Effect of Lactoferrin Supplementation on Inflammation, Immune Function, and Prevention of Respiratory Tract Infections in Humans: A Systematic Review and Meta-analysis

A comprehensive review of research advances in the study of lactoferrin to treat viral infections

Lactoferrin (Lf) is a naturally occurring glycoprotein known for its antiviral and antibacterial properties and is present in various physiological fluids. Numerous studies have demonstrated its antiviral effectiveness against multiple viruses, such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza virus (IFV), herpes simplex virus (HSV), hepatitis B virus (HBV), and human immunodeficiency virus (HIV). Lf, a vital component of the mucosal defense system, plays a crucial role in inhibiting viral infection by binding to both host cells and viral particles, such as the Hepatitis C virus (HCV). This interaction enables Lf to keep viral particles away from their target cells, emphasizing its significance as a fundamental element of mucosal defense against viral infections. Additionally, Lf has the ability to modulate cytokine expression and enhance cellular immune responses. In the innate immune system, Lf serves as a unique iron transporter and helps suppress various pathogens like bacteria, fungi, and viruses. This article summarises the potential antiviral properties of Lf against various viruses, along with its other mentioned functions. The advancement of Lf-based therapies supports the homology of food and medicine, providing a promising avenue to address viral infections and other public health challenges.

Pica practices, anemia, and oral health outcomes: a systemic review

OBJECTIVES

Pica is a non-nutritive eating behavior. The potential impact of pica on oral health and the association between pica and anemia are understudied. We examined the current evidence on the relationship between pica practices, anemia, and oral health outcomes.

METHODS

We used Population, Intervention, Control, and Outcomes (PICO) terms to create MeSH terms to assess 1) the relationship between pica and iron deficiency anemia (IDA), 2) the relationship between IDA and oral health, and 3) the relationship between pica, anemia, and oral health outcomes. The review was registered on Prospero [CRD42022349022]. We searched databases including PubMed, Embase, Web of Science, Cochrane Library, and, clinicaltrials.gov in June 2022.

RESULTS

From 4,159 searched articles, 89 met the inclusion criteria. Studies were published between 1959 and 2022 from 33 countries. Nearly half of these studies (55.1%, n = 49) were case reports. The most common picas included geophagia (soil/dirt) (44.9%, n = 40 papers), pagophagia (ice) (22.5%, n = 20), amylophagia (starch) (15.7%, n = 14), paint/metal (5.6%, n = 5), paper (5.6%, n = 5) and others such as pica for foam and hair. Fifteen case reports and one intervention study showed the effects of pica practice on oral health, such as tooth abrasion, dental caries, and de-papillated tongue. Furthermore, 81% of the papers reported the co-occurrence of pica with anemia and 15 papers reported a significant association (p < 0.05) between pica and low hemoglobin levels ranging from < 12.0 to 2.7g/dL among all age groups, including among pregnant and postpartum women. Pica practices were strongly associated with IDA (serum ferritin < 15.0 - 4.3 mcg/ml) but showed a non-statistically significant trend of association with oral health outcomes.

CONCLUSION

Pica was strongly associated with anemia and IDA. Tooth abrasion and dental caries were observed among pica users. Future studies could define the strength of the pica-oral health association, and the potential mediators, such as anemia.

Food-based biomaterials: pH-responsive alginate/gellan gum/carboxymethyl cellulose hydrogel beads for lactoferrin delivery

The present study utilizes a combination of sodium alginate (Alg), gellan gum (GG), and sodium carboxymethyl cellulose (CMC) to fabricate a ternary composite hydrogel system to encapsulate and release lactoferrin (LF). Rheological properties as well as extensive microscopy and spectroscopy characterization are performed on these materials demonstrating that the physical properties of the resultant hydrogels, such as particle size, water content, gray value, and shrinkage rate were related to the concentration of Alg. In addition, most of these hydrogels were found to have reticulated shells and inner laminar structures assembled based on hydrogen bonding and electrostatic forces. Furthermore, the encapsulation efficiency of LF in hydrogels ranged from 78.3 ± 0.3 to 83.5 ± 0.2 %. Notably, a small amount of encapsulated LF was released from the hydrogel beads in an acid environment (up to 2.2 ± 0.3 % in 2 h), while a controlled release manner was found to take place in an alkaline environment. This phenomenon indicated the potential of these hydrogels as promising matrices for bioactive compound loading and adsorption. The release mechanism varied from Alg concentration suggesting the tunable and versatile properties of this ternary composite hydrogel system. Our findings identify the potential of Alg-GG-CMC hydrogel as a delivery system suitable for various applications in the food industry.

