The extract is obtained from the leaves of the perennial evergreen plant Bambusa arundinacea (nigro Munro), Phyllostachys nigra (Lodd.) Munro, of the cereal family - Gramineae, which is cultivated along the river valleys in southern China, the procurement of raw materials is carried out during the autumn-winter period. Dried and crushed bamboo leaves are extracted with an aqueous-alcoholic solvent, then the extract is purified, concentrated, and a thick extract is obtained. After drying, a dry extract is obtained.