The invention relates to application of a horseradish tree leaf extract in preparation of fat-reducing medicines or functional foods, and belongs to the technical field of medicines. The application comprises the following steps that S1, mice are evenly divided into five groups according to the weight of the mice after being fed for one week under the conditions of constant temperature and
humidity, each group comprises eight mice, and the five groups comprise a
normal control Con group, a high-fat and high-
cholesterol HFC model group, a low-
dose moringa oleifera leaf extract L-MOL intervention group, a high-
dose moringa oleifera leaf extract H-MOL intervention group and a positive
drug rosiglitazone RSG intervention group; s2, except the
normal control Con group, high-fat feed is administered to other groups, administration is performed in an
intragastric administration mode at ten o'
clock in the
morning every day, the weight of the mice is observed and recorded, and continuous administration is performed for 60 days; s3, stopping taking
medicine for 24 hours after the step S2, anesthetizing and sampling blood, dissecting after cervical
vertebra dislocation and killing, dissecting the
abdomen of the mouse, taking a picture, and recording the
subcutaneous fat weight and the white fat weight of the
abdomen of each group of mouse. The
moringa oleifera leaf extract provided by the invention shows an excellent fat reducing effect.