环孢霉素滴眼液联合人工泪液治疗角结膜干燥症患者的临床研究

目的观察环孢霉素滴眼液联合人工泪液治疗角结膜干燥症患者的临床研究及对泪液乳铁蛋白的影响。方法将80例角结膜干燥症患者随机分为对照组和试验组,每组40例。对照组给予聚乙烯醇滴眼液治疗,tid,每次1滴。试验组在对照组的基础上,用环孢霉素滴眼液治疗,tid,每次1滴。2组均持续治疗8周。比较2组患者的乳铁蛋白、泪液分泌试验(SIT)、泪膜破裂时间(BUT)、角膜荧光素染色(FS)评分及药物不良反应发生情况。结果治疗后,试验组和对照组乳铁蛋白分别为(1.72±0.22)和(1.57±0.18)g·L^-1,SIT分别为(13.60±1.90)mm/5 min和(11.65±1.18)mm/5 min,BUT分别为(8.86±1.22)和(7.59±1.11)s,FS评分分别为(0.87±0.10)和(1.43±0.21)分,差异均有统计学意义(均P<0.05)。试验组出现结膜轻度充血3例,眼部刺激2例,药物不良反应发生率为12.50%(5例/40例);对照组出现短暂性视力模糊3例,药物不良反应发生率为7.50%(3例/40例),差异无统计学意义(P>0.05)。结论环孢霉素滴眼液联合人工泪液治疗角结膜干燥症的效果较好,能够增加泪液乳铁蛋白水平,改善泪液环境。     

Immunization of pregnant cows with Shiga toxin-2 induces high levels of specific colostral antibodies and lactoferrin able to neutralize E. coli O157:H7 pathogenicity

E. coli O157:H7 is a foodborne pathogen responsible for bloody diarrhea, hemorrhagic colitis and hemolytic uremic syndrome (HUS). The objective of the present work was to evaluate the ability of colostral IgG obtained from Stx2-immunized cows to prevent against E. coli O157:H7 infection and Stx2 cytotoxicity. Hyperimmune colostrum (HC) was obtained from cows intramuscularly immunized with inactivated Stx2 or vehicle for controls. Colostral IgG was purified by affinity chromatography. Specific IgG antibodies against Stx2 and bovine lactoferrin (bLF) levels in HC and the corresponding IgG (HC-IgG/bLF) were determined by ELISA. The protective effects of HC-IgG/bLF against Stx2 cytotoxicity and adhesion of E. coli O157:H7 and its Stx2-negative mutant were analyzed in HCT-8 cells. HC-IgG/bLF prevention against E. coli O157:H7 was studied in human colon and rat colon loops. Protection against a lethal dose of E. coli O157:H7 was evaluated in a weaned mice model. HC-IgG/bLF showed high anti-Stx2 titers and high bLF levels that were able to neutralize the cytotoxic effects of Stx2 in vitro and in vivo. Furthermore, HC-IgG/bLF avoided the inhibition of water absorption induced by E. coli O157:H7 in human colon and also the pathogenicity of E. coli O157:H7 and E. coli O157:H7Δstx2 in rat colon loops. Finally, HC-IgG/bLF prevented in a 100% the lethality caused by E. coli O157:H7 in a weaned mice model. Our study suggests that HC-IgG/bLF have protective effects against E. coli O157:H7 infection. These beneficial effects may be due to specific anti-Stx2 neutralizing antibodies in combination with high bLF levels. These results allow us to consider HC-IgG/bLF as a nutraceutical tool which could be used in combination with balanced supportive diets to prevent HUS. However further studies are required before recommendations can be made for therapeutic and clinical applications.     

Preparation,Optimization and Characterization of Bovine Lactoferrin‐loaded Liposomes and Solid Lipid Particles Modified by Hydrophilic Polymers Using Factorial Design

Bioadhesive liposomes and solid lipid particles (SLPs) modified by pectin and chitosan for oral administration of bovine lactoferrin (bLf) were prepared using a 2⁴ full‐factorial design to identify the key formulation variables influencing particle size and drug entrapment efficiency (EE). Netlike structures of the polymer–particle mixture consisting of a polymeric network in which multiple particles were imbedded were observed by scanning electron microscopy (SEM). Chemical stability of bLf after encapsulation into pectin‐ and chitosan‐modified liposomes and SLPs was confirmed by Fourier transform infrared spectra (FTIR). Bovine lactoferrin was located within phospholipid bilayer, whereas in SLPs bLf was within the matrix. The crystalline nature of bLf after encapsulation was investigated by differential scanning calorimetry (DSC) of drug‐loaded particles, indicating amorphous dispersion of bLf in the polymer–lipid matrix of pectin‐ and chitosan‐modified liposomes and SLPs. In vivo pharmacokinetic investigation of bLf in pectin‐ and chitosan‐modified liposomes and SLPs showed prolonged mean residence time (MRT) of bLf in rat blood and increased the relative bioavailability (F_bio%) by 1.95‐ to 2.69‐fold compared with free bLf. The developed carrier systems are considered to be promising vehicles for oral delivery.     

