Background:Lactoferrin (LF)is an innate-defence non-heme iron binding glycoprotein of 80 kDa able to support the immune system and influence immune cell activity by antioxidant, antibacterial and antiviral properties. This work focusses on the study of the in vitroanti-inflammatory activity of Bovine LF(bLF)on Lipopolysaccharide (LPS)-induced cytokines expression.
Methods:We investigated the immunomodulatory effect of bLF on tumor necrosis factor alpha (TNF-α), interleukin-10 (IL-10) and interleukin-12 (IL-12) cytokineson human keratinocytes NCTC2544 and human myelomonocyticleukaemia cells, THP-1.
Results:Bovine LF exerted an anti-inflammatory activity since early phase to 8h of treatment, by modulating cytokines expression and secretion.
Conclusions: These data encourage the use of bLF as immunomodulatory agent in the treatment of different dermatological conditions linked to inflammatory processes.
Keywords:Acne Vulgaris; Cutaneous Disorder; Cytokines;Immunomodulation; Interleukin-10 (IL-10); Interleukin-12 (IL-12); Lactoferrin; Lipopolysaccharide (LPS); Nutritional Supplement;Tumor Necrosis Factor Alpha (TNF-α)
LF : Lactoferrin
TNF-α : Tumor Necrosis Factor Alpha
LPS : Lipopolysaccharide
IL-10 : Interleukin-10
IL-12 : Interleukin-12
hLF : Human Lactoferrin
bLF : Bovine Lactoferrin
LF10 : Lactoferrin 10 µg/mL
LF40 : Lactoferrin 40 µg/mL
PC : Positive Control
FBS : Fetal Bovine Serum
MTT : 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide
GAPDH : Human glyceraldehyde-3-phosphate dehydrogenase
SD : Standard Deviation
SEM : Standard Error from Mean
ROS : Reactive Oxygen Species
Lactoferrin (LF), is an 80 kDaglycoprotein belonging to the transferrin family of non-heme iron binding proteins together with transferrin [1,2,3], ovotransferrin, melanotransferrin  and a recently identified carbonic anhydrase inhibitor .The main role of these proteins is to control the levels of free iron in biological fluids. LF was discovered for first time from bovine milk by Sorensen and Sorensens in 1939  and then purified by three independent laboratories in 1960 [8-10].
It consists of a single polypeptide chain of 703 amino acids, folded in two globular lobes, C (carboxy) and N(amino) terminal respectively, connected by a α-helix, with one iron binding site on each lobe. LF binds primarily Fe+2or Fe+3but is also capable of binding other metals ions traces like Al3+, Ga3+, Mn3+, Co3+, Cu2+, Zn2+but with much lower affinity .
LF is found primarily in exocrinesecretions such as milk [12,13] tears, nasal exudate or bronchial mucus [11,14-18], and is also known as a major component of the secondarygranules of neutrophils . Conversely, blood, plasma and serum levels of LF are very low . An increase of LF in blood may occur during infection, inflammation or tumor growth .
Due to its higher affinity for iron , the ability to retain iron over a broad pH range [22,23], and differential tissue relative distribution than other transferrins, LF own unique functional properties.
Following infection of inflammation, pH levels on sites of inflammation become very low (<4.5) due to metabolic activity of bacteria. In such a condition LF prevents bacterial proliferation by its bound to iron, also the one released from transferrin .
Being a multifunctional molecule, LF own several physiological functions: i) iron absorption and metabolism [25,26]; ii) as a part of the innate immune system, LF protects against microbial infections, both Gram-positive and negative bacteria, viruses, protozoa, or fungi ; iii) antibacterial  and antiviral activity ; stimulation of bone growth ; prevention of inflammation by reducing production of pro-inflammatory cytokines [30,31] and diminishing oxidative stress ; antiparasitic activity ; antitumoractivity [34-36].
Recently, LF has been named “Nutraceutical Protein”, due to its multiple properties and the potential for use as a therapeutic protein .
Until recently, the main source of LF was from human breast milk. Nowadays, however, LF from bovine source, Bovine Lactoferrin (bLF) is ready available.bLFhas about 69% amino acids identity with Human LF(hLF)  but, despite slight changes in domains orientation and closure any functional differences are found . Therefore, the carbohydrate structure of bLF is much better defined than that of hLF and it has been shown that bLF bind to humanneutrophils with higher affinity than hLF.
bLFis generally recognized as safe (GRAS) by the Food and Drug Administration (FDA) and permitted as food and dietary supplement ingredient in many countries. Supplements of bLF are reported to have the ability to support the immune system by anti-infective, anti-cancer, and anti-inflammatory effects  highlighting the bLF potential as therapeutic agent.
Nowadays several studies have re-evaluated the role of dietary interventions in the developmentand therapy of skin disease. This led to an increasing interest in nutraceutical and dietary supplement as novel therapeutic agents.
Due to its various and interesting functions, LF has attracted a growing interest for potential clinical applications and there are increasing evidences for its use in treatments of different dermatological conditions .
