Silicon dioxide, in the form of nanoparticles, possesses unique physicochemical properties (size, shape, and a large surface to volume ratio). Therefore, it is one of the most promising materials used in biomedicine. In this paper, we compare the biological effects of both mesoporous silica nanoparticles extracted from Urtica dioica L. and pyrogenic material. Both SEM and TEM investigations confirmed the size range of tested nanoparticles was between 6 and 20 nanometers and their amorphous structure. The cytotoxic activity of the compounds and intracellular ROS were determined in relation to cells HMEC-1 and erythrocytes. The cytotoxic effects of SiO2 NPs were determined after exposure to different concentrations and three periods of incubation. The same effects for endothelial cells were tested under the same range of concentrations but after 2 and 24 h of exposure to erythrocytes. The cell viability was measured using spectrophotometric and fluorimetric assays, and the impact of the nanoparticles on the level of intracellular ROS. The obtained results indicated that bioSiO2 NPs, present higher toxicity than pyrogenic NPs and have a higher influence on ROS production. Mesoporous silica nanoparticles show good hemocompatibility but after a 24 h incubation of erythrocytes with silica, the increase in hemolysis process, the decrease in osmotic resistance of red blood cells, and shape of erythrocytes changed were observed.

• MeSH
• endoteliální buňky účinky léků   MeSH
• erytrocyty účinky léků   MeSH
• hemolýza účinky léků   MeSH
• lidé MeSH
• nanočástice aplikace a dávkování   chemie   MeSH
• oxid křemičitý aplikace a dávkování   chemie   MeSH
• oxidační stres účinky léků   MeSH
• poréznost MeSH
• povrchové vlastnosti MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• viabilita buněk MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Lithium (Li) represents a first choice mood stabilizer for bipolar disorder (BD). Despite extensive clinical use, questions regarding its mechanism of action and pathological mechanism of renal function impairment by Li remain open. The present study aimed to improve our knowledge in this area paying special attention to the relationship between the length of Li action, lipid peroxidation (LP), and Na+/K+-ATPase properties. The effects of therapeutic Li doses, administered daily to male Wistar rats for 1 (acute), 7 (short term) and 28 days (chronic), were studied. For this purpose, Na+/K+-ATPase activity measurements, [3H]ouabain binding and immunoblot analysis of α-Na+/K+-ATPase were performed. Li-induced LP was evaluated by determining the malondialdehyde concentration by HPLC. Sleep deprivation (SD) was used as an experimental approach to model the manic phase of BD. Results obtained from the kidney were compared to those obtained from erythrocytes and different brain regions in the same tested animals. Whereas treatment with therapeutic Li concentration did not bring any LP damage nor significant changes of Na+/K+-ATPase expression and [3H]ouabain binding in the kidney, it conferred strong protection against this type of damage in the forebrain cortex. Importantly, the observed changes in erythrocytes indicated changes in forebrain cortices. Thus, different resistance to SD-induced changes of LP and Na+/K+-ATPase was detected in the kidney, erythrocytes and the brain of Li-treated rats. Our study revealed the tissue-specific protective properties of Li against LP and Na+/K+-ATPase regulation.

• MeSH
• antimanika aplikace a dávkování   farmakologie   MeSH
• bipolární porucha farmakoterapie   MeSH
• časové faktory MeSH
• erytrocyty účinky léků   metabolismus   MeSH
• krysa rodu rattus MeSH
• ledviny účinky léků   metabolismus   MeSH
• lithiumkarbonát aplikace a dávkování   farmakologie   MeSH
• modely nemocí na zvířatech MeSH
• mozek účinky léků   metabolismus   MeSH
• peroxidace lipidů účinky léků   MeSH
• potkani Wistar MeSH
• sodíko-draslíková ATPasa metabolismus   MeSH
• spánková deprivace psychologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Oxime-based acetylcholinesterase reactivators (briefly oximes) regenerate organophosphate-inactivated acetylcholinesterase and restore its function. Poor blood-brain-barrier passage and fast elimination from blood limit their actual use in treatment of patients exposed to organophosphates. Previous in vitro results implicated further testing of cucurbit[7]uril as a delivery vehicle for bisquaternary oximes. The present paper focuses on cell toxicity, in vivo safety and influence of cucurbit[7]uril on oxime pharmacokinetics and pharmacodynamics. Neither the K027 nor the complex caused any cell toxicity, changes in blood biochemistry or hepato- or nephrotoxicity in tested concentrations. The encapsulation of K027 increased and accelerated the blood-brain-barrier penetration. The peripheral oxime exposure also increased, supporting the suggestion that cucurbit[7]uril protects the circulating oxime from rapid renal clearance. Contrary to the comparable in vitro reactivation power of K027 and the encapsulated K027, we failed to confirm this in vivo. In theory, this might result from the non-specific binding of molecules to the cucurbit[7]uril or the interaction of K027 with cucurbit[7]uril being too strong for acetylcholinesterase reactivation. Precise explanation requires additional in silico, in vitro and also in vivo experiments.

• MeSH
• acetylcholinesterasa krev   metabolismus   MeSH
• buňky A549 MeSH
• buňky Hep G2 MeSH
• erytrocyty účinky léků   enzymologie   MeSH
• GPI-vázané proteiny krev   metabolismus   MeSH
• hodnocení rizik MeSH
• imidazoly aplikace a dávkování   farmakokinetika   toxicita   MeSH
• injekce intramuskulární MeSH
• lidé MeSH
• maximální tolerovaná dávka MeSH
• mozek účinky léků   enzymologie   MeSH
• myši inbrední ICR MeSH
• oximy aplikace a dávkování   farmakokinetika   toxicita   MeSH
• přemostěné cyklické sloučeniny aplikace a dávkování   farmakokinetika   toxicita   MeSH
• pyridinové sloučeniny aplikace a dávkování   farmakokinetika   toxicita   MeSH
• reaktivátory cholinesterázy aