Eun Young Jung

Feeding silk protein hydrolysates to C57BL/KsJ-db/db mice improves blood glucose and lipid profiles

The hypothesis for the research is that hydrolyzed silk protein has an antidiabetic effect by reducing plasma glucose levels. To investigate this potential antidiabetic activity of hydrolyzed silk protein by protease-N (silk protein hydrolysate E5K6) in vivo, male C57BL/KsJ-db/db mice were separated into 3 groups: control group, db/db mice treated with vehicle (distilled water); SP-1 group, db/db mice treated with silk protein hydrolysate E5K6 at 0.1 g/kg body weight; and SP-2 group, db/db mice treated with silk protein hydrolysate E5K6 at 0.2 g/kg body weight. After 4 weeks of treatment, plasma glucose levels were lower in the SP-1 (177.3 ± 20.8 mg/dL) and SP-2 (151.8 ± 9.2 mg/dL) groups as compared to those in the control group (236.0 ± 31.2 mg/dL). Furthermore, blood glycated hemoglobin was significantly reduced in the SP-2 (6.6% ± 0.1%) compared to that in the control mice (7.7% ± 0.1%). The SP-2 group also had significant reductions in plasma concentrations of total cholesterol, low-density lipoprotein cholesterol, and the atherogenic index by 11%, 27%, and 26%, respectively, compared to the control group. Insulin levels on plasma concentrations were significantly increased in the silk protein hydrolysate E5K6 groups (SP-1, 4.2 ± 1.1 ng/mL; SP-2, 4.8 ± 0.4 ng/mL) compared to those in the control group (2.9 ± 0.9 ng/mL). The silk protein hydrolysate E5K6-treated db/db mice (SP-1, 62.8 ± 1.6 arbitrary units [AU]; SP-2, 63.0 ± 4.0 AU) displayed pancreatic islets with significantly enhanced (P < .05) insulin staining as compared to the intensity of staining of those from the control group (55.8 ± 2.5 AU). The results suggest that silk protein hydrolysate E5K6 has insulin-releasing activity through the induction of β-cell activity in the pancreatic islets.

Stimulation of osteoblastic differentiation and mineralization in MC3T3-E1 cells by antler and fermented antler using Cordyceps militaris.

ETHNOPHARMACOLOGICAL RELEVANCE For thousands of years antlers have been used in Asian countries to promote rapid healing, treat weight loss, slow growth in children, strengthen weak bones, and alleviate cold hands and feet. AIM OF THE STUDY The present study was performed to examine the effect of fermentation on the ability of antler to act as a stimulator of bone growth. MATERIALS AND METHODS This study used pre-osteoblast MC3T3-E1 cells to examine factors related to bone growth, such as cell proliferation, production of alkaline phosphatase (ALP), and deposition of extracellular matrix proteins (e.g., collagens, osteonectin, bone sialoprotein (BSP)), via the treatment of non-fermented and fermented antler. RESULTS Antler fermentation using Cordyceps militaris was carried out at 25°C for seven days. The total content of sugar, sialic acid, and protein increased with fermentation time. Cell proliferation was greater in the fermented antler- (FA-) treated groups than in the NFA- (non-fermented antler-) treated groups, in which proliferation increased significantly up to 137% of the basal value. Significant increases in mRNA expression and ALP activity were found at FA concentrations of 50-100 μg/ml; at 100 μg/ml the activity had increased 119% compared to the control activity. For NFA and FA the expression levels of type I collagen mRNA significantly increased in a dose-dependent manner at all treatment doses. However, significant differences between the antler groups were not observed. Mineralization significantly increased by NFA and FA treatment to 183% and 241%, respectively, when compared to colostrum, as a positive control (165%). CONCLUSIONS Antler treatment increased the proliferation of osteoblasts and bone matrix proteins, such as type I collagen and BSP. Antler fermented with Cordyceps militaris showed enhanced activity, and its stimulatory effects on cell proliferation and ALP production were greater than those of NFA. We surmise that these increases in activity were related to increased sialic acid content. Therefore, the results of this study suggest that the physiological effects of antler, including bone growth, may be increased through the fermentation process.

Physical stability, antioxidative properties, and photoprotective effects of a functionalized formulation containing black garlic extract.