The aim of the present work was to study the effects of bLF on Lipopolysaccharide (LPS)-induced cytokinesexpression and secretion in two cell lines (human keratinocytes NCTC2544 and THP-1 myelomonocyticleukaemia cells) to deeper understand its potential in the treatment of skin related disease.
Materials and Methods
Lactoferrin Moringa Low endotoxin bovine milk Lactoferrin (LF) (<1 EU/mg, <20% iron saturated, >95% purity) was provided by C.F.M. CO. Farmaceutica Milanese S.p.A. (Milan, Italy). Cell culture media and all supplements were from Lonza Inc. (Barcelona, Spain), for NCTC2544 cell and from Sigma (St Louis, MO, USA) for THP-1 cells. Bacterial Lipopolysaccharide (LPS) (Escherichia coli, Serotype 0111:B4, 3×106EU/mg) and Elisa reagents were purchased from Sigma. Antibodies and protein for ELISA assay were from R&D System (Minneapolis, MN, USA).
Cell culture and Viability
Normal human keratinocyte NCTC 2544 (Istituto Nazionale di RicercasulCancro–Italy) were cultured under humidified atmosphere (5% CO2, 37°C) on Eagle’s Minimum Essential Medium Balanced with salt solution (EMEM-EBSS) containing 2mM l-glutamine, 1% of Non-Essential Amino Acids (NEAA) and penicillin (100 U/ml)/streptomycin (100 U/ml) supplemented with 10% Fetal Bovine Serum (FBS) (basal medium). THP-1 cells (IstitutoZooprofilattico di Brescia, Bres-cia, Italy) were cultured in RPMI 1640 containing 2 mM l-glutamine, 0.1 mg/ml streptomycin, 100 IU/ml penicillin, 50µM-2-mercaptoethanol, supplemented with 10% heated-inactivated fetal calf serum (media).
Both cell types were incubated in 25 cm2 surface culture flasks at 37°C with 5% CO2 until ca. 80% of confluence was reached. Following harvesting with trypsin/EDTA cells were seeded at 5×104 cells per well into 96 well plates or 1×106 cells per well into 12 well plates for 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide proliferation (MTT) assay and cytokines quantification, respectively.
Effect of bLF Preparations on Viability of Cells
Cytotoxicity of LF on NCTC2544 and THP-1 cell lines was analyzed by MTT assay according to the method of Hansen  with minor modifications. After reaching 80% confluence, cells were exposed to bLF at the following concentrations: 2.5, 5, 10, 20, 40, 80 and 160µg/mL, for 24h at 37°C, under 5% of CO2. Cells in basal medium alone were used as control. At the end of treatment, the medium was replaced with 100 μl per well of the MTT solution and cells were incubate for 3h in darkness, at 37°C, under 5%. MTT was previously dissolved (5 mg/ml) in PBS and diluted 1:10 in the cell culture medium without phenol red. Following incubation, 100 μl per well of Dimethylsulphoxide (DMSO) were added to dissolve purple formazan product and the solution shaked for 15 min at room temperature. Finally, the absorbance of the solutions was read at 550 nm in a microplate reader (BioTek Instruments Inc., Bad Friedrichshall, Germany). Each experiment was carried out in triplicate. Data were expressed as the mean percentage of viable cells compared with control.
TNF-α, IL-10 and IL-12 Immunomodulation by bLF
Immunomodulatory properties of bLF were investigated first by mean of qRT-PCR. Total RNA was isolated at different times of treatment using a commercial available kit (TriReagent from Sigma) as described by Chomczynski and Mackey . 2µg of total RNA were retro-transcribed in cDNA using a high-capacity cDNA kit from Applied Biosystems (Foster City, CA, USA) in a thermal cycler (Stratagene Mx3000P Real Time PCR System, Agilent Technologies Italia S.p.A., Milan, Italy) according to these conditions: 25°C for 10 min, 37°C for 120 min and 85°C for 60 s. mRNA levels where then quantified by using Taq-ManTM-PCR technology. Following 20X TaqMan® assay (Applied Biosystems) were used: Hs00174128-m1 (TumorNecrosis Factor Alpha, TNF-α), Hs00961622_m1 (Interleukin-10, IL-10), Hs01011518_m1 (Interleukin-12, IL-12) and Hs999999-m1 (Human glyceraldehyde-3-phosphate dehydrogenase, GAPDH). PCR amplifications were carried out using 40 ng of cDNA in a 20 μl of mixture reaction containing 10 μl of 2XPremix Ex Taq (Takara, Clontech Laboratories, Inc, Mountain View, USA), 1 μl of 20× TaqMan gene expression assay, 0.4 μl of 50X RoxTM reference dye II (Takara, Clontech Laboratories, Inc,), 4.6 μl of water and 4 μl of cDNA. PCR conditions were 95°C for 30 secs (for Amplitaq activation) followed by 40 amplification cycles (95°C for 5 s; 60°C for 20sec). Analyses were carried out in triplicate. Average value of Human GAPDH gene was used as endogenous reference for target gene and the quantification of transcripts levels was performed by the 2−ΔΔCTmethod .
