• International Journal of Industrial Entomology and Biomaterials
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• v.27 no.2
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• pp.277-281
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• 2013

Silkworm powder, which contains 1-deoxynojirimycin (DNJ), is a promising complementary and alternative medicine (CAM) in Korea. Silkworm powder was produced from Yeonnokjam pupae at d 3 of the 5th instar at the National Academy of Agricultural Science. The powder was derivatized with 9-fluorenylmethyl chloroformate (FMOC-Cl), and the DNJ-FMOC content was measured by HPLC. We investigated the content of 1-DNJ in the silkworm powder and its glucose-lowering effect when it was treated at different temperatures. The content of 1-DNJ was the lowest at $150^{\circ}C$, while it was constant at other temperatures. The silkworm extract powder was orally administered to diabetic mice (20 mg/kg/d) for 4 wk. Water intake did not significantly change when compared with the control group (T0). The blood glucose levels significantly decreased when mice where administered silkworm powder treated at $60^{\circ}C$ (T60) compared to the control group, but no difference was observed between the groups T100 and T150. Moreover, the blood levels of TG significantly decreased compared with the control group. Based on these results, we surmise that the properties of the silkworm extract powder were stable upon heating at $100^{\circ}C$ but not at $150^{\circ}C$.

• Toxicological Research
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• v.29 no.4
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• pp.263-278
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• 2013

The silkworm extract powder contain 1-deoxynojirimycin (DNJ), a potent ${\alpha}$-glycosidase inhibitor, has therapeutic potency against diabetes mellitus. Therefore, natural products containing DNJ from mulberry leaves and silkworm are consumed as health functional food. The present study was performed to evaluate the safety of the silkworm extract powder, a health food which containing the DNJ. The repeated toxicity studies and gentic toxicity studies of the silkworm extract powder were performed to obtain the data for new functional food approval in MFDS. The safety was evaluated by a single-dose oral toxicity study and a 90 day repeated-dose oral toxicity study in Sprague-Dawley rats. The silkworm extract powder was also evaluated for its mutagenic potential in a battery of genetic toxicity test: in vitro bacterial reverse mutation assay, in vitro chromosomal aberration test, and in vivo mouse bone marrow micronucleus assay. The results of the genetic toxicology assays were negative in all of the assays. The approximate lethal dose in single oral dose toxicity study was considered to be higher than 5000 mg/kg in rats. In the 90 day study, the dose levels were wet at 0, 500, 1000, 2000 mg/kg/day, and 10 animals/sex/dose were treated with oral gavage. The parameters that were monitored were clinical signs, body weights, food and water consumptions, ophthalmic examination, urinalysis, hematology, serum biochemistry, necropsy findings, organ weights, and histopathological examination. No adverse effects were observed after the 90 day administration of the silkworm extract powder. The No-Observed-Adverse-Effect-Level (NOAEL) of silkworm extract powder in the 90 day study was 2000 mg/kg/day in both sexes, and no target organ was identified.

• International Journal of Industrial Entomology and Biomaterials
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• v.27 no.2
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• pp.237-242
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• 2013

We investigated the 1-deoxynojirimycin (1-DNJ) content of extracts from silkworm larvae at each developmental stage within three silkworm varieties. We also compared the content of the following polyhydroxylated alkaloids in the silkworm extracts: 1-DNJ, fagomine, and 1,4-dideoxy-1,4-imino-d-arabinitol (DAB). In addition, we evaluated the glucose-lowering effects of silkworm extract powder in db/db mice. The 1-DNJ content was the highest in Yeonnokjam $5^{th}$ instar $3^{rd}$ d larvae and Hansaengjam $5^{th}$ instar $3^{rd}$ d larvae, which contained 18.4 mg/100 g dry weight and 18.3 mg/100 g dry weight, respectively. The $5^{th}$ instar $3^{rd}$ d larvae exhibited a higher content of 1-DNJ than that of $5^{th}$ instar $5^{th}$ d larvae among all varieties. The glucose-lowering effects of silkworm extracts and Yeonnokjam powder were tested on db/db mice, and the blood glucose levels were found to decrease significantly in the YR70 group. Silkworm extracts (180 mg/kg, 90 mg/kg, 45 mg/kg, and 22.5 mg/kg) and acarbose (50 mg/kg) were administered orally for 4 wk. Changes in water intake were not statistically significant between control and silkworm extract-treated groups. Compared to the control group, blood glucose levels in the silkworm extract powder-treated group decreased in the 22.5 mg/kg/d group after being administered for 4 wk. This decrease was statistically significant. Furthermore, biochemical changes in the AST(Aspartate aminotransferase), ALT(Alanine aminotransferase), TCHO(Total Cholesterol), TG(Triglyceride), LDL(Low density lipoprotein), and HDL(High density lipoprotein) levels in blood were not observed. However, statistically significant decreases in blood GLU in the 22.5 mg/kg/d group compared to that of the control group occurred. In addition, the epididymal fat weight of the silkworm extract powder-treated group decreased significantly in both the 22.5 mg/kg/d group and 180 mg/kg/d group compared to that of the control group, but there were no statistically significant changes in perirenal fat weight. These results demonstrate that silkworm extracts inhibit changes in blood glucose levels in model diabetic mice.

