Effects Of L-lysine Research Articles

L-lysine as a Potential Agent for Controlling Biofilm Formation Using Fusobacterium nucleatum and Porphyromonas gingivalis

Background Periodontitis, a globally-pervasive chronic inflammatory condition, is precipitated by forming microbial biofilms. A key player in this process is Fusobacterium nucleatum (F. nucleatum), an anaerobic bacterium exhibiting invasive and pro-inflammatory characteristics primarily associated with the onset of periodontitis. Consequently, developing novel biofilm control strategies specifically targeting F. nucleatum is essential. The objective of this research is to examine the suppressive impact of L-lysine on biofilm formation using F. nucleatum. Methods Fusobacterium nucleatum(F. nucleatum) and Porphyromonas gingivalis (P. gingivalis) were cultured in a liquid medium containing L-lysine of different concentrations. The antimicrobial activity of L-lysine was evaluated using the broth microdilution method. The effect of L-lysine on the mono-species and dual-species F. nucleatum biofilms was assessed using techniques such as crystal violet staining. The synthesis of extracellular polysaccharide substances (EPSs) from biofilms was measured using phenol-sulfuric acid. The expression level of virulence factors (FN1420, FN0669, FN0634, FN1162) and the biofilm-formation-related gene radD were quantified using real-time PCR. Results L-lysine exhibited the antibacterial and antibiofilm activity of F. nucleatum and F. nucleatum/ P. gingivalis double strains, which was concentration-dependent. The MIC and MBC values were 10 mg/ml and 20 mg/ml in F. nucleatum single strains, while those in F. nucleatum/ P. gingivalis double strains were 20 mg/ml and 40 mg/ml. L-lysine with a concentration ≥20 mg/ml could reduce the EPS production in F. nucleatum and F. nucleatum/ P. gingivalis dual-species biofilms. L-lysine also inhibited the expression of genes encoding the F. nucleatum virulence factor (FN1420, FN0669, FN0634, FN1162) and the adhesive factor radD. Conclusion These findings corroborate the potential of L-lysine as an agent impeding the development of both mono-species biofilms of F. nucleatum and dual-species biofilms of F. nucleatum and P. gingivalis.

Based on hydrogen and disulfide-mediated bonds, l-lysine and l-arginine enhanced the gel properties of low-salt mixed shrimp surimi (Antarctic krill and Pacific white shrimp)

This study delved into the effects of l-lysine (Lys) and l-arginine (Arg) on the gel properties and intermolecular interactions of low-salt (NaCl, 1 g/100 g) mixed shrimp surimi (Antarctic krill and Pacific white shrimp). The addition of Lys and Arg improved the gel strength and water holding capacity of low-salt gels, which were superior to the properties of STPP and high-salt (NaCl, 2.25 g/100 g) gels. These results can be attributed to the role of Lys and Arg in enhancing hydrogen and disulfide bonds within the low-salt gel system, promoting the solubilization of myofibrillar proteins (MP) and consequently increasing the number of MP molecules participating in gel formation. Antarctic krill MP did not show gel-forming ability and exerted a diluting effect on low-salt mixed shrimp surimi gels. Molecular docking analysis indicated the stable binding of Lys and Arg to myosin.

Effects of L-lysine and L-arginine on the structure and gel properties of konjac glucomannan

To explore greener modifier of konjac glucomannan, a new type of thermal irreversible gel using konjac glucomannan (KGM) and basic amino acids (l-lysine, and l-arginine) was prepared in the present study. The effects of different concentrations (1%, 2%, 3%, 4%, and 5%) of these two basic amino acids on the structure and properties of KGM hydrogels were mainly studied. The results showed that there was a better texture characteristic of composite gel as the concentration of amino acids was above 4%. Besides, with the increase in amino acid concentrations, the pore size of composite gel was denser and the syneresis of composite gel was more obvious, respectively. The rheological results indicated that the storage modulus (G′) was influenced by the concentration of amino acids and temperature. It was found that the two basic amino acids removed the acetyl group of KGM molecule and changed the original crystalline domain of KGM as evidenced by FT-IR and X-ray diffraction (XRD) analysis. Furthermore, compared to l-lysine, l-arginine could exert a greater effect on the KGM gel. In conclusion, the two basic amino acids (l-lysine, and l-arginine) could remarkedly improve the structure and properties of natural KGM and could be used as modifiers of the KGM hydrosol.

Effects of l-Lysine on the physiochemical properties and sensory characteristics of salt-reduced reconstructed ham

This paper aimed to investigate the dose-effects of l-Lysine (Lys, 0.2% to 0.8%) on the water holding capacity (WHC), textural properties, water mobility and distribution, microstructures and sensory acceptance of reconstructed ham with 50% reduction of added salt. Results showed that reducing salt from 2.50% to 1.25% caused significant increase in cooking loss and centrifuge loss, and decrease in hardness, springiness and chewiness. 0.8% Lys significantly improved the WHC and textural properties of salt-reduced hams, whereas 0.2% Lys further impaired these attributes. Moreover, 0.8% Lys improved the sensory scores for mouthfeel, appearance, taste and global acceptance. The NMR analysis reveals that water distribution and mobility were affected by salt reduction and Lys addition, and hams with 0.8% Lys contained more entrapped water with decreased mobility. Furthermore, a fine network with more bridge-linkage among myofibrils was formed in hams with 0.8% Lys. Therefore, addition of 0.8% Lys showed great potential in developing salt-reduced reconstructed ham with premium technological and sensory qualities.

Effects of L-lysine on cytogenetical and physiological parameters in Allium cepa L. under salt stress

The role of L-lysine (Lys) on some cytogenetic and physiological parameters in Allium cepa L. seeds exposed to salt was evaluated. NaCl stress on the other hand showed a significantly inhibitory effect on the seedling growth and seed germination of Allium cepa. Besides, it significantly reduced the mitotic index in the root tip meristems of seeds and increased micronuclei which are the most effective and simplest indicator of cytological damage and chromosomal abnormalities. However, the effects of salinity on chromosomal aberrations, seedling growth, seed germination and mitotic activity have decreased significantly with Lys application.

L-Lysine protects against sepsis-induced chronic lung injury in male albino rats

Sepsis is a severe, life-threatening condition primarily caused by the cellular response to infection. Sepsis leads to increased tissue damage and mortality in patients in the intensive care unit. L-Lysine is an essential amino acid required for protein biosynthesis and is abundant in lamb, pork, eggs, red meat, fish oil, cheese, beans, peas, and soy. Male albino rats were divided into sham, control, 10-mg/kg bwt L-lysine, and 20-mg/kg bwt L-lysine groups. At the end of treatment, we determined the levels of oxidative and inflammatory markers, myeloperoxidase (MPO) and catalase activities, total cell count, the wet/dry ratio of lung tissue, and total protein content. Furthermore, the effect of L-lysine on the cellular architecture of lung tissue was evaluated. L-Lysine significantly reduced the magnitude of lipid peroxidation; total protein content; wet/dry ratio of lung tissue; tumor necrosis factor-alpha, interleukin-8, and macrophage inhibitory factor levels; MPO activity; and total cell, neutrophil, and lymphocyte counts, and it increased the reduced glutathione levels and the glutathione peroxidase, superoxide dismutase, and catalase activities. A normal cellular architecture was noted in rats in the sham group, whereas proinflammatory changes, such as edema and neutrophilic infiltration, were detected in rats in the control group. L-lysine significantly ameliorated these proinflammatory changes. Thus, L-lysine has the potential for the treatment of sepsis-induced CLI.

Effect of L-Lysine on the Phase Transition Temperature in a Three-Component Water/Sodium Bis(2-ethylhexyl)sulfosuccinate/Isopropyl Myristate System

Novel prospective transport systems are prepared that consist of lyotropic liquid crystals (LLCs), water/sodium bis(2-ethylhexyl)sulfosuccinate (AOT)/isopropyl myristate. The temperature boundaries of phase transitions at different water contents and in the presence of guest molecule L-lysine amino acid and the types of mesophases formed are determined via differential scanning calorimetry (DSC), polarization optical microscopy (POM), and measurements of the wetting angle. It is shown that upon a reduction in the H2O content and the introduction of L-lysine, the thermal stability of a system and the temperature of a phase transition increase, while the mass loss upon heating is diminished. The concentration dependences of thermodynamic properties allow us to control the phase transition temperatures that determine the processes of the controlled release of bioactive molecules from the studied LLC-system.

