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1.
Collagen treated with (+)-catechin becomes resistant to the action of mammalian collagenase 总被引:1,自引:0,他引:1
Treatment of radioactively labeled guinea-pig skin soluble collagen or calf skin collagen with the flavonoid (+)-catechin makes the collagen resistant to the action of mammalian collagenase but not to the action of bacterial collagenase. Complete resistance to the action of the mammalian enzyme may be achieved by incubating 0.6 mg of collagen (dry weight) with 0.1 mM (+)-catechin, followed by dialysis to remove the unbound flavonoid. Since incubation of the mammalian enzyme with (+)-catechin does not inhibit its activity, it is postulated that (+)-catechin binds tightly to collagen and modifies its structure sufficiently to make it resistant to enzyme degradation. 相似文献
2.
G. Francis Patricia V. Donnelly N. di Ferrante 《Cellular and molecular life sciences : CMLS》1976,32(6):691-693
Summary Abnormally soluble collagen is synthesized in vitro not only by skin fibroblasts of Marfan patients but also by those of patients with Ehlers-Danlos type V and cutis laxa. The excessive solubility of collagen is corrected by the addition to the culture medium of a synthetic flavonoid, (+)-catechin.Supported by grants from the National Institutes of Health (Nos. AM-10811, HL-05435, GM-19513 and GM-00081), the National Fondation-March of Dimes, and Zyma, S.A., Nyon, Switzerland. 相似文献
3.
The ability of dog renal cortex slices to accumulate beta-methyl-glucoside or glycine is enhanced by the flavonoid (+)-catechin at a concentration of 3.5 mM. This stimulatory effect is apparently due to a decreased rate of efflux of either substrate. On the other hand, the uptake of p-amino-hippuric acid and N1-methyl-nicotinamide is inhibited by (+)-catechin. The drug at the same concentration is without action on amino-acid transport by guinea-pig intestine in vitro. 相似文献
4.
Inhibitory effects of phenolic compounds on CCl4-induced microsomal lipid peroxidation 总被引:2,自引:0,他引:2
The antiperoxidative effects of 35 phenolic compounds, most of them belonging to the flavonoid class, were investigated using CCl4-induced peroxidation of rat liver microsomes. This system was rather insensitive to gallic acid, methyl gallate and ellagic acid. Nevertheless it was inhibited by flavonoids and structure/activity relationships were established. The most potent compounds were gardenin D, luteolin, apigenin (flavones), datiscetin, morin, galangin (flavonols), eriodictyol (flavanone), amentoflavone (biflavone) and the reference compound, (+)-catechin. The natural polymethoxyflavone gardenin D has shown a potency comparable to that of (+)-catechin and higher than that of silybin. Thus, it may be considered as a new type of natural antioxidant with potential therapeutical applications. 相似文献
5.
Summary The antiperoxidative effects of 35 phenolic compounds, most of them belonging to the flavonoid class, were investigated using CCl4-induced peroxidation of rat liver microsomes. This system was rather insensitive to gallic acid, methyl gallate and ellagic acid. Nevertheless it was inhibited by flavonoids and structure/activity relationships were established. The most potent compounds were gardenin D, luteolin, apigenin (flavones), datiscetin, morin, galangin (flavonols), eriodictyol (flavanone), amentoflavone (biflavone) and the reference compound, (+)-catechin. The natural polymethoxyflavone gardenin D has shown a potency comparable to that of (+)-catechin and higher than that of silybin. Thus, it may be considered as a new type of natural antioxidant with potential therapeutical applications. 相似文献
6.
Summary The ability of dog renal cortex slices to accumulate -methyl-glucoside or glycine is enhanced by the flavonoid (+)-catechin at a concentration of 3.5 mM. This stimulatory effect is apparently due to a decreased rate of efflux of either substrate. On the other hand, the uptake of p-amino-hippuric acid and N1-methyl-nicotinamide is inhibited by (+)-catechin. The drug at the same concentration is without action on amino-acid transport by guineapig intestine in vitro.This study was supported by grants from Zyma S.A., Nyon. We are grateful to MmesH. Capt andP. Ganguillet and MlleD. Mettraux for their skilful technical assistance. 相似文献
7.
Zusammenfassung Experimentelle Prüfung beim Goldhamster,Mesocricetus auratus, ob Nieren- oder Gehirnmissbildungen einen Einfluss auf die Quantität der Amnionflüssigkeit ausüben, was nur für die Gehirnmissbildungen bejaht werden konnte.