Lactoferrin Prevents Hepatic Injury and Fibrosis via the Inhibition of NF-κB Signaling in a Rat Non-Alcoholic Steatohepatitis Model

Non-alcoholic steatohepatitis (NASH) can cause liver cirrhosis and hepatocellular carcinoma (HCC), with cases increasing worldwide. To reduce the incidence of liver cirrhosis and HCC, NASH is targeted for the development of treatments, along with viral hepatitis and alcoholic hepatitis. Lactoferrin (LF) has antioxidant, anti-cancer, and anti-inflammatory activities. However, whether LF affects NASH and fibrosis remains unelucidated. We aimed to clarify the chemopreventive effect of LF on NASH progression. We used a NASH model with metabolic syndrome established using connexin 32 (Cx32) dominant negative transgenic (Cx32ΔTg) rats. Cx32ΔTg rats (7 weeks old) were fed a high-fat diet and intraperitoneally injected with dimethylnitrosamine (DMN). Rats were divided into three groups for LF treatment at 0, 100, or 500 mg/kg/day for 17 weeks. Lactoferrin significantly protected steatosis and lobular inflammation in Cx32ΔTg rat livers and attenuated bridging fibrosis or liver cirrhosis induced by DMN. By quantitative RT–PCR, LF significantly down-regulated inflammatory (Tnf-α, Il-6, Il-18, and Il-1β) and fibrosis-related (Tgf-β1, Timp2, and Col1a1) cytokine mRNAs. Phosphorylated nuclear factor (NF)-κB protein decreased in response to LF, while phosphorylated JNK protein was unaffected. These results indicate that LF might act as a chemopreventive agent to prevent hepatic injury, inflammation, and fibrosis in NASH via NF-κB inactivation.     

Comparative Effects between Oral Lactoferrin and Ferrous Sulfate Supplementation on Iron-Deficiency Anemia: A Comprehensive Review and Meta-Analysis of Clinical Trials

Ferrous sulfate is a commonly used iron supplement for the correction of iron-deficiency anemia but with frequent gastrointestinal side effects. Milk-derived iron-binding glycoprotein lactoferrin possesses well gastrointestinal tolerance and fewer side effects caused by the intake of high-dose iron. However, the underlying mechanism of the iron-enhancing effect of lactoferrin remains unclear. In addition, the comparative efficacies between lactoferrin and ferrous sulfate are also remained to be determined. We conducted a systematic review and meta-analysis on published intervention studies to investigate how lactoferrin modulate iron metabolism and evaluate the comparative effects between lactoferrin and ferrous sulfate supplementation on iron absorption, iron storage, erythropoiesis and inflammation. Lactoferrin supplementation had better effects on serum iron (WMD: 41.44 ug/dL; p < 0.00001), ferritin (WMD: 13.60 ng/mL; p = 0.003) and hemoglobin concentration (11.80 g/dL; p < 0.00001), but a reducing effect on fractional iron absorption (WMD: −2.08%; p = 0.02) and IL-6 levels (WMD: −45.59 pg/mL; p < 0.00001) compared with ferrous sulfate. In conclusion, this study supports lactoferrin as a superior supplement to ferrous sulfate regarding the improvement in serum iron parameters and hemoglobin levels. Considering the weak influence of lactoferrin on iron absorption, the anti-inflammation effect of lactoferrin may be the potential mechanism to explain its efficacy on iron status and erythropoiesis.     

