Research on the antipruritic active ingredients of Mikania micrantha

Mikania micrantha is a perennial liana of the genus Mikania of the Asteraceae family. It is a commonly used medicine in South America for treating fever, malaria, dysentery, snake bites, etc. Because of its strong adaptability and ability to inhibit the growth of its associated plants, Mikania micrantha is considered an invasive species in China and is known as a plant killer. Preliminary studies have shown that Mikania micrantha has an antipruritic effect, but the antipruritic active substance is not yet clear. In this study, a 4-aminopyridine-induced itching model in mice was used to determine the antipruritic effects of petroleum ether, ethyl acetate, ethanol extraction site, and Mikania micrantha volatile oil. GC–MS was used to analyze the components of the antipruritic fractions, combined with mice itch-causing models to study the antipruritic effects of β-caryophyllene and humulene. The safety of β-caryophyllene was preliminarily evaluated through the acute toxicity test of mice skin. The ethyl acetate and volatile oil of Mikania micrantha have apparent antipruritic effects. Humulene and β-caryophyllene have a quantitative-effective relationship to inhibit itching in mice. The acute toxicity test of mouse skin showed that β-caryophyllene has no acute toxicity. This study indicated that the main antipruritic active ingredients of Mikania micrantha are β-caryophyllene and humulene.