Cocaine is a natural pesticide

COCAINE owes its narcotic properties to the fact that it is a natural pesticide, acting as a nerve agent on insects, writes Steve Connor.

Scientists believe they have discovered why coca plants produce relatively high concentrations of cocaine, which until now had no obvious botanical function.

They found that cocaine blocks a nerve transmitter found in insects. In low concentrations it puts them off their food, and in higher concentrations it kills them.

James Nathanson, a pharmacologist at the Massachusetts General Hospital, Boston, said yesterday his findings indicated it may be possible to produce safer pesticides based on cocaine derivatives.

Research published in the Proceedings of the National Academy of Sciences showed that the concentration of cocaine in coca leaves was sufficient to have an insecticidal effect, Dr Nathanson said.

He suggested it would be possible to tinker with the cocaine molecule so that it worked on insects but was harmless to humans.