Abstract: The present invention relates to pharmaceutical compositions, food supplement compositions and cosmetic compositions comprising diaminooxidase, and to the use thereof.

Abstract: Disclosed is a method for determining histaminase (DAO; EC 1.4.3.6) activity in a sample. Said method comprises the following steps: an aqueous solution is supplied which contains a predefined amount of a diamine; the aqueous solution is mixed and incubated with the sample for a given period of time in conditions in which the diamine can be reacted with a DAO possibly present in the sample; the diamine is derivatized; the amount of derivatized diamine is determined; the predefined amount of diamine is compared to the amount of derivatized diamine; and the activity of histaminase possibly present is determined.