This work was supported by research grants from the Easter Seal Research Foundation of the National Society for Crippled Children and Adults, Inc. and from USPHS grant No. HD 03298. 相似文献
This work was supported by research grants from the Easter Seal Research Foundation of the National Society for Crippled Children and Adults, Inc. and from USPHS grant No. HD 03298. 相似文献
8.
Stabilisation of collagen by betel nut polyphenols as a mechanism in oral submucous fibrosis 总被引:3,自引:0,他引:3
Treatment of reconstituted collagen fibrils and pieces of rat dermis with the crude extract, purified tannins or (+)-catechin from betel nut (Areca catechu) increases their resistance to both human and bacterial collagenases in a concentration-dependent manner. These tanning agents may stabilise collagen in vivo following damage to the oral epithelium, and promote the sub-epithelial fibrosis which occurs in betel nut chewers. 相似文献
9.
Suppressed collagenolytic activity in polymorphonuclear leucocytes from diabetic humans 总被引:1,自引:0,他引:1
G. A. Nicoll G. M. Gollapudi N. S. Ramamurthy L. M. Golub 《Cellular and molecular life sciences : CMLS》1981,37(3):315-317
Summary Extracts of polymorphonuclear leucocytes (PMNL) from diabetic human exhibited less collagenolytic activity than extracts from normoglycemic control subjects. Partially purified control extracts produced A and B collagen breakdown products of the type generated by mammalian collagenase; the diabetic preparation produced decreased amounts of the same products. The diabetic PMNLs may synthesize abnormally low levels of collagenase or contain inactive forms of this enzyme.Supported by a grant (No. DE-03987) from the National Institute of Dental Research (N.I.H.), USA. This study forms part of the Ph.D. thesis of G.A. Nicoll.Acknowledgments. The authors wish to thank Ms Salema Karim and Mr F.R. Singh for excellent technical assistance. 相似文献
10.
A. Scutt S. Meghji J. P. Canniff W. Harvey 《Cellular and molecular life sciences : CMLS》1987,43(4):391-393
Summary Treatment of reconstituted collagen fibrils and pieces of rat dermis with the crude extract, purified tannins or (+)-catechin from betel nut (Areca catechu) increases their resistance to both human and bacterial collagenases in a concentration-dependent manner. These tanning agents may stabilise collagen in vivo following damage to the oral epithelium and promote the sub-epithelial fibrosis which occurs in betel nut chewers. 相似文献
11.
A. M. Hackett I. C. Shaw L. A. Griffiths 《Cellular and molecular life sciences : CMLS》1982,38(5):538-540
Summary The major urinary metabolites of (+)-catechin (cyanidanol-3) in the rat were (+)-catechin glucuronide, 3′-O-methyl-(+)-catechin
glucuronide and 3′-O-methyl-(+)-catechin sulphate. The latter conjugate was the major metabolite in marmoset urine.
To whom reprint requests should be addressed.
Acknowledgment. The authors wish to thank Miss Rosemary Dring and Mr P.B. Wood for skilled technical assistance, Zyma S.A.,
Nyon, Switzerland, for financial support, and the Medical Research Council for a research studentship (to I.C.S.). 相似文献
12.
J. V. Mai V. R. Edgerton R. J. Barnard 《Cellular and molecular life sciences : CMLS》1970,26(11):1222-1223
Résumé Le dressage des cochons d'Inde sur un moulin de discipline augmente la capillarité des fibres musculaires rouges, tandis que les fibres blanches et intermédiaires ne changent pas. Ces résultats sont compatibles avec les données précédentes qui conseillent d'employer de préférence les fibres rouges dans les exercices de résistance.
This study was supported in part by the Easter Seal Research Foundation of the National Society for Crippled Children and Adults, Inc. and USPHS Grants Nos. NB 07587, HD 02584 and GM 15759. 相似文献
This study was supported in part by the Easter Seal Research Foundation of the National Society for Crippled Children and Adults, Inc. and USPHS Grants Nos. NB 07587, HD 02584 and GM 15759. 相似文献
13.
S Despres H Métivier R Weill 《Comptes rendus des séances de l'Académie des sciences. Série D, Sciences naturelles》1980,290(1):41-44
The behaviour of cariogenic Bacteria (Streptococcus mutans) is studied with regard to collagen, which represents 90% of the dentine organic matrix. Collagenase activity of cariogenic Bacteria is measured with radioactive precursors and gel electrophoresis and compared to reference bacterial collagenase (Clostridium histolyticum). Labelled collagen substrate has been prepared with two different methods: extraction by 0,5 M acetic acid from young Rat skin, previously labelled with L-proline 14C, or reduction by Na B3H4. Both collagen sutstrates have been incubated for 2 h in Terleckyj medium in which the Streptococcus mutans have been inoculated. The experiments show a proteolytic activity of Streptococcus Mutans on the collagen substrate. 相似文献
14.