The expression of cytokines at protein levels was also assessed in cell free supernatants, stored at -80°C until measurement, after centrifugation at 1200 rpm for 5 mins. Before ELISA assay samples were concentrated with Vivaspin Sartorius centrifugal concentrators (with cut off 10000 and 30000 MW, respectively for IL-10 and IL-12/TNF-α). Protein expression was assessed by custom sandwich Elisa assays, according to manufacturer recommendations as regards antibodies and standards dilutions and following a custom home-made protocol for coating and detection of antibodies. Results were expressed as pg/mg protein.
All experiments were repeated at least three times, with representative results shown. Data are expressed as Mean ±SEM for qRT-PCR analysis and Standard Deviation (SD) for other experiments. Results were checked for normal distribution using Shapiro-Wilk test before further analyses. Analysis of Variance (ANOVA) was carried out following by Sidak’s multiple comparison test, using GraphPad Prism version 6.00 for Windows (GraphPad Software, La Jolla California USA, www.graphpad.com). P-values equal to or less than 0.05 were considered significant.
In vitro Effects of bLF on TNF-α, IL-10 and IL-12 Anti-Inflammatory Cytokines
Primarily, lactoferrin 10 µg/mL (LF10) and 40 µg/mL (LF40) effect on LPS-induced cytokines gene expression was determined by mean of qRT-PCR. Down-regulation in cytokines expression reflects into an anti-inflammatory action. Both LFs exerted a significant (P<0.0001) immunomodulatory action on TNF-α since 1 to 8h of treatment (Figure 1a) respect to Positive Control (PC), when tested on human keratinocytes NCTC2544. On THP-1 cells (Figure 1b), even if treatment with both LFs produced a significant (P<0.0001) down-regulation of TNF-α after 1h of treatment, the strongest LF dose-independent immunomodulation was found from 5h to 7h of incubation. At 8h LF40 was most effective than LF10. In addition, IL-10 expression was strongly significant (P<0.0001) influenced by LFs (vs PC), independently from concentrations and in general, independently from cell line (Figure 2a and 2b). Most interesting, on THP-1 cells this effect was evident since 1h of incubation (Figure 2b).
On the contrary, immunomodulation of IL-12 cytokine was strongly dependent from cell line used. Both LFs showed to exert a similar significant (P<0.0001) anti-inflammatory action on NCTC2544 cells from 2h of incubation (Figure 3a). This effect wears off after 5h and 6h of incubation for LF40 and LF10, respectively. On THP–1 cells, immunomodulation by LFs respect to PC was less time and dose dependent (Figure 3b). The strongest significant (P<0.0001) effect was found for LF10 from 3 to 5h of incubation and LF40 after 7h. Statistical significance (p value) is reported in Table S1.
qRT-PCR results were mostly confirmed by ELISA assay and this was according to the delayed expression of a protein respect to the related gene. In particular, according to TNF-α gene expression, Elisa assay (Table 1) confirmed LFs anti-inflammatory activity, independently from cell line used. On NCTC2544 cells IL-10 protein expression was delayed at 6h of treatment and continued up to 8h. LF10 and LF40 produced the same anti-inflamamtory effect, respect to PC, with the exception of 7h treatment, following which LF40 was most effective than LF10 (Table 2). On THP-1, IL-10 expression was delayed above 8h of treatment (Table 2). Same results were found for IL-12 expression on NCTC2544 (Table 3).
On the contrary, according to gene expression evaluation, on THP-1 cell line, LFs immunomodulation was most evident from 6 to 7h of incubation (Table 3), independently from doses.
bLFis an iron-binding glycoprotein that consists of a single polypeptide chain of 689 amino acids; the sequence homology with human LF is 69% .
As an integral part of the innate immune system LF is considered a well-known immunomodulator of leukocyte populations [47-52] and many recent evidences support the role of Lf in regulation of host acting by inhibition of several cytokines [30,53] and act primarily as key modulators and regulators of immune processes. Produced also by cells other than immune cells, after the binding to specific receptors, cytokines produce multiple signals and induce target cell to new mRNA and protein synthesis . This results in a specific biological response.
Among cytokines, TNF-α [55-58], IL-10 [59-63], IL-12[64–66], are key effectors both in immune and infectious response.
Studies on various human monocytic cell lines, included THP-1 cells, showed that LF, both bovine and human,can modulate basal and LPS-mediated pro-inflammatory cytokines release [31,68,69]. LPS is the major constituent of the outer membrane of bacterial pathogens and is a well-known initiator of inflammation . Among others, Appelmelk and coworkers  suggested that, in systemic infections, the inhibition of primary inflammatory response TNF-α-linked could be due to the binding between LF and the lipid A moiety of LPS released from bacteria, inhibiting subsequent LPS-mediated pro-inflammatory response.
LF, both human and bovine, present similar binding to THP-1 cells . In a more recent study on THP-1 monocytes, Haversen demonstrated that LF regulates the LPS-induced cytokine expression on a transcriptional level, by interference with the intracellular events leading to NF-kB activation. Therefore, in the same study, bLFseemed somewhat more efficient compared to human LF and that TNF-α, the most inhibited cytokine, down-regulates IL-10 expression.
