Lactoferrin ameliorates corticosterone-related acute stress and hyperglycemia in rats

A review of the biological activities of lactoferrin: mechanisms and potential applications

Lactoferrin, a multifunctional iron-binding protein found in milk and other body fluids, possesses numerous biological activities. The functional activity of lactoferrin lies not only in its iron-binding capacity but also in the molecular mechanisms by which it can affect important chemical components in the host. However, the molecular mechanisms underlying these activities remain unelucidated. In this paper, we review the structure, properties, and contents of different lactoferrin milk sources. The different biological activities, namely antibacterial, antiviral, immunomodulatory, anti-inflammatory, bone regeneration, and improved metabolic disorder bioactivities, and the associated potential mechanisms of lactoferrin are summarized with the aim of providing a reference for the development of lactoferrin-related products.

Lactoferrin decorated bilosomes for the oral delivery of quercetin in type 2 diabetes: In vitro and in vivo appraisal

Despite its tremendous potential for type 2 diabetes management, quercetin (QRC) suffers poor gastric stability, poor bioavailability, and extensive first pass metabolism. Drug encapsulation into bilosomes (BSL) has proven enhanced properties in-vitro and in-vivo. Herein, this work endeavoured to evaluate efficacy of QRC-encapsulated bilosomes capped with lactoferrin (LF); a milk protein with antidiabetic potential, for type 2 diabetes oral treatment. The optimized formulation (LF-QRC-BSL) was evaluated in-vitro on α-amylase enzyme inhibition and insulin resistant HepG2 cell model and in vivo on streptozocin/high fat diet induced diabetes in rats. LF-QRC-BSL showed a small size (68.1 nm), a narrow PDI (0.18) and a -25.5 mV zeta potential. A high entrapment efficiency (94 %) with sustained release were also observed. LF-QRC-BSL displayed 100 % permeation through excised diabetic rat intestines after 6 h, 70.2 % inhibition of α-amylase enzyme in-vitro and an augmented recovery of glucose uptake in insulin resistant cells. In diabetic rats, LF-QRC-BSL resulted in significant decrease in blood glucose level, improved lipid profile and tissue injury markers with reduced oxidative stress and inflammatory markers. Further, histopathological examination of the kidneys, liver and pancreas revealed an almost restored normal condition comparable to the negative control. Overall, LF-QRC-BSL have proven to be a promising therapy for type 2 diabetes.

To Boost or to Reset: The Role of Lactoferrin in Energy Metabolism

Many pathological conditions, including obesity, diabetes, hypertension, heart disease, and cancer, are associated with abnormal metabolic states. The progressive loss of metabolic control is commonly characterized by insulin resistance, atherogenic dyslipidemia, inflammation, central obesity, and hypertension, a cluster of metabolic dysregulations usually referred to as the "metabolic syndrome". Recently, nutraceuticals have gained attention for the generalized perception that natural substances may be synonymous with health and balance, thus becoming favorable candidates for the adjuvant treatment of metabolic dysregulations. Among nutraceutical proteins, lactoferrin (Lf), an iron-binding glycoprotein of the innate immune system, has been widely recognized for its multifaceted activities and high tolerance. As this review shows, Lf can exert a dual role in human metabolism, either boosting or resetting it under physiological and pathological conditions, respectively. Lf consumption is safe and is associated with several benefits for human health, including the promotion of oral and gastrointestinal homeostasis, control of glucose and lipid metabolism, reduction of systemic inflammation, and regulation of iron absorption and balance. Overall, Lf can be recommended as a promising natural, completely non-toxic adjuvant for application as a long-term prophylaxis in the therapy for metabolic disorders, such as insulin resistance/type II diabetes and the metabolic syndrome.

Colostrum and Lactoferrin Protect against Side Effects of Therapy with Antibiotics, Anti-inflammatory Drugs and Steroids, and Psychophysical Stress: A Comprehensive Review

In this article, we review the benefits of applying bovine colostrum (BC) and lactoferrin (LF) in animal models and clinical trials that include corticosteroid application and psychic stress, treatment with non-steroid anti-inflammatory drugs (NSAIDs) and antibiotics. A majority of the reported investigations were performed with native bovine or recombinant human LF, applied alone or in combination with probiotics, as nutraceutics and diet supplements. Apart from reducing adverse side effects of the applied therapeutics, BC and LF augmented their efficacy and improved the wellness of patients. In conclusion, LF and complete native colostrum, preferably administered with probiotic bacteria, are highly recommended for inclusion in therapeutic protocols in NSAIDs and corticosteroid anti-inflammatory, as well as antibiotic, therapies. These colostrum-based products can also be of value for individuals subjected to prolonged psychophysical stress (mediated by endogenous corticosteroids), especially at high ambient temperatures (soldiers and emergency services), as well as physically active people and training athletes. They are also recommended for patients during recovery from trauma and surgery, which are always associated with severe psychophysical stress.

Vitamin D and lactoferrin attenuate stress-induced colitis in Wistar rats via enhancing AMPK expression with inhibiting mTOR-STAT3 signaling and modulating autophagy

Irritable bowel syndrome (IBS) is a global gastrointestinal disorder closely related to psychological stress exposure and local colonic inflammation. Herein, we investigated the effect of wrap-restraint stress (WRS) on rat behavior, on adenosine monophosphate-activated protein kinase-mammalian/mechanistic target of rapamycin-signal transducer and activator of transcription 3 (AMPK-mTOR-STAT3) signaling, and autophagy in colonic mucosa. The impact of chronic administration of vitamin D₃ and lactoferrin was compared. Twenty-four male Wistar rats were randomly divided into four groups. Chronic WRS protocol was applied as a rodent model of IBS. Group I: naïve animals, Group II: WRS animals, Group III: WRS-exposed and treated with vitamin D₃ (500 IU/kg/day), and Group IV: WRS-exposed and treated with lactoferrin (300 mg/kg/day). In this study, we found that chronic administration of each of vitamin D₃ and lactoferrin resulted in a significant increase in social interaction test, interleukin-10, AMPK, optical density of LC3B, goblet cell count and marked decrease in serum cortisol level, STAT3, inflammatory cell count, and optical density of mTOR in comparison to the WRS rats. Our findings suggest that both vitamin D₃ and Lactoferrin could augment colonic autophagy through enhanced AMPK expression and inhibition of mTOR-STAT3 signaling, which offers practical insights into their clinical use in the prevention and therapy of IBS. However, lactoferrin intake as a nutritional supplement could be more helpful for stress-induced colitis treatment than vitamin D_3.

Changes in the Histological Structure of Adrenal Glands and Corticosterone Level after Whey Protein or Bee Pollen Supplementation in Running and Non-Running Rats

Due to the many health-promoting properties of bee pollen and whey protein, both products are widely used as dietary supplements. According to these reports on their health-promoting properties, the aim of our study is to assess whether these products can influence the structure and function of the adrenal glands in rats. Thirty male Wistar rats were divided into six equal groups. Among them, there were three groups which included non-running rats and three groups which included running rats. Both of these running (n = 3) and non-running (n = 3) groups included non-supplemented (control groups), bee-pollen-supplemented groups, and whey-protein-supplemented groups. After 8 weeks, the rats were decapitated, their adrenal glands were collected, and paraffin slides were prepared. Then, staining according to the standard H&E and Masson's trichrome protocols was performed. Fecal and urine samples were collected prior to the end of the study to measure corticosterone levels. In the group of non-running rats, the consumption of bee pollen was noted to be significantly higher when compared to the group of running rats (p < 0.05). The thickness of the particular adrenal cortex layers was similar among all of the groups (p > 0.05). The statistically significant changes in the microscopic structure of the adrenal glands, especially regarding cell nuclei diameter and structure, as well as the architecture of sinusoids, were observed between the groups. Moreover, urine corticosterone concentrations were found to vary between all of the analyzed groups (p < 0.05). These results indicate that both bee pollen and whey protein have limited stress-reducing potential.

Functional Correlates and Impact of Dietary Lactoferrin Intervention and its Concentration-dependence on Neurodevelopment and Cognition in Neonatal Piglets

SCOPE

Lactoferrin (Lf), a sialylated milk glycoprotein, promotes early neurodevelopment and cognition. Functional concentrations of Lf, however, remain unknown. Our objective is to determine the concentration-dependency of Lf on genes associated with neurodevelopment and cognition in neonatal piglets.

METHODS AND RESULTS

Piglets are given milk replacer with Lf at concentrations of 155 (low) or 285 mg kg^-1 day^-1 (high) from postnatal days 3 to 38. Gene expression associated with neurodevelopment, cognition, and cognate proteins were quantitated. This study found 1) The rate of learning and long-term memory was higher with 155 mg kg^-1 day^-1 assessed in an eight-arm radial maze; 2) Global gene transcription profiling showed this lower concentration upregulated genes and functions correlated with neurodevelopment and cognition, while the higher concentration regulated cellular processes for neuroprotection; 3) Expression of BDNF genes and proteins were higher with both concentrations, while genes regulating BDNF signaling, including SLC6A3, IGF-1 responded more to the lower concentration; 4) The lower concentration modulated genes in the five highest networks associated with cellularity and neurocognition, while the prevention of neurodevelopmental and neurological pathologies was associated with the higher concentration.

CONCLUSION

The lower concentrations of Lf enhanced neurodevelopment and cognition, while higher concentrations are greater neuroprotective, findings of potential novel clinical relevance.

Lactoferrin promotes bile acid metabolism and reduces hepatic cholesterol deposition by inhibiting the farnesoid X receptor (FXR)-mediated enterohepatic axis

BACKGROUND

Lactoferrin (LF) is a multifunctional glycoprotein that can regulate lipid metabolism, lower cholesterol, reduce body weight, and prevent atherosclerosis. Bile acid (BA) metabolism plays an important role in removing excess cholesterol from the body. However, studies on the effects of LF on BA metabolism are limited and inconsistent.

METHODS

Male C57BL/6J mice aged 6-8 weeks were fed with a normal diet (control group), high-fat/high-cholesterol diet containing cholate (HFCCD group), or HFCCD and 1.0% LF in drinking water (LF group) for 8 weeks. Serum and hepatic lipid profiles, and glucose tolerance were measured. Fecal BA composition was determined through ultra-high performance liquid chromatography-tandem mass spectrometry. The gene expression of BA synthase in the liver and farnesoid X receptor (FXR)-mediated BA negative feedback regulation pathway in the liver and ileum were analyzed via RNA analysis.

RESULTS

HFCCD resulted in abnormal cholesterol levels in the serum and liver. LF intervention significantly increased the serum high-density lipoprotein cholesterol level by 24.9% and decreased the hepatic total cholesterol content by 26%. LF treatment significantly increased the BA content per gram by 109.8%, the total amount of BA excretion by 153.5% and conjugated BAs by 87.6% in the feces. Furthermore, LF upregulated the expression of the hepatic sterol 12α-hydroxylase (CYP8B1) gene, which expresses important enzymes in the classical pathway of BA synthesis, and the bile acid-CoA amino acid N-acetyltransferase (BAAT) gene, which is responsible for the formation of conjugated BAs. The FXR-mediated pathways in the enterohepatic axis, including FXR, fibroblast growth factor 15, and fibroblast growth factor receptor 4, were inhibited by LF.

CONCLUSIONS

LF ameliorated hepatic cholesterol deposition in mice fed with a high-fat and high cholesterol diet containing cholate. LF elevated the conjugated BA level, inhibited the ileum FXR and FXR-mediated enterohepatic axis, and increased BA synthesis and excretion.

Identification of possible new salivary biomarkers of stress in sheep using a high-resolution quantitative proteomic technique

The aim of this study was to identify biological pathways and proteins differentially expressed in the saliva proteome of sheep after the application of a model of stress, using high-resolution quantitative proteomics. In addition, one of the proteins differently expressed was verified and evaluated as a possible biomarker of stress in this species. Saliva paired samples from eight sheep before and after the application of a model of stress based on shearing were analysed using tandem mass tags (TMT). The TMT analysis allowed for the identification of new stress-related metabolic pathways and revealed 13 proteins, never described in saliva of sheep, that were differentially expressed between before and after the stress. Six of these proteins pertain to four major metabolic pathways affected, namely: canonical glycolysis, oxygen transport, neural nucleus development, and regulation of actin cytoskeleton reorganization. The rest of proteins were unmapped original proteins such as acyl-coenzyme-A-binding protein; complement C3; alpha-2-macroglobulin isoform-X1; type-II small proline-rich protein; lactoferrin; secretoglobin family-1D-member; and keratin, type-II cytoskeletal 6. Of these proteins, based on its biological significance and specific immunoassay availability, lactoferrin was selected for further validation. The immunoassay intra- and inter-assay coefficients of variation were lower than 13%. The method showed good linearity under dilution and recovery, and the detection limit was low enough to detect salivary lactoferrin levels. A significant decrease (P < 0.01) in salivary lactoferrin concentration in the sheep following the application of the model of stress was observed, suggesting that this protein could be a potential salivary biomarker of stress situations in sheep.

