• Journal of Sericultural and Entomological Science
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• v.50 no.2
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• pp.76-81
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• 2012

Silk protein has been explored to be used for biomedical applications for several decades. However, it has not been used in this field cause to their irreversible crystallization after dissolving in water. The existing methods of silk protein hydrolysis using silkworm cocoon were used with harmful solvents and through a very complicated process. Therefore, we have developed novel methods for the production of water-soluble hydrolysate using silkworm gland. We manufactured two types of silkworm gland-derived hydrolysate (water-soluble SGH, SSGH; total SGH, TSGH) and compared the characteristics with commercial cocoon-derived sericin hydrolysate (CSH). The molecular weight of SGH ranged from 7 to 50 kDa (SSGH) and 5 to 15 kDa (TSGH) within glycine, alanine, and aspartic acid as a main amino acid composition. In contrast, CSH ranged from 15 to 50 kDa within serine and aspartic acid. The results of FTIR implied that SGH was more soluble form than CSH, as shown by the decrease in the ${\beta}$-sheet structure at $1630cm^{-1}$ on amide I peak. In comparison with 10% fetal bovine serum, 0.1% (1 mg/ml) SSGH had equivalent effect on the proliferation of human dermal fibroblasts and mesenchymal stem cells. All results of the SSGH made by novel manufacturing process indicate the SSGH is more preferable as a culture medium supplement than cocoon-derived sericin.

• Korean Journal of Pharmacognosy
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• v.33 no.1 s.128
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• pp.21-28
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• 2002

Antidiabetic effects of the acid hydrolysate of silk fibroin were investigated by oral administration to animal models for diabetes mellitus, Fibroin protein was extracted from cocoon and digested to peptides of low-molecular weight range (mainly below 3,000) and amino acids by acid hydrolysis, Feeding of the fibroin hydrolysate resulted in a significant recovering effect on reduction of body weight gain and a lowering effect on blood glucose gain in streptozotocin-induced diabetic Sprague Dawley rats (STZ rats) which were used as an insulin-dependent diabetic animal model. But the body weight and blood glucose level in C57BL/KsJ-db/db mice (db/db mice), an non-insulin-dependent diabetic animal model, were not changed significantly by the feeding, On the other hand, plasma leptin levels increased according to increased feeding amount of the hydrolysate in STZ rats and db/db mice in common, It was concluded from the results that the fibroin hydrolysate might stimulate the insulin secretion by recovering or activating pancreatic ${\beta}$ cells and result in the increased plasma leptin level. It was also deduced that the antidiabetic improvements in body weight and blood glucose gain in STZ were thought to be due to the increased insulin secretion, but in db/db mice of which the diabetic symptoms were caused by insulin resistance, the stimulated secretion of insulin was unlikely to be able to change body weight and blood glucose level significantly.

• Microbiology and Biotechnology Letters
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• v.30 no.1
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• pp.39-45
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• 2002

It was found that the peptides originated from the hydrolysates of silk fibroin have in vitro immunostimulating effects in murine macrophage RAW264.7 cells. The stimulation effects on nitric oxide (NO) production resulted from treatments of acid or enzymatic hydrolysates were measured. The silk fibroin preparation isolated from cocoon was most efficiently digested by acid hydrolysis. Even though the sole treatment of acid hydrolysate stimulated the NO production in dose-dependent pattern, a part of its activity was found to be caused by the contaminated endotoxin, LPS. When each endotoxin-free hydrolysates obtained by filtering it through an ultrafiltration membrane of molecular weight (MW) cut-off 10,000 to eliminate LPS was used, the peptic hydrolysate with lowest degree of hydrolysis showed the highest activity. The fractions of peptic hydrolysate with MW ranges of 1,000∼10,000, 500∼1,000 and below 500 also showed a higher MW-higher activity correlation. From the analyses of amino acid composition of each hydrolysate, it was found that the contents of arginine, lysine, alanine and glycine residues affected the activity level of hydrolysate. The results of this study showed a possibility of utilizing fibroin as a source for immunostimulating (chemopreventive) functional peptides.

• KSBB Journal
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• v.23 no.5
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• pp.439-444
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• 2008

In this study, hair care effects of the hair cosmetics including low molecular weight silk peptide, hydrolysate which is produced from cocoon were investigated. After producing the hair cosmetics including silk peptide which has 300-500 molecular weight, we measured its hair care effects through the various tests; change of the hair weight, hair thickness, absorbance rate and hair moisture value and micro structure analysis. As a result, S.P.T. (Silk peptide Treatment) was effectively penetrated into the hair which has been damaged by chemical treatments, increased the hair weight, thickness and hair moisture value and also recovered the cuticle of the hair. Thus, the treatment of hair with silk peptide hydrolysate would be effective to recover the damaged hair into the normal conditions.

• Applied Biological Chemistry
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• v.46 no.2
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• pp.123-129
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• 2003

This study is to investigate consequent nutrient intake status, Influences of body mass index (BMI) and serum lipid composition, and fat distribution on the cocoon hydrolysate, green tea leaves and dietary fiber supplementation. During 2 months of this research (April to May, 2002), 47 women aged 20 yr-30 yr (average age 26.2 yr) were selected as subjects. Nutrient intake was investigated by questionnaire and 24-hr recall method. Antropometric assessments of the subjects were investigated by SBIA method (Segmental bioimpedance assay, Inbody 3.0). The results were as follows: mean body weight was 60.7 kg, mean body height 161.7 cm and mean BMI 23.4. Status of energy intakes significantly decreased (p<0.01) and dietary fiber intakes significantly increased (p<0.001) after supplementation. BMI and WHR (waist-hip ratio) significantly decreased (p<0.01) and body fat significantly decreased after supplementation (p<0.001). Total cholesterol and LDL-cholesterol significantly decreased after supplementation (p<0.05). HDL-cholesterol was negatively correlated with BMI and WHR (p<0.01). LDL/HDL ratio was positively correlated with BMI (p<0.01) and WHR (p<0.05). Above results of this study show that low-molecule peptide, green tea leaves and dietary fiber supplementation-added routine diet improves lessening body fat distribution, total cholesterol, LDL-cholesterol. Especially, decrease of abdominal fat and WHR were notable. That meant decrease of risk factors.