 He also noted that Chinese would chew it with areca nut.The plant extract contains some 150 identified phytochemicals, including catechins, proanthocyanins, and chalcone-flavan-3-ol dimers, called gambiriins.Cat's claw ("U. tomentosa") and the Chinese "Uncaria" species are used in traditional medicine, although there is no high-quality clinical evidence they have any medicinal properties.