Activity of selected aromatic amino acids in biological systems

Besides the structural function in proteins, aromatic amino acids are precursors of many important biological compounds essential for normal functioning of the human organism. Many of these compounds may be used as markers for identification of specific pathological states. Comprehensive knowledge about the metabolism of aromatic amino acids and mechanisms of action of their metabolites made it possible to develop effective treatments for many disorders. However, it should not be forgotten that in some pathological conditions, these compounds could not only be involved in the pathogenesis of many disease entities but could also be used as an important tool in prediction of many diseases. This paper contains a review of published literature on aromatic amino acids in the context of physiological processes of the human body and chosen social disorders, such as cancers; psychiatric disorders: depression, anxiety states, schizophrenia, bipolar affective disorders; neurodegenerative, and cardiovascular diseases; chronic kidney insufficiency or diabetes

Generation of reactive oxygen species by a sufficient, insufficient and varicose vein wall

Despite numerous theories, the etiology and pathogenesis of primary varicose veins remain unclear. The etiology of chronic venous diseases (CVDs) known as chronic venous insufficiency (CVI) is related to leukocyte trapping. Leukocyte trapping involves trapping of white cells in vessel walls followed by their activation and translocation outside the vessel. Release of reactive oxygen species (ROS) from trapped white cells has been documented. Superoxide dismutase (SOD) directly inhibits the generation of free radicals and compounds that are produced during oxidation by ROS, such as malonyldialdehyde (MDA). The aim of this study was to determine the involvement of free radicals in the etiology of venous changes. The following material was used for the study: fragments of sufficient or insufficient venous system and varices from 31 patients diagnosed with chronic venous disease in the 2nd or 3rd degree, according to clinical state, etiology, anatomy and pathophysiology (CEAP), which were qualified for surgical procedure. The levels of oxidative stress markers strongly correlated with lesions observed by USG in insufficient and varicose veins. In both a higher concentration of MDA was observed, which is a sign of lipid peroxidation. Antioxidative mechanisms, SOD activity and total antioxidative power expressed as FRAP were inversely proportional to MDA concentration. In insufficient and varicose veins both FRAP and SOD activities were significantly lower than in normal veins. The severity of clinical changes was inversely dependent on the efficiency of scavenging of ROS, which additionally proves the participation of free radicals in pathogenesis of CVDs

The antioxidant quercetin protects HL-60 cells with high myeloperoxidase activity against pro-oxidative and apoptotic effects of etoposide

The protective action of quercetin against the pro-oxidant and apoptotic effect of etoposide was investigated in HL-60 cells with a high level of myeloperoxidase (MPO) activity and in cells treated with MPO inhibitor, 4-aminobenzoic acid hydrazide (ABAH). Quercetin significantly protected MPO-rich cells against the pro-oxidative (p<0.05) and apoptotic (p<0.05) effects of etoposide. Pre-treatment with ABAH abolished this protective influence of quercetin on apoptosis induced by etoposide but actually enhanced the action effect of quercetin against etoposide-generated reactive oxygen species (ROS) level by this cytostatic drug. Thus quercetin can protect HL-60 cells against the pro-oxidative activity of etoposide regardless of MPO activity

The Role of Human Oral Microbiome in Dental Biofilm Formation

Each surface of the human body, which stays in contact with the external environment, is covered by a layer of microorganisms. This layer—the human microbiome—is characterized by a high diversity of species and huge number of cells. Its name was proposed by Joshua Lederberg at the turn of the twentieth and twenty-first centuries and was originally referred to as a group of microorganisms colonizing a certain habitat. Currently, the term also defines a set of genomes of all organisms inhabiting a particular niche. Since the human microbiota affects many aspects of human health, it has become the subject of different studies. The use of sequencing methods enabled to obtain genetic material derived directly from the human environment with simultaneous explanation of mutual relationships between microorganisms inhabiting different ecological niches of human organism (i.e., commensal, symbiotic, and pathogenic microorganisms). It is hard to determine the amount of microbiota inhabiting human oral cavity because microbiota represents distinct anatomically limited ecological niches; for example, microbiota of tongue surface, cheek, teeth, palate, gingiva, and periodontal pocket. Apart from anatomical structure, other factors determine different composition of particular oral cavity microbiota. These factors are various qualities of saliva—a natural protective barrier ensuring maintenance of healthy condition of the oral cavity—and habits of diet and hygiene. Generally, bacteria are passively transported by flowing saliva toward teeth surfaces. In turn, the pioneering microorganisms initiating changes in the environment of oral cavity through the production and secretion of products of their metabolism induce mutual microbiota–biofilm interactions. The formation of biofilm of the plaque is a complex and rapidly evolving process in which several stages of development can be distinguished arbitrarily: (i) reversible binding of bacteria to solid surfaces, (ii) production of exopolysaccharide matrix, (iii) irreversible binding to the surface, (iv) maturation of biofilm structure, (v) disintegration and dispersion of an organized structure, and (vi) the formation of new habitats. An oral microbiome analysis depending on the genotypic characteristics of the host, as well as its metabolic phenotype, will allow us to understand all these factors which are responsible for maintaining host-microbiota homeostasis. The formation of genetic maps (including host, as well as microbiota) of such environments and the detection of biofactors indicating the predisposition for a given disease may contribute to the development of new diagnostic methods in reference to individual persons, and thus individualized therapy

