• Proceedings of the PSK Conference
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• 2003.04a
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• pp.154.1-154.1
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• 2003

Hydroxyproline (HYP) is a post-translational product of proline hydroxylation catalyzed by an enzyme prolyl 4-hydroxylase which plays a crucial role in the synthesis of all collagens, because the 4-hydroxyproline residues are essential for the folding of the newly synthesized collagen polypeptide chains into triple-heical molecules. Considering the role of collagen and its significance in many clinically important diseases such as liver cirrhosis, a great deal of attention has been directed toward the development of an assay at cell-based system. (omitted)

• Journal of Nutrition and Health
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• v.28 no.5
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• pp.442-450
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• 1995

This study determined plasma glucose, free fatty acid(ffa), epinephrine, norepinephrine, creatine the phosphokinase(CPK), calcium (Ca), magnesium(Mg) and hydroxyproline, Ca and Mg in the heart muscle. Thirty six male Sprague Dawley rats average weighing 110g divided into two diet group : normal Mg group(0.05% Mg), Marginal Mg group(0.005% Mg). After the rats were on experimental diets for 2 weeks, rats for each group were randomly assigned to stress and no stress group and 30 minutes IMMB stress was administered to stress group every day for two weeks. The following were found : 1) Rats fed normal magnesium diet showed decreased plasma glucose and non signficant change in norepinephrine and CPK with IMMB stress, while magnesium deficient rats showed elevated plasma glucose, norepinephrine and CPK with stress. 2) Myocardial hydroxyproline and plasma epinephrine were not significantly different among groups. 3) In the rats fed adequate magnesium, stress increased plasma magnesium while rats on marginal magnesium diet did not show significant change with stress. 4) Plasma and myocardial calcium were increased in rats fed marginal Mg diet, but did not show any significant difference with stress.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.511-519
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• 1999

To prevent the denaturation of ficin(EC 3.4.22.3) that is a proteolytic enzyme in fig(Ficus carica L.), fig conserve was heated to 55oC. The fig conserve was added as a tenderizer to native Korean cattle beef(KCB), dairy cattle beef(DCB), castrated dairy cattle beef(CDCB), and imported beef(IB). The composition of free amino acids, hydroxyproline content, shear force, cooking loss, morphological changes and sensory evaluation were then investigated to observe the effect of tenderizing beef with fig conserve. Free amino acids and cooking loss of treated beef were higher than those of control, whereas hydroxyproline and shear force were lower. Glutamine in treated beef decreased relatively but asparagine increased. Hydroxyproline was found, in increasing order of abundance, in DCB, CDCB, IB and KCB. By portion, loin was higher than tenderloin in free amino acids, hydroxyproline and shear force but was lower in cooking loss. Observation with a light microgram revealed a surprising loss of muscle fiber in treated beef. In sensory evaluation of uncooked beef, the control was redder than the treated beef(p<0.01~p<0.05). Treatment with fig conserve increased the juiciness of both cooked CDCB and IB(p<0.001) and decreased their hardness(p<0.01~p<0.001).

• 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.

• 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.

• 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 Preventive Medicine and Public Health
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• v.35 no.4
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• pp.282-286
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• 2002

Objectives : The level of 4-hydroxyproline (4-Hyp) in human urine was measured using high performance liquid chromatography (HPLC) with a fluorescence detector. This method is useful for medical examinations and investigating the radicals induced by physical, chemical, mental stresses. This method is superior to many published several methods in terms of its low cost and ability to analyze many samples. Methods : The urine from workers in a tire manufacturing company (22 male pre- and post-shift workers) and 18 office-workers as controls were analyzed. Data concerning age, the cumulative drinking amount and the cumulative smoking amount was collected with a questionnaire. The optimum applied amount of dansyl-Cl, the optimum reaction temperature and time, the recoveries and the optimum pH of the eluent and buffer were determined.4-Hyp from human urine was derivatized with dansyl-Cl (dimethylamino-naphthalene-1-sulfonyl chloride) after removing the a-amino acid by a treatment with phthalic dicarboxaldehyde (OPA) and cleaned with Bond Elut C18 column. The 4-Hyp derivatives were separated on a reversed phase column by gradient elution with a phosphate buffer (5 mmol, pH 8.0) and acetonitrile, and detected by fluorescence measurements at 340 nm (excitation) and 538 nm (emission). Results : The detection limit for the urinary free 4-Hyp was $0.364{\mu}mol/l$. The recovery rate of 4-Hyp was 99.7%, and the effective pH of the phosphate buffer and borate buffer were 3.0 and 8.0, respectively. From statistical analysis, age, drinking and smoking did not affect the urinary free 4-Hyp in both the controls and workers. The range of urinary 4-Hyp in the controls, pre-shift, and post-shift workers were 0.33-16.44, N.D-49.06, and $0.32-56.27{\mu}mol/l$. From the pared-sample t-test, the urinary 4-Hyp levels in post-shift workers ($11.82{\pm}6.73\;nmmol/mg\;Cre$) were 2-fold higher than in pre-shift workers ($5.36{\pm}5.53\;nmol;/mg\;Cre$) and controls ($4.91{\pm}4.89\;nmol;/mg\;Cre$). Conclusions : This method was developed with high sensitivity, accuracy, and precision. The present method was effectively applied to analyze the urinary free 4-Hyp in both controls and workers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.657-661
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• 2001

Osteoporosis that is associated with ovarian hormone deficiency following menopause (postmenopausal osteoporosis) is by far the most common cause of age-related bone loss. Isoflavone has been reported as a natural substance that possibly minimizes bone loss in postmenopausal women. This study was conducted to investigate the preventing, treating effects of isoflavone on bone loss in ovariectomized rats. 120 Sprague Dawley rats of 13 week-old were devided into 2 groups, a treatment group and prevention group. Each group was consisted of six subgroups; control (CON), sham operated (SH) or ovariectomized (OVX) and isoflavone supplemented goups: OVX+0.25mg isoflavone/kg diet (OL), OVX+0.8mg isoflavone/kg diet(OM) and OVX+2.5mg isoflavone/kg diet(OH). to study the preventing effects of isoflavone on bone loss, OL, OM and OH groups were fed with isoflavone from 4 days after ovariectomization. Treating effects of isoflavone on bone metabolism were investigated with OL, OM, OH groups supplemented with isoflavone from 8 weeks after ovariectomization. Isoflavone supplementation continued for 8 weeks. At 8 weeks after ovariectomization significant increase in alkaline phosphatase occurred comparing with CON and SH group. By isoflavone supplementation from 4 days after ovariectomy alkaline phosphatase and urinary hydroxyproline were lowered and bone mineral density, bone strength of the femur and tibia and bone dry weight were slightly enhanced with no significant difference. Isoflavone supplemented group at the level of 0.8mg/kg diet (OM group) had significantly lower serum alkaline phosphatase, urinary hydroxyproline, and higher strength of femur than OVX group. Groups with isoflavone supplementation fro 8 weeks after ovariectomy had lower level of serum alkaline phosphatase, urinary hydroxyproline than OVX group. Bone mineral density, bone dry weight and bone strength of the femur and tibia were slightly enhanced by isoflavone supplementation. However there was no significanct difference between OVS ad isoflavone supplementation groups. The results suggest that isoflavone might have potential role for preventing postmenopausal bone loss. Isoflavone supplementation at early stage of postemenopause may be beneficial to age-related bone health.

• 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.

• 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.