Safety assessment of meat from transgenic cattle by 90-day feeding study in rats

The study was carried out to evaluate the subchronic toxicity of meat derived from human lactoferrin gene-modified cattle in male and female Wistar rats. Rats were fed 5% or 10% transgenic meat diet, 5% or 10% conventional meat diet, or AIN93G diet for 90 days. During the study, body weight and food consumption were weighed weekly and clinical observations were conducted daily. At the end of the study, urinary examination, hematology and blood biochemistry examination, macroscopic and microscopic examinations were performed. There were no biologically significant differences in these factors between the rat groups fed transgenic meat diet and conventional meat diet. Therefore, the present 90-day rodent feeding study suggests that meat derived from the transgenic cattle is equivalent to meat from conventional cattle in use as dietary supplements.     

A rapid and sensitive non-competitive avidin-biotin assay for lactoferrin

We have developed an avidin-biotin assay for the detection of lactoferrin in human seminal plasma. We compared 5 modifications of this assay, and found the non-competitive avidin-biotin assay (NABA) to be the most sensitive. The detection limit of 3-step NABA was 0.2 or 0.1 ng lactoferrin/ml, depending whether avidin-biotin-peroxidase complex (ABC) or avidin-peroxidase was used. The intra-assay and inter-assay coefficients of variation for 3-step NABA were 6.2 and 8.5%, respectively. The lactoferrin levels of human seminal plasma samples measured by 3-step NABA and radioimmunoassay (RIA) showed good correlation (r = 0.96). The total performance time of 3-step NABA is flexible and the method can be modified for rapid (less than 1 h) or overnight assay according to need.     

慢性牙周炎患者龈沟液中LF的检测及临床意义

目的 检测慢性牙周炎患者龈沟液中乳铁蛋白(LF)浓度,并探讨其与牙周临床指标的关系.方法 收集慢性牙周炎患者基础治疗前、基础治疗后及健康对照者各位点的龈沟液样本,用ELISA法检测各样本中LF的浓度.结果 慢性牙周炎患者龈沟液中LF平均浓度显著高于健康对照者(P＜0.05),牙周基础治疗可使慢性牙周炎患者龈沟液中LF含量显著下降(P＜0.05),治疗前后LF的浓度与牙龈指数、探诊深度、附着丧失均呈正相关性(p＜0.05).结论 LF与慢性牙周炎的发生、发展过程关系密切,龈沟液中的LF可以作为一种生物标志物对慢性牙周炎进行疗效评估.     

Clinical applications of antimicrobial host proteins lactoperoxidase, lysozyme and lactoferrin in xerostomia: efficacy and safety

Innate human salivary defence proteins, lysozyme, lactoferrin and peroxidase, are known to exert a wide antimicrobial activity against a number of bacterial, viral and fungal pathogens in vitro. Therefore, these proteins, alone or in combinations, have been incorporated as preservatives in foods and pharmaceuticals as well as in oral health care products to restore salivas' own antimicrobial capacity in patients with dry mouth. These antimicrobials used in oral health care products, such as dentifrices, mouth-rinses, moisturizing gels and chewing gums, have been purified from bovine colostrum. In this review I critically evaluate the clinical efficacy and safety of this kind of preventive approach against various oral diseases and symptoms.     

Lactoferrin bioconjugated solid lipid nanoparticles: a new drug delivery system for potential brain targeting

Background: Delivery of drugs to brain is a subtle task in the therapy of many severe neurological disorders. Solid lipid nanoparticles (SLN) easily diffuse the blood–brain barrier (BBB) due to their lipophilic nature. Furthermore, ligand conjugation on SLN surface enhances the targeting efficiency. Lactoferin (Lf) conjugated SLN system is first time attempted for effective brain targeting in this study.

Purpose: Preparation of Lf-modified docetaxel (DTX)-loaded SLN for proficient delivery of DTX to brain.

Methods: DTX-loaded SLN were prepared using emulsification and solvent evaporation method and conjugation of Lf on SLN surface (C-SLN) was attained through carbodiimide chemistry. These lipidic nanoparticles were evaluated by DLS, AFM, FTIR, XRD techniques and in vitro release studies. Colloidal stability study was performed in biologically simulated environment (normal saline and serum). These lipidic nanoparticles were further evaluated for its targeting mechanism for uptake in brain tumour cells and brain via receptor saturation studies and distribution studies in brain, respectively.