The role of oxidative stress in the cooperation of parthenolide and etoposide in HL-60 cells

Background: The aim of this study was to determine the effect of sesquiterpene lactone parthenolide on the cytotoxic and pro-oxidative effects of etoposide in HL-60 cells. Methods: Cytotoxic effects were determined by incubation of HL-60 cells with various concentrations of examined compounds and combinations thereof, which were then stained with propidium iodide and analyzed using a flow cytometer. To determine the role of oxidative stress in the action of the compounds, co-incubation with N-acetyl-l-cysteine (NAC) and parthenolide and/or etoposide was used and the level of reduced glutathione (GSH) was detected. Results: Parthenolide significantly enhanced the cytotoxic and pro-apoptotic effects of etoposide. However, in most cases of the combinations of parthenolide and etoposide, their effect was antagonistic, as confirmed by an analysis using the CalcuSyn program. The examined compounds significantly reduced the level of GSH in HL-60 cells. Combination of etoposide at a concentration of 1.2 μM and parthenolide also significantly reduced GSH level. However, in the case of a combination of etoposide at a concentration of 2.5 μM with parthenolide, a significant increase in the level of GSH was obtained compared to compounds acting alone. This last observation seems to confirm the antagonism between the compounds tested. Conclusions: Parthenolide did not limit the cytotoxic effect of etoposide in HL-60 cells even in the case of antagonistic interaction. If parthenolide does increase GSH levels in combination with etoposide in the normal hematopoietic cells, it could protect them against the pro-oxidative effects of this anti-cancer drug

Salivary proteins in health and disease

Besides their structural catalytic and diverse regulatory functions, proteins are also precursors of many important biological compounds essential for normal functioning of humans. Many of these compounds may be used as markers for identification of specific pathological states. A comprehensive knowledge about the metabolism of salivary proteins and the mechanisms of action of their metabolites allowed the development of effective treatment for many disorders. However, it should not be forgotten that in some pathological conditions, these compounds not only could be involved in the pathogenesis but also could be used as tool in the prediction of many diseases. This paper is a review of the published literature on selected salivary proteins in the context of the physiological processes of the human body and chosen chronic disorders, such as diabetes, diabetic nephropathy, mucositis, oral mycoses and caries

Oxidative DNA Damage in Blood of CVD Patients Taking Detralex

The main goal of the work reported here was to determine the degree of oxidative/alkali-labile DNA damages in peripheral blood as well as in the blood stasis from varicose vein of (chronic venous disorder) CVD patients. Moreover, determination of the impact of Detralex usage on the level of (oxidative) DNA damages in CVD patients was evaluated as well

Methods of biotyping of Streptococcus mutans : species with the routine test as a prognostic value in early childhood caries

Purpose. In order to investigate the suitability of Streptococcus mutans species biotyping by measuring the activity of selected enzymes from a commercial test, criteria were established for biotyping clinical strains from children with dental caries. In addition, the relationships between the selected biotypes, sensitivity to commonly used antibiotics, and early childhood caries were determined. Methods. A total of 142 S. mutans isolates from dental plaque of children with caries were divided into different biotypes. Patients were divided into two groups: noncavitated (1-2 in ICDAS) and cavitated (5-6 in ICDAS) lesions. Biotyping criteria were determined based on both the arbitrary method and the clusterization method. The susceptibility of the strains to amoxicillin, cefazolin, erythromycin, and teicoplanin was studied by diluting a solid medium. Results. Biotype I was the most common. Mean MIC values showed that the strains belonging to biotypes II and IV were the most sensitive to amoxicillin. For predetermined biotypes, observed differences were dependent on the severity of dental caries. Conclusions. The proposed method of S. mutans strains biotyping is relatively quick and simple to use, provided the application of suitable biotyping criteria, and may contribute to the effective prevention of dental caries induced by S. mutans