Four-Week GLP Immunotoxicity Assessment of Lactoferrin Alpha Produced by Komagataella phaffii in Sprague-Dawley Rats

Oral toxicity and toxicokinetic properties of human lactoferrin (LF) alpha produced in Komagataella phaffii (effera™) were investigated in adult Sprague-Dawley rats over a 28-day period under good laboratory practice conditions. Main study dosing used groups of 10 rats/sex/dose, and a secondary study evaluating toxicokinetic parameters used 6 rats/sex/dose. The vehicle control group received sodium citrate buffer, test groups received daily doses of 200, 600, and 2000 mg of effera™ per kg body weight, and the comparative control group received 2000 mg bovine LF (bLF)/kg body weight per day. T-cell-dependent antibody response against keyhole limpet hemocyanin and immunophenotyping of the spleen were performed as measures of immunotoxicity. Clinical observations, body weight, hematology, coagulation, clinical chemistry, urinalysis, immunotoxicity, gross necropsy, and histopathology were assessed. Toxicokinetic parameters were analyzed as an indication of LF bioavailability, and anti-LF antibody assays were conducted to detect antibodies produced against LF to measure immunogenicity. No treatment related toxicologically significant changes were observed. Based on the absence of toxicologically relevant changes, effera™ is well tolerated in rats at doses up to 2000 mg rhLF/kg/day, an amount ∼400 times that of the estimated daily intake at the 90th percentile proposed for human adult use.

A Randomized, Double-Blind, Controlled Trial to Assess the Effects of Lactoferrin at Two Doses vs. Active Control on Immunological and Safety Parameters in Healthy Adults

Recombinant human lactoferrin (rhLF) is of commercial interest for immune support as a food ingredient. The objective was to evaluate the immunogenicity/alloimmunization potential of Helaina rhLF (effera™) from K. phaffii over a 28-day period compared to bovine LF (bLF). Study 1 was a randomized, double-blind, parallel arm, controlled trial where 66 healthy adults were randomly allocated to 1 of 3 groups: high-dose rhLF (3.4 g/d), low-dose rhLF (0.34 g/d), or bLF (3.4 g/d). Participants completed a 28-day supplementation period with follow-up visits on Days 28, 56, and 84. Study 2 was a 12-week observational study with no intervention that enrolled 24 healthy adults. In both studies, serum was obtained for analysis of anti-LF antibody levels as the primary endpoint. In Study 1, change from baseline to Day 56 in serum anti-bLF antibodies in the bLF group (least squares geometric mean and 95% confidence interval for the post/pre ratio: 3.01; 2.08, 4.35) was greater than the changes in serum anti-hLF antibodies in the low-dose rhLF (1.07; 0.77, 1.49; P < 0.001) and high-dose rhLF (1.02; 0.62, 1.70; P < 0.001) groups. The rhLF groups had similar changes to the observational study, indicating no change in anti-hLF antibodies and no evidence of alloimmunization following ingestion. Changes in safety outcomes were similar between groups and within normal ranges. These results show that under the conditions of the protocol, no increased anti-hLF antibodies or adverse events were identified following ingestion of effera™ as a food ingredient at an intake level up to 3.4 g/d in healthy adults (clinicaltrials.gov: NCT06012669).

