Pharmacological Blockade of the Calcium Plateau Provides Neuroprotection Following Organophosphate Paraoxon Induced Status Epilepticus in Rats

Organophosphate (OP) compounds which include nerve agents and pesticides are considered chemical threat agents. Currently approved antidotes are crucial in limiting OP mediated acute mortality. However, survivors of lethal OP exposure exhibit delayed neuronal injury and chronic behavioral morbidities. In this study, we investigated neuroprotective capabilities of dantrolene and carisbamate in a rat survival model of paraoxon (POX) induced status epilepticus (SE). Significant elevations in hippocampal calcium levels were observed 48-h post POX SE survival, and treatment with dantrolene (10 mg/kg, i.m.) and carisbamate (90 mg/kg, i.m.) lowered these protracted calcium elevations. POX SE induced delayed neuronal injury as characterized by Fluoro Jade C labeling was observed in critical brain areas including the dentate gyrus, parietal cortex, amygdala, and thalamus. Dantrolene and carisbamate treatment provided significant neuroprotection against delayed neuronal damage in these brain regions when administered one-hour after POX-SE. These results indicate that dantrolene or carisbamate could be effective adjuvant therapies to the existing countermeasures to reduce neuronal injury and behavioral morbidities post OP SE survival

IMUNOFLUORESCENČNÍ ANALÝZA PROAPOPTICKÝCH SIGNÁLNÍCH MOLEKUL V BUŇKÁCH LIDSKÉHO MELANOMU PO FOTODYNAMICKÉ TERAPII

IMMUNOFLUORESCENCE ANALYSIS OF PROAPOPTOTIC SIGNALING MOLECULES IN HUMAN MELANOMA CELLS AFTER PHOTODYNAMIC TREATMENT. Photodynamic therapy (PDT) is connected with oxidative damage of biomolecules causing significant impairment of essential cellular functions that lead to cell death. It is the reason, why photodynamic therapy has also found its application in treatment of different oncological, cardiovascular, skin and eye diseases. The cell death after PDT is mediated by an apoptotic and/or necrotic process including activation of various biomolecules. In the presented study we have used immunofluorescence method to detect caspase 3 and 9, poly ADP-ribose polymerase (PARP) in their active forms, and release of the cytochrome c as the proapoptotic protein after photodynamic treatment of human melanoma cells

FOTOTOXICKÝ VLIV PORFYRINOVÝCH SENSITIZERŮ A VIDITELNÉHO ZÁŘENÍ NA GRAM-POZITIVNÍ METHICILIN-REZISTENTNÍ KMEN S. AUREUS

The use of antimicrobial photodynamic therapy (aPDT) as a therapeutic modality for the treatment of localized microbial infections represents an developing new field. The emergence of strains resistant to antibiotics has provided the necessary impulse for new drug or technology discoveries to combat these resistant compounds. Although the aPDT is still in infancy, its need is still growing. Like PDT, main components of antimicrobial photodynamic therapy are appropriate light, dye called photosensitizer and created reactive oxygen species. In this article photosensitizers TMPyP and ZnTPPS4 are investigated for antimicrobial photodynamic therapy. We tested these porphyrins on bacterial methicilin – resistant strain MRSA alone and bound in complex created with hp-β-cyclodextrin. The light emitting diodes (414 nm) were used at the doses 0 and 150 J/cm2. Tested concentrations were from 0.78 to 100 μM. This experimental work predicated that TMPyP is very successful compound in aPDT. In contrary to ZnTPPS4 which was efficient for eradication of tested gram-positive bacteria only in higher concentrations

VLIV ULTRAZVUKU NA ÚČINNOST FOTODYNAMICKÉ TERAPIE – IN VITRO STUDIE

Photodynamic therapy (PDT) belongs in perspective modalities of cancer treatment. It is based on the tumour-selective accumulation of a photosensitizer followed by irradiation with light of a specific wavelength. PDT is widely developed nowadays due to its high specificity and selectivity along with absence of the unadvisable side-effects. Sonodynamic therapy (SDT) exploits ultrasound to induce cytotoxic effect of sensitizer. In our study we tested the possibility of combination of this therapies and icrease of efficiency. Our results suggest that irradiation in combination with application of therapeutic ultrasound increases production of reactive oxygen species and reduces viability of tumour MCF7 cells, compared to irradiation of ZnTPPS4 only, especially in the case of higher therapeutic doses. In the future, the combination of PDT and SDT can bring a new treatment modality for malignant and also nonmalignant diseases

Differences in the Effects of Broad-Band UVA and Narrow-Band UVB on Epidermal Keratinocytes

Background: The sun is a natural source of UV radiation. It can be divided into three bands, UVA (315–400 nm), UVB (280–315 nm) and UVC (100–280 nm), where the radiation up to 290 nm is very effectively eliminated by the stratospheric ozone. Although UV radiation can have a beneficial effect on our organism and can be used in the treatment of several skin diseases, it must primarily be considered harmful. Methods: In the presented work, we focused on the study of the longer-wavelength UV components (UVA and UVB) on the human epidermal keratinocyte line HaCaT. As UVA and UVB radiation sources, we used commercially available UVA and UVB tubes from Philips (Philips, Amsterdam, The Netherlands), which are commonly employed in photochemotherapy. We compared their effects on cell viability and proliferation, changes in ROS production, mitochondrial function and the degree of DNA damage. Results: Our results revealed that UVB irradiation, even with significantly lower irradiance, caused greater ROS production, depolarization of mitochondrial membrane potential and greater DNA fragmentation, along with significantly lowering cell viability and proliferative capacity. Conclusions: These results confirm that UV radiation causes severe damages in skin cells, and they need to be protected from it, or it needs to be applied more cautiously, especially if the component used is UVB