Moreover, many receptors have been identified both on the surfaces of immunocompetent cells [73-75] and epithelial cells suggesting also a direct involvement of LF in the signaling pathways of pro-inflammatory cytokines.
Inflammation playsan important role in pathogenesis of many cutaneous disorders such as for example psoriasis , atopic dermatitis , contact dermatitis , acne vulgaris[79,80], UV-induced inflammation [81-83].
Although there are still few studies evaluating LF usage for dermatological conditions, the reported studies encourage the use of LF for these purposes .
In a first explorative study, Muller and coworkers demonstrated the efficacy and tolerability of oral bLFsupplementation in subjects with mild to moderate facial acne vulgaris. Previously, Kim and coworkers showed the ameliorating effect of Lactoferrin-enriched fermented milk on acne vulgaris. LF exerted these effects probably due to its anti-bacterial and anti-inflammatory effects.
LF has also the potential to prevent UV-induced skin damage by the inhibition of UV-stimulated cytokines  and acting as a sacrificial scavenger for Reactive Oxygen Species (ROS) . Most interesting, also topical exposure to LF is able to influence inflammatory responses acting on local production pro-inflammatory cytokines .
The in vitro experiment presented in this work confirmed the immunomodulatory activity of bLF, which exerted its action at a transcriptional level since to the early phase to 8h of treatment. The anti-inflammatory activity occurs by immune-modulation of cytokines expression in an LPS-mediated inflammatory systemon normal human keratinocytes and THP-1 cells. Most likely bLF exerted its effect both by inhibition of binding of lipopolysaccharide endotoxin to cells, as well as acting directly on cells cytokines production.
Our results add an important element to the knowledge on the anti-inflammatory potential of bovine LF in an LPS-mediated system. bLF is capable of immunomodulate pro-inflammatory cytokines at a transcriptional level. These findings encourage the use of bLF as immunomodulator agentin the treatment of different cutaneous disorder (eg. acne vulgaris) both as dietary supplement and topically administered.
However larger randomized clinical trials are necessary to better define its role and pharmacokinetic behaviorfor dermatological purposes.
Conflicts of Interest:R.F. serves as a consultant for Giuliani S.p.A. P.D. and M.B. are employed by Giuliani S.p.A.
Funding: This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.
Author Contributions: P.D. performed experiments and wrote the paper; M.B. performed experiments, analyzed the data, wrote the paper; S.E. review the paper; R.F. conceived and designed the experiments, review the paper.
- Metz-Boutique MH, Jolles J, Mazurier J, Schoentgen F, Legrand D, et al. (1984) Human lactotransferrin: amino acid sequence and structural comparisons with other transferrins. Eur J Biochem145: 659-676.
- MacGillivray RT, Mendez E, Shewale JG, Sinha SK, Lineback-Zins J, et al. (1983) The primary structure of human serum transferrin.The structures of seven cyanogen bromide fragments and theassembly of the complete structure. J Biol Chem258: 3543-3553.
- Yang F, Lum JB, McGill JR, Moore CM, Naylor SL, et al. (1984) Human transferrin: cDNA characterizationand chromosomal localization. Proc Natl Acad Sci USA 81: 2752-2756.
- Jeltsch JM, Chambon P(1982) The complete nucleotide sequence of thechicken ovotransferrin mRNA. Eur J Biochem 122: 291-295.
- Rose TM, Plowman GD, Teplow DB, Dreyer WJ, Hellstrom KE, et al. (1986) Primary structure of the human melanoma-associatedantigen p97 (melanotransferrin) deduced from the mRNA sequence. Proc Natl Acad Sci USA 83:1261-1265.
- Wuebbens MW, Roush ED, Decastro CM, Fierke CA (1997) Cloning sequencing, and recombinant expression of the porcine inhibitor ofcarbonic anhydrase: a novel member of the transferrin family. Biochemistry 36: 4327-4336.
- Soerensen M, Soerensen SPL (1939)The proteins in whey. C R Trav Lab Carlsberg 23: 55-99.
- Groves ML(1960) The isolation of a red protein from milk. J Am Che Soc 82: 3345-3350.
- Johansson B (1960) Isolation of an iron-containing red protein from human milk. Acta ChemScand 14: 510-512.
- Montreuil J, Tonnelat J, Mullet S (1960) Preparation and properties of lactosiderophilin (lactotransferrin) of human milk. BiochimBiophys Acta 45: 413-421.
- Baker EN, Baker HM (1995) Molecular structure, binding properties and dynamics of lactoferrin. Cell MolLife Sci 62: 2531-2539.
- Brock JH(1980) Lactoferrin in human milk: its role in iron absorption and protection against enteric infection in the newborn infant. Arch Dis Child55: 417-421.
- Masson PL, Heremans JF(1971) Lactoferrin in milk from different species. Comp Biochem Physiol B 39: 119-129.
- Masson PL, Heremans JF, Dive C(1966) An iron-binding protein common to many external secretions. ClinicaChimicaActa 14:735-739.
- Baker EN(1994) Structure and reactivity of transferrins. Adv InorgChem 41: 389-463.
