牛初乳中IGF-I提取物对肠黏膜修复作用的研究

目的:研究牛初乳中胰岛素生长因子-I（IGF-I）对大鼠受损肠黏膜的修复作用。方法:应用氨甲喋呤制备大鼠小肠炎模型,实验设正常对照组,MTX模型对照组（20μg/kg）,牛初乳IGF-I提取物修复组（75μg/kg）,IGF-I修复组（75μg/kg）。后2组每天灌胃给药1次,给药时间从造模后第2d开始至实验结束,共5d。第6d检测大鼠血浆二氨氧化酶（DAO）活性、血浆D-乳酸水平,光镜下观察小肠组织病理形态学改变。结果:与对照组相比,模型组大鼠血浆DAO活性和血浆D-乳酸水平明显升高（P<0.05）,小肠损伤程度明显高于对照组（P<0.05）,牛初乳中IGF-I提取物组和IGF-I组可降低血浆DAO活性及D-乳酸水平（P<0.05）,减轻小肠损伤程度（P<0.05）。结论:牛初乳中IGF-I提取物能够明显减轻大鼠肠黏膜的损伤,同时可减轻炎细胞的浸润,对实验性大鼠的小肠炎具有修复作用。      

Exploration of the bovine colostrum proteome and effects of heat treatment time on colostrum protein profile

Heat treatment of colostrum is performed on modern dairy farms to reduce pathogenic contamination before hand-feeding the colostrum to newborn calves; however, limited data are available concerning effects of heat treatment on biologically active proteins in colostrum. The objective of this exploratory study was to investigate effects of heat treatment and length of heat treatment on colostrum protein profile. Colostrum samples were collected from Holstein cows within 12 h after parturition and assigned to the following groups: heat treatment at 60°C for 0 (untreated control), 30, 60, or 90 min. Samples were fractionated using acid precipitation, followed by ultracentrifugation and ProteoMiner (Bio-Rad Laboratories, Hercules, CA) treatment, and tandem-mass tagging was used to comparatively assess the low abundance protein profile. A total of 162 proteins were identified with more than 2 peptides in the low abundance protein enriched fraction. Of these, 62 differed in abundance by more than 2-fold in heat-treated samples compared with the unheated control. The majority of proteins affected by heat treatment were involved in immunity, enzyme function, and transport-related processes; affected proteins included lactadherin, chitinase-3-like protein 1, and complement component C9. These results provide a foundation for further research to determine optimum heat treatment practices to ensure newborn calves are fed colostrum-containing proteins with the highest nutritional and biological value.     

In vitro cytomodulatory and immunomodulatory effects of bovine colostrum whey protein hydrolysates

Bovine colostrum possesses biological compounds involved in the development of the newborn. Among them, the proteins have drawn attention as a source of bioactive peptides. This study shows the in vitro cytotoxic and immunostimulatory potential of two colostrum whey protein (CWP) hydrolysates obtained by in vitro digestion with pepsin and pancreatin. MTT cell viability, apoptosis induction, polymorphonuclear proliferation and phagocytic activity assays were performed. Treatment with the hydrolysates induced a significant decrease in the viability of MDA-MB-231 cell lines due to apoptosis and also a significant increase in the proliferation of blood mononuclear cells. It could also be observed that for the RM-1 and PC-3 prostate cancer cell lines and for the two times of exposure (24 and 48 h), the hydrolysate H1 is significantly more cytotoxic than CWP. These results showed the potential of bovine CWP and its hydrolysates for the treatment of chronic diseases such as cancer.     

Inhibitory effect of d-allose on neutrophil activation after rat renal ischemia/reperfusion

D-Allose is one of the rare sugars produced from D-psicose. We examined whether d-allose reduces the extent of rat renal ischemia/reperfusion (I/R) injury by suppressing the activation of neutrophils. The renal concentrations of cytokine-induced neutrophil chemoattractant (CINC)-1 and myeloperoxidase were significantly increased after renal I/R. These increases were significantly inhibited by D-allose administration. Furthermore, D-allose significantly inhibited the increase in the concentrations of blood urea nitrogen (BUN), creatinine, N-acetyl beta-D-glucosaminidase (NAG) and histopathologic changes after renal I/R. These findings strongly suggest that D-allose protects against I/R-induced renal injury by inhibiting the activation of neutrophils that play an important role in I/R-induced renal injury. These findings may have important implications in understanding the biologic functions of D-allose. D-Allose may prove useful in renal surgery and transplantation.     

中国北方人初乳、牛初乳、牛常乳、牛血中胰岛素样生长因子-1和神经生长因子含量的比较

目的检测人初乳、集中饲养的新西兰进口荷斯坦乳牛的初乳、常乳和血液中胰岛素样生长因子-1(IGF-1)和神经生长因子(NGF)的含量,比较人初乳和牛初乳、牛初乳和牛常乳以及牛乳和同期采集的血液中IGF-1、NGF的含量。方法采用放射免疫试剂盒测定人初乳、牛初乳、牛常乳和血中IGF-1、NGF的含量,使用SPSS 13.0进行统计分析。结果本研究中测定的人初乳中IGF-1的含量是26.91μg/L,荷斯坦乳牛的初乳、常乳和血清中IGF-1的含量分别是38.40、20.14和37.35μg/L。人初乳中NGF的含量是300.47 ng/L,荷斯坦乳牛的初乳、常乳和血清中NGF的含量分别是69.82、110.37和9.63 ng/L。经统计学分析发现牛初乳和人初乳中IGF-1的含量差异没有显著性,牛初乳中IGF-1的含量高于牛常乳(P<0.05),牛乳中IGF-1的含量与同期血液中IGF-1的含量差异没有显著性。人初乳中NGF的含量高于牛初乳(P<0.05),牛初乳和牛常乳中NGF的含量差异没有显著性,同期牛血中NGF的含量低于牛乳中NGF的含量(P<0.05)。结论本研究发现牛初乳与人初乳IGF-1含量无明显差别,...     

Immunoglobulins,growth factors and growth hormone in bovine colostrum and the effects of processing

In colostrum collected 0–80 h postpartum the contents of immunoglobulins (Igs), transforming growth factor beta-2 (TGF-β2), insulin-like growth factor-1 (IGF-1) and growth hormone (GH) were analysed. Colostrum initially contained 90 mg mL⁻¹ IgG1, 2.8 mg mL⁻¹ IgG2, 1.6 mg mL⁻¹ IgA, 4.5 mg mL⁻¹ IgM, and these concentrations declined by 92%, 87%, 93% and 84%, respectively, in the samples collected later. Of the growth factors, colostrum initially contained 289–310 ng mL⁻¹ TGF-β2 and the concentration diminished to 66 ng mL⁻¹. The content of IGF-1 and GH postpartum decreased from 870 to 150 ng mL⁻¹, and from 0.17 to <0.03 ng mL⁻¹, respectively. Heat treatment and freeze-drying of colostral whey decreased the content of Igs to 75%, while the contents of IGF-1 and TGF-β2 were unaffected. A similar processing, including filtration steps reduced also the IGF-1 and TGF-β2 by 25%. IgM seems to be the most sensitive of the Igs to processing.     

牛初乳sIgA的制备与检测

牛初乳sIgA与人初乳sIgA具有相同的免疫源性,对提高机体的免疫力有着重要的作用。采用盐析、超滤、凝胶过滤层析和离子交换层析的方法进行分离sIgA,并用HPLC进行检测,制得的sIgA纯度为75.38%,收率约为54%,本研究为实现牛初乳sIgA的工业化生产提供了有益的探索。     

