Analgesic activity of di-caffeoylquinic acids from roots of Lychnophora ericoides (Arnica da serra)

The Brazilian medicinal plant Lychnophora ericoides Mart. (Asteraceae) has been used in traditional medicine to treat wounds, pain and inflammation. As part of our continuing investigation of this commercial phytomedicine, we focused on the polar fractions of the plant, since it is employed as alcoholic and hydroalcoholic preparations. The analgesic bioguided fractionation of the root polar extract yielded 3,5-di-O-[E]-caffeoylquinic acid, 4,5-di-O-[E]-caffeoylquinic acid and 3,4,5-tri-O-[E]-caffeoylquinic acid. The n-butanol fraction and the di-caffeoylquinic acids showed significant analgesic activity in the acetic acid-induced mouse writhing test at low but not at high doses. These findings support, at least in part, the validity of the use of Lychnophora ericoides roots in traditional medicine.