When your feline friend rubs, rolls, chews and licks catnip leaves, it’s not just about playful toys caused by the intoxicating qualities of the plant. The behavior leads to the release of certain compounds that could protect cats from annoying mosquitoes, according to new research from Japan.
The compounds called iridoids in the leaves of catnip (Nepeta cataria) and the silver vine plant (Actinidia polygama) act as an insect repellent as they are released when cats rub their bodies against leaves, found the same team in a study published last year. .
Catnip, sometimes called mint, and silver vine are flowering plants with aromatic leaves that grow in many parts of the world. Dried catnip and silver vine leaves are also used in cat toys.
The latest research from the group has shown that the way cats lick and chew the leaves causes 10 times the amount of these compounds to be released, with the leaves damaged, making the insect repellent properties more effective.
With the help of 16 cats, the researchers compared the felines’ responses to the intact silvery vine leaves and leaves that the team crumpled and torn by hand. Cats showed a longer interest in interacting with damaged leaves than with intact leaves.
Then, to test whether cats reacted specifically to iridoids, cats were given dishes with pure nepetalactone and nepetalactol, key active compounds in catnip and silver vines, respectively.
“Cats show the same response to iridoid cocktails and natural plants except chewing,” Masao Miyazaki, a professor in the department of biological chemistry and food sciences at Iwate University in Japan, said in a press release. . “They lick the chemicals from the plastic plate and rub and spin on the plate.”
It is the smell of the plant that triggers the behavior, according to research.
“When iridoid cocktails were applied to the bottom of the plates which were then covered by a perforated plastic cover, the cats still showed licking and chewing even though they could not come in direct contact with the chemicals,” Miyazaki said. “This means that licking and chewing is an instinctive behavior caused by the olfactory stimulation of iridoids.”
In the case of the silver vine, damaging the leaves led to the release of other iridoids.
“Nepetalactol accounts for more than 90% of total iridoids in intact leaves, but that goes down by about 45% in damaged leaves as other iridoids increase greatly,” he said. “The altered iridoid mixture corresponding to the damaged leaves promoted a much longer response in cats.”
The work could help identify plant enzymes that could be used as insect repellents for humans, according to the study.
Miyazaki said catnip and silver vines posed no risk to cats and were not addictive. The plants probably gave the cats a feeling of “euphoria,” he explained by email.