Major and Trace Element Content of Tribulus terrestris L. Wildlife Plants.

The genus Tribulus L. (Zygophyllaceae) includes 12 species, the most important of which is Tribulus terrestris L. This annual herb grows in temperate and tropical climates, and has a rich chemical composition of biologically active substances and chemical elements. Medicinal plants, and the phytopreparations obtained from them, are becoming more and more popular in world practice as they are used to successfully treat human diseases. Their therapeutic effect is due to the presence in them, of a variety of natural compounds and biologically important trace elements, especially in higher concentrations present in higher doses. T. terrestris is becoming more and more popular for the treatment of diseases of the human genital area and sexual dysfunctions. The elemental content in the tissues of leaf, flower, and fruit of T. terrestris was determined by using multi-element instrumental epithermal neutron activation analysis. For the first time, 26 essential and trace elements were observed in the plant species collected in Russia (from cultivated) and China (wild growing). It was confirmed that the elemental composition of T. terrestris grass varies depending on the habitat (geographic zones). The place of growth affects the accumulation of elements by the plant.

Hypoxia and Neonatal Haemorrhagic Stroke: Experimental Study of Mechanisms.

We studied the level of blood oxygen saturation (SpO2) in the brain in newborn rats in the pre- and post-stroke periods, as well as the changes in cerebral blood flow and beta-arrestin-1 as a marker of hypoxic stress. Our results show that mild hypoxia precedes the stroke development and is associated with venous relaxation and decrease blood outflow from the brain resulting in the elevation of synthesis of beta-arrestin-1 in the brain. The incidence of stroke is characterized by severe hypoxia, which is accompanied by the progression of pathological changes in cerebral veins and the high level of beta-arrestin-1.

The Stress and Vascular Catastrophes in Newborn Rats: Mechanisms Preceding and Accompanying the Brain Hemorrhages.

In this study, we analyzed the time-depended scenario of stress response cascade preceding and accompanying brain hemorrhages in newborn rats using an interdisciplinary approach based on: a morphological analysis of brain tissues, coherent-domain optical technologies for visualization of the cerebral blood flow, monitoring of the cerebral oxygenation and the deformability of red blood cells (RBCs). Using a model of stress-induced brain hemorrhages (sound stress, 120 dB, 370 Hz), we studied changes in neonatal brain 2, 4, 6, 8 h after stress (the pre-hemorrhage, latent period) and 24 h after stress (the post-hemorrhage period). We found that latent period of brain hemorrhages is accompanied by gradual pathological changes in systemic, metabolic, and cellular levels of stress. The incidence of brain hemorrhages is characterized by a progression of these changes and the irreversible cell death in the brain areas involved in higher mental functions. These processes are realized via a time-depended reduction of cerebral venous blood flow and oxygenation that was accompanied by an increase in RBCs deformability. The significant depletion of the molecular layer of the prefrontal cortex and the pyramidal neurons, which are crucial for associative learning and attention, is developed as a consequence of homeostasis imbalance. Thus, stress-induced processes preceding and accompanying brain hemorrhages in neonatal period contribute to serious injuries of the brain blood circulation, cerebral metabolic activity and structural elements of cognitive function. These results are an informative platform for further studies of mechanisms underlying stress-induced brain hemorrhages during the first days of life that will improve the future generation's health.

Antimicrobial photodynamic efficiency of novel cationic porphyrins towards periodontal Gram-positive and Gram-negative pathogenic bacteria.

The Gram-negative Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum are major causative agents of aggressive periodontal disease. Due to increase in the number of antibiotic-resistant bacteria, antimicrobial Photodynamic therapy (aPDT) seems to be a plausible alternative. In this work, photosensitization was performed on Gram-positive and Gram-negative bacteria in pure culture using new-age cationic porphyrins, namely mesoimidazolium-substituted porphyrin derivative (ImP) and pyridinium-substituted porphyrin derivative (PyP). The photophysical properties of both the sensitizers including absorption, fluorescence emission, quantum yields of the triplet excited states and singlet oxygen generation efficiencies were evaluated in the context of aPDT application. The studied porphyrins exhibited high ability to accumulate into bacterial cells with complete penetration into early stage biofilms. As compared with ImP, PyP was found to be more effective for photoinactivation of bacterial strains associated with periodontitis, without any signs of dark toxicity, owing to its high photocytotoxicity.

