• Korean Journal of Food Science and Technology
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• v.40 no.4
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• pp.436-442
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• 2008

Hydroxyproline and Pro-Hyp dipeptide are the digestive products of collagen hydrolysate called collagen peptide. Some suggested that collagen peptides could improve aged or damaged skins, however, the effects of collagen peptides on the skin have not been known. In this study, we investigated the effects of digestive products of collagen peptides, hydroxyproline and Pro-Hyp dipeptide on skin quality using the UV-damaged dorsal skin of hairless mouse as a model system. Female SKH hairless mice were pre-irradiated with UV for 7 weeks, and then hydroxyproline, Pro-Hyp dipeptide were orally administered for 7 weeks with UV irradiation. Wrinkle formation (by replica image), skin elasticity, barrier status (by TEWL, transepidermal water loss), epidermis thickness, and biophysical changes in the stratum comeum (by hematoxylin & eosin staining) were examined. With the oral peptide treatment, effects such as skin barrier maintenance, anti-skin thickening, and recovery of the stratum corneum were observed. These results indicate that oral intake of collagen peptides may have beneficial effects on damaged skin cells.

• Tuberculosis and Respiratory Diseases
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• v.39 no.2
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• pp.131-140
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• 1992

In order to investigate the changes of hydroxyproline amount and pathologic finding in rat lung which were instilled the natural coal and free silica dust intratracheally, the subjects were divided into two groups as follows. The control group was only administered intratracheally 0.5 ml of normal saline, and the experimental groups were instilled at once the turbid solution containing 10 mg, 30 mg and 50 mg of natural coal and free silica dust each, subjects were sacrified at the 3rd and the 20th week each after the experiment. Hydroxyproline amount in the right upper lung was measured by Woessner method and HPLC (modified Dunphy) method, and the pathlogic finding of lung tissue were observed for hematoxylin-eosin staining, Bielschowski method and Masson's trichrome method. The results were as follows. 1) The wet lung weights of all experimental groups excluding in the groups instilled 10 mg and 30 mg of natural coal dust at 3rd week, were significantly increased (p<0.05) compared with control group. The weight in each free silica group was markedly increased (p<0.05) at 20th week compared with the same dose of natural coal dust group, while the weight in the same dose group of free silica dust was increased significantly at 20th week compared with at 3rd week. 2) The amount of hydroxyproline were significantly increased (p<0.05) in the natural coal and free silica groups at 20th week compared with the control groups, and in each experimental group instilled the same kind and dose of dust, its amount was markedly increased (p<0.05) at 20th week compared with at 3rd week. And also the hydroxyproline in 30 mg and 50 mg free silica groups increased markedly (p<0.05) at 20th week compared with the natural coal dust of the same dose. 3) The polymorphonuclear leukocytes, fibroblasts and macrophages in interstitium and alveolar space showed the increasing tendency in the free silica group more markedly than in the natural coal dust group. The exudate in alveolar space at 3rd week was disappeared at 20th week, and pneumoconiotic nodules observed microscopically in all experimental groups at 20th week, while the nodules apeared already at 3rd week in the 30 mg and 50 mg free silica dust groups. The significant increase of Hydroxyproline content in lung tissue and pneumoconiotic nodule formation in experimental groups found in this study indicate that the observation period, dust amount and kind of dust is important factors associated with pneumoconiosis. And these findings were generally more severe in free silica dust groups than in natural coal groups.

• Journal of Preventive Medicine and Public Health
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• v.44 no.1
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• pp.9-13
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• 2011

Objectives: Although increased reactive oxygen species (ROS) is caused by stress accelerates collagen degradation, there was no data on the relationship between stress and urinary hydroxyproline (Hyp) and proline (Pro), a good marker of collagen degradation. The purpose of this study was to evaluate the relationship between depression, anxiety, and stress (DAS) and concentrations of urinary Hyp and Pro. Methods: 97 hospital employees aged 20 to 58 were asked to fill out comprehensive self-administrated questionnaires containing information about their medical history, lifestyle, length of the work year, shit-work and DAS. Depression Anxiety Stress Scale (DASS) was applied to evaluate chronic mental disorders. Urine samples were analyzed using High Performance Liquid Chromatography (HPLC) with double derivatization for the assay of hydroxyproline and proline. Results: The mean value of Hyp and Pro concenturation in all subjects was $194.1{\pm}113.4\;{\mu}mol/g$ and $568.2{\pm}310.7\;{\mu}mol/g$. DASS values and urinary Pro concentrations were differentiated by sex (female > male, p < 0.05) and type of job (nurse > others, p < 0.05). In the stepwise multiple linear regressions, urinary Hyp and Pro concentrations were influenced by stress (Adjusted $r^2$ = 0.051) and anxiety and job (Adjusted $r^2$ = 0.199), respectively. Conclusions: We found that stress and anxiety were correlated with urinary Hyp and Pro concentrations. To identifying a definite correlation, further study in large populations will be needed.

