Extraction of Sericin from Cocoons of the Silkworm Bombyx Mori, Its Characteristics, and a Dietary Supplement on Its Basis to Prevent Diabetes Mellitus

Abstract

A dietary supplement for the prevention of diabetes mellitus was obtained based on sericin separated from the cocoons of the silkworm Bombyx mori. By hydrolyzing Bombyx mori silkworm threads in an aqueous medium at a temperature of 110°C and a pressure of 0.143 MPa for 24 h, a sericin solution was separated. By evaporating the filtrate in a rotary evaporator, pure sericin powder with a molecular weight of 72 × 10³ and a yield of 29.8% was obtained. Subsequent repeated hydrolysis of pure sericin powder with the indicated molecular weight in an aqueous medium at a temperature of 130°C and a pressure of 2.8 MPa for 120 min resulted in the isolation of sericin powder with a molecular weight of (5‒6) × 10³, containing free amino acids, with a yield of 18.6%. The amino acid composition, molecular weight, and functional groups of sericin were determined using high-performance liquid chromatography, viscometry, and Fourier transform infrared spectroscopy. Sericin samples with different molecular weights were tested on rats with nutritional hyperglycemia. When sericin, containing free amino acids with a molecular weight of (5‒6) × 10³, was administered at a dose of 65 mg/kg twice a day, a decrease by 159.5% in blood sugar levels in the rats was registered after 30 days compared to the control group.