Disclosed is a composition comprising a flavone compound of formula I, and an anthelmintic selected from the group comprising: levamisole, macrocyclic lactones selected from the group comprising avermectins or from the group comprising milbemycins, benzimidazole derivatives selected from albendazole, thiabenzole, mebendazole, fenbendazole, oxfendazole, febantal, and oxibendazole, that increases the bioavailable amount of the anthelmintic to treat parasitosis for example nematodes. Also disclosed is the use of the composition for preparing a medicinal product that is able to increase the bioavailability of anthelmintics in nematodes, for the treatment or prevention in a vertebrate of a parasitosis due to a nematode belonging to the Helminths phylum of the Metazoa.