Results: Particle size of lipidic nanoparticles was found to be optimum. Surface morphology (zeta potential, AFM) and surface chemistry (FTIR) confirmed conjugation of Lf on SLN surface. Cytotoxicity studies revealed augmented apoptotic activity of C-SLN than SLN and DTX. Enhanced cytotoxicity was demonstrated by receptor saturation and uptake studies. Brain concentration of DTX was elevated significantly with C-SLN than marketed formulation.

Conclusions: It is evident from the cytotoxicity, uptake that SLN has potential to deliver drug to brain than marketed formulation but conjugating Lf on SLN surface (C-SLN) further increased the targeting potential for brain tumour. Moreover, brain distribution studies corroborated the use of C-SLN as a viable vehicle to target drug to brain. Hence, C-SLN was demonstrated to be a promising DTX delivery system to brain as it possessed remarkable biocompatibility, stability and efficacy than other reported delivery systems.     

重组人乳铁蛋白抑制口腔癌KB细胞增殖及诱导细胞凋亡

目的 研究重组人乳铁蛋白(recombinate human lactoferrin,rhLF)对人口腔KB细胞增殖及凋亡的影响,为口腔癌患者提供新的有效治疗途径提供参考。方法 采用CCK-8法检测不同浓度(0、12.5、25、50、100、200 μg/mL)的rhLF分别处理KB细胞24、48、72 h后对细胞增殖的影响;Immunofluorescence及Western blotting方法检测rhLF处理前后DNA损伤相关蛋白γ-H2AX的表达。并分别用0、50、200 μg/mL的rhLF处理KB细胞,14 d后观察其对集落克隆形成的影响;0、200 μg/mL rhLF处理KB细胞48 h后,收集细胞并使用线粒体膜电位检测试剂盒(JC-1)检测rhLF处理前后线粒体膜电位的变化。Annexin V-PI染色检测rhLF对口腔癌KB细胞凋亡的影响;Western blotting检测0、50、200 μg/mL的rhLF处理口腔癌KB细胞48 h后Parp、Caspase-3的表达情况。结果 rhLF处理KB细胞的增殖有显著的抑制作用。Immunofluorescence结果显示rhLF处理后γ-H2AX的表达明显增加,Western blotting结果也显示rhLF处理后γ-H2AX的表达成浓度依赖性增加。rhLF抑制KB细胞集落克隆的形成;JC-1荧光检测结果表明红绿荧光的相对比例降低,这种红绿荧光的相对比例降低提示膜电位下降;0、50、200 μg/mL的rhLF处理口腔癌KB细胞48 h的凋亡率为2.02%、7.60%、48.07%;同时rhLF刺激口腔癌KB细胞能诱导Parp、Caspase-3的激活。结论 rhLF能显著抑制KB细胞的增殖并且诱导其细胞凋亡,其机制与线粒体凋亡途径的激活应激有关。     

Early life diets with prebiotics and bioactive milk fractions attenuate the impact of stress on learned helplessness behaviours and alter gene expression within neural circuits important for stress resistance

Manipulating gut microbes may improve mental health. Prebiotics are indigestible compounds that increase the growth and activity of health‐promoting microorganisms, yet few studies have examined how prebiotics affect CNS function. Using an acute inescapable stressor known to produce learned helplessness behaviours such as failure to escape and exaggerated fear, we tested whether early life supplementation of a blend of two prebiotics, galactooligosaccharide (GOS) and polydextrose (PDX), and the glycoprotein lactoferrin (LAC) would attenuate behavioural and biological responses to stress later in life. Juvenile, male F344 rats were fed diets containing either GOS and PDX alone, LAC alone, or GOS, PDX and LAC. All diets altered gut bacteria, while diets containing GOS and PDX increased Lactobacillus spp. After 4 weeks, rats were exposed to inescapable stress, and either immediately killed for blood and tissues, or assessed for learned helplessness 24 h later. Diets did not attenuate stress effects on spleen weight, corticosterone and blood glucose; however, all diets differentially attenuated stress‐induced learned helplessness. Notably, in situ hybridization revealed that all diets reduced stress‐evoked cfos mRNA in the dorsal raphe nucleus (DRN), a structure important for learned helplessness behaviours. In addition, GOS, PDX and LAC diet attenuated stress‐evoked decreases in mRNA for the 5‐HT_1A autoreceptor in the DRN and increased basal BDNF mRNA within the prefrontal cortex. These data suggest early life diets containing prebiotics and/or LAC promote behavioural stress resistance and uniquely modulate gene expression in corresponding circuits.