"Hierba santa," a Peruvian herbal medicine, is used to alleviate many symptoms, including headache, hemorrhoids, fever, and rheumatism. Several Cestrum species are said to be the origin of hierba santa. Three lots of hierba santa: Cestrum auriculatum (herb 1 and herb 2) and C. hediundinum (herb 3), which were purchased from Peruvian markets at Cuzco (Andes area) and Equitos (Amazon area), respectively, were examined for their pharmacological activities and active components. Herbs 1-3 showed anti-inflammatory and analgesic activities in the in vivo writhing inhibition test in mouse and inhibited prostaglandin E(1)-, E(2)-, or ACh-induced contractions of guinea pig ileum in the Magnus method. Activity-based separation of each extract yielded cestrumines A and B, cestrusides A and B, a mixture of (+)- and (-)-pinoresinol glucosides, nicotiflorin, rutin, sinapoyl glucose, ursolic acid, beta-sitosteryl glucoside, and 2-sec-butyl-4,6-dihydroxyphenyl-beta-D: -glucopyranoside. Among them, cestrumine A and cestrusides A and B are new compounds. All three lots of hierba santa do not contain exactly the same active components.