This invention relates to the use of an extract of Aloysia triphylla or a fraction thereof or of a lyophilisate thereof, or of one or more active ingredients of the extract, or of an Aloysia triphylla extract as a matrix protector for inhibiting the angiogenesis of different geneses, for chemoprevention, and for treating chronic diseases such as cancer, rheumatoid arthritis, inflammatory intestinal diseases, psoriasis and neurological diseases in which the pathogenesis is caused by reactive oxygen species. The invention also relates to an extract produced from Aloysia triphylla.