Study On Extraction And Purification Of Insulin-like Growth Factor-1 From Antler Velvet

Antler velvet, as a kind of traditional Chinese medicine, has long been recognized as one of the most effective and powerful invigorants for strengthening the kidney, sexual-reinforcing and pro-longing life. It contains various active ingredients including insulin-like growth factor-1(IGF-1), which has special effect on diabetes mellitus and its complications. Therefore, it has important values to extract and purify IGF-1 from antler velvet by modern separation technologySupercritical carbon dioxide extraction of sex hormone from antler velvet was explored in our laboratory previously. Based on the idea of comprehensive utilization, the extracted antler velvet residue was employed as raw material for further obtaining IGF-1 by ultrasonic extraction. Influences of the kind of solvent, volume of solvent, extraction time, extraction temperature and extraction times on the yield of IGF-1 were investigated. Under the optimum conditions, the recovery of IGF-1 and protein are 96.43% and 94.36%, respectively. At the same time, some compounds in the extracts such as IGF-1, protein, amino acids and polysaccharide were analyzed by means of radioimmunoassay, Bradford method, m-hydroxydiphenyl-sulfuric acid method and automatic amino acid analyzer, respectively. Under the optimum conditions, the contents of the components extracted from one gram of antler velvet residue are 7745 ng IGF-1, 71897μg protein, 536.47μg polysaccharide and 80.71mg total amino acid, respectively.Ultrafiltration technology was used to concentrate the crude extract before the purification of the IGF-1. The experimental results show that 4KDa of ultrafiltration membrane has a better separation effect compared to other size of membranes. Then the gel chromatography was used to remove salt. Finally, the recovery of IGF-1 and protein are up to 71.12% and 65.00%, respectively.The cation exchange chromatography was used to purify the IGF-1. Influences of the pH, ionic strength, type of elution, flow rate of eluent were investigated. Under the optimum conditions, the recovery of the IGF-1 and protein was 57.10% and 86.95%, respectively, and the purifying multiple of IGF-1 compared to the solution extracted by ultrasonic method was up to 10.16.