D. Campbell L. Hellgren B. Karlstam J. Vincent 《Cellular and molecular life sciences : CMLS》1987,43(5):578-579
Summary The wound-debriding activity of various types of proteolytic enzymes and proteases from Antarctic krill (multi-enzyme system consisting of both endo- and exopeptidases) was evaluated. The results, based on the enzymatically acieved weight reduction of a necrotic animal material (excised rat skin) in vitro, clearly showed that the multi-enzyme system (krill) had a higher degrading activity than the single enzyme preparation, or that with only a few enzymes. The debriding effect of the krill enzymes was markedly related to the enzyme concentration, resulting in 70–100% substrate degradation after 24 h. The digesting capacity of trypsin reached about 50%, but an increase in concentration of this enzyme did not substantially influence its overall activity. The effect of streptokinase-streptodornase, collagenase and plasmin-desoxyribonuclease was weak (10–20% digested). 相似文献
15.
Tyrosinase inhibitors from natural and synthetic sources: structure, inhibition mechanism and perspective for the future 总被引:2,自引:0,他引:2
Tyrosinase is known to be a key enzyme in melanin biosynthesis, involved in determining the color of mammalian skin and hair. Various dermatological disorders, such as melasma, age spots and sites of actinic damage, arise from the accumulation of an excessive level of epidermal pigmentation. In addition, unfavorable enzymatic browning of plant-derived foods by tyrosinase causes a decrease in nutritional quality and economic loss of food products. The inadequacy of current conventional techniques to prevent tyrosinase action encourages us to seek new potent tyrosinase inhibitors. This article overviews the various inhibitors obtained from natural and synthetic sources with their industrial importance.Received 9 February 2005; received after revision 4 April 2005; accepted 14 April 2005 相似文献
16.
Summary The granule fraction of human polymorphonuclear leucocytes (PMNs), the concentrated product of gingival washing from 2 human volunteers and the culture fluid of samples of human gingiva were incubated with neutral salt soluble collagen from rat skin and the patterns of collagen degradation were studied by SDS polyacrylamide gel electrophoresis. Collagenase from human gingiva cleaved the collagen molecules in a fashion similar to that of the PMN granule fraction. Collagen was also attacked by elastase from human PMNs and, to a lesser extent, by elastase from the gingival washings.Supported by a grant of Swiss National Fund for Scientific Research No. 3.604.0.75.Acknowledgments. We thank Prof. M. Baggiolini, Wander S.A., Bern for his helpful advice. We are very grateful to Mrs I. Condacci and Miss E. Andersen for their skillful technical assistance. 相似文献
17.
Summary The (+)-catechin stimulates the multiplication and the protidic biosynthesis ofP. fluorescens. Its effect seems related to a modification of the terminal respiratory pathway. 相似文献
18.
Annexin V was originally identified as a collagen-binding protein called anchorin CII and was isolated from chondrocyte membranes
by affinity chromatography on native type II collagen. The binding of annexin V to native collagen type II is stable at physiological
ionic strength when annexin V is reconstituted in liposomes. The binding to native collagen types II and X, and to some extent
to type I as well, was confirmed using recombinant annexin V. A physiological role for annexin V interactions with extracellular
collagen is consistent with the localization of annexin V on the outer cell surface of chondrocytes, microvilli of hypertrophic
chondrocytes, fibroblasts and osteoblasts. A breakthrough in our understanding of the function of annexin V was made with
the discovery of its calcium channel activity. At least one of several putative functions of annexin V became obvious from
studies on matrix vesicles derived from calcifying cartilage. It was found that calcium uptake by matrix vesicles depend on
collagen type II and type X binding to annexin V in the vesicles and was lost when collagens were digested with collagenase;
calcium influx was reconstituted after adding back native collagen II or V. These findings indicate that annexin V plays a
major role in matrix vesicle-initiated cartilage calcification as a collagen-regulated calcium channel. 相似文献
19.
The epiphyseal cartilage from new-born mouse was treated with collagenase in two ways: either before fixation or after glutaraldehyde fixation. The electron dense granules of the matrix were not seen in the micrographs of cartilage treated with collagenase before fixation. It is concluded that collagen plays a definite role in the formation of the granules at the time of tissue fixation and that the granules are fixation artifacts. 相似文献
20.
Summary Silybin significantly antagonises the lethal poisoning of mice with -amanitine or phalloidine. In the same test, taxifolin, coniferyl alcohol, fisetin and (+)-catechin were not effective. 相似文献