House cats love catnip. The fluffy animals are very wild on the violet flowering plant: they rub their heads on it, throw themselves on it, roll around and lick and chew the leaves. In addition to the euphoric effect, this also has a practical reason, researchers led by Masao Miyazaki from the Japanese University of Iwate in the journal »Iscience«: the chewed or crumpled leaves, but increasingly certain substances, the Iridoids. These are distributed on the cat fur when contacted with the plant and help to ward off mosquitoes.
As early as 2021, the team had already found out that iridoids in catnip (Nepeta cataria) and the Japanese ray pen (Actinidia polygama), also known as matabi, not only trigger euphoric states in domestic cats, but can also protect the animals from mosquitoes. For the current study, the experts investigated how intact and destroyed leaves differed in the amount and composition of the secreted iridoids and how cats reacted to the leaves.
The researchers or the cats damaged leaves of catnip and the Japanese radiation handle bumped out more iridoids than intact leaves. In the case of torn leaves of the radiation handle, the team also found a changed composition of the outcast iridoids. Here also those that were not measurable or only measurable in very small quantities could be measured here.
In order to test whether the cats' reaction to the damaged leaves was different from that of undamaged ones, the researchers placed the leaves in bowls and sealed them with holey lids. The cats licked and chewed on the lid, rubbed against it or rolled around – this reaction lasted longer with the torn leaves. According to the team, more iridoids are transferred to the cats' fur and the animals are better protected against mosquitoes.
