Soursop leaves, wood, and seeds contain a chemical known as annonacin, which is a neurotoxin and in a class of chemicals which are found exclusively in the annonacae family. It can also give rats who regularly consume it a problem similar to Parkinson's. It is a very good cell killer, and is commonly used to treat cancer. The seeds of cherimoya are commonly ground as a natural pesticide alternative. It was once thought that all annona fruits contained annonacin (which has been proven false), and would kill braincells.