MAD-microbial (origin of) Alzheimer's disease hypothesis: from infection and the antimicrobial response to disruption of key copper-based systems

Microbes have been suspected to cause Alzheimer's disease since at least 1908, but this has generally remained unpopular in comparison to the amyloid hypothesis and the dominance of Aβ and Tau. However, evidence has been accumulating to suggest that these earlier theories are but a manifestation of a common cause that can trigger and interact with all the major molecular players recognized in AD. Aβ, Tau and ApoE, in particular appear to be molecules with normal homeostatic functions but also with alternative antimicrobial functions. Their alternative functions confer the non-immune specialized neuron with some innate intracellular defenses that appear to be re-appropriated from their normal functions in times of need. Indeed, signs of infection of the neurons by biofilm-forming microbial colonies, in synergy with herpes viruses, are evident from the clinical and preclinical studies we discuss. Furthermore, we attempt to provide a mechanistic understanding of the AD landscape by discussing the antimicrobial effect of Aβ, Tau and ApoE and Lactoferrin in AD, and a possible mechanistic link with deficiency of vital copper-based systems. In particular, we focus on mitochondrial oxidative respiration via complex 4 and ceruloplasmin for iron homeostasis, and how this is similar and possibly central to neurodegenerative diseases in general. In the case of AD, we provide evidence for the microbial Alzheimer's disease (MAD) theory, namely that AD could in fact be caused by a long-term microbial exposure or even long-term infection of the neurons themselves that results in a costly prolonged antimicrobial response that disrupts copper-based systems that govern neurotransmission, iron homeostasis and respiration. Finally, we discuss potential treatment modalities based on this holistic understanding of AD that incorporates the many separate and seemingly conflicting theories. If the MAD theory is correct, then the reduction of microbial exposure through use of broad antimicrobial and anti-inflammatory treatments could potentially alleviate AD although this requires further clinical investigation.

Lactoferrin Supplementation in Preventing and Protecting from SARS-CoV-2 Infection: Is There Any Role in General and Special Populations? An Updated Review of Literature

At the beginning of the pandemic, SARS-CoV-2 infection represented a great medical burden worldwide, as targeted and effective therapeutic options were lacking. This resulted in the revival of existing molecules and the increasing popularity of over-the-counter nutritional supplements. Among the latter, lactoferrin has been investigated as an adjuvant in COVID-19 therapy with conflicting results, mainly depending on different study designs. Considering that lactoferrin is one of the main components of human breast milk with anti-microbial and anti-inflammatory activity, it is conceivable that such bioactive molecule could be effective in supporting anti-SARS-CoV-2 infection therapy, especially in infants and pregnant women, two subpopulations that have been poorly evaluated in the existing clinical trials. This narrative review is intended to offer insight into the existing literature on lactoferrin's biological functions and protective effects against COVID-19, with a special focus on pregnant women and their infants.

Addressing Post-Acute COVID-19 Syndrome in Cancer Patients, from Visceral Obesity and Myosteatosis to Systemic Inflammation: Implications in Cardio-Onco-Metabolism

Cardiovascular disease and cancer are the two leading causes of morbidity and mortality in the world. The emerging field of cardio-oncology described several shared risk factors that predispose patients to both cardiovascular disease and cancer. Post-acute COVID-19 syndrome is a chronic condition that occurs in many patients who have experienced a SARS-CoV-2 infection, mainly based on chronic fatigue, sedentary lifestyle, cramps, breathing difficulties, and reduced lung performance. Post-acute COVID-19 exposes patients to increased visceral adiposity, insulin resistance, myosteatosis, and white adipose tissue content (surrounded by M1 macrophages and characterized by a Th1/Th17 phenotype), which increases the risk of cardiovascular mortality and cancer recurrence. In this review, the main metabolic affections of post-acute COVID-19 syndrome in cancer patients at low and high risk of cardiomyopathies will be summarized. Furthermore, several non-pharmacological strategies aimed at reducing atherosclerotic and cardiac risk will be provided, especially through anti-inflammatory nutrition with a low insulin and glycemic index, appropriate physical activity, and immune-modulating bioactivities able to reduce visceral obesity and myosteatosis, improving insulin-related signaling and myocardial metabolism.