Lactoferrin Induces Erythropoietin Synthesis and Rescues Cognitive Functions in the Offspring of Rats Subjected to Prenatal Hypoxia

The protective effects of recombinant human lactoferrin rhLF (branded “CAPRABEL™”) on the cognitive functions of rat offspring subjected to prenatal hypoxia (7% O₂, 3 h, 14th day of gestation) have been analyzed. About 90% of rhLF in CAPRABEL was iron-free (apo-LF). Rat dams received several injections of 10 mg of CAPRABEL during either gestation (before and after the hypoxic attack) or lactation. Western blotting revealed the appearance of erythropoietin (EPO) alongside the hypoxia-inducible factors (HIFs) in organ homogenates of apo-rhLF-treated pregnant females, their embryos (but not placentas), and in suckling pups from the dams treated with apo-rhLF during lactation. Apo-rhLF injected to rat dams either during pregnancy or nurturing the pups was able to rescue cognitive deficits caused by prenatal hypoxia and improve various types of memory both in young and adult offspring when tested in the radial maze and by the Novel Object Recognition (NOR) test. The data obtained suggested that the apo-form of human LF injected to female rats during gestation or lactation protects the cognitive functions of their offspring impaired by prenatal hypoxia.     

Inhibition of In Vitro Infection of Hepatitis B Virus by Human Breastmilk

Despite the presence of hepatitis B virus (HBV) in the human breastmilk of mothers infected with HBV, it has been shown that breastfeeding does not increase the risk of mother-to-child transmission (MTCT) of HBV. We tested the hypothesis that human breastmilk may contain active components that bind to HBV and inhibit the infectivity of HBV. The results show that human whey significantly inhibited the binding of the hepatitis B surface antigen (HBsAg) to its antibodies in competitive inhibition immunoassays. The far-western blotting showed that HBsAg bound to a protein of 80 kD in human whey, which was identified as lactoferrin by mass spectrometry. Competitive inhibition immunoassays further demonstrated that both human lactoferrin and bovine lactoferrin bound to HBsAg. Human whey, human lactoferrin, and bovine lactoferrin each significantly inhibited the infectivity of HBV in vitro. Our results indicate that human breastmilk can bind to HBsAg and inhibit the infectivity of HBV, and the active component is lactoferrin. The findings may explain the reason that breastfeeding has no additional risk for MTCT of HBV, although human breastmilk contains HBV. Our study provides experimental evidence that HBV-infected mothers should be encouraged to breastfeed their infants     

Are faecal markers good indicators of mucosal healing in inflammatory bowel disease?

AIM: To review the published literature concerning the accuracy of faecal inflammatory markers for identifying mucosal healing. METHODS: Bibliographical searches were performed in MEDLINE electronic database up to February 2015,using the following terms: "inflammatory bowel disease","Crohn′s disease","ulcerative colitis","faecal markers","calprotectin","lactoferrin","S100A12","endoscop*","mucosal healing","remission". In addition,relevant references from these studies were also included. Data were extracted from the published papers including odds ratios with 95%CI,P values and correlation coefficients. Data were grouped together according to each faecal marker,Crohn's disease or ulcerative colitis,and paediatric compared with adult study populations. Studies included in this review assessed mucosal inflammation by endoscopic and/or histological means and compared these findings to faecal marker concentrations in inflammatory bowel diseases(IBD) patient cohorts. Articles had to be published between 1990 and February 2015 and written in English. Papers excluded from the review were those where the faecal biomarker concentration was compared between patients with IBD and controls or other disease groups,those where serum biomarkers were used,those with a heterogeneous study population and those only assessing post-operative disease. RESULTS: The available studies show that faecal markers,such as calprotectin and lactoferrin,are promising non-invasive indicators of mucosal healing. However,due to wide variability in study design,especially with regard to the definition of mucosal healing and evaluation of marker cut offs,the available data do not yet indicate the optimal roles of these markers. Thirty-six studies published between 1990 and 2014 were included. Studies comprised variable numbers of study participants,considered CD(15-164 participants) or UC(12-152 participants) separately or as a combined group(11-252 participants). Eight reports included paediatric patients. Several indices were used to document mucosal inflammation,encompassing elevenendoscopic and eight histologic grading systems. The majority of the available reports focused on faecal calprotectin(33 studies),whilst others assessed faecal lactoferrin(13 studies) and one study assessed S100A12. Across all of the biomarkers,there is a wide range of correlation describing the association between faecal markers and endoscopic disease activity(r values ranging from 0.32 to 0.87,P values ranging from 0.0001 to 0.7815). Correlation coefficients are described in almost all studies and are used more commonly than outcome measures such as sensitivity,specificity,PPV and/or NPV. Overall,the studies that have evaluated faecal calprotectin and/or faecal lactoferrin and their relationship with endoscopic disease activity show inconsistent results. CONCLUSION: Future studies should report the results of faecal inflammatory markers in the context of mucosal healing with clear validated cut offs.