When garlic is fermented, certain aspects of its bioactivity are changed. Black garlic is a type of fermented garlic used as a food ingredient in Asian cuisine. Black garlics popularity has spread around the world as it has become a sought-after ingredient used in high-end cuisine. The formulations containing 10% black garlic extract or 10% normal garlic extract showed stable pH, color, precipitation, and organoleptic features, although these characteristics changed slightly. The 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities of the black garlic formulation were significantly (p<0.05) higher compared to those of the base formulation and normal garlic formulation. Mice treated with the black garlic formulation (119.63 μM/g) had significant (p<0.05) decreases in thiobarbituric acid reactive substance (TBARS) levels by lipid peroxidation compared to ultraviolet B (UVB)-control mice (142.37 μM/g). Moreover, significant (p<0.05) prevention of glutathione reduced form (GSH) depletion was observed in the black garlic formulation treated mice (vehicle: 3.46 mM/g vs. black garlic: 5.60mM/g). The formulation containing 10% black garlic extract retained physical stability and had high anti-radical efficiencies. Furthermore, it is possible to suggest that this formulation may be effective in protecting skin from UVB photodamage.

Physiological effects of formulation containing tannase-converted green tea extract on skin care: physical stability, collagenase, elastase, and tyrosinase activities

Background Green tea contains numerous polyphenols, which have health-promoting effects. The purpose of this study was to evaluate the effect of tannase-converted green tea extract (TGE) formulation on the physical stability and activities of skin-related enzymes. Methods Physical stability was evaluated by measuring the pH, precipitation, and colors at 25 ± 2 °C/ambient humidity and at 40 ± 2 °C/70% ± 5% relative humidity for 4 months. Activities of collagenase, elastase, and tyrosinase as skin-related enzymes were assessed on TGE formulation. Results The concentrations of epigallocatechin-3-gallate and epicatechin-3-gallate in green tea extract were greatly decreased to the extent of negligible level when treated with tannase. The formulation containing 5% tannase-converted green tea extract showed relatively stable pH, precipitation, and color features for 16 weeks. When TGE was added to the formulation, there was a significant increase in the inhibition of elastase and tyrosinase activities (p < 0.05) compared with the formulation containing 5% normal green tea extract. Conclusion The TGE could be used in cosmetics as skin antiwrinkling or depigmenting agent.

Uncooked rice of relatively low gelatinization degree resulted in lower metabolic glucose and insulin responses compared with cooked rice in female college students

Cooking processes that gelatinize granules or disrupt structure might increase the glucose and insulin responses because a disruption of the structure of starch by gelatinization increases its availability for digestion and absorption in the small intestine. We hypothesized that the uncooked form of rice, which has a relatively low degree of gelatinization even though in powder form, would result in lower metabolic glucose and insulin responses compared with cooked rice (CR). To assess the effects of the gelatinization of rice on metabolic response of glucose and insulin, we investigated the glucose and insulin responses to 3 rice meals of different gelatinization degree in female college students (n = 12): CR (76.9% gelatinized), uncooked rice powder (UP; 3.5% gelatinized), and uncooked freeze-dried rice powder (UFP; 5.4% gelatinized). Uncooked rice powders (UP and UFP) induced lower glucose and insulin responses compared with CR. The relatively low gelatinization degree of UPs resulted in low metabolic responses in terms of the glycemic index (CR: 72.4% vs UP: 49.7%, UFP: 59.8%) and insulin index (CR: 94.8% vs UP: 74.4%, UFP: 68.0%). In summary, UPs that were less gelatinized than CR induced low postprandial glucose and insulin responses.

Enzymatic Improvement in the Polyphenol Extractability and Antioxidant Activity of Green Tea Extracts

This study describes increases in extraction efficiency and the bioconversion of catechins after treatment with several commercial enzymes. Tannase was also used to improve the anti-radical activities of green tea extracts. Enzymatic treatment with various commercial enzymes was introduced to improve the extraction efficiency of polyphenols. The total polyphenol, flavonoid, and catechin contents and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of the green tea extract treated with Viscozyme (VG) were significantly higher than those treated with other commercial enzymatic extractions (p<0.05). More than 95% of the epigallocatechingallate (EGCG) and of the epicatechingallate (ECG) was hydrolyzed to epigallocatechin (EGC) and to epicatechin (EC) in successive 20 min treatments with Viscozyme and tannase (TG). Due to its hydrolytic activity, treatment involving tannase resulted in a significant release of gallic acid (GA), EGC, and EC, leading to greater radical scavenging activities. Regarding the IC(50) values of the DPPH and 2,2-azino-di-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radicals, the green tea extract treated with TG showed values of 131.23 and 28.83 µg/mL, VG showed values of 224.70 and 32.54 µg/mL, and normal green tea extract (NG) showed values of 241.11 and 66.27 µg/mL, respectively. These results indicate that successive treatment with Viscozyme and tannase improves the extraction efficiency of polyphenols and increases radical scavenging activities.