A review of the safety evidence on recombinant human lactoferrin for use as a food ingredient

Published studies on the glycosylation, absorption, distribution, metabolism, excretion, and safety outcomes of orally ingested recombinant human lactoferrin (rhLF) were reviewed in the context of unanswered safety questions, including alloimmunization, allergenicity, and immunotoxicity potential of rhLF during repeated exposure. The primary objective was to summarize current safety data of rhLF produced in transgenic host expression systems. Overall, results from animal and human studies showed that rhLF was well tolerated and safe. Animal data showed no significant toxicity-related outcomes among any safety or tolerability endpoints. The no observed adverse effect levels (NOAEL) were at the highest level tested in both iron-desaturated and -saturated forms of rhLF. Although one study reported outcomes of rhLF on immune parameters, no animal studies directly assessed immunogenicity or immunotoxicity from a safety perspective. Data from human studies were primarily reported as adverse events (AE). They showed no or fewer rhLF-related AE compared to control and no evidence of toxicity, dose-limiting toxicities, or changes in iron status in various subpopulations. However, no human studies evaluated the immunomodulatory potential of rhLF as a measure of safety. Following this review, a roadmap outlining preclinical and clinical studies with relevant safety endpoints was developed to address the unanswered safety questions.

Effects of Lactoferrin and Lactobacillus Supplementation on Immune Function, Oxidative Stress, and Gut Microbiota in Kittens

Immune deficiency is a prevalent issue among kittens, severely threatening their health and development by increasing susceptibility to infections and diseases. This study investigates the effects of dietary supplements containing lactoferrin and Lactobacillus plantarum (L. plantarum) on the immune function, intestinal health, and microbiota composition of kittens. The results demonstrate that these supplements significantly enhance immune responses, with immunoglobulin A (IgA) levels increasing by 14.9% and IgG levels by 14.2%. Additionally, there was a notable 28.7% increase in catalase activity, indicating a reduction in oxidative stress. Gastrointestinal (GI) health improved markedly, evidenced by increased populations of beneficial bacteria such as Lactobacillus, which rose from 4.13% to 79.03% over the study period. The DNC group also showed significant reductions in pro-inflammatory cytokines, including decreases of 13.94% in IL-2, 26.46% in TNF-α, and 19.45% in IFN-γ levels. Furthermore, improvements in physical conditions were observed, including enhanced coat condition and mental status. These findings underline the potential of lactoferrin and L. plantarum as effective dietary interventions to improve kitten health, thereby reducing dependency on antibiotics and mitigating associated risks. This research provides a scientific foundation for optimizing nutritional management practices to enhance the overall vitality of kittens during their critical growth phases.

Characterization of recombinant human lactoferrin expressed in Komagataella phaffii

This work presents a thorough characterization of Helaina recombinant human lactoferrin (rhLF, Effera™) expressed in a yeast system at an industrial scale for the first time. Proteomic analysis confirmed that its amino acid sequence is identical to that of native human LF. N-linked glycans were detected at three known glycosylation sites, namely, Asparagines-156, -497, and -642 and they were predominantly oligomannose structures having five to nine mannoses. Helaina rhLF's protein secondary structure was nearly identical to that of human milk lactoferrin (hmLF), as revealed by microfluidic modulation spectroscopy. Results of small-angle X-ray scattering (SAXS) and analytical ultracentrifugation analyses confirmed that, like hmLF, Helaina rhLF displayed well-folded globular structures in solution. Reconstructed solvent envelopes of Helaina rhLF, obtained through the SAXS analysis, demonstrated a remarkable fit with the reported crystalline structure of iron-bound native hmLF. Differential scanning calorimetry investigations into the thermal stability of Helaina rhLF revealed two distinct denaturation temperatures at 68.7 ± 0.9 °C and 91.9 ± 0.5 °C, consistently mirroring denaturation temperatures observed for apo- and holo-hmLF. Overall, Helaina rhLF differed from hmLF in the N-glycans they possessed; nevertheless, the characterization results affirmed that Helaina rhLF was of high purity and exhibited globular structures closely akin to that of hmLF.

Recommendations for nutritional supplements for dry eye disease: current advances

Dry eye disease (DED) represents a prevalent ocular surface disease. The development of effective nutritional management strategies for DED is crucial due to its association with various factors such as inflammation, oxidative stress, deficiencies in polyunsaturated fatty acids (PUFAs), imbalanced PUFA ratios, and vitamin insufficiencies. Extensive research has explored the impact of oral nutritional supplements, varying in composition and dosage, on the symptoms of DED. The main components of these supplements include fish oils (Omega-3 fatty acids), vitamins, trace elements, and phytochemical extracts. Beyond these well-known nutrients, it is necessary to explore whether novel nutrients might contribute to more effective DED management. This review provides a comprehensive update on the therapeutic potential of nutrients and presents new perspectives for combination supplements in DED treatment.

Unlocking the power of Lactoferrin: Exploring its role in early life and its preventive potential for adult chronic diseases

Nutrition during the early postnatal period exerts a profound impact on both infant development and later-life health. Breast milk, which contains lactoferrin, a dynamic protein, plays a crucial role in the growth of various biological systems and in preventing numerous chronic diseases. Based on the relationship between early infant development and chronic diseases later in life, this paper presents a review of the effects of lactoferrin in early life on neonates intestinal tract, immune system, nervous system, adipocyte development, and early intestinal microflora establishment, as well as the preventive and potential mechanisms of early postnatal lactoferrin against adult allergy, inflammatory bowel disease, depression, cancer, and obesity. Furthermore, we summarized the application status of lactoferrin in the early postnatal period and suggested directions for future research.

Vitamin D Supplementation in Neonatal and Infant MIS-C Following COVID-19 Infection

To date, the SARS-CoV-2 pandemic still represents a great clinical challenge worldwide, and effective anti-COVID-19 drugs are limited. For this reason, nutritional supplements have been investigated as adjuvant therapeutic approaches in disease management. Among such supplements, vitamin D has gained great interest, due to its immunomodulatory and anti-inflammatory actions both in adult and pediatric populations. Even if there is conflicting evidence about its prevention and/or mitigation effectiveness in SARS-CoV-2 infection, several studies demonstrated a strict correlation between hypovitaminosis D and disease severity in acute COVID-19 and MIS-C (multisystem inflammatory syndrome in children). This narrative review offers a resume of the state of the art about vitamin D's role in immunity and its clinical use in the context of the current pandemic, specially focusing on pediatric manifestations and MIS-C. It seems biologically reasonable that interventions aimed at normalizing circulating vitamin D levels could be beneficial. To help clinicians in establishing the correct prophylaxis and/or supportive therapy with vitamin D, well-designed and adequately statistically powered clinical trials involving both adult and pediatric populations are needed. Moreover, this review will also discuss the few other nutraceuticals evaluated in this context.

Lactoferrin in the Prevention of Recurrent Respiratory Infections in Preschool Children: A Prospective Randomized Study

Few studies have evaluated the effect of bovine lactoferrin (bLf) on reducing respiratory infections in preschool children. This randomized controlled trial evaluated the effect of bLf in preschool children with recurrent respiratory infections. Participants were randomly assigned bLf (n = 25) or control (n = 25). Outcomes included respiratory infection episodes (RIEs), symptom duration, school absence and medication. Fifty children aged 4.2 ± 0.1 years were included. During the active 4-month phase, median number of RIEs was reduced by 50% in the bLf group [1-episode, interquartile range (IQR): 0-2] vs. control (2, IQR: 1-3; p = 0.02). The proportion of participants with >3 RIEs was significantly lower in bLf (n = 1, 4%) vs. control (n = 7, 28%) with 80% lower odds of upper RIEs in the bLf arm (odds ratio: 0.20, 95% CI:0.06-0.74, p = 0.015). The duration of symptoms (3 vs. 6, p = 0.009) and days absent from school (3 vs. 6, p = 0.15) were lower in the active arm. Over the 2-month follow-up, no significant differences were observed between groups for infection episodes, symptom duration or school absence. However, bLf-treated children received significantly less corticosteroids over the entire 6-month study period (32% vs. 60%; p = 0.047). bLf supplementation significantly reduced the frequency and duration of RIEs in children with decreased corticosteroid use.

