4 种食源性肽改善SD大鼠光老化皮肤弹性及机理的比较分析

为评价4 种食源性肽口服后对SD大鼠光老化皮肤弹性的改善效果并探讨其力学机制,将健康成年雌性SD 大鼠随机分为空白对照组、紫外线（ultraviolet,UV）辐照模型组、4 种活性肽摄取组,空白组不施行UV辐照,模 型组及肽组均行UVA＋UVB联合辐照,4 种活性肽分别配制成0.3、0.9、1.5 g/L的含肽水溶液口服,脱毛后连续UV 辐照18 周至光老化模型建立,测定皮肤弹性后将动物处死,取其背部皮肤制备匀浆,生化法测定羟脯氨酸和透明 质酸含量,酶联免疫吸附法检测Ⅰ型胶原蛋白（collagen I,Col I）、III型胶原蛋白（Col III）含量及基质金属蛋白 酶-1（matrix metalloproteinase-1,MMP-1）活力,另取部分皮肤组织进行石蜡包埋、切片后进行苏木精-伊红染色 观察。结果表明,与空白组相比,模型组大鼠皮肤弹性,Col I、羟脯氨酸、透明质酸含量显著降低（P＜0.05）, 而Col III含量及MMP-1活力显著升高（P＜0.05）,组织化学显示皮肤表皮增生,真皮层胶原纤维排列紊乱、且断 裂呈片段化聚集扭曲,基底膜溶解呈扁平化。与模型组相比,4 种活性肽口服后均能改善皮肤弹性,且样品2效果 最显著,其皮肤组织中Col I、羟脯氨酸、透明质酸含量显著升高（P＜0.05）,而Col III含量及MMP-1活力显著降 低（P＜0.05）。组织化学显示样品2摄食组大鼠表皮增生明显改善,真皮层增厚、胶原纤维增加,排列趋向均匀化 致密分布,不同程度上恢复到空白组波浪状规律排列,提示样品2提高光老化SD大鼠皮肤弹性的机理在于促进了胞 外基质（extracellular matrix,ECM）的生物合成,抑制了ECM降解酶MMP-1活力,修复了受损皮肤的力学结构。     

Characterization of fibrillar collagen types using multi-dimensional multiphoton laser scanning microscopy

In dermal photodamage the ratio of the collagen types III to I changes. This makes the investigation of the fibrillar collagen type characteristics interesting for skin research. In this study collagen types were characterized using 5-dimensional multiphoton laser scanning microscopy (5D-IVT) that can be applied in vivo. Second harmonic generation (SHG) signals and fluorescence lifetimes of the collagen autofluorescence were analysed. Collagen type I generates a higher SHG intensity and a longer fluorescence lifetime compared to collagen type III. Thus, the SHG intensity decrease found in photodamaged skin might be explained by the increase in collagen type III. Calculating the in vivo relevant increase of collagen type III gives a negligible difference in fluorescence lifetime not qualifying this method for the determination of collagen type changes in dermal photodamage in vivo in human skin. However, for pathologies that exhibit higher differences in collagen types 5D-IVT analysis might be a suitable method.     