• Journal of Sericultural and Entomological Science
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• v.41 no.1
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• pp.9-13
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• 1999

The experiment was carried out to investigate the absorption profile of blood glucose in mice administered to silkworm powder MeOH extract. The mice was injected to oral load of maltose, sucrose and lactose(2 g/kg) and silkworm powder MeOH extract at the same time. After injecting the sample, blood glucose concentration was measured at 0, 30, 60, 120, 180 and 240 minutes. Blood glucose lowering effect of silkworm powder for loading maltose was 69% in postprandial 30 minutes. After the postprandial 60 minutes, the glucose was absorbed slowly. Total amount of blood glucose absorption in mice administered to maltose were 560.7 mg/dl during 240 minutes. That of silkworm powder MeOH extract marked 534.7 mg/dl. Total amount of blood glucose from oral loading sucrose reached to 508.9 mg/dl. That of loading silkworm powder MeOH extract were 468.8. But, silkworm powder was not inhibited lactose absorption. As a above results, silkworm powder inhibits the transient rising of blood glucose after postprandial 30 minuts through inhibition of ${\alpha}$-glucosidases. In case of starvation silkworm powder don't promote the hypoglycemia. In addition, silkworm powder induces the delay absorption of glucose without loss of it.

• Journal of Life Science
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• v.20 no.11
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• pp.1718-1724
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• 2010

Bioactive and chemical properties of silkworm powder (SP) degradation by fruit extract containing the proteolytic enzymes of kiwifruit, papaya, pineapple and pear were investigated. Silkworm powder was incubated with extracts from each fruit at $60^{\circ}C$ for 24 hr. Protein content was slightly higher in the SP treated with fruit extract than that in the control SP. Major minerals were K, Ca, Mg, and Zn. Major fatty acids were linolenic acid, oleic acid, and palmitic acid. When total protein patterns were analyzed by SDS-polyacrylamide gel electrophoresis (PAGE), silkworm protein was strongly degraded by the treatment of fruit extract from pineapple, papaya, and pear, but little silkworm degradation was observed in kiwifruit extract treatment. Fibriolytic activity was only detected in the SP by the fruit extract treatments from papaya and pear. DPPH radical scavenging activity was slightly stronger in the SP treated with fruit extract than that in silkworm powder. However, all these samples exhibiteda relatively low activity compared with the butylated hydroxytoluene (BHT). These results may provide the basic data for understanding the biological activities and chemical characteristics of SP treated with fruit extract for development of functional foods.

• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.2
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• pp.93-100
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• 2002

Cocoon production, which is a representative of traditional sericulture shifted into silkworm powder production in the spring of 1995. This, infect, signifies the change from the dress-centered textile business to the bio-industry and the functional resource industry. One of the most outstanding shifting is utilization of silkworm larvae for anti-diabetic agent. In Asian countries including Korea, silkworm powder derived from the domestic silkworm (Bombyx mori L.) has long been favored for anti-diabetic agent, but its efficacy was not tested until last decade by modern scientific methods. In this article, we reviewed the major researches on the silkworm powder as a blood glucose-lowering substance. After the beginning test of the efficacy of silkworm powder by a cooperative research between Department of Sericulture and Entomlogy, NIAST, RDA and Kyung Hee University, substantial data have been accumulated so far, In a serial experiment to select best condition, the fifth instar larvae prepared by freeze dry method turned out to have the best blood glucose-lowering effect. In the pharmacological experiment to understand the mechanism of silkworm powder in small intestine, the silkworm powder turned out to inhibit the activity of ${\alpha}$-glucosidase, by competitively binding to $\alpha$-type disaccharides. The animal experiment showed that the extract of silkworm powder prevents a rapid increase of blood glucose level after meal and prevents hunger and law blood glucose level during empty stomach. In the experiment to isolate the major component of silkworm powder, which exerts blood glucose-lowering effect, 1-deoxynojirimy-cin (DNJ) was eventually mass-purified, and it turned out that DNJ isolated from silkworm powder was excellent in its blood glucose-lowering effect. In the experiment to understand the personal difference of the efficacy of the silkworm powder, clinical candidates were divided on the basis of the criterion of traditional Chinese medicine: Tae-Yang, Tae-Um, So-yang, and So-Um. The result showed that silkworm powder has a tendency to reduce blood glucose level at fasting and at 2 hours after meal, and this trend was somewhat obvious in the Tae-Um body type. In summary, we reviewed scientific papers on the efficacy of silkworm powder and its purified DNJ as a blood glucose-lowering agent. These suggest that silkworm powder truly possesses blood glucose-lowering effect as documented in the traditional Chinese medicine, although further researches will be required to develop them as "medical" resource instead of functional food.