Effect of lactoferrin in oral nutrition supplement (ONS) towards IL-6 and IL-10 in failure to thrive children with infection

Background

Growth failure due to infection in children is a major health problem throughout the world. It provokes a systemic immune response, with increased interleukin (IL)-6 and reduced IL-10. Lactoferrin (Lf) is a multifunctional iron-binding protein that can be found in whey protein inside formula milk such as oral nutrition supplement (ONS), which is able to upregulate anti-inflammatory cytokines (IL-10) and modulate pro-inflammatory cytokines. We conducted this study to investigate the effect of Lf supplementation in ONS on IL-6 and IL-10 levels in children with failure to thrive and infection.

Methods

We performed a quasi-experimental pre- and post-study in children aged 12-60 months old with failure to thrive due to infectious illness. The subjects received 400 ml of oral nutritional supplements (ONS, 1 ml equivalent to 1 kcal) each day for 90 days, and their parents received dietary advice and medication based on the underlying illness. Blood was drawn to measure IL-6 and IL-10 before and after the intervention.

Results

There were 75 subjects recruited and divided into group-1 and group-2 based on age. The incidence of undernutrition was 37.33%. Lf in ONS intervention improved body weight and body length. Lf also reduced IL-6, although there was not a significant difference before and after the intervention. However, the IL-6 reduction was significantly higher in subjects with undernutrition compared with subjects with weight faltering. Pre-intervention IL-6 levels were higher in children with stunting than in children with normal stature. There was a greater change in IL-6 in children with severe stunting than in children with normal stature or stunting. IL-10 was significantly reduced after the intervention.

Conclusions

In addition to improving body weight and length, Lf supplementation in ONS improved immune response homeostasis by balancing IL-6 and IL-10 levels and by improving the IL-6/IL-10 ratio.ClinicalTrials.gov number ID: NCT05289674, dated May 3 rd 2022.

Association between serum copper-zinc ratio and respiratory tract infection in children and adolescents

BACKGROUND

The aim of this study was to explore the association between serum copper-zinc (Cu-Zn) ratio and the risk of respiratory tract infection in children and adolescents.

METHODS

This cross-sectional study collected the data of 1695 participants who aged 6-17 years with follow-up data on respiratory tract infection in 2011-2012, 2013-2014 and 2015-2016 cycles from the National Health and Nutrition Examination Survey (NHANES) database. Univariate logistic regression analysis was applied to explore the covariates. Each covariate was adjusted in multivariate logistic regression analysis to explore the correlation between serum Cu-Zn ratio and respiratory tract infection. Subgroup analysis was performed to stratify the data according to age, gender and BMI. Restricted cubic spline (RCS) curve was plotted to identify the association between serum Cu-Zn ratio and respiratory tract infection.

RESULTS

The results of RCS curve depicted that the risk of respiratory tract infection was increased as the elevation of the serum Cu-Zn ratio. After adjusting for confounders, risk of respiratory tract infection in children and adolescents was elevated with the increase of serum copper-zinc ratio (OR = 1.38, 95%CI: 1.19-1.60). Compared with people with serum copper-zinc ratio <1.25, subjects who had serum copper-zinc ratio >1.52 was associated with increased risk of respiratory tract infection in children and adolescents (OR = 1.88, 95%CI: 1.19-2.98). Subgroup analysis demonstrated that the risk of respiratory tract infection was elevated as the increase of serum copper-zinc ratio in participants <12 years (OR = 1.65, 95%CI: 1.28-2.12), ≥12 years (OR = 1.27, 95%CI: 1.03-1.57), males (OR = 1.63, 95%CI: 1.29-2.06), females (OR = 1.26, 95%CI: 1.01-1.57), underweight and normal (OR = 1.35, 95%CI: 1.11-1.65), and overweight and obese participants (OR = 1.44, 95%CI: 1.15-1.80).

CONCLUSION

Higher serum Cu-Zn ratio was associated with increased risk of respiratory tract infection in children and adolescents, which suggests the importance of Zn supplement and the balance of serum Cu-Zn ratio in children and adolescents.

Potential of Lactoferrin in the Treatment of Lung Diseases

Lactoferrin (LF) is a multifunctional iron-binding glycoprotein that exhibits a variety of properties, such as immunomodulatory, anti-inflammatory, antimicrobial, and anticancer, that can be used to treat numerous diseases. Lung diseases continue to be the leading cause of death and disability worldwide. Many of the therapies currently used to treat these diseases have limited efficacy or are associated with side effects. Therefore, there is a constant pursuit for new drugs and therapies, and LF is frequently considered a therapeutic agent and/or adjunct to drug-based therapies for the treatment of lung diseases. This article focuses on a review of the existing and most up-to-date literature on the contribution of the beneficial effects of LF on the treatment of lung diseases, including asthma, viral infections, cystic fibrosis, or lung cancer, among others. Although in vitro and in vivo studies indicate significant potency of LF in the treatment of the listed diseases, only in the case of respiratory tract infections do human studies seem to confirm them by demonstrating the effectiveness of LF in reducing episodes of illness and shortening the recovery period. For lung cancer, COVID-19 and sepsis, the reports are conflicting, and for other diseases, there is a paucity of human studies conclusively confirming the beneficial effects of LF.

Lactoferrin regulates sebogenesis and inflammation in SZ95 human sebocytes and mouse model of acne

BACKGROUND

The aim of this study was to explore the anti-inflammatory and anti-lipid effects of lactoferrin on SZ95 human sebaceous gland cells and mouse model of acne.

METHODS

SZ95 cells were co-cultured with different concentrations of lactoferrin, and cell viability was determined using the 2,5-diphenyl-2H-tetrazolium bromide method. Oil red O and Nile red staining were performed to determine the lipid content. The mRNA expression of genes related to lipid metabolism (sterol regulatory element-binding protein-1 [SREBP-1], fatty acid synthase [FAS], stearoyl-CoA desaturase-1 [SCD-1], fatty acid desaturase 2 [FADS2]) and inflammation (interleukin-8 [IL-8]) was determined by reverse transcription-polymerase chain reaction. An acne mouse model was established using injection of P. acnes on the backs of mice. The proliferation and apoptosis of sebaceous gland cells were examined by immunohistochemistry against proliferating cell nuclear antigen (PCNA) and TUNEL staining, respectively. Western blotting was used to detect FADS2 and CXCL15 protein expression.

RESULTS

Lactoferrin treatment at 10-500 μg/ml significantly decreased the lipid content, as revealed by the oil red O and Nile red staining. It also attenuated the increase of mRNA expression of SREBP-1, FAS, SCD-1, FADS2, and IL-8 in insulin-treated SZ95 cells. Moreover, lactoferrin treatment at the doses of 1-50 mg/mouse significantly reduced the inflammation and lipid production in the mouse model of acne. Also, the number of sebaceous gland cells was significantly reduced, and apoptosis was significantly increased by lactoferrin treatment in the mice. Mechanically, the levels of FADS2 and CXCL15 proteins in tissues were significantly decreased after lactoferrin treatment in the model mice.

CONCLUSION

Our results demonstrate the potential of lactoferrin against sebogenesis, sebaceous gland inflammation in acne.

Preventing Respiratory Viral Diseases with Antimicrobial Peptide Master Regulators in the Lung Airway Habitat

The vast surface area of the respiratory system acts as an initial site of contact for microbes and foreign particles. The whole respiratory epithelium is covered with a thin layer of the airway and alveolar secretions. Respiratory secretions contain host defense peptides (HDPs), such as defensins and cathelicidins, which are the best-studied antimicrobial components expressed in the respiratory tract. HDPs have an important role in the human body's initial line of defense against pathogenic microbes. Epithelial and immunological cells produce HDPs in the surface fluids of the lungs, which act as endogenous antibiotics in the respiratory tract. The production and action of these antimicrobial peptides (AMPs) are critical in the host's defense against respiratory infections. In this study, we have described all the HDPs secreted in the respiratory tract as well as how their expression is regulated during respiratory disorders. We focused on the transcriptional expression and regulation mechanisms of respiratory tract HDPs. Understanding how HDPs are controlled throughout infections might provide an alternative to relying on the host's innate immunity to combat respiratory viral infections.

