperm, which reduces their mobility and leads to a temporary infertility.

Earlier, Danish researchers found that female oral contraceptives increase the risk of breast cancer.