• International Journal of Industrial Entomology and Biomaterials
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• v.41 no.2
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• pp.19-27
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• 2020

The aim of this study was to elucidate the difference in the amount of phytochemicals and anti-oxidant activities of the freeze-dried 5th instar 3rd day silkworm powder (FDSP) and 7 HongJams (HJs). Three primary colors of light of 8 silkworm powders revealed why each sample had unique color. The visual and absorption spectrum analyses of 80% methanol (MeOH) extracts of 8 silkworm powders revealed that white jade (WJ)-FDSP extracts showing strong forest-green colors had different absorption spectrum from 7 HJs. Among 7 HJs, the absorption spectrum of light green silkworm (LGS)-HJ extract was different from those of other HJ extracts. The amounts of total flavonoids and phenolic compounds of WJ-FDSP were 423.0±9.21% and 252.3±12.86%, respectively, more than those of WJ-HJ. Among 7 HJs, the amounts of total flavonoids and phenolic compounds in LGS-and red silkorm (RS)-HJ extracts were significantly more than those of WJ-HJ extract. Consistent with the amounts of phytochemicals, radical scavenging activity and reducing ability of WJ-FDSP extract were significantly higher that other HJ extracts. Among 7 silkworm powder extracts, LGS-HJ extract showed significantly higher radical scavenging activity and reducing ability than those of WJ-HJ extract. But, RS-HJ extract only showed significantly higher radical scavenging activity than that of WJ-HJ extract. Taken together, the amounts of phytochemicals in 8 silkworm powders contributed on their colors and anti-oxidant activities.

• The Korean Journal of Food And Nutrition
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• v.18 no.2
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• pp.140-145
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• 2005

Changes of plasma lipids, total cholesterol and phospholipids content according to diet of silkworm extract powder were as follows. Decrease ratios of plasma lipids at 3, $5\%(w/w)$ treating groups were plasma lipids 5.16, $9.15\%$, those of total cholesterols were 1.63, $2.76\%$ and those of phospholipids were 1.37, $2.00\%$, respectively. Decreasing effects of plasma triglyceride content according to diet of silkworm extract powder was higher than those of total cholesterols and phospholipids contents. Decrease of plasma glucose concentrations were $4.62\%\;and\;6.46\%\;at\;3\%,\;5\%(w/w)$ treating group than control group, respectively. These results were not proportional decrease according to treating amount. In the other hand, changes of insulin concentration of plasma, pancreas and femur were appeared the similar tendency with plasma glucose concentration. Relationship between treating amount of silkworm extract powder and insulin concentration had not positive relativity, In conclusion, treatment of silkworm extract powder about $3\%(w/w)$ could be expected to prevention and/or medical treatment effect of diabetic patients.

• Journal of the Korea Convergence Society
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• v.13 no.5
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• pp.97-102
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• 2022

In this study, the antibacterial effect of silkworm extract and Momordica charantia extract on S. mutans and F. nucleatum was investigated. S. mutans or F. nucleatum and 0%, 2%, 4%, 8% concentration of silkworm powder or Momordica charantia powder extract were added to the BHI liquid medium and cultured, and the sample was measured at an optical density of 600nm. As a result, S. mutans, the absorbance value was significantly decreased only in 8% of the silkworm extract, and the absorbance value was significantly decreased in all concentrations in the Momordica charantia extract. The absorbance of F. nucleatum was significantly decreased in a concentration-dependent manner in both the silkworm extract and the Momordica charantia extract. This suggests the possibility that silkworm extract and Momordica charantia extract can be used as materials for the prevention and treatment of oral diseases.

• Journal of Sericultural and Entomological Science
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• v.51 no.2
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• pp.123-129
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• 2013

The purpose of this study is to investigate the effects of supplementation of mulberry powder, mulberry extract and silkworm powder during the 8 weeks of resistance exercise on muscle increase of rats. Fifty males, Sprague-Dawley rat, were randomly divided into 5 groups: CON(control group, n = 10), REG(resistance exercise group, n = 10), MP REG(mulberry powder intake and resistance exercise group, n = 10), ME REG(mulberry extract intake and resistance exercise group, n = 10) and SP REG(silkworm powder intake and resistance exercise group, n = 10). After climbing the ladder without weights during the 1 week of adaptation period, the rats in the resistance exercise group were trained to climb a 0.98-m vertical(80 degree incline) ladder with weights in their tail during 7 weeks(10 times each day, 2 days per week). After exercise, the skeletal muscle was extracted from the flexor hallucis longus. The absolute weight of skeletal muscle was measured by the electronic balance and the relative weight of skeletal muscle about the weight was calculated. The strength and density of legs muscle were analyzed by the computed tomography scan. After 8 weeks of resistance exercise, the absolute weight of skeletal muscle wasn't significant, but it increased in MP REG 8%, ME REG 8% and SP REG 10% compared to REG. The relative weight of skeletal muscle increased significantly in SP REG compared to REG (p < 0.05). Additionally, there was a significant increase of density and strength of the forelegs in SP REG compared to CON (p < 0.05). However, there was no significant increase of density and strength of the hind legs. In conclusion, regular resistance exercise made rats muscle increase and there was more muscle increase effected by providing silkworm.