膳食补充n-3多不饱和脂肪酸保护大鼠衰老皮肤胶原的作用及机制研究

目的:探索膳食补充n-3多不饱和脂肪酸(n-3 PUFAs)对大鼠自然老化皮肤真皮胶原的保护作用及机制。方法:选取9月龄大鼠为年轻组,22月龄大鼠作为老化n-3 PUFAs组(膳食补充n-3 PUFAs)及老化对照组(膳食中脂质成分模拟日常饮食中成分作为对照)。通过HE染色、Masson染色及Weigert染色观察年轻组大鼠、老化n-3 PUFAs组和老化对照组大鼠真皮结构变化,ELISA检测Ⅰ、Ⅲ型胶原表达量,RT-qPCR检测Ⅰ、Ⅲ、Ⅳ、Ⅴ型胶原和MMP1、MMP3、MMP9、MMP10、MMP13的mRNA表达量。结果:老化大鼠表皮较年轻大鼠变平变薄,真皮胶原排列紊乱,Ⅰ、Ⅲ型胶原含量显著减少(P<0.05),Ⅰ、Ⅲ、Ⅳ、Ⅴ型胶原mRNA表达量显著下调(P<0.05)。老化n-3 PUFAs组中Ⅰ、Ⅲ型胶原含量及mRNA相对表达量均较老化对照组显著提高(P<0.05)。老化大鼠皮肤中MMP1、MMP9、MMP10、MMP13 mRNA相对表达量均较年轻大鼠显著增多(P<0.05),老化n-3 PUFAs组中MMP10、MMP13 mRNA相对表达量较老化对照组显著降低(P<0.05)。结论:膳食补充n-3 PUFAs可促进老化大鼠皮肤Ⅰ、Ⅲ型胶原合成,减少MMP10、MMP13的表达,增加皮肤中Ⅰ、Ⅲ型胶原含量,延缓皮肤自然老化进程。     

Protective and restorative effects of a Commiphora mukul gum resin and triheptanoin preparation on the CCL-110 skin fibroblast cell line

Coenzyme Q10 (CoQ10) is a major ingredient in skin care products because of its anti‐wrinkle effects, although it has some side effects especially at higher amounts. In this study, we compare the anti‐wrinkle related properties of CoQ10 and a proprietary Commiphora mukul gum resin (guggul) and triheptanoin preparation (GU‐TC7). GU‐TC7 is prepared with a supercritical CO₂‐co‐solvent extraction with ethanol, standardized to 2% guggulsterones and triheptanoin, a triglyceride composed of three 7‐carbon fatty acids. Treatment of CCL‐110 skin fibroblasts with GU‐TC7 demonstrates a mild proliferative effect compared to CoQ10 and increased type I collagen synthesis. Additionally, GU‐TC7 inhibited matrix metalloproteinase‐1 (MMP‐1) expression in a dose‐dependent manner at 20–100 μg mL^?1 and inhibited human elastase expression by more than 50% as compared to no elastase inhibition with CoQ10 treatment. These results suggest that GU‐TC7 possesses properties that are applicable to the treatment of wrinkles and may be considered for its further evaluation in skin care products.     

The protective effects of long-term oral administration of marine collagen hydrolysate from chum salmon on collagen matrix homeostasis in the chronological aged skin of Sprague-Dawley male rats

To investigate the long-term effects of marine collagen hydrolysate (MCH) from Chum Salmon skin on the aberrant collagen matrix homeostasis in chronological aged skin, Sprague-Dawley male rats of 4-wk-old were orally administrated with MCH at the diet concentrations of 2.25% and 4.5% for 24 mo. Histological and biochemical analysis revealed that MCH had the potential to inhibit the collagen loss and collagen fragmentation in chronological aged skin. Based on immunohistochemistry and western blot analysis, collagen type I and III protein expression levels in MCH-treated groups significantly increased as compared with the aged control group. Furthermore, quantitative real-time polymerase chain reaction and western blot analysis showed MCH was able to increase the expressions of procollagen type I and III mRNA (COL1A2 and COL3A1) through activating Smad signaling pathway with up-regulated TGF-βRII (TβRII) expression level. Meanwhile, MCH was shown to inhibit the age-related increased collagen degradation through attenuating MMP-1 expression and increasing tissue inhibitor of metalloproteinases-1 expression in a dose-dependent manner. Moreover, MCH could alleviate the oxidative stress in chronological aged skin, which was revealed from the data of superoxide dismutase activity and the thiobarbituric acid reactive substances level in skin homogenates. Therefore, MCH was demonstrated to have the protective effects on chronological skin aging due to the influence on collagen matrix homeostasis. And the antioxidative property of MCH might play an important role in the process.     

Temperature effects on type I pepsin‐solubilised collagen extraction from silver‐line grunt skin and its in vitro fibril self‐assembly

BACKGROUND: Fish skin is a potential source of collagen. Increasing the extraction temperature increases the yield of collagen. However, it may also result in degradation of the peptide chains, thus damaging the 3D structure of collagen that is vital for its application as a biomaterial. This work investigated the effects of extraction temperature on the yield and characteristics, including fibril self‐assembly, of type I pepsin‐solubilised fish skin collagen. RESULTS: Pepsin‐solubilised collagens were extracted from fresh skin of silver‐line grunt at 4, 10, 20 and 28 °C for 6 h. Extraction at 10 °C gave the highest yield of collagens (439.32 ± 96.43 mg g^?1 fresh skin, dry basis), which were identified as type I and comprised β, α1 and α2 subunits. Extraction at higher temperatures (20 and 28 °C) resulted in the formation of low‐molecular‐weight peptide fragments, thus reducing the yield of the resultant type I collagen. The denaturation temperatures of collagens extracted at 4 and 10 °C, as determined by thermal analysis using differential scanning calorimetry, were 39.5 and 37.5 °C respectively. In vitro fibril self‐assembly of 1 mg mL^?1 collagen solution (pH 6) incubated at 25 °C was only observed with collagens extracted at 4 and 10 °C. The 10 °C collagen not only showed a higher rate of self‐assembly, but its matrix also had a larger fibril diameter of 0.50 ± 0.07 µm (compared with 0.41 ± 0.07 µm for the 4 °C collagen) after 4 h of incubation. CONCLUSION: The results indicated strong effects of extraction temperature on the yield and characteristics of the collagen obtained. Extraction of pepsin‐solubilised collagen from silver‐line grunt skin at 4–10 °C gave a high yield of type I collagen with molecular integrity suitable for tissue‐engineering applications. Copyright © 2010 Society of Chemical Industry     

几种生物大分子对罗非鱼皮Ⅰ型胶原自聚集性的影响

研究海藻酸钠、硫酸软骨素、透明质酸和壳聚糖对罗非鱼皮Ⅰ型胶原自聚集动力学和聚集后微观结构的影响。结果表明:在海藻酸钠、硫酸软骨素、透明质酸和壳聚糖存在的情况下,胶原自聚集过程仍然包含两个阶段:成核阶段和生长阶段,但是各物质对两阶段的动力学参数影响不同。海藻酸钠、透明质酸和壳聚糖均能够降低生长阶段的速率常数,然而对成核阶段的影响各有差异。海藻酸钠对成核阶段的速率常数没有显著影响,但是随着含量的增加能够延长成核时间;壳聚糖能够提高成核阶段的速率常数,同时缩短成核时间;透明质酸对成核阶段的速率常数和成核时间却没有显著影响。而硫酸软骨素对成核阶段和生长阶段均没有显著影响。扫描电子显微镜结果表明海藻酸钠、硫酸软骨素、透明质酸易使胶原纤维横向聚集形成纤维束,影响其直径大小的顺序为硫酸软骨素海藻酸钠透明质酸,而壳聚糖却未表现类似作用。     

Daily Ingestion of Aloe Vera Gel Powder Containing Aloe Sterols Prevents Skin Photoaging in OVX Hairless Mice

Estrogen deficiencies associated with menopause accelerate spontaneous skin aging and stimulate the ultraviolet (UV) irradiation‐induced photoaging of skin. However, food compositions with the potential to ameliorate the UV irradiation‐induced acceleration of skin aging with menopause have not yet been investigated in detail. In the present study, we examined the ability of plant sterols derived from Aloe vera gel to prevent the UV irradiation‐induced acceleration of skin aging in ovariectomized mice. Skin transepidermal water loss (TEWL) was significantly higher in the ovariectomy group than in the sham operation group following UVB irradiation, whereas skin elasticity was significantly lower. Ultraviolet B (UVB) irradiation induced greater reductions in skin hyaluronic acid levels and more severe collagen fiber damage in the derims in the ovariectomy group than in the sham group. The intake of AVGP significantly ameliorated this acceleration in skin aging by reducing the expression of matrix metalloproteinases (MMPs) and increasing that of epidermal growth factor (EGF) and hyaluronan synthase (HAS) in the skin. These results indicate that AVGP supplementation prevents skin damage induced by UVB irradiation and ovariectomy in part by inhibiting damage to the extracellular matrix.     