• Journal of Nutrition and Health
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• v.29 no.9
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• pp.1013-1020
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• 1996

The purpose of this study was to investigate nutrient intake and bone status in rural postmenopausal women in Korea. Ten postmenopausal women in An-Sung area participated in this study and they were divided into two groups ; women in group I had been postmenopausal for 4 years or less and those in group II had been postmenopausal for 5 years or more before the present study began. Their environmental factors and dietary intakes were surveyed through the personal interviews. Serum levels of calcium, phosphorus, parathyroid hormone(PTH), estradiol and urinary Ca, P, creatinine, hydroxyproline levels were measured from December 4 to December 27 in 1993. The reults of this study are summarized as follows : Average ages of group I and II were 54.8 and 57.2 years. Average menopausal ages of group I and II were 50.8 and 47.3 years. The nutrient intakes of subjects were higher than recommended dietary allowances(RDA) except calorie, protein, calcium, and vitamin A. The nutrient status did not show any significant difference between group I and II. Serum levels of Ca, P, PTH, estradiol and urinary P, creatinine excretion did not show any significant difference between group I and II, and all levels were in normal range. Urinary Ca excretion(p<0.05) and hydroxyproline excretion(p<0.01) were significantly lower in group I than in group II. Urinary Ca/creatinine(Ca/cr) and hydroxyproline/creatinine(Hpr/cr) rations were significantly higher in group II than in group I(p<0.01. And Hpr/cr levels of group I were in normal range, but most of subjects in group II were higher than 0.017 indicating sign of osteoporosis. Correlations between parameters showed that serum PTH adn urinary Ca, Ca/cr levels were positive related (p<0.01), and the years of the after menopausal year and urinary Hpr/cr was also positive related(p<0.05). The present results suggests that it is difficult to protect postmenopausal women's bone destruction having Korean usual diets. Therefore, to prevent osteoporosis with aging, minimizing the hormonal changes in postmenopausal women is needed as well as Ca supplementation and proper exercise before menopause begins.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.1
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• pp.135-140
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• 2004

Anti-skin aging agent could be have an inhibition effect of ROS production as well as fragmentation and change of collagen cross linkage in collagen molecule. For the monitoring of lipid peroxidation and collagen degradation, the skin of young and old rats were incised and observed 7 days. In the result, the wound closure was observed in the skin from 10 of 11 young rats and in 8 of 11 old rats. And the longer wound length but shorter wound closure, weaker collagen density and thicker epidermis were observed in old rats than in young rats. The level of hydroxyproline as a parameter of collagen synthesis and MDA as a parameter of lipid peroxidation was lower in old group than in young group. The cyst and lacuna between collagen bundle and fibroblast were observed in old rats in contrast to young rats. So that we propose that MDA and hydroxyproline could be used for monitoring of anti-skin aging agent.

• Toxicological Research
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• v.12 no.2
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• pp.213-221
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• 1996

In order to develop a suitable secondary renal disease model and diagnostic markers of renal disease in the rat, the change of PIIIP (aminoterminal procollagen III peptide) in serum and hydroxyproline levels in the renal tissue that reflect the synthesis of extracellular matrix (ECM) during development of experimental renal diseases were observed. Two types of experimental primary diseases, diabetes mellitus administrated by streptozotocin (STZ, 75 mg/kg, i.p.) and liver cirrhosis produced by bile duct ligation/scission (BDL/s) operation, were induced. The hydroxyproline level increased according to the high PIIIP and NCl(carboxyterminal procollagen IV peptide) in Western blot analysis as early as 1 week in the STZ treated-rat kidney. Increased renal ECM was observed at 15 weeks in STZ and BDL/s model under the microscopic examination. High PAS positive reaction was found in capillary basement membrane in STZ treated-rats and mesangium in BDL/s operated rats at this time, showing the histological characteristics of diabetic nephropathy and cirrhotic glomerulonephritis in human, respectively. Such secondary renal failure were supported by additional tests including urinalysis and renal function test. The serum PIIIP detected by ELISA was a useful parameter to estimate synthesis rate of renal ECM during development of renal disease without extrarenal fibrosis i.e. liver cirrhosis in rats. This study is proposed that STZ treatment or BDL/s operation may be a suitable experimental animal model for the induction and development of chronic secondary renal diseases. Morover, it was found that hydroxyproline level in renal tissues was a good parameter of the change of renal ECM at the early stage of the diseases without apparent histological changes. Especially, serum PIIIP could be a choice as a diagnostic or prognostic marker during the development of renal diseases in rats.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.1
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• pp.65-69
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• 2010

