Pyrethrin is a kind of insecticide that widely used in veterinary medicine for agricultural and domestic purpose. It was originally identified from the extracts of the flower heads of Chrysanthemum cinerariaefolium. Based on the slight differences in structure, the pyrethrins contain six compounds including pyrethrins I and II, cinerins I and II, and jasmolins I and II. Pyrethrins are often used in indoor sprays, pet shampoos, and aerosol bombs to kill both flying and jumping insects. Pyrethrins act primarily on the nervous system of insects through majorly disrupting the normal function of voltage-sensitive sodium channel, chloride channel and calcium channel contained in nerve cells.
