• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.501-506
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• 1997

As pyridinoline is one of the predominant cross-lins in a mature collagen, pyridinoline formation may be an essential step during the growth process to obtain normal mechanical strength in collagen fibrils. However, the excess formation of pyridinoline in collagen will probably make the tissue stiffer, less soluble and less digestible by enzymes. We investigated the changes of pyridinoline of bone collagen and the role of ascforbic acid(AsA) on the formation of pyridinoline. The pyridinoline content of bone collagen significantly increased during incubation for 1~5 weeks at 37$^{\circ}C$ in vitro. The addition of AsA decreased pyridinoline to half the amount found in controls with 5 week incubation. When dehydroascorbic acid(DHA) and L-2, 3-diketogulonic acid (DKG), the oxidative products of AsA, were supplemented to bone collagen solution instead of AsA, the content of pyridinoline in bone collagen was about 80% or 70% that of controls, respectively. These results suggest that pyridinoline content decreases by the addition of AsA in vitro. Furthermore, it was shown that AsA in oxidized from also affected the formation of pyridinoline.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.2
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• pp.305-312
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• 1998

Normal tensile strength in collagen fibrils is due to intermolecular and intramolecular crosslinks which are known to be altered in aging. Pyridinoline, a mature crosslink which is stable and nonreducible, is derived from two hydroxyallysine and one hydroxylysine residues of collagen fibrils. The excess formation of pyridinoline in collagen is associated with making the tissue stiffer, less soluble and less digestible by enzymes. Lysyl oxidase is the enzyme that initiates the biosynthesis or crosslinks in collagen by catalyzing the oxidative deamination of the lysyl and hydroxylysyl residues in these molecules, and its activity is inhibited by $\beta$-aminopropionitrile(BAPN). Our previous work demonstrated that the pyridinoline content of bone collagen significantly was increased during incubation for 5 weeks at 37$^{\circ}C$ invitro, but it was diecrased by the addition of ascorbic acdi(AsA). In this study, we clarified the specific action of AsA in aging process in vitro enzymatic reaction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.324-330
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• 2004

The purpose of this study was to investigate the effects of Porphyra tenera (PT) extracts on formation of collagen cross-link in ovariectomized rats. From day 3 until 42 after the ovariectomy, Sprague-Dawley female rats were randomly assigned to the following groups : sham-operated rats (Sham), ovariectomized control rats (OVX-control), ovariectomized rats supplemented with PT at 50 mg/kg bw/day (OVX-PT5O), 200 mg/kgbw/day (OVX-PT200). The PT ethanol extracts were orally administrated 1 mL per day. Body weight gain, food intake and food efficiency ratio were significantly different among the groups. The change of collagen content was studied in lung, bone, cartilage and skin of ovariectomized rats. The effects of PT extracts on the amount of collagen were examined by measuring the hydroxyproline, which is a specific amino acid existing in collagen. Pyridinoline is pyridinium cross-link formed in the mature form of collagen from lysine and hydroxylysine residues. Pyridinoline content was analyzed by HPLC. Pyridinoline content in bone collagen was decreased by ovariectomy but supplementation with the PT extracts was similarly increased to Sham. These results suggest that the PT supplementation could decrease bone loss in postmenopausal women.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.6
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• pp.1332-1338
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• 1999

Intermolecular collagen cross links stabilize collagen fibrils and are necessary for normal tensile strength in collagen fibrils. Once the fibrils are aligned, hydroxyllysine, hydroxylysine derived aldehyde modified enzymatically, reacts with hydroxylysine to form the dehydrodihydroxylysinonorleucine (DHLNL), an immature crosslink. Pyridinoline, one of matured cross links is presumably formed nonenzymatically through condensation of DHLNL and hydroxylysine residue. It is widely distributed in hard connective tissues such as cartilage, bone and tendon. L ascorbic acid(AsA) is well known to be required for the enzymatic hydroxylation of proline and lysine in collagen fibrils. The purpose of this study is to clarify the role of AsA on the biosynthesis of DHLNL in vitro. We examined the effect of AsA on the formation of hydroxylysine and DHLNL in collagen. Pyridinoline and DHLNL were measured as a function of time. The contents of DHLNL was increased, reached maximum within 2 hr and was held until 24 hr, then it decreased slowly. On the contrary, pyridinoline increased gradually after 24 hr and continued to increase for 2 weeks. Moreover, the contents of DHLNL remarkably decreased at 60 min after incubation, the contents of DHLNL was decreased by addition of AsA or dehydroascorbic acid(DHA). These results suggest that the supplementation of AsA causes decrease in DHLNL formation and pyridinoline formed by nonenzymatic reaction of DHLNL.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.475-479
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• 1997

A decrease in the circulating levels of estrogen, occuring as a consequence of post menopausal decline or from surgical ovariectomy, results in an accelerated loss of bone. Estrogen has been shown to stimulate lysyl oxidase activity, and the treatment with estrogen increased the pyridinium content of cortical bone. a trivalent mature cross-links collagen fibrils named pyridinoline, which is especially abundant in collagen of cartilage and bone, markedly increases with growth in humans and rats. The main aim of this study was to examine the increased bone loss caused by ovariectomy through monitoring the concentrations of the collagen and the pyridinium cross-links of collagen, pyridinoline. The ovariectomized rats, 4 weeks old, were divided at random into two or three groups of 5. Ovariectomies were carried out on both of the saline-treated group(OVX(NH)) and the estrogen-treated group(OVX(H)) using the dorsal approach and sham operations were performed on the sham-operated group(sham). They were maintained under identical conditions for 4 or 8 weeks and were allowed free access to food and water. it was observed that there was no significant difference between the control group and the sham-operated group, however, the control group had a higher content of collagen than the saline-treated group after 4 weeks and 8 weeks. Based on these results, iot is supposed that estrogen can enhance collagen synthesis and affects the pyridinoline formation in collagen fibrils through stimulating lysyl oxidase activity.