Photodynamic inactivation of Aeromonas hydrophila by cationic phthalocyanines with different hydrophobicity.

Antibacterial photodynamic therapy is a pioneering method for the inactivation of pathogenic bacteria. Four tetra alkyl-substituted cationic phthalocyanines with different hydrocarbon chains attached to the pyridyloxy group were synthesized. These photodynamic sensitizers were studied for antibacterial inactivation of a multidrug-resistant strain of Gram-negative bacterium Aeromonas hydrophila. Aeromonas species are recognized as etiological agents of a wide spectrum of diseases in humans and animals. The uptake of phthalocyanines by the bacterial cells decreased with an increase in cell density. Following the phthalocyanine solubility from hydrophilic to hydrophobic complexes, the accumulation capacity increased. Full inactivation was achieved with phthalocyanine with (methoxy) pyridyloxy substitution following a short exposure time, low drug concentration and mild irradiation. Although the phthalocyanine with the longest hydrocarbon chain (C12) has some toxic effect in the absence of light, substantial phototoxic effect was obtained with the optimal combination of drug-irradiation parameters.

Photodynamic activity of water-soluble phthalocyanine zinc(II) complexes against pathogenic microorganisms.

Photodynamic activity of tetrakis-(3-methylpyridyloxy)- and tetrakis-(4-sulfophenoxy)-phthalocyanine zinc(II) toward the gram-positive Staphylococcus aureus, the gram-negative Pseudomonas aeruginosa, and the fungi Candida albicans was studied. The drug uptake dependency with an inverse behavior to the cell density was observed. The cationic photosensitizer completely inactivated S. aureus and C. albicans, and with 4 log10 P. aeruginosa. The photoinactivation at mild experimental conditions, such as drug dose of 1.5 microM and fluence of 50 mW cm(-2) for 10 min irradiation time, was shown.

Laser-induced autofluorescence study of caries model in vitro.

Laser-induced autofluorescence spectra of teeth irradiated by a 337 nm nitrogen laser were measured during in vitro caries formation through initial enamel demineralization and introducing of carious bacterial flora in the lesions developed. Spectra obtained from sound teeth consist of an intensive maximum at 480-500 nm and secondary maximum at 430-450 nm. In the process of caries formation, we observed an increase in the intensity at 430-450 nm and the appearance of two maxima in the red spectral region-at 590-650 nm. The intensity increase at 430-450 nm was related to the tooth demineralization. Bacteria presence and their metabolism products induced an increase in the absorption in the UV-blue spectral region at 350-420 nm and the appearance of a fluorescence signal in the long-wave spectral region at 590-650 nm. From the point of view of tissue optics, these results allow caries to be considered as consisting of two different phenomena-tissue destruction and bacterial flora and its metabolism products increase. The results could be used to obtain a more complete picture of caries formation on the base of its fluorescent properties.

Early differentiation between caries and tooth demineralization using laser-induced autofluorescence spectroscopy.

BACKGROUND AND OBJECTIVES: The intrinsic fluorescence of carious human teeth, of different stages of teeth demineralization, and the correspondence of such fluorescence to the mineral and organic distribution within the lesions were investigated. STUDY DESIGN/MATERIALS AND METHODS: Fluorescence spectra of teeth excited with 337 nm nitrogen laser were recorded. Spectra were obtained from healthy enamel, dentine, demineralized areas, and different carious stages of the teeth investigated. RESULTS: Spectra obtained from sound enamel consisted of one intensive peak at 480-500 nm and one secondary peak at 430-450 nm. In dentine, this secondary component had much higher intensity. Fluorescence spectra of normal teeth were similar to those of enamel layer. A significant decrease of the intensity of the fluorescence signal was observed in both cases-in demineralized teeth and in carious lesion. The appearance of a fluorescence peak in the red spectral region was observed in the spectra of the initial carious lesions. In the teeth demineralization process, we observed an increase of the relative fluorescence peak intensity at 430-450 nm related to thinned out of enamel. CONCLUSIONS: A differentiation between initial tooth demineralization and early stages of caries could be made by the laser-induced fluorescence spectroscopy method.