Bovine lactoferrin for the prevention of COVID-19 infection in health care personnel: a double-blinded randomized clinical trial (LF-COVID)

Lactoferrin (LF) has in vitro antiviral activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This study aimed to determine the effect of bovine lactoferrin (bLF) in the prevention of SARS-CoV-2 infection in health care personnel. A randomized, double-blinded, placebo-controlled clinical trial was conducted in two tertiary hospitals that provide care to patients with SARS-CoV-2 infection in Lima, Peru. Daily supplementation with 600 mg of enteral bLF versus placebo for 90 days was compared. Participants were weekly screened for symptoms suggestive of SARS-CoV-2 infection and molecular testing was performed on suspected episodes. A serological test was obtained from all participants at the end of the intervention. The main outcome included symptomatic and asymptomatic cases. A sub-analysis explored the time to symptomatic infection. Secondary outcomes were the severity, frequency, and duration of symptomatic infection. The study was prematurely cancelled due to the availability of vaccines against SARS-CoV-2 in Peru. 209 participants were enrolled and randomized, 104 received bLF and 105 placebo. SARS-CoV-2 infection occurred in 11 (10.6%) participants assigned to bLF and in 9 (8.6%) participants assigned to placebo without significant differences (Incidence Rate Ratio = 1.23, 95%CI 0.51-3.06, p-value = 0.64). There was no significant effect of bLF on time to symptomatic infection (Hazard Ratio = 1.61, 95%CI 0.62-4.19, p-value = 0.3). There were no significant differences in secondary outcomes. A significant effect of bLF in preventing SARS-CoV-2 infection was not proven. Further studies are needed to assess the effect of bLF supplementation on SARS-CoV-2 infection.Clinical trial registration ClinicalTrials.gov Identifier: NCT04526821, https://clinicaltrials.gov/ct2/show/NCT04526821?term=LACTOFERRIN&cond=COVID-19&cntry=PE&city=Lima&draw=2&rank=1 .

Research Advances of Lactoferrin in Electrostatic Spinning, Nano Self-Assembly, and Immune and Gut Microbiota Regulation

Lactoferrin (LF) is a naturally present iron-binding globulin with the structural properties of an N-lobe strongly positively charged terminus and a cage-like structure of nano self-assembly encapsulation. These unique structural properties give it potential for development in the fields of electrostatic spinning, targeted delivery systems, and the gut-brain axis. This review will provide an overview of LF's unique structure, encapsulation, and targeted transport capabilities, as well as its applications in immunity and gut microbiota regulation. First, the microstructure of LF is summarized and compared with its homologous ferritin, revealing both structural and functional similarities and differences between them. Second, the electrostatic interactions of LF and its application in electrostatic spinning are summarized. Its positive charge properties can be applied to functional environmental protection packaging materials and to improving drug stability and antiviral effects, while electrostatic spinning can promote bone regeneration and anti-inflammatory effects. Then the nano self-assembly behavior of LF is exploited as a cage-like protein to encapsulate bioactive substances to construct functional targeted delivery systems for applications such as contrast agents, antibacterial dressings, anti-cancer therapy, and gene delivery. In addition, some covalent and noncovalent interactions of LF in the Maillard reaction and protein interactions and other topics are briefly discussed. Finally, LF may affect immunological function via controlling the gut microbiota. In conclusion, this paper reviews the research advances of LF in electrostatic spinning, nano self-assembly, and immune and gut microbiota regulation, aiming to provide a reference for its application in the food and pharmaceutical fields.