Collagen is the most abundant animal protein in mammals, accounting for about 30 % of all proteins. It is present in connective tissue and contributes to the structural framework of most organs. The tripeptide (glycineproline-hydroxyproline) with the INCI name Tripeptide-29 is main component of collagen type I. The palmitoyl tripeptide (palmitoyl-glycine-proline-hydroxyproline) with the INCI name Paimitoyi Tripeptide-29 is a synthetic material that was designed as a topical agent to stimulate collagen production. We synthesized the palmitoyl tripeptide as a potential anti-wrinkle compound. This compound has been characterized using HPLC. This compound proved, through in vitro tests, to stimulate collagen production and fibroblast proliferation. These results were very promising, so human studies were subsequently performed. We investigated the skin improvement effect of the palrnitoyl tripeptide on human skin by using non-invasive instruments. We measured physiological effects such as skin wrinkles and elasticity after volunteers applied the cosmetic products for 8 weeks. We observed significant improvement in skin wrinkles and elasticity after use of the cosmetic products for 8 weeks. We concluded that the palmitoyl tripeptide had an anti-aging effect on human facial skin.

• Korean Journal of Poultry Science
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• v.21 no.4
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• pp.277-284
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• 1994

The functional properties of mechanically deboned chicken meat(MDCM) from whole carcass, whole carcass without exsanguination, neck without skin, leg hone, and upper back and rib were studied. Also, the effects of adding different levels of gelatin and MDCM to the comminuted meats were investigated. Proximate composition values of MDCM ranged from 54.2 to 68.6% moisture, 14.5 to 19.7% protein, 12.3 to 30.1% fat, and 1.1 to 1.3% ash. The MDCM from leg hone had a higher content of fat, and a lower contents of moisture and protein. The MDCM from neck without skin tended to be opposite to the MDCM from leg hone. The total pigment and myoglobin levels were highest in MDCM from whole carcass without exsanguination such as 3.83 and 0.29 rng /g, and those from the other parts were 1.58~2.93 mg /g and 0. 17~0.31 mg /g, respectively. The emulsifying capacity and water holding capacity were highest in MDCM from neck without skin which contained lower levels of fat, collagen and hydroxyproline, but a higher level of salt soluble protein. The emulsifying capacity of comminuted meat decreased as gelatin content increased. The extractability of hydroxyproline from gelatin showed a higher solubility in acidic solution. The MDCM could he added up to 20% level without detrimentally affecting functional properties of comminuted meats although they had less water holding capacity and cooking loss as the proportion of MDCM increased.

• Biomolecules & Therapeutics
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• v.32 no.2
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• pp.240-248
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• 2024

We observed that treatment with dimethyl α-ketoglutarate (DMK) increased the amount of intracellular α-ketoglutarate significantly more than that of α-ketoglutarate in HaCaT cells. DMK also increased the level of intracellular 4-hydroxyproline and promoted the production of collagen in HaCaT cells. In addition, DMK decreased the production of collagenase and elastase and down-regulated the expression of selected matrix metalloproteinases (MMPs), such as MMP-1, MMP-9, MMP-10, and MMP-12, via transcriptional inhibition. The inhibition of MMPs by DMK was mediated by the suppression of the IL-1 signaling cascade, leading to the attenuation of ERK1/2 phosphorylation and AP-1 transactivation. Our study results illustrate that DMK, an alkylated derivative of α-ketoglutarate, increased the level of 4-hydroxyproline, promoted the production of collagen, and inhibited the expression of selected MMPs by affecting the IL-1 cascade and AP-1 transactivation in HaCaT cells. The results suggest that DMK might be useful as an anti-wrinkle ingredient.

• Food Science of Animal Resources
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• v.26 no.3
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• pp.362-367
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• 2006

This study was conducted to evaluate the feasibility of determination of hydroxyproline (Hyp) contents in pork meat for the quality evaluation of meat products. The relationship between the Hyp contents and pork grade was not high in porcine semitendinosus muscle. Whereas, Hyp contents of pork fresh ham and hamburger patties prepared with them were significantly increased as the decrease of pork grade. These results showed that the determination of Hyp contents might be a useful method for the quality evaluation of meat products.