Stimulation of osteoblastic differentiation and mineralization in MC3T3‐E1 cells by yeast hydrolysate

In a previous study, it was reported that yeast hydrolysate (YH) was effective in promoting bone growth in Sprague‐Dawley (SD) rats. To further clarify the mechanism of YH, the effects of YH on proliferation, differentiation and gene expression in vitro were investigated using osteoblastic cell lines (MC3T3‐E1). Cell proliferation increased significantly as much as 110% of the basal value when cells were treated with 100 µg/mL of YH. Alkaline phosphatase (ALP) activity increased significantly with a YH concentration of 25–100 µg/mL, and the activity increased 152% that of the control at 100 µg/mL. The calcium content increased as much as 129% at 100 µg/mL YH. The gene expression levels of ALP and collagen type II (COL II) significantly increased approximately 1.3‐fold and 1.7‐fold of control, respectively, at 100 µg/mL. YH increased significantly the mRNA level of bone sialoprotein (BSP) but not in a dose‐dependent manner. The mRNA levels of bone morphogenetic proteins (BMP)‐2, BMP‐4, collagen type I (COL I) and osteonectin (ON) did not increase. In summary, YH increased the proliferation of osteoblasts and directly stimulated ALP and bone matrix proteins (e.g. BSP, COL II), and these increases trigger osteoblastic differentiation (e.g. mineralized nodule formation). Copyright

Enzymatic transformation of ginsenosides in Korean Red Ginseng (Panax ginseng Meyer) extract prepared by Spezyme and Optidex

Background In this study, we examined the effects of various enzymes on chemical conversions of ginsenosides in ginseng extract prepared by amylases. Methods Rapidase, Econase CE, Viscozyme, Ultraflo L, and Cytolase PCL5 were used for secondary enzymatic hydrolysis after amylase treatment of ginseng extract, and ginsenoside contents, skin permeability, and chemical compositions including total sugar, acidic polysaccharide, and polyphenols were determined on the hydrolyzed ginseng extract. Results Rapidase treatment significantly elevated total ginsenoside contents compared with the control (p < 0.05). In particular, deglycosylated ginsenosides including Rg3, which are known as bioactive compounds, were significantly increased after Rapidase treatment (p < 0.05). The Rapidase-treated group also increased the skin permeability of polyphenols compared with the control, showing the highest level of total sugar content among the enzyme treatment groups. Conclusion This result showed that Rapidase induced the conversion of ginsenoside glycosides to aglycones. Meanwhile, Cytolase PCL5 and Econase treatments led to a significant increase of uronic acid (acidic polysaccharide) level. Taken together, our data showed that the treatments of enzymes including Rapidase are useful for the conversion and increase of ginsenosides in ginseng extracts or products.

Effects of yeast hydrolysate on neuropeptide Y (NPY) and tryptophan hydroxylase (TPH) immunoreactivity in rats.

To investigate the appetite regulation mechanism of low and high molecular weight yeast hydrolysate, neuropeptide Y (NPY) and tryptophan hydroxylase (TPH) expressions were analyzed in the brains on rats using immunohistochemical method; normal diet (control), 0.1 g/kg (BY‐1) or 1.0 g/kg (BY‐2) of yeast hydrolysate below 10 kDa, 0.1 g/kg (AY‐1) or 1.0 g/kg (AY‐2) of yeast hydrolysate of 10–30 kDa. Body weight gain was lower in the BY‐2 (133.0 g) than in the control (150.1 g) (p < 0.05). Triacylglyceride, total cholesterol, and LDL‐cholesterol levels were lower in the BY‐2 as compared to control, BY‐1 and AY‐2 (p < 0.05). NPY staining intensities at paraventricular nucleus (PVN) were lower in the BY groups (BY‐1: 96.1, BY‐2: 88.6) as compared to the control (105.6) and AY groups (AY‐1: 110.5, AY‐2: 114.1) (p < 0.05). NPY expression at lateral hypothalamic area (LHA) was lower in the BY‐2 (92.3) than in the control (98.9) (p < 0.05). The BY groups (BY‐1: 143.9, BY‐2: 154.6) had higher TPH staining intensities at dorsal raphe (DR) than the AY‐2 (115.9) (p < 0.05). In conclusion, the results indicate that administering yeast hydrolysate of below 10 kDa to normal diet‐fed rats reduced body weight gain and serum lipids by altering NPY and TPH expressions. Copyright

Tannase‐converted green tea catechins and their anti‐wrinkle activity in humans

This study was performed to investigate the anti‐wrinkle effects of topical applications of green tea extract with high antioxidant activity by tannase treatment. Increases in gallic acid (GA), (−)‐epigallocatechin (EGC), and (−)‐epicatechin (EC) were observed in the green tea extract after tannase treatment.