Separation of lactoferrin-a and -b from bovine colostrum

Bovine lactoferrin was separated into lactoferrin-a and lactoferrin-b from bovine colostrum. Lactoferrin-a was eluted at 0.38 M NaCl and lactoferrin-b was eluted at 0.43 M NaCl by carboxymethyl cation-exchange chromatography at pH 7.7, 0.05 M phosphate buffer. The molecular weights were estimated at 84,000 for lactoferrin-a and 80,000 for lactoferrin-b. Lactoferrin-a contents were 258.0 mg/L and lactoferrin-b contents were 524.3 mg/L of colostrum for cow 19. From colostrum to normal milk, total lactoferrin was from 17.1 to 129.4 mg/L during the normal lactational period; however, lactoferrin did not separate clearly into lactoferrin-a and lactoferrin-b. The lactoferrin-a measured from six cows was 258.0, 114.0, 112.8, 64.0, 59.7, and 22.4 mg/ L and the lactoferrin-b 524.3, 331.8, 184.7, 170.7, 129.3, and 44.0 mg/L, respectively. The average was 105.2 mg (31.3%) for lactoferrin-a and 230.8 mg (68.7%) for lactoferrin-b.     

HPLC法检测牛初乳中IgG含量

建立了牛初乳中IgG的高效液相色谱检测法,并测定了初乳中IgG的经时变化过程.结果显示,IgG浓度在0.2～15mg/mL的范围内峰面积与浓度呈现良好的线性关系,回收率实验平均大于98.5%.采用本法测定了六头幽门螺杆菌免疫牛初乳中IgG及两头正常牛初乳中IgG的经时变化过程.母牛分娩后24h内,初乳中免疫球蛋白IgG平均含量在40～70mg/mL之间;3d后,初乳中免疫球蛋白总量下降较快;至第7d,初乳中免疫球蛋白含量平均在1～5mg/mL之间.     

牛初乳的营养保健与产品质量控制

阐述了牛初乳的营养保健功能特点．并对牛初乳产品加工的影响因素、质量控制，特别是免疫球蛋白的检测方法进行了综述．     

牛初乳中sIgA的分离纯化

为进一步开发利用牛初乳中生物活性物质sIgA,有必要建立快速分离纯化sIgA的方法。利用凝胶层析和亲和层析等技术进行分离sIgA。采用非还原SDS-PAGE和HPLC进行检测。结果表明:分离纯化的sIgA纯度为97.52%,质量浓度为5.03 g/L。成功建立了纯化牛初乳中sIgA的方法,为实现sIgA的规模化生产提供参考。     

Specific gravity of bovine colostrum immunoglobulins as affected by temperature and colostrum components.

The effects of temperature and colostrum components on specific gravity in bovine colostrum were investigated. Thirty-nine first milking colostrum samples were collected from Holstein cows. The samples were assayed for alpha-tocopherol, fat, protein, total solids, and IgG. The concentrations of total solids, total protein, total IgG, and fat in colostrum were 26.6, 12.5, 3.7, and 9.4 g/100 g, respectively. A range of 1.8 to 24.7 micrograms/ml for alpha-tocopherol was measured in the colostrum samples. Specific gravity of the colostrum was measured using a hydrometer in increments of 5 degrees C from 0 to 40 degrees C. Specific gravity explained 76% of the variation in colostral total IgG at a colostrum temperature of 20 degrees C. The regression model was improved only slightly with the addition of protein, fat, and total solids. The model for samples at 20 degrees C was IgG (milligrams per milliliter) = 958 x (specific gravity) - 969. Measurement of specific gravity at variable temperatures necessitated inclusion of temperature in the model for estimation of IgG. Inclusion of the other components of colostrum into the model slightly improved the fit. The regression model for samples at variable temperatures was as follows: IgG (milligrams per milliliter) = 853 x (specific gravity) + .4 x temperature (Celsius degrees) - 866.     

