Castor oil causes outbreaks

Gynecology: The effect of castor oil on the labor force has been clarified

If a pregnant woman is a few days past the calculated due date, the "labor cocktail" usually comes up in conversation with the midwife and some doctors, along with other tips. Its main ingredient is castor oil, which is best known as a laxative. In both cases violent intestinal cramps, diarrhea and nausea can occur, which is why the remedy is viewed very critically. Only now, however, have researchers found out how castor oil works on a molecular level in the body and can thus promote labor.

The scientists led by Stefan Offermanns from the Max Planck Institute for Heart and Lung Research in Bad Nauheim have found out using human cell cultures that ricinoleic acid, which is produced in the intestine when castor oil is broken down, binds directly to two receptors that normally act as docking points for the Prostaglandin E.2 serve. They then bred mice that lacked these intestinal receptors - and unlike their normal conspecifics, the animals did not show diarrhea after being given castor oil if they had one type of receptor called EP3 was missing. Was the second - EP4 - switched off, but her bowels were still rumbling.

In further experiments, the researchers were able to discover that the effect of ricinoleic acid is limited to the cells of the smooth muscles, although other cell types also carry these receptors. And this is exactly where the labor cocktail apparently unfolds its effect on the uterus: pregnant mice without EP3- Receptors showed no contractions after administration of castor oil.

This article is included in Spectrum - Die Woche, KW 21, 2012

Prostaglandins are used to induce labor themselves, and previous studies had shown that when EP is activated, it can help3 the uterus contracts. What is surprising about these results is therefore less that a prostaglandin receptor mediates the effect, but rather that castor oil is so specifically and directly active - a non-specific spectrum of several effects had previously been expected here. This high specificity makes ricinoleic acid interesting as a basis for drugs that can be used to stimulate intestinal activity in a well-tolerated manner - and perhaps also for other medically proven methods of promoting labor.