The present invention describes the use of bioactive plant extracts, preferably from the species Pinta Route y Psoralea bituminosa, These extracts exhibit antiseptic, phytosanitary, and antiparasitic activity against both animal and human parasites, as well as against agricultural and domestic pests. Furthermore, the present invention describes the process for obtaining these bioactive extracts, as well as a composition in the form of animal feed and/or a galenic or pharmaceutical formulation comprising these bioactive extracts and also exhibiting antiparasitic, antiseptic, and phytosanitary activity. The invention also describes a method for treating and preventing parasitic infections in animals, including humans, which consists of administering a pharmaceutically effective dose of the active plant extracts described in the invention, along with excipients at pharmaceutically acceptable doses.