Abstract: The present invention relates to a method for producing an extract which is capable of inducing an antioxidant stress response comprising the step of treating an extract from organic material with UV light, said extract being derived from a non-mammalian cell or a non-mammalian organism and said cell or organism being capable of synthesizing polyunsaturated fatty acids. Furthermore, an extract capable of inducing an antioxidant stress response produced in accordance with the inventive methods, in particular an extract capable of inducing an antioxidant stress response for the preparation of a cosmetic composition is disclosed. The present invention also relates to a cosmetic composition comprising the inventive extract obtainable by the method provided herein.