The Functional Role of Lactoferrin in Intestine Mucosal Immune System and Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), encompassing ulcerative colitis (UC) and Crohn's disease (CD), is one of the main types of intestinal inflammatory diseases with intestine mucosal immune disorder. Intestine mucosal immune system plays a remarkable and important role in the etiology and pathogenesis of IBD. Therefore, understanding the intestine mucosal immune mechanism is a key step to develop therapeutic interventions for IBD. Intestine mucosal immune system and IBD are influenced by various factors, such as inflammation, gut permeability, gut microbiota, and nutrients. Among these factors, emerging evidence show that nutrients play a key role in inflammation activation, integrity of intestinal barrier, and immune cell modulation. Lactoferrin (LF), an iron-binding glycoprotein belonging to transferrin family, is a dietary bioactive component abundantly found in mammalian milk. Notably, LF has been reported to perform diverse biological functions including antibacterial activity, anti-inflammatory activity, intestinal barrier protection, and immune cell modulation, and is involved in maintaining intestine mucosal immune homeostasis. The improved understanding of the properties of LF in intestine mucosal immune system and IBD will facilitate its application in nutrition, clinical medicine, and health. Herein, this review outlines the recent advancements on LF as a potential therapeutic intervention for IBD associated with intestine mucosal immune system dysfunction. We hope this review will provide a reference for future studies and lay a theoretical foundation for LF-based therapeutic interventions for IBD by understanding the particular effects of LF on intestine mucosal immune system.

A Review on Lactoferrin and Central Nervous System Diseases

Central nervous system (CNS) diseases are currently one of the major health issues around the world. Most CNS disorders are characterized by high oxidative stress levels and intense inflammatory responses in affected tissues. Lactoferrin (Lf), a multifunctional iron-binding glycoprotein, plays a significant role in anti-inflammatory, antibacterial, antiviral, reactive oxygen species (ROS) modulator, antitumor immunity, and anti-apoptotic processes. Previous studies have shown that Lf is abnormally expressed in a variety of neurological diseases, especially neurodegenerative diseases. Recently, the promotion of neurodevelopment and neuroprotection by Lf has attracted widespread attention, and Lf could be exploited both as an active therapeutic agent and drug nanocarrier. However, our understanding of the roles of Lf proteins in the initiation or progression of CNS diseases is limited, especially the roles of Lf in regulating neurogenesis. This review highlights recent advances in the understanding of the major pharmacological effects of Lf in CNS diseases, including neurodegenerative diseases, cerebrovascular disease, developmental delays in children, and brain tumors.

Supplementation of Bovine Colostrum in Inflammatory Bowel Disease: Benefits and Contraindications

Inflammatory bowel disease (IBD) is a group of chronic relapsing disorders whose etiology has not been fully explained. Therefore, available therapeutic approaches for IBD patients are still insufficient. Current treatment strategies are targeted to immune system dysfunctions, often associated with alternations in the microbiota, which contribute to the development of chronic intestinal inflammation. Therapeutics include anti-inflammatory drugs such as aminosalicylates and corticosteroids, immunosuppressive agents, antibiotics, and biological agents such as infliximab and vedolizumab. Auxiliary therapies involve a balanced and personalized diet, healthy lifestyle, avoiding stress, as well as dietary supplements. In this review, we discuss the use of bovine colostrum (BC) as a therapeutic agent, including its advantages and contraindications. We summarize our knowledge on well-researched BC constituents and their effects on the gastrointestinal tract as evidenced in in vitro and in vivo studies.

Protective effects of human lactoferrin during Aggregatibacter actinomycetemcomitans-induced bacteremia in lactoferrin-deficient mice

Aggregatibacter actinomycetemcomitans, a periodontopathogen, has been associated with several systemic diseases. Herein, we report the protective effect of human lactoferrin (hLF) during A. actinomycetemcomitans bacteremia in lactoferrin knockout (LFKO(-/-)) mice. The prophylactic, concurrent, and therapeutic intravenous (i.v.) administrations of hLF significantly cleared the bacteria from blood and organs. Nevertheless, all modes of hLF administration significantly decreased the concentrations of serum proinflammatory cytokines, such as interferon gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), IL-6, IL-10, and IL-12p70. Additionally, hLF administration significantly decreased hepatic and splenic proinflammatory cytokine expression levels compared to those in the non-hLF-treated group. Furthermore, administration of hLF decreased the serum C-reactive protein level, inducible nitric oxide synthase (iNOS) and myeloperoxidase (MPO) gene expression levels in liver and spleen. hLF treatment has also resulted in a 6-fold decrease in spleen weight with the migration of typical inflammatory cells in infected mice as a result of decreased inflammatory response. These results reveal that hLF protects against A. actinomycetemcomitans bacteremia, as indicated by rapid bacterial clearance and decreased host proinflammatory mediators.

