The invention relates to a method for obtaining an aqueous extract of Anethum graveolens, enriched with small RNAs having a maximum length of 150 nucleotides, from a plant material, said method comprising the following steps: a) aerial parts of dill is brought into contact with water; b) tetrasodium ethylenediaminetetraacetic acid (EDTA) is added at a pH of between 10.5 and 11; c) the pH of the mixture obtained in b) is then adjusted to a value of between 6 and 8; d) the mixture obtained in c) is purified; and e) the pH is checked and readjusted if necessary to a value of between 6 and 8. The invention also relates to an aqueous extract of Anethum graveolens, enriched with small RNAs having a maximum length of 150 nucleotides, obtained by the method.