Towards frailty biomarkers: Candidates from genes and pathways regulated in aging and age-related diseases

OBJECTIVE

Use of the frailty index to measure an accumulation of deficits has been proven a valuable method for identifying elderly people at risk for increased vulnerability, disease, injury, and mortality. However, complementary molecular frailty biomarkers or ideally biomarker panels have not yet been identified. We conducted a systematic search to identify biomarker candidates for a frailty biomarker panel.

METHODS

Gene expression databases were searched (http://genomics.senescence.info/genes including GenAge, AnAge, LongevityMap, CellAge, DrugAge, Digital Aging Atlas) to identify genes regulated in aging, longevity, and age-related diseases with a focus on secreted factors or molecules detectable in body fluids as potential frailty biomarkers. Factors broadly expressed, related to several "hallmark of aging" pathways as well as used or predicted as biomarkers in other disease settings, particularly age-related pathologies, were identified. This set of biomarkers was further expanded according to the expertise and experience of the authors. In the next step, biomarkers were assigned to six "hallmark of aging" pathways, namely (1) inflammation, (2) mitochondria and apoptosis, (3) calcium homeostasis, (4) fibrosis, (5) NMJ (neuromuscular junction) and neurons, (6) cytoskeleton and hormones, or (7) other principles and an extensive literature search was performed for each candidate to explore their potential and priority as frailty biomarkers.

RESULTS

A total of 44 markers were evaluated in the seven categories listed above, and 19 were awarded a high priority score, 22 identified as medium priority and three were low priority. In each category high and medium priority markers were identified.

CONCLUSION

Biomarker panels for frailty would be of high value and better than single markers. Based on our search we would propose a core panel of frailty biomarkers consisting of (1) CXCL10 (C-X-C motif chemokine ligand 10), IL-6 (interleukin 6), CX3CL1 (C-X3-C motif chemokine ligand 1), (2) GDF15 (growth differentiation factor 15), FNDC5 (fibronectin type III domain containing 5), vimentin (VIM), (3) regucalcin (RGN/SMP30), calreticulin, (4) PLAU (plasminogen activator, urokinase), AGT (angiotensinogen), (5) BDNF (brain derived neurotrophic factor), progranulin (PGRN), (6) α-klotho (KL), FGF23 (fibroblast growth factor 23), FGF21, leptin (LEP), (7) miRNA (micro Ribonucleic acid) panel (to be further defined), AHCY (adenosylhomocysteinase) and KRT18 (keratin 18). An expanded panel would also include (1) pentraxin (PTX3), sVCAM/ICAM (soluble vascular cell adhesion molecule 1/Intercellular adhesion molecule 1), defensin α, (2) APP (amyloid beta precursor protein), LDH (lactate dehydrogenase), (3) S100B (S100 calcium binding protein B), (4) TGFβ (transforming growth factor beta), PAI-1 (plasminogen activator inhibitor 1), TGM2 (transglutaminase 2), (5) sRAGE (soluble receptor for advanced glycosylation end products), HMGB1 (high mobility group box 1), C3/C1Q (complement factor 3/1Q), ST2 (Interleukin 1 receptor like 1), agrin (AGRN), (6) IGF-1 (insulin-like growth factor 1), resistin (RETN), adiponectin (ADIPOQ), ghrelin (GHRL), growth hormone (GH), (7) microparticle panel (to be further defined), GpnmB (glycoprotein nonmetastatic melanoma protein B) and lactoferrin (LTF). We believe that these predicted panels need to be experimentally explored in animal models and frail cohorts in order to ascertain their diagnostic, prognostic and therapeutic potential.

Physiological stress-induced corticosterone increases heme uptake via KLF4-HCP1 signaling pathway in hippocampus neurons

Iron overload has attracted much attention because of its adverse effect in increasing the risk of developing several neurodegenerative disorders. Under various pathologic conditions, a lot of heme are released. The aggregation of heme is more neurotoxic than that of iron released from the heme breakdown. Our previous studies demonstrated that psychological stress (PS) is a risk factor of cerebral iron metabolism disorders, thus causing iron accumulation in rat brains. In the present study, we found PS could increase heme uptake via heme carrier protein 1 (HCP1) in rat brains. We demonstrated that Glucocorticoid (GC), which is largely secreted under stress, could up-regulate HCP1 expression, thus promoting heme uptake in neurons. We also ascertained that HCP1 expression can be induced by GC through a transcription factor, Krüppel-like factor 4 (KLF4). These results may gain new insights into the etiology of heme uptake and iron accumulation in PS rats, and find new therapeutic targets of iron accumulation in Parkinson’s disease or Alzheimer’s disease.