 Tannin, which is extracted from the nut, is used in foods as natural colouring agent, and also in the leather industry.Other minor constituents in the areca nut alkaloids, in terms of the total weight of the nut, is about 1.6%, which are comprise arecoline, arecolodine, arecaidine, guvacine, isoguvacine, and govacolidine; the pharmacological and other uses of these alkaloids are as "antihelminithic, ophthalmic, antibacterial, antidiabetic.