COLLAGEN TYPES IN MECHANICALLY DEBONED CHICKEN MEAT

Mechanically deboned chicken meat (MDCM) from neck parts was digested with pepsin for 24 h at 4C. The solubilized collagens were subjected to salt fractionation both at acidic and neutral pH. The precipitates obtained after centrifugation, dialysis and lyophilization were quantitatively evaluated and collagen types were identified. The precipitate formed at 0.7 M NaCl pH 2.5, was dissolved in 1.0 M NaCl, 0.05 M-Tris-HCl, pH 7.5 buffer and further fractionated by sequential salt precipitation at 1.8, 2.5 and 4.5 M. Collagen types I, II, III and V were detected by electrophoresis techniques. Type I collagen was the major component. The presence of type II collagen indicated MDCM contained cartilaginous tissues.     

Soybean extract showed modulation of retinoic acid‐related gene expression of skin and photo‐protective effects in keratinocytes

Soy extracts are well known as medicinal and nutritional ingredients, and exhibit benefits towards human skin including depigmenting or anti‐ageing effects. Despite the wrinkle decreasing effects of retinoids on skin as an anti‐ageing ingredient, retinoid application can causes photo‐sensitive responses such as skin irritation. Thus, their daytime usage is not recommended. The aim of this study is the investigation into the activities of soybean extract as an anti‐ageing ingredient and their comparison to retinoids in this respect. Soybean extract decreased the relative ratio of MMP‐1/TIMP‐1 mRNA to the same degree as retinoic acid in normal human fibroblasts. It also affected mRNA levels of HAS2 and CRABP2 in normal human keratinocytes. Furthermore, we investigated its effect on mRNA expression of histidase, an enzyme that converts histidine into urocanic acid, the main UV light absorption factor of the stratum corneum. Unlike the complete inhibition of histidase exhibited by the mRNA expression of retinoic acid, the effect of soybean extract on histidase gene expression was weaker in normal human keratinocytes. Also, soybean extract pretreatment inhibited UVB‐induced cyclobutane pyrimidine dimer formation dose‐dependently in normal human keratinocytes. In this study, we found that soybean extract modulated retinoic acid‐related genes and showed photo‐protective effects. Our findings suggest that soybean extract could be an anti‐ageing ingredient that can be safely used under the sunlight.     

皮胶原的结构、性质与提取方法

简要介绍了动物皮胶原的结构组成和物化性质,着重综述了最近几年国内外从猪皮、牛皮和鱼皮中提取胶原的工艺方法。     

Epidermal and dermal changes in response to various skin rejuvenation methods

During the last years, a number of new devices have been developed to improve the dermal and epidermal signs of photo‐ and chronological skin ageing. There are well‐established ablative and non‐ablative skin resurfacing options using different lasers and light sources, but side effects have been observed frequently. A recently developed photorejuvenation method using non‐thermal stimulation of skin cells with low energy and narrow band light has been termed photomodulation. Light emitting diodes are the ideal source of this kind of light that stimulate mitochondrial cell organelles leading to up‐regulation of cytochrome electron transport pathway leading to mitochondrial DNA gene modulation. This paper reviews the most current knowledge of intrinsic and extrinsic changes of ageing and summarizes different systems for skin rejuvenation with focus on non‐thermal non‐ablative skin rejuvenation modalities.     

