Abstract: It is disclosed a pharmaceutical and/or phytosanitary composition comprising an aqueous extract of Chelidonium majus root and an acceptable pharmaceutical or phytosanitary excipient for the prevention or treatment of nail infections. The composition may further comprise an aqueous extract of Thuja occidentalis leaf; and from about 1 to 5% of at least one natural phenolic compound. The composition is efficient in the treatment of plant infection (mildew fungus, blight fungus, etc); the treatment of intumescence of a plant; the treatment of potatoes (powdery or common scab, Rhizoctonia, etc), and also allows a higher crop yield: without the use of a chemical fungicide. The composition also allows rapid treatment of fungus infection of nails.