A survey of bovine colostrum composition and colostrum management practices on Pennsylvania dairy farms

Colostrum composition and management were surveyed via sample and data collection from 55 dairy farms in Pennsylvania. Colostrum samples were analyzed for fat, protein, lactose, total solids, ash, Ig, lactoferrin, water- and fat-soluble vitamins, and minerals. Mean percentages of fat, protein, and lactose in colostrum were 6.7, 14.9, and 2.5, respectively. Concentrations of IgG₁, IgG₂, IgA, IgM, and lactoferrin were 35.0, 6.0, 1.7, 4.3, and 0.8 mg/mL, respectively. Mean concentrations of fat-soluble vitamins, including retinol, tocopherol, and β-carotene, were 4.9, 2.9, and 0.7 μg/g, respectively. Mean concentrations of water-soluble vitamins were 0.34, 0.90, 4.55, 0.60, 0.15, 0.21, and 0.04 μg/mL for niacin, thiamine, riboflavin, vitamin B₁₂, pyridoxal, pyridoxamine, and pyridoxine, respectively. Mean concentrations (mg/kg) of selected minerals in colostrum were also determined (Ca 4,716; P 4,452; Mg 733; Na 1,058; K 2,845; Zn 38; Fe 5.3; Cu 0.3; S 2,595; and Mn 0.1). The findings of this study revealed that the mean concentrations of most nutrients in colostrum have increased when compared with values previously reported. Results also showed that management practices have improved over time, particularly with regard to colostrum storage and feeding. Additionally, we observed that herd size influenced colostrum management and quality. It can be inferred, based on these findings, that although improvements have been made with regard to colostrum management and quality, there is still a need to educate producers on issues related to storage and timely feeding of colostrum to increase passive transfer and decrease the rate of calf morbidity and mortality.     

牛初乳免疫球蛋白稳定性研究概述

牛初乳富含很多营养成分,其中含有大量的免疫球蛋白,能够抵抗外界病毒侵害,增强机体自身免疫力,但在加工过程中,其活性受到很多因素影响。文中综述了温度、p H值、蛋白酶、超高压等因素对牛初乳免疫球蛋白稳定性的影响,对提高其稳定性的方法如食品添加剂保护法及微胶囊法的研究现状做出总结,为进一步开展牛初乳免疫球蛋白研究提供了参考。     

牛初乳免疫球蛋白微胶囊化方法的研究进展

免疫球蛋白是牛初乳中最重要的免疫因子,大量研究表明:牛初乳免疫球蛋白具有多种生理功能.通过对各种微胶囊化方法进行比较,阐述了不同方法的特点,并对牛初乳免疫球蛋白微胶囊化方法进行了展望.     

牛初乳原料杀菌和酸奶加工研究

通过添加稳定剂提高牛初乳的热稳定性并将其加工成酸奶。牛初乳中按0.5 g/100g添加Na2HPO4,65℃加热,记录凝固时间及评价杀菌效果;确定葡萄糖和蔗糖的添加比例,将杀菌初乳制成酸奶,进行乳酸菌和杂菌计数。结果表明,添加Na2HPO4的牛初乳加热40 min才开始凝固,而未添加组加热6 min完全凝固。65℃加热15 min,牛初乳菌落总数和大肠菌群均合格;当葡萄糖添加量为3 g/100g,蔗糖添加量为4 g/100g时,牛初乳酸奶口感最佳,乳酸菌数为1.26×106 cfu/mL。因此按0.5 g/100g添加Na2HPO4可以显著提高牛初乳的热稳定性,加工制成的初乳酸奶兼具了牛初乳和酸乳的双重功效。     

Protective effects of bovine colostrum acid proteins on bone loss of ovariectomized rats and the ingredients identification

Scope: Milk basic proteins and bovine colostrum extracts have preventive effects on osteoporosis. However, the effects of bovine colostrum acidic proteins (BCAP) on properties of bone have not been reported. This study investigated the effect of BCAP on the prevention of bone loss in ovariectomized (OVX) rats. Methods and results: Forty‐eight 3‐month old female Sprague–Dawley rats were OVX and another 12 rats underwent a sham operation (Sham). The OVX rats were randomly separated into four groups, i.e. OVX control, OVX plus 2 mg/day BCAP, OVX plus 10 mg/day BCAP, and OVX plus 50 mg/day BCAP, and were gavaged once per day for 12 wk. The effects on bone mineral content, bone mineral density, microarchitecture and biomechanical properties were determined. The bioactive ingredients in BCAP were isolated and identified. Results showed that BCAP increased the bone mineral content and bone mineral density of the femur in a dose‐dependent manner. Scanning electron microscope observation and mechanical testing further confirmed the positive effects of BCAP. These positive effects attribute to the fact that osteopontin, lactoferrin, epidermal growth factor and insulin‐like growth factor‐2 are the dominant proteins in BCAP. Conclusions: BCAP (2–50 mg/day) could prevent osteoporosis caused by bone loss in OVX rats.     