Hyperoside as a UV Photoprotective or Photostimulating Compound—Evaluation of the Effect of UV Radiation with Selected UV-Absorbing Organic Compounds on Skin Cells

Ultraviolet (UV) radiation is a non-ionizing radiation, which has a cytotoxic potential, and it is therefore necessary to protect against it. Human skin is exposed to the longer-wavelength components of UV radiation (UVA and UVB) from the sun. In the present paper, we focused on the study of eight organic UV-absorbing compounds: astragalin, beta-carotene, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, hyperoside, 3-(4-methylbenzylidene)camphor, pachypodol, and trans-urocanic acid, as possible protectives of skin cells against UVA and UVB radiation. Their protective effects on skin cell viability, ROS production, mitochondrial membrane potential, liposomal permeability, and DNA integrity were investigated. Only some of the compounds studied, such as trans-urocanic acid and hyperoside, had a significant effect on the examined hallmarks of UV-induced cell damage. This was also confirmed by an atomic force microscopy study of morphological changes in HaCaT cells or a study conducted on a 3D skin model. In conclusion, hyperoside was found to be a very effective UV-protective compound, especially against UVA radiation. Commonly used sunscreen compounds such as 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, and 3-(4-methylbenzylidene)camphor turned out to be only physical UV filters, and pachypodol with a relatively high absorption in the UVA region was shown to be more phototoxic than photoprotective

New planar light source for the induction and monitoring of photodynamic processes in vitro

We recently developed a new light source that allows for the continuous monitoring of light-induced changes using common spectrophotometric devices adapted for microplate analyses. This source was designed primarily to induce photodynamic processes in cell models. Modern light components, such as LED chips, were used to improve the irradiance homogeneity. In addition, this source forms a small hermetic chamber and thus allows for the regulation of the surrounding atmosphere, which plays a significant role in these light-dependent reactions. The efficacy of the new light source was proven via kinetic measurements of reactive oxygen species generated during the photodynamic reaction of chloroaluminium phthalocyanine disulfonate (ClAlPcS2) in three cell lines: human melanoma cells (G361), human breast adenocarcinoma cells (MCF7), and human fibroblasts (BJ)

Assessment of Cellular Damage by Comet Assay After Photodynamic Therapy in vitro

The aim of this study was analysis of DNA damage in the cell line of the human melanoma G361 after photodynamic therapy (PDT) by comet assay. Photodynamic therapy is based on cytotoxic action of sensitizers (10 µM ZnTPPS4 fixed into 1 mM cyclodextrin hpβCD) and light with a suitable wavelength. Single-cell gel electrophoresis (SCGE, comet assay) is a rapid and sensitive method for detecting DNA strand breaks at the level of single cells. Great amount of DNA damage was detected with the dose of irradiation of 0.1; 0.5 J and 2.5 J.cm-2. Only radiation dose of visible light in the presence of sensitizers can induce DNA breaks of tumour cells. Cells with DNA damage appear as fluorescent comets with tails of DNA fragmentation. In contrast, cells with undamage DNA appear as round spots, because their intact DNA does not migrate out of the cell

Acute pre-exercise hydrogen rich water intake does not improve running performance at maximal aerobic speed in trained track and field runners: A randomized, double-blind, placebo-controlled crossover study.

PurposeThis study investigated the effects of acute, pre-exercise, hydrogen rich water (HRW) ingestion on running time to exhaustion at maximal aerobic speed in trained track and field runners.MethodsTwenty-four, male runners aged 17.5 ± 1.8 years, with body mass index = 21.0 ± 1.3 kg⋅m-2, and maximal oxygen uptake = 55.0 ± 4.6 ml⋅kg-1⋅min-1 (mean ± standard deviation) participated in this randomized, double-blind, placebo-controlled crossover study. All runners ingested 1260 ml of HRW which was divided into four doses and taken at 120 min (420 ml), 60 min (420 ml), 30 min (210 ml), and 10 min (210 ml) prior to exercise. The running protocol consisted of three phases: warm-up performed at 10 km⋅h-1 for 3 min, followed by a transition phase performed at an individually determined speed (10 km⋅h-1 + maximal aerobic speed)/2 for 1 min, and finally the third phase performed at individual maximal aerobic speed until exhaustion. Time to exhaustion, cardiorespiratory variables, and post-exercise blood lactate concentration were measured.ResultsWhen running to exhaustion at maximal aerobic speed, compared with placebo, HRW had no significant effects on the following variables: time to exhaustion (217 ± 49 and 227 ± 53 s, p = 0.20), post-exercise blood lactate concentration (9.9 ± 2.2 and 10.1 ± 2.0 mmol⋅L-1, p = 0.42), maximal heart rate (186 ± 9 and 186 ± 9 beats⋅min-1, p = 0.80), and oxygen uptake (53.1 ± 4.5 and 52.2 ± 4.7 ml⋅kg-1⋅min-1, p = 0.33). No variable assessed as a candidate moderator was significantly correlated with time to exhaustion (Spearman's correlation coefficients ranged from -0.28 to 0.30, all p ≥ 0.16).ConclusionsPre-exercise administration of 1260 ml of HRW showed no ergogenic effect on running performance to exhaustion at maximal aerobic speed in trained track and field runners