Effects of L-lysine\xb7H2SO4 product on the intestinal morphology and liver pathology using broiler model

BackgroundLysine is used widely in livestock production due to the shortage of feed protein resources. L-lysine·H2SO4 contains L-lysine sulphate as well as fermentation co-products which contain other amino acids and phosphorus. However, there are few articles about L-lysine·H2SO4 product regarding intestinal morphology and liver pathology of broiler chickens. In this article, we focus on the absorption and metabolism of L-lysine·H2SO4 revealed in the variation of intestinal morphology and liver pathology to determine the tolerance of chicks for L-lysine·H2SO4.MethodsTo evaluate the tolerance of broilers for L-lysine·H2SO4, 240 one day old broilers were allocated randomly to one of five dietary treatments which included corn-soybean diets containing 0, 1%, 4%, 7% or 10% L-lysine·H2SO4 (L-lysine content = 55%).ResultsSupplementation of 1% L-lysine·H2SO4 in the diet had no negative effects. However, 4%, 7% or 10% L-lysine·H2SO4 supplementation produced negative responses on broiler performance, carcass characteristics, blood biochemistry, and particularly on intestinal morphology and liver pathology compared with broilers fed the control diet.ConclusionOur results show that supplementation with 1% L-lysine·H2SO4 had no negative effects on performance, carcass characteristics, blood biochemistry, intestinal morphology and liver pathology in broilers, but supplementation with 4%, 7% or 10% L-lysine·H2SO4 produced a negative response, particularly with respect to intestinal morphology and liver pathology.

The effect of L-Lysine in recurrent herpes labialis: pilot study with a 8-year follow up

ABSTRACT Several treatments for recurrent herpes labialis have been tested, including intradermal snake venom, camphor compresses, psychiatric treatments, vitamin C and other vitamin complexes. Nowadays, topical and systemic retroviral drugs such as acyclovir, valacyclovir and vadarabina are the drugs of choice. However they are only effective for symptoms minimization of existing lesions, without eliminating the virus permanently. In this study an alternative treatment with oral L-lysine is presented. This is one of the eight essential not manmade amino acids which should be acquired through feeding since they are important for protein synthesis and organism development. It was observed a significant effect on the annual incidence reduction of recurrent herpes in 12 patients with 8-year follow up.

Effects of l-lysine on thermal gelation properties of chicken breast actomyosin.

The effects of l-lysine (l-Lys) on the water holding capacity (WHC) and texture of actomyosin (AM) gel and the possible mechanisms were investigated. l-Lys increased the WHC and hardness of the AM gel. These effects may be related to the even and continuous microstructure of the gel according to the scanning electron microscopy analysis. Furthermore, l-Lys increased the surface hydrophobic residues and the reactive sulfhydryl groups. l-Lys decreased the storage modulus at the first transition temperature but increased it at the second transition temperature and the third transition enthalpy. These results suggested that l-Lys varied the thermal behaviors and the microstructure of the AM gel by increasing the surface hydrophobicity and reactive sulfhydryl groups, ultimately contributing to the increased WHC and hardness. The changes in pH did not fully explain the results from the present study. The results were useful for understanding previous findings and may serve as a reference for the preparation of reduced-sodium and phosphate-free meat products.

A study regarding friction behaviour of lysine and isoleucine modified epoxy matrix

The aim of this study is to point out the effect of L-lysine and L-isoleucine used as modifying agents for epoxy resins. The amino acids are largely used to turn the usual polymers in bio-compatible materials but they effect also other significant proprieties of formed materials. The general study developed in Polymer Composite Laboratory is focused on analysis of 14 amino acids used as modifying agents but the two above mentioned showed a special behaviour namely they re-crystalized during the polymerization of the matrix. The coefficient of friction was obtained through the calculation of friction torque measured with a loaded cell sensor. As far as we know, there is no report on the friction proprieties of amino acids modified epoxy resins.

Effect of Selected Plant Extracts and D- and L-Lysine on the Cyanobacterium Microcystis aeruginosa

We tested extracts from Fructus mume, Salvia miltiorrhiza and Moringa oleifera as well as L-lysine and D-Lysine as curative measures to rapidly suppress the cyanobacterium Microcystis aeruginosa NIVA-CYA 43. We tested these compounds under similar conditions to facilitate comparisons. We hypothesized that for each compound, relatively low concentrations—i.e., 5–50 mg L−1, would reduce M. aeruginosa biomass. At these low concentrations, only L-lysine caused a decline in M. aeruginosa biomass at ≥4.3 mg L−1. F. mume extract was effective to do so at high concentrations, i.e., at ≥240 mg L−1, but the others were virtually non-effective. Low pH caused by organic acids is a probable explanation for the effect of F. mume extract. No complete wipe-outs of the experimental population were achieved as Photosystem II efficiency showed a recovery after six days. L-lysine may be effective at low concentrations—meaning low material costs. However, the effect of L-lysine seems relatively short-lived. Overall, the results of our study did not support the use of the tested plant extracts and amino-acid as promising candidates for curative application in M. aeruginosa bloom control.