• Journal of Food Hygiene and Safety
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• v.14 no.1
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• pp.45-54
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• 1999

The purpose of this study was to examine the increased bone loss caused by ovariectomy through monitoring the concentrations of the collagen and the pyridinoline crosslinks of collagen. The ovariectomized rats treated for 8 weeks, were divided at random into two or three groups of 10. Ovariectomies were carried out from the saline-treated group (Ovx), the estrogentreated group (Ovx+ES) and chondroitin sulfate-treated group (Ovx+CS). Sham operations were performed on the sham-operated group (Sham). Ovx+ES and Ovx+CS groups showed the remarkably increased collagen and pyridinoline amount in the bone and cartilage compared to Ovx group. And as the result of the measurement of SOD, Catalase and GPx which are antioxidant enzyme, SOD and Catalase activities in Ovx group were much higher than in Sham group. But they were significantly decreased in Ovx+CS group. Based on these results, it is supposed that estrogen and condroitin sulfate can enhance collagen synthesis and affect the pyridinoline formation in collagen fibrils through stimulating lysyl oxidase activity. And it is also thought that chondroitin sulfate can inhibit aging by reducing antioxidant enzyme.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.931-936
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• 2007

The aim of this study was to evaluate the effects of Codium Fragile(CF) extract on the collagen content and collagen cross-link content of the connective tissues, alkaline phosphatase activity and calcium levels of serum in ovariectomized estrogen-deficient rats. Three groups were surgically ovariectomized. The fourth group was sham operated. Sprague-Dawley female rats were randomly assigned to the following groups : sham-oper-ated rats(Sham), ovariectomized control rats (OVX-CON), ovariectomized rats supplemented with CF at 50 mg/kg body wt and 200 mg/kg body wt, respectively The CF were orally administrated at 1mLa day. The ovariectomy caused a decreasing in collagen content in bone, cartilage, skin and lung tissues. However CF groups, supplementation with Codium Fragile extract, increased in collagen contentin bone and cartilage tissues than OVX-CON group. Fyridinoline content in cartilage collagen was de-creased by ovariectomy but supplementation with the CF extracts was similarly increased to Sham. Alkaline phosphatase activity on serum of CF groups decreased than OVX-CON group. These results suggest that CF supplementation prevents post-menopausal bone loss, thus it may be used possibly to improve the quality of life in menopausal women.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.1
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• pp.33-39
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• 2013

Menopause is often associated with several chronic diseases, including osteoporosis, cardiovascular disease, and obesity. In this study, we investigated the ability of Eisenia bicyclis (EB) to prevent bone loss in ovariectomized rats, a model for postmenopausal osteoporosis. Extracts from EB obtained using ethanol or hot water were analyzed for total polyphenol content and osteoporosis effects in vivo. Total polyphenol content was higher with extraction by hot water compared to ethanol extraction. Fifty 8-week-old female Sprague-Dawley rats were randomly assigned to four groups: the group were sham-operated rats (SHAM), ovariectomized rats (OVX-CON), and ovariectomized rats that were treated with EB at 50 mg/kg body weight (OVX-EB50) and 200 mg/kg body weight (OVX-EB200), respectively. The diets were fed to rats for 6 weeks after their operation. We found that the alkaline phosphatase (ALP) activity was lower in the EB extract group compared to the OVX-CON group. Collagen and pyridinoline content, in bone and cartilage, were reduced by ovariectomy, but the supplemented EB extract groups exhibited higher concentrations in their bones. These results suggest that EB can be used for the industrial development of foods with therapeutic functions.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.863-866
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• 2001

Antioxidative activites and anti skin aging effects of radish(Raphanus sativus L. var. sativus) extracts were studied. The DPPH(1,1-Diphenyl-2-picrylhydrazal) inhibitory effects and CAT(Catalase) activities of hydrophilic radish extracts(DPPH 81.0%, CAT 175units/mg) were significantly higher than lipophilic radish extracts(DPPH 50.0%, CAT 45unitg/mg). But, SOD(superoxide dismutase) activities of hydrophilic radish extracts(SOD 81.3%) were lower than lipophilic radish extracts(SOD 92.3%) In the Bovine Achilles Tendon collagen treated with hydrophilic radish extracts and lipophilic radish extracts, the pyridinoline concentration of collagen were decreased, respectively.

• Journal of Nutrition and Health
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• v.28 no.9
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• pp.817-824
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• 1995

This study was performed to evaluate the effect of dietary protein level on Ca efficiency in bone mineral density in growing male rats. Twenty male rate were divided into two groups. The rats in one group were fed on casein 20% diet as control group and the others were fed on casein 40% diet as protein group. All rats were fed on experimental diet and deionized water ad libitum for 9 weeks. The total body, spine and femur bone mineral density and bone mineral content were measured using dual energy-x ray absorptiometry. Urinary calcium, phosphate, pyridinoline and creatinine, serum calcium, phosphate, total protein, albumin, alkaline phosphatase(ALP) and osteocalcin were measured. Urinary Ca excretion, pyridinoline and crosslinks value and serum ALP content seem to be increased in high protein group. It appears that the growing rats in high protein group had a higher bone resprption and bone formation than those in control group. Animal fad a high protein diet had a siginficantly higher Ca efficiency in BMD, BMC of total body, spine and femur. The results of this show that increasing of dietary protein level (40%) is beneficial of improvement of Ca efficiency during growing period.