- Levay PF, Viljoen M (1995) Lactoferrin: a general review. Haematologica 80: 252-267.
- Lonnerdal B, Iyer S (1995) Lactoferrin: molecular structure and biological function. Ann Rev Nutr 15: 93-110.
- Kikuchi M, Mizoroki S, Kubo T, Ohiwa Y, Kubota M, et al. (2003) Seminal plasma lactoferrin but not transferrin reflects gonadal function in dogs. J Vet Med Sci65: 679-684.
- Iyer S, Lonnerdal B (1993) Lactoferrin, lactoferrin receptors and iron metabolism. Eur J Clin Nutr 47: 232-241.
- Birgens HS (1995) Lactoferrin in plasma measured by an ELISA technique: evidence that plasma lactoferrin is an indicator of neutrophil turnover and bone marrow activity in acute leukaemia. Scand J Haematol 34: 326-331.
- Baker HM, Baker EN(2004) Lactoferrin and iron: structural and dynamic aspects ofbinding and release. Biometals 17: 209-216.
- Baker EN, Anderson BF, Baker HM, Faber HR, Smith CA, et al. (1997) In: Lactoferrin: Interactions and Biological Functions; Hutchens TW, Lonnerdal, Eds.; Humana Press: Totowa, New Jersey: 177-191.
- Mazurier J, Spik G(1980) Comparative study of the iron-binding properties of human transferrins. I. Complete and sequential iron saturation and desaturation of the lactotransferrin. Biochim Biophys Acta 629: 399-408.
- Valenti P, Antonini G (2005) Lactoferrin: an important host defense against microbial and viral attack. Cell Mol Life Sci 62: 2576-2587.
- Artym J (2008) The role of lactoferrin in the iron metabolism. Part I. Effect of lactofferin on intake, transport and iron storage. Postepy Hig Med Dosw 62: 599-612.
- Artym J (2010) The role of lactoferrin in the iron metabolism. Part II. Antimicrobial and antiinflammatory effect of lactoferrin by chelation of iron. Postepy Hig Med Dosw 64: 604-616.
- Yamauchi K, Tomita M, Giehl TJ, Ellison RT(1993) Antibacterial activity of lactoferrin and a pepsin-derived lactoferrin peptide fragment. Infect Immun 61: 719-728.
- Berlutti F, Pantanell F, Natalizi T, Frioni A, Paesano R, et al. (2011) Antiviral properties of lactoferrin–a natural immunity molecule. Molecules 16: 6992-7018.
- Cornish J, Callon KE, Naot D, Palmano KP, Banovic T, et al. (2004) Lf is a potent regulator of bone cell activity and increases bone formation in vivo. Endocrinology 145: 4366-4374.
- Machnicki M, Zimecki M, Zagulski T (1993) Lactoferrin regulates the release of tumour necrosis factor alpha and interleukin 6 in vivo. Int J ExpPathol 74: 433-439.
- Haversen L, Ohlsson BG, Hahn-Zoric M, Hanson LA, Mattsby-Baltzer I (2002) Lactoferrin down-regulates the LPS-induced cytokine production in monocytic cells via NF-kappa B. Cell Immunol 220: 83-95.
- Ward PP, Paz E, Conneely OM (2005) Multifunctional roles of lactoferrin: a critical overview. Cell Mol Life Sci 62: 2540-2548.
- Cirioni O, Giacometti A, Barchiesi F, Scalise G(2000) Inhibition of growth of Pneumocystis carinii by lactoferrins alone and in combination with pyrimethamine, clarithromycin and minocycline. J AntimicrobChemother 46: 577-582.
- Bezault J, Bhimani R, Wiprovnick J, Furmanski P(1994) Human lactoferrin inhibits growth of solid tumors and development of experimental metastases in mice. Cancer Research 54: 2310-2312.
- Wang WP, Iig M, Sato J, Sekine K, Adachi I, et al. (2000) Activation of intestinal mucosal immunity in tumor-bearing mice by lactoferrin. Jpn J Cancer Res 91: 1022-1027.
- Wolf JS, Li D, Taylor RJ, O’Malley BWJR (2003) Lactoferrin inhibits growth of malignant tumors of the head and neck. ORL J Otorhinolaryngol Relat Spec 65:245-249.
- Vogel HJ (2012) Lactoferrin, a bird’s eye view. Biochem Cell Biol 90: 233-244.
- Pierce A, Colavizza D, Benaissa M, Maes P, Tartar A, et al. (1991) Molecular cloning and sequence analysis of bovine lactotransferrin. Eur J Biochem 196: 177-184.
- Moore SA, Anderson BF, Groom CR, Haridas M, Baker EN (1997) Three-dimensional structure of diferric bovine Lf at 2.8 A resolution. J MolBiol274: 222-236.
- Spik G, Legrand JM, Parraudin J (1998) Advances in Lactoferrin Research1sted; Springer, New York, USA.
- Maneva AI, Taleva BM, Maneva VV, Sirakov LM(1994) Bovine lactoferrin bind to plasma membrane receptors on human polymorphonuclear leucocytes. Med Sci Res22:863-866.
- Yamauchi K, Wakabayashi H, Shin K, Takase M(2006) Bovine lactoferrin: benefits and mechanism of action against infections. Biochem Cell Biol 84: 291-296.
- Hassoun LA, Sivamani RK (2016) A Systematic Review of Lactoferrin Use in Dermatology. Crit Rev Food Sci Nutr 55: 3632-3639.
- Hansen MB, Nielsen SE, Berg K (1989) Re-examination and further development of a precise and rapid dye method for measuring cell growth/cell kill. J Immunol Methods 119: 203-210.
- Chomczynski P, Mackey K (1995) Short technical reports. Modification of the TRI reagent procedure for isolation of RNA from polysaccharide- and proteoglycan-rich sources. Biotechniques 19: 942-945.
- Vigetti D, Ori M, Viola M, Genasetti A, Karousou E, et al. (2006) J BiolChem 281: 8254-8263
- Miyauchi H, Hashimoto S, Nakajima M, Shinoda I, Fukuwatari Y, et al. (1998) Bovine lactoferrin stimulates the phagocytic activity of human neutrophils: identification of its active domain. Cell Immunol 187: 34-37.
- Edde L, Hipolito RB, Hwang FF, Headon DR, Shalwitz RA, et al. (2001) Lactoferrin protects neonatal rats from gut-related systemic infection. Am J Physiol Gastrointest Liver Physiol 281: G1140-1150.
- Damiens E, Mazurier J, Yazidi I, Masson M, Duthille I, et al. (1998) Effects of human lactoferrin on NK cell cytotoxicity against haematopoietic and epithelial tumour cells. Biochim Biophys Acta 1402: 277-287.
- Shau H, Kim A, Golub SH (1992) Modulation of natural killer and lymphokine-activated killer cell cytotoxicity by lactoferrin. J LeukocBiol 51: 343-349.
- Dhennin-Duthille I, Masson M, Damiens E, Fillebeen C, Spik G, et al. (2000) Lactoferrin upregulates the expression of CD4 antigen through the stimulation of the mitogen-activated protein kinase in the human lymphoblastic T Jurkat cell line. J Cell Biochem 79: 583-593.
- Zimecki M, Mazurier J, Spik G, Kapp JA (1995) Human lactoferrin induces phenotypic and functional changes in murine splenic B cells. Immunology86: 122-127.
- Crouch SP, Slater KJ, Fletcher J (1992) Regulation of cytokine release from mononuclear cells by the iron-binding protein lactoferrin. Blood 80: 235-240.
- Khan MM (2008) Role of cytokines. Immunopharmacology. In:1st; Khan MM. Elsevier: Amsterdam, Netherlands: 33-59.
- Kock A, Schwarz T, Kirnbauer R, UrbanskiA, Perry P, et al. (1990) Human keratinocytes are a source for tumor necrosis factor a: evidence for synthesis and release upon stimulation with endotoxin or ultraviolet light. I Exp Ued 172: 1609-1614.
- Collins T, Lapierre LA, Fiers W, Strominger JL, Pober IS(1986) Recombinant human tumor necrosis factor increases mRNA levels and surface expression of HLA-A, B antigens in vascular endothelial cells and dermal fibroblasts in vitro. Proc Natl Acad Sri USA 83: 446-451.
- Peetre C, Gullberg U, Nilsson E, Olsson I (1986) Effects of recombinant tumor necrosis factor on proliferation and differentiation of leukemic and normal hemopoietic cells in vitro. J Clin Invest 78:1694-1701.
- Wang M, Friedman H, Dje JY (1989) Enhancement of human monocyte function agianst Candida albicans by the colony-stimulating factor (CSF): IL-3 granulocytemacrophage CSF and macrophage-CSF. J Immunol 143: 671-677.
- MacNeil IA, Suda T, Moore KW, Momann TR, Zlotnik A (1990) IL-10, a novel growth factor for mature and immature T-cells. J Immunol 145:4167-4173.
- Fiorentino DF, Zlotnik A, Viera P (1991) IL-10 acts on the antigen presenting cell to inhibit cytokine production byThl cells. J Immunol 146: 3444-3451.
- Taga K, Tosato G (1992) IL-10 inhibits human T-cell proliferation and IL-2 production. J Immunol 148: 1143-1148.
- Enk CD, Sredni D, Blauvelt A, Katz SI (1995) Induction of IL-10 gene expression in human keratinocytes by UVB exposure in vivo and in vitro. J Immunol 154: 4851-4856.
- Rivas JM, Ullrich SE (1992)Keratinocyte-derived IL-10 (abstract). J Invest Dermatol98: 578.
- Del Vecchio M, Bajetta E, Canova S, Lotze MT, Wesa A,et al. (2007) Interleukin-12: biological properties and clinical application. Clin Cancer Res 13: 4677-4685.
- Aragane Y, Riemann H, Bharwai RS, Schwarz A, Sawada Y, et al. (1994) IL-12 is expressed and released by human keratinocytes and epidermoid carcinoma cell lines. J Immunol 153: 5366-5372.
- Muller G, Saloga I, Germann T, Bellinghausen I, Mohamadzadeh M, et al. (1994) Identification and induction of human keratinocyte-derived IL-12. J Clin Invest 94:1799-1805.
- Abbas AK, Lichtman AH (2003) Cytokines and effector mechanisms of cell-mediated immunity. In:Cellular and Molecular Immunology, 5th;Saunders: Philadelphia, Pa, USA: 243-317.
- Choe YH, Lee SW (1999) Effect of lactoferrin on the production of tumor necrosis factor-alpha and nitric oxide. J Cell Biochem 76: 30-36.
- Mattsby-Baltzer I, Roseanu A, Motas C, Elverfors J, Engberg I, et al. (1990) Lactoferrin or a fragment thereof inhibits the endotoxin-induced interleukin-6 response in human monocytic cells. Pediatr Res 40: 257-262.
- Welsh BM, Mason RS, Halliday GM(1999) Topical All-trans Retinoic Acid Augments Ultraviolet Radiation-Induced Increases in Activated Melanocyte Numbers in Mice. J Invest Dermatol 112: 271-278.
- Appelmelk BJ, An YQ, Geerts M, Thijs BG, de Boer HA, et al. (1994) Lactoferrin is a lipid A-binding protein. Infect Immun 62: 2628-2632.
- Roşeanu A, Chelu F, Trif M, Motaş C, Brock JH (2000) Inhibition of binding oflactoferrin to the human promonocyte cell line THP-1 by heparin: the role of cell surface sulphated molecules. BiochimBiophys Acta 1475: 35-38.
- Birgens HS, Karle H, Hansen NE, Ostergaard Kristensen L(1984) Lactoferrin receptors in normal and leukemic human blood cells. Scand J Haematol 33: 275-280.
- Van Snick JL, Masson PL (1976) The binding of human lactoferrin to mouse peritoneal cells. J Exp Med 144:1568-1580.
- Mazurier J, Legrand D, Hu WL, Montreuil J, Spik G (1989) Expression of human lactotransferrin receptors in phytohemagglutininstimulated human peripheral blood lymphocytes. Isolation of the receptors by antiligand-affinity chromatography. Eur J Biochem 179: 481-487.
- Kormeili T, Lowe NJ, Yamauchi PS (2004) Psoriasis: Immunopathogenesis and evolving immunomodulators and systemic therapies:US experiences. Br J Dermatol151: 3-15.
- Leung DY, Bieber T (2003) Atopic dermatitis. Lancet361:151-160.
- Corsini E, Galli CL(1998) Cytokines and irritant contact dermatitis. Toxicol Lett 102-103: 277-282.
- Schaller M, Loewenstein M, Borelli C, Jacob K, Vogeser M, et al. (2005) Induction of a chemoattractive proinflammatory cytokine response after stimulation of keratinocytes with Propionibacteriumacnes and coproporphyrin III. Br J Dermatol 153: 66-71.
- Choi JY, Piao MS, Lee JB, Oh JS, Kim IG, et al. (2008) Propionibacterium acnes stimulates pro-matrix metalloproteinase-2 expression through tumor necrosis factor-alpha in human dermal fibroblasts. J Invest Dermatol 128: 846-854.
- Brink N, Szamel M, Young AR, Wittern KP, Bergemann J (2000) Comparative quantification of IL-1beta, IL-10, IL-10r, TNF alpha and IL-7 mRNA levels in UV-irradiated human skin in vivo. Inflamm Res 49: 290-296.
- Bashir MM, Sharma MR, Werth VP (2009) UVB and proinflammatory cytokinessynergistically activate TNF-alpha production in keratinocytes through enhanced gene transcription. J Invest Dermatol 129: 994-1001.
- Clydesdale GJ, Dandie GW, Muller HK (2001) Ultraviolet light induced injury: immunological and inflammatory effects. Immunol Cell Biol 79:547-568.
- Mueller EA, Trapp S, Frentzel A, Kirch W, Brantl V (2011) Efficacy and tolerability of oral lactoferrin supplementation in mild to moderate acne vulgaris: an exploratory study. Curr Med Res Opin27: 793-797.
- Kim J, Ko Y, Park YK, Kim NI, Ha WK, et al. (2010) Dietary effect of lactoferrin-enriched fermented milk on skin surface lipid and clinical improvement of acne vulgaris. Nutrition 26:902-909.
- Yalcin AS (2006) Emerging therapeutic potential of whey proteins and peptides. Curr Pharm Des 12:1637-1643.
- Murata M, Satoh T, Wakabayashi H, Yamauchi K, Abe F, et al. (2014) Oral administration of bovine lactoferrin attenuates ultraviolet B-induced skin photodamage in hairless mice. J Dairy Sci 97: 651-658.
- Ogasawara Y, Imase M, Oda H, Wakabayashi H, Ishii K (2014) Lactoferrin Directly Scavenges Hydroxyl Radicals and Undergoes Oxidative Self-Degradation: A Possible Role in Protection against Oxidative DNA Damage. Int J Mol Sci 15: 1003-1013.
- Griffiths CE, Cumberbatch M, Tucker SC, Dearman RJ, Andrew S, et al. (2001) Exogenous topical lactoferrin inhibits allergen-induced Langerhans cell migration and cutaneous inflammation in humans. Br J Dermatol 144: 715-725.
Figure 1: Time course of Tumor Necrosis Factor-α (TNF-α) gene expression on NCTC2544 (a) and THP-1 cells (b), respectively. Cells were seeded at 106 cells/well and, after reaching 80% confluency, treated for different times (1-8h) with LF10 (Lactoferrin 10µg/mL) ( ), LF40 (Lactoferrin 40µg/mL) ( ) or basal medium 2.5% FBS (positive control-PC) ( ). Simultaneously inflammation was induced by adding basal medium at 2.5% FBS with LPS (10µg/mL). Data are the means±SEM of three separate experiments, n = 3. Statistical analysis was performed with Sidak’s.
Figure 2: Interleukin 10 (IL-10) gene expression on NCTC2544 (a) and THP-1 cells (b), respectively. Cells were seeded at 106 cells/well and, after reaching 80% confluency, treated for different times (1-8h) with LF10 (Lactoferrin 10µg/mL) ( ), LF40 (Lactoferrin 40µg/mL) ( ) or basal medium 2.5% FBS (Positive Control-PC)
( ). Simultaneously inflammation was induced by adding basal medium at 2.5% FBS with LPS (10µg/mL). Data are the means±SEM of three separate experiments, n = 3. Statistical analysis was performed with Sidak’s.
Figure 3: Interleukin 12 (IL-12) gene expression on NCTC2544 (a) and THP-1 cells (b), respectively.Cells were seeded at 106 cells/well and, after reaching 80% confluency, treated for different times (1-8h) with LF10 (Lactoferrin 10µg/mL) ( ), LF40 (Lactoferrin 40µg/mL) ( ) or basal medium 2.5% FBS (Positive Control-PC)
( ). Simultaneously inflammation was induced by adding basal medium at 2.5% FBS with LPS (10µg/mL). Data are the means±SEM of three separate experiments, n = 3. Statistical analysis was performed with Sidak’s.
Table 1: Tumor Necrosis Factor-α (TNF-α) protein expression as determined by ELISA. Cells were seeded at 106 cells/well and, after reaching 80% confluency, treated with LF10 (Lactoferrin 10µg/mL), LF40 (Lactoferrin 40µg/mL) or basal medium 2.5% FBS (Positive Control-PC). Simultaneously inflammation was induced by adding basal medium at 2.5% FBS with LPS (10µg/mL). Analyses were carried on collected cell free supernatant after incubation at 37°C for 1-8h, under 5% CO2. Data are the means±SD of three separate experiments, n = 3. Statistical analysis was performed with Sidak’s multiple comparison test. N.d. = Not Detectable. a-abValues with different superscript letters, differ significantly (P < 0.001).
Table 2:Interleukin 10 (IL-10) protein expression as determined by ELISA. Cells were seeded at 106 cells/well and, after reaching 80% confluency, treated with LF10 (Lactoferrin 10µg/mL), LF40 (Lactoferrin 40µg/mL) or basal medium 2.5% FBS (Positive Control-PC). Simultaneously inflammation was induced by adding basal medium at 2.5% FBS with LPS (10µg/mL). Analyses were carried on collected cell free supernatant after incubation at 37°C for 1-8h, under 5% CO2. Data are the means±SD of three separate experiments, n = 3. Statistical analysis was performed with Sidak’s multiple comparison test. N.d. = Not Detectable. a-gValues with different superscript letters, differ significantly (P < 0.001)
Table 3:Interleukin 12 (IL-12) protein expression as determined by ELISA. Cells were seeded at 106 cells/well and, after reaching 80% confluency, treated with LF10 (Lactoferrin 10µg/mL), LF40 (Lactoferrin 40µg/mL) or basal medium 2.5% FBS (Positive Control-PC). Simultaneously inflammation was induced by adding basal medium at 2.5% FBS with LPS (10µg/mL). Analyses were carried on collected cell free supernatant after incubation at 37°C for 1-8h, under 5% CO2. Data are the means±SD of three separate experiments, n = 3. Statistical analysis was performed with Sidak’s multiple comparison test. N.d. = Not Detectable. a-dValues with different superscript letters, differ significantly (P < 0.001).
(% of the control)±SD
Table 4:Effect of Lactoferrin on the cell viability. Cells were seeded at 105 cells/well and, after reaching 80% confluency, treated with Lactoferrin (LF) (2.5-160µg/mL) or basal medium (control), for 24h at 37°C, under 5% of CO2. The percentage of viable cells was measured through the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Data are the means of three independent experiments±SD, n = 3. a: Values with different superscript letters, differ significantly (P < 0.05).
Citation: Pinto D, Marzani B, Sorbellini E, Rinaldi F (2017) Bovine Lactoferrin: A Nutritional Supplement for Down-Regulation of Inflammatory Response in Cutaneous Disorder. Clin Exp Dermatol Ther: CEDT-126.