The oil from the plant’s seeds also can be an effective repellant of mosquitoes.
Agricultural Research Service scientist Charles Cantrell has identified the first mosquito-repelling triglyceride, which he found in Jatropha curcas seed oil, a folk remedy commonly burned in lamps in Africa and India to drive off bugs, said the parent U.S. Department of Agriculture.
The service’s Natural Products Utilization Research Unit checks out all kinds of folk remedies and gathers many plants in the wilds.
After learning that people in India burn the seed oil in lamps to keep insects out of their homes and other areas, Cantrell, a chemist with the research unit, extracted smoke from the plant in a laboratory and analyzed its properties. Free fatty acids and triglycerides were among a number of active compounds found to be effective at preventing mosquitoes from biting, said the Agriculture Department in announcing the find.
Researchers have known for some time that fatty acids repel insects, but this was the first known report that identified triglycerides as having mosquito repellent activity, according to Cantrell, as quoted by the department.
The seeds are used as a folk remedy in many other countries. They even are being considered a good source of animal feed, although they must be treated to remove highly toxic materials.