Characteristics of collagen from the skin of clown featherback (Chitala ornata)

Acid soluble collagen (ASC) and pepsin soluble collagen (PSC) from the skin of clown featherback (Chitala ornata) were isolated and characterised. Yields of ASC and PSC were 27.64 and 44.63% (dry weight basis) with total collagen recovery of 82.08%. Both collagens contained glycine as the major amino acid with relatively high content of proline, hydroxyproline and glutamic acid/glutamine. Nevertheless, they had the low content of cysteine, histidine and tryrosine. The collagen was characterised as type I, comprising (α1)₂α2‐heterotrimer. Pepsin‐aided process did not affect triple‐helical structure of PSC as determined by FTIR spectra. Thermal transition temperature of ASC (36.28 °C) was slightly higher than that of PSC (35.23 °C). However, no differences in isoelectric point (5.54–5.68) between ASC and PSC were observed. Therefore, collagen from the skin of clown featherback could be successfully extracted for further applications.     

Effect of Raw and Heat‐Moisture Treated High‐Amylose Corn Starch on Fermentation by the Rat Cecal Bacteria

Resistant starch content of high‐amylose corn starch (HAS) was doubled by heat‐moisture treatment. Resistant starch content of HAS and heat‐moisture treated high‐amylose corn starch (HMT‐HAS) were 31.8 and 67.3%, respectively, as determined by enzymatic‐gravimetric method. Effects of the two types of high‐amylose corn starches, HAS and HMT‐HAS, on starch fermentation, microflora, pH, short chain fatty acid (SCFA) content and β‐glucuronidase activity in the cecal content have been investigated. Rats were given ordinary corn starch (OCS; control), HAS or HMT‐HAS at 10% level for 10 13 days. The cecal and colorectal content s weights were larger in HAS and HMT‐HAS groups than in the OCS group. The cecal content s weight did not differ between HAS and HMT‐HAS groups, while the colorectal content s weight was higher in the HMT‐HAS group than in the HAS group. The upper and lower small intestinal and cecal starch contents were significantly higher in the HAS and HMT‐HAS groups than in the OCS group, whereas there were no differences between colorectal starch content in group OCS and HAS. Starch excretion in feces was significantly higher in groups HAS and HMT‐HAS than in group OCS, the increase in the HMT‐HAS group was especially remarkable. The composition of the cecal microflora was not effected by the diet. β‐Glucuronidase activities in rats fed HAS or HMT‐HAS decreased. SCFA concentration was higher in groups HAS and HMT‐HAS than in group OCS, and the cecal pH was lower in groups HAS and HMT‐HAS than in group OCS.     

Collagens from the skin of arabesque greenling (Pleurogrammus azonus) solubilized with the aid of acetic acid and pepsin from albacore tuna (Thunnus alalunga) stomach

BACKGROUND: Due to the low extraction efficiency of collagen from fish skin by the typical acid solubilization process, pepsin has been widely used to aid further extraction of collagen from the residue. The aim of this study was to characterize collagen from the skin of arabesque greenling extracted with the aid of albacore tuna pepsin, in comparison with collagen obtained from the acid solubilization process. RESULTS: Acid‐solubilized collagen (ASC) from the skin of arabesque greenling was extracted with acetic acid. Pepsin‐solubilized collagen (PSC) was further extracted from the skin residue with the aid of pepsin from albacore tuna. The yields of ASC and PSC were 303 and 140 g kg^?1 (dry weight), respectively. Both collagens contained α‐ and β‐chains as their major components and were characterized as type I collagen. Both collagens contained glycine as a major amino acid and had imino acid content of 157–159 residues per 1000 residues. The degradation induced by lysyl endopeptidase and V8‐protease was more pronounced in PSC compared with ASC. Maximal transition temperatures of both collagens were in the range of 15.4–15.7 °C. Fourier transform infrared spectra revealed some differences in molecular order between ASC and PSC. Nevertheless, the triple‐helical structure of PSC was still predominant. Based on ζ‐potential, pI of ASC and PSC was estimated to be 6.31 and 6.38, respectively. CONCLUSION: Isolation of collagens from the skin of arabesque greenling could be achieved by acid or albacore tuna pepsin solubilization. However, there was a slight difference in properties between ASC and PSC. Copyright © 2010 Society of Chemical Industry     

