THURSDAY, March 4, 2021 (HealthDay News) – A common herb keeping your favorite cat high can hold the key to a mosquito-free summer in your yard.
Researchers say catnip is as effective as synthetic insect repellants, including DEET, and they report why this common member of the mint family is positive buggy bugs.
The active ingredient in catnip – nepetalactone – activates an ancient pain receptor found in animals as diverse as flatworms, fruit flies, and humans, said researcher Marco Gallio, associate professor of neurobiology at Northwestern University in Evanston, Illinois.
“We now think that catnip is so averse to so many species of insects because it activates this widespread stimulus receptor,” he said in a university press release.
Gallio’s lab members and others have previously shown that humans, insects, and many other animals have some version of the receptor that senses irritants.
“What is particularly interesting is that, unlike wasabi or garlic compounds, which also activate these receptors in humans, catnip appears to selectively activate the insect receptor,” said Gallio. “This explains why people are indifferent and offers a serious benefit to its use as a repellent.”
For this study, his laboratory worked with researchers from Lund University in Sweden, who mainly focus on mosquitoes and other insects that can transmit diseases to humans.
One of their tests was offering mosquitoes a blood meal in a bowl covered with a nylon sock doused with catnip. Experiments with a wind tunnel and those where volunteers put their hand in a cage with live mosquitoes, with or without protection from catnip oil.
“Mosquitoes, especially those that carry disease, are becoming a bigger problem as climate change creates attractive conditions for them further north and south of the equator,” said study co-author Marcus Stensmyr, associate professor at the Lund University. “Plant-derived compounds represent a new approach to insect repellant development because plants have long known how to protect themselves from insect pests.”
Catnip is often an additive to cat toys and treats because of its euphoric and hallucinogenic effects on cats.
Its use could be a boon to developing countries, where mosquito-borne diseases are a major concern, as herbal repellants are often readily available and cost less, Gallio said.
The researchers said that understanding why catnip compounds repel insects could lead to the development of next-generation repellants that selectively target the mosquito stimulus receptor.
The research was published on March 4 in the journal Current Biology.
The World Health Organization is more concerned with vector-borne diseases.
SOURCE: Northwestern University, press release, March 4, 2021