Effect of l-lysine on the physicochemical properties of pork sausage

Effects of l-lysine on physicochemical properties of pork sausage were investigated. WHC values significantly increased using 0.8% l-lysine, but significantly decreased at 0.4% l-lysine (p<0.05), compared with controls. l-Lysine increased pH values and a* values, but significantly decreased CL, cohesiveness, L* values, and b* values (p<0.05), compared with controls. Addition of 0.4% l-lysine significantly (p<0.05) increased hardness, springiness, and chewiness values, compared with controls. SEM analysis showed that addition of 0.8% l-lysine induced formation of a smoother, more compact, and more uniform gel matrix, compared with controls. DSC analysis indicated that addition of 0.8% l-lysine significantly (p<0.05) increased thermal transition temperatures and enthalphy values, compared with controls, showing that interactions between l-lysine and myofibrillar proteins affected the properties of pork sausages.

Effects of l-lysine and d-lysine on ɛ-Poly-l-lysine biosynthesis and their metabolites by Streptomyces ahygroscopicus GIM8

ɛ-Poly-l-lysine (ɛ-PL), produced by Streptomyces or Kitasatospora strains, is a homo-poly-amino acid of l-lysine, which is used as a safe food preservative. In this study, the effects of l-lysine and its isomer, d-lysine, on ɛ-PL biosynthesis and their metabolites by the ɛ-PL-producing strain Streptomyces ahygroscopicus GIM8 were determined. The results indicated that l-lysine added into the fermentation medium in the production phase mainly served as a precursor for ɛ-PL biosynthesis during the flask culture phase, leading to greater ɛ-PL production. At an optimum level of 3 mM l-lysine, a ɛ-PL yield of 1.16 g/L was attained, with a 41.4% increment relative to the control of 0.78 g/L. Regarding d-lysine, the production of ɛ-PL increased by increasing its concentrations up to 6 mM in the initial fermentation medium. Interestingly, ɛ-PL production (1.20 g/L) with the addition of 3 mM d-lysine into the initial fermentation medium in flasks was higher than that of the initial addition of 3 mM L-lysine (1.06 g/L). The mechanism by which d-lysine improves ɛ-PL biosynthesis involves its utilization that leads to greater biomass. After S. ahygroscopicus GIM8 was cultivated in the defined medium with L-lysine, several key metabolites, including 5-aminovalerate, pipecolate, and l-2-aminoadipate formed in the cells, whereas only l-2-aminoadipate was observed after d-lysine metabolism. This result indicates that l-lysine and d-lysine undergo different metabolic pathways in the cells. Undoubtedly, the results of this study are expected to aid the understanding of ɛ-PL biosynthesis and serve as reference for the formulation of an alternative approach to improve ɛ-PL productivity using l-lysine as an additional substrate in the fermentation medium.

Effect of L-lysine in culture medium on nodule formation by bone marrow cells

The aim of this study was to estimate the effect of L-lysine on nodule formation by rat bone marrow cells in vitro. In this study, L-lysine was added to medium for mesenchymal stem cell culture to promote proliferation and differentiation of the cells, and then nodule formation was estimated in an in vitro rat bone marrow cell culture. Bone marrow cells from the bone shafts of the femora of Fischer 344 rats were cultured in minimum essential medium with 20 μl of L-lysine solution at 10﹣4, 10﹣5, 10﹣6, 10﹣7 or 10﹣8 M. Dexamethasone was also added to the medium at 10 nM for differentiation of stem cells from bone marrow into osteoblast progenitor cells. The subculture was performed for 2 weeks. The quantity of osteocalcin in rat bone marrow cell culture with dexamethasone was 392 ng/ml. In the medium with dexamethasone and 10﹣8 M L-lysine, the quantity of osteocalcin was 437 ng/ml. Nodules only formed upon addition of 20 μl of L-lysine at 10﹣8 M. It was indicated that 10﹣8 M L-lysine should be the optimal concentration for calcification. For nodule formation by rat bone marrow cells in vitro, the optimum concentration of L-lysine in culture medium might be 20 μl of 10﹣8 M. L-lysine could play an important role in matrix production for bone formation in vitro.

