Wolfberry glycopeptide composition and methods for preparing and using the same

A method for preparing a glycopeptide composition, comprising:

• (a) soaking fruit of wolfberry in water and centrifuging to remove precipitated solids to obtain a first extract solution;
• (b) heating the first extract solution to provide a flocculation in the first extract solution, and centrifuging the first extract solution to remove the flocculation to obtain a second extract solution, wherein the second extract solution has a light transmittance at 50% or higher at 400 nm;
• and
• (c) treating the second extract solution with an ultrafiltration membrane, obtaining a cut-off solution with a molecular weight cutoff of the ultrafiltration membrane, concentrating, and drying the cut-off solution to obtain a glycopeptide composition,
• wherein the flocculation is formed by agglomerating insoluble substances in the first extract solution into precipitates, the molecular weight cutoff of the ultrafiltration membrane is in a range of 1000 Da to 2000 Da, and each of the steps (1) to (3) is conducted in water only.