Prophylactic effects of Lonicera japonica extract on dextran sulphate sodium-induced colitis in a mouse model by the inhibition of the Th1/Th17 response

Inflammatory bowel diseases (IBD) are chronically relapsing inflammatory disorders of the intestine. Although some therapeutic agents, including steroids, are available for the treatment of IBD, these agents have limited use. Therefore, dietary supplements have emerged as possible interventions for IBD. Japanese honeysuckle flower, the flower of Lonicera japonica, is a well-known dietary supplement and has been used to prevent or treat various inflammatory diseases. In the present study, we investigated the effects of L. japonica on experimental murine colitis. Colitis was induced by 5 % dextran sulphate sodium (DSS) in Balb/c mice. The water extract of L. japonica (LJE) at doses of 20, 100 or 500 mg/kg was orally administered to mice twice per day for 7 d. Body weight, colon length and a histological damage score were assessed to determine the effects on colitis. Cytokine profiles were assessed to examine the effects on helper T (Th) cell-related immunological responses. In addition, CD4+CD25+Foxp3+T cells were analysed in vivo and in vitro for investigating the effects on regulatory T (Treg) cells. LJE showed dose-dependent inhibitory effects against colon shortening, weight loss and histological damage. LJE down-regulated IL-1β, TNF-α, interferon-γ, IL-6, IL-12 and IL-17. However, LJE did not show any significant effects on IL-10, IL-23, transforming growth factor-β1 and Treg cell populations. In conclusion, LJE showed protective effects against DSS-induced colitis via the Th1/Th17 pathway and not via Treg cell-related mechanisms.

Exercise affects tissue lymphocyte apoptosis via redox-sensitive and Fas-dependent signaling pathways

Intensive and exhaustive exercise induces an activation of blood T-lymphocytes, which seems to be terminated by apoptotic processes in the postexercise period. Here, we report that exercise-induced T-lymphocyte apoptosis is a systemic phenomenon occurring in various lymphoid and nonlymphoid tissues. The apoptosis rate could be related to exercise intensity and type. Although in some tissues, such as the spleen and Peyer's patches, an early start of apoptosis (1-3 h postexercise) could be detected, a delayed apoptosis (24 h postexercise) was observed in lung, bone marrow, and lymph nodes. Further analysis showed a similar apoptosis distribution among lymphocyte subpopulations. We tested whether components of the extrinsic or the intrinsic apoptotic pathways or both were involved in these processes. Elevated levels of lipid peroxidation-product malondialdehyde (MDA), indicating an increased production of reactive oxygen species (ROS), were found after exercise in Peyer's patches, lung, and spleen, but not in lymph nodes. Application of N-acetyl-cysteine (NAC) prevented exercise-induced T-cell apoptosis completely in spleen and bone marrow, partially in lung and Peyer's patches, while it was ineffective in lymph nodes. Additionally, exercise addressed the Fas-mediated apoptosis. The percentage of Fas-receptor (Fas+) and Fas-ligand positive (FasL+) lymphocytes was enhanced in Peyer's patches after exercise. Moreover, FasL+ T cells were increased in the lung, while in lymph nodes Fas+ cells were increased. The critical role of Fas signaling in exercise-induced apoptosis was supported by using Fas-deficient MRL/lpr-mice. In Fas-deficient mice, exercise-induced T-lymphocyte apoptosis was prevented in spleen, lung, bone marrow, and lymph nodes, but not in Peyer's patches. These data demonstrate that exercise-induced lymphocyte apoptosis is a transient systemic process with tissue-type specific apoptosis-inducing mechanisms, whose relevance for the adaptive immune competence remains to be shown.