Effect of raw and heat–moisture‐treated high‐amylose corn starches on the process of digestion in the rat digestive tract

High‐amylose corn starch (HAS) is widely known as a resistant starch foodstuff. We developed heat–moisture‐treated high‐amylose corn starch (HMT‐HAS) that was more resistant to enzymatic hydrolysis. Resistant starch contents of HAS and HMT‐HAS using the enzymatic–gravimetric method were found to be 30% and 65% respectively. Rats were given 10% ordinary corn starch (CS), HAS or HMT‐HAS by meal feeding for 10 days. The caecum contents increased and the caecal pH was lower after their diets were supplemented with HAS and HMT‐HAS. Starch contents increased in the upper and the lower small intestine with HAS and HMT‐HAS. Caecal starch with HAS and HMT‐HAS was more than that with CS. Particularly, caecal starch with HMT‐HAS was seven times more than that with HAS. There were no differences in starch content in the large bowel between CS and HAS, but the content increased with HMT‐HAS. These results suggested that HAS and HMT‐HAS were resistant to digestion and absorption in the small intestine, and any indigestible starches reached the caecum. In the caecum, HAS was hydrolysed almost completely by intestinal bacteria; however, some HMT‐HAS escaped bacterial hydrolysis. This escaped HMT‐HAS reached the large bowel and was excreted in the faeces. © 1999 Society of Chemical Industry     

Effect of Excitation Wavelength on the Separation of Types I and III Collagen by Fiber Optic Fluorimetry

The fluorescence of bovine tendon and adipose tissue and purified Types I and III collagen was measured with fiber optics. Fluorescence of Type I collagen was stronger than for Type III collagen over a range from 410 to 470 nm. Around 510 and 520 nm, however, both Type I and Type III collagen exhibited a similar degree of weak fluorescence. Fluorescence of intact tendons and adipose tissue resembled that of Type I and Type III collagen, respectively. The 510/440 nm ratio of fluorescence was used to identify Types I and III collagen. The optimum excitation wavelength for identification was 370 nm. Type IV (basement membrane) collagen had a similar fluorescence to Type III collagen so that fluorescence from these two sources would be combined in measurements made on intact samples of meat.     

Sorption of Eu(III) on humic acid or fulvic acid bound to hydrous alumina studied by SEM-EDS, XPS, TRLFS, and batch techniques

To identify the effect of humic acid (HA) and fulvic acid (FA) on the sorption mechanism of Eu(III) on organic--inorganic colloids in the environment at a molecular level, surface adsorbed/ complexed Eu(III) on hydrous alumina, HA-, and FA-hydrous alumina hybrids were characterized by using X-ray photoelectron spectroscopy (XPS) and time-resolved laser fluorescence spectroscopy (TRLFS). The experiments were performed in 0.1 mol/L KNO3 or 0.1 mol/L NaClO4 under ambient conditions. The pH values were varied between 2 and 11 at a fixed Eu(III) concentration of 6.0 x 10(-7) mol/L and 4.3 x 10(-5) mol/L. The different Eu(III)/FA(HA)/hydrous alumina complexes were characterized by their fluorescence emission spectra ((5D0-F1)/ (5D0 --> 7F2)) and binding energy of Eu(III). Inner-sphere surface complexation may contribute mainly to Eu(III) sorption on hydrous alumina, and a ternary surface complex is formed at the HA/ FA-hydrous alumina hybrid surfaces. The sorption and species of Eu(III) in ternary Eu-HA/FA-hydrous alumina systems are not dominated by either HA/FA or hydrous alumina, but are dominated by both HA/FA and hydrous alumina. The results are important for understanding the sorption mechanisms and the nature of surface adsorbed Eu(III) species and trivalent chemical homologues of Eu(III) in the natural environment.