Heat treatment of bovine colostrum. I: effects of temperature on viscosity and immunoglobulin G level

The objective of this study was to identify the critical temperature, at or below which heat-treatment of bovine colostrum would produce no significant changes in viscosity, IgG concentration, or Ig activity. Results of preliminary work, using a Rapid Visco Analyzer (RVA) to heat 50-mL aliquots from 6 unique batches of bovine colostrum at 59, 60, 61, 62, and 63°C, suggested that colostrum could be heated to 60°C for up to 120 min without changing viscosity or IgG concentration. This finding was confirmed by heating 50-mL aliquots from 30 unique batches of colostrum in an RVA for 120 min at 60 and 63°C. Heating colostrum to 63°C resulted in an estimated 34% decrease in IgG concentration and 33% increase in viscosity. However, there was no difference in IgG concentration between preheat-treated (73.4 ± 26.5 mg/mL) and post-heat-treated (74.5 ± 24.3 mg/mL) samples after heating colostrum to 60°C in an RVA for 120 min. Similarly, viscosity was unaffected after heating colostrum to 60°C in an RVA for 120 min. High quality colostrum (≥73.0 mg/mL) suffered greater losses of IgG and greater viscosity changes when heated to 63°C than did moderate quality colostrum (<73.0 mg/mL). However, the effects of colostrum quality were minor if high quality colostrum was only heated to 60°C. The results of a bovine viral diarrhea serum neutralization assay suggested that antibody activity was unchanged after heating colostrum to either 60 or 63°C. However, these results were interpreted as being inconclusive due to a high proportion of missing results because of the congealing of many samples after heat treatment. The results of this study indicate that 50-mL volumes of bovine colostrum can be heat treated at 60°C for up to 120 min in an RVA without affecting IgG concentration or viscosity.     

Heat-treatment of bovine colostrum. II: effects of heating duration on pathogen viability and immunoglobulin G

Batches (30-L) of first-milking bovine colostrum, inoculated with Mycoplasma bovis (10⁸ cfu/mL), Listeria monocytogenes (10⁶ cfu/mL), Escherichia coli O157:H7 (10⁶ cfu/mL), Salmonella enteritidis (10⁶ cfu/mL), and Mycobacterium avium subsp. paratuberculosis (Map; 10³ cfu/mL), were heat-treated at 60°C for 120 min in a commercial on-farm batch pasteurizer system. Duplicate 50-mL subsamples of colostrum were collected at 15-min intervals throughout the heat-treatment process for the purpose of bacterial culture and for measurement of IgG concentration (mg/mL) and antibody activity [log₂(bovine viral diarrhea virus type 1 serum neutralization titer)]. Four replicate batches of colostrum were run for each of the 5 pathogens studied. There was no effect of heating moderate- to high-quality colostrum at 60°C for at least 120 min on mean IgG concentration (pre = 60.5 mg/mL; post = 59.1 mg/mL). Similarly, there was no effect of heat-treatment on the mean log₂ bovine viral diarrhea virus type 1 serum neutralization titer (pre = 12.3; post = 12.0). Viable M. bovis, L. monocytogenes, E. coli O157:H7, and S. enteritidis added to colostrum could not be detected after the colostrum was heat-treated at 60°C for 30 min. Average bacteria counts showed that Map was not detected when batches were heated at 60°C for 60 min. Although the authors believe that heat-treating colostrum at 60°C for 60 min should be sufficient to eliminate Map from colostrum in most situations, further research is needed to determine whether these findings may be replicated, given that variability was observed in Map culture results.