The effect of l-Lysine on structure–function of fibrinogen in the presence of high glucose concentration

The effect of l-Lysine on structure–function of fibrinogen in the presence of high glucose concentration

Neurotropic effects of L-lysine in formation of pain-induced behavior

In experiments on Wistar rats L-lysine (0.15, 0.5, 1.5, 5.0, 15.0, and 50.0 microg/kg intraperitoneally) exhibited a dose-dependent algic effect during electrocutaneous stimulation of the tail and dose-dependent effects in aggressive defense behavior caused by electrical painful stimulation of paws. It was found that the effect of L-lysine depended on situation determining the predominance of defense or aggression, rather than on the intensity of painful stimulation.

Mechanistic aspects of apoptosis induction by l-lysine in both HTLV-1-positive and -negative cell lines

The retrovirus human T-cell lymphotrophic virus type-1 (HTLV-1) causes adult T-cell leukemia (ATL), which remains with no cure. This study evaluates the effects of l-lysine on proliferation and induction of apoptosis using non-cytotoxic concentrations of the test compound against HTLV-1 positive and negative malignant cell lines. The anti-proliferative effect of lysine was established and confirmed by studying the effects of the test compound on the expression of TGF mRNA expression by RT-PCR. To investigate the effect of l-lysine on the induction of apoptosis, DNA flow cytometry analyses was done and the results verified by cell death ELISA. The results indicated that a significant increase in the preG(1) phase and a decrease in the S phase of the cell cycle in all of the ATL cells tested. l-Lysine up-regulated p53, p21, and Bax protein levels and a down-regulation of Bcl-2alpha in all the cell lines tested. l-Lysine was found to exert its effect through the NF-kappaB pathway by inhibiting the p65 subunit specifically. Also l-lysine caused a decrease in the levels MMP-2 and MMP-9 as well as their enzymatic activity.

L-Lysine acts like a partial serotonin receptor 4 antagonist and inhibits serotonin-mediated intestinal pathologies and anxiety in rats.

The purpose of this investigation was to determine whether a nutritionally essential amino acid, l-lysine, acts like a serotonin receptor 4 (5-HT4) antagonist, and if l-lysine is beneficial in animal models of serotonin (5-HT)-induced anxiety, diarrhea, ileum contractions, and tachycardia and in stress-induced fecal excretion. The radioligand-binding assay was used to test the binding of l-lysine to various 5-HT receptors. The effects of l-lysine on 5-HT-induced contractions of isolated guinea pig ileum were studied in vitro. The effects of oral administration of l-lysine on diarrhea, stress-induced fecal excretion, and 5-HT-induced corticosterone release, tachycardia, and anxiety (an elevated plus maze paradigm) were studied in rats in vivo. l-Lysine (0.8 mmol/dl) inhibited (9.17%) binding of 5-HT to the 5-HT4 receptor, without any effect on 5-HT1A,2A,2B,2C,3 binding. l-Lysine (0.07 and 0.7 mmol/dl) blocked 5-HT-induced contractions of an isolated guinea pig ileum in vitro (P < 0.05 and P < 0.01). Orally applied l-lysine (1 g/kg of body weight) inhibited (P < 0.12) diarrhea triggered by coadministration of restraint stress and 5-hydroxytryptophane (10 mg/kg of body weight), and significantly blocked anxiety induced by the 5-HT4 receptor agonist (3.0 mmol/liter) in rats in vivo. No effects of l-lysine or the 5-HT4 receptor agonist on plasma corticosterone and heart rate were recorded. l-Lysine may be a partial 5-HT4 receptor antagonist and suppresses 5-HT4 receptor-mediated intestinal pathologies and anxiety in rats. An increase in nutritional load of l-lysine might be a useful tool in treating stress-induced anxiety and 5-HT-related diarrhea-type intestinal dysfunctions.

Metabolic interactions between restraint stress and L-lysine: the effect on urea cycle components.

We studied the effects of L-lysine on wrap-restraint stress-induced changes in ureagenesis. An exposure to wrap-restraint stress did not affect the plasma concentration of L-lysine, but did decrease plasma urea and arginine. Oral L-lysine (1 g/kg) blocked the effect of stress on ureagenesis, and enhanced the effect of stress on L-arginine. No influence of L-lysine were found in controls. The results imply a stress-specific, ureagenesis-stimulating effect of L-lysine, and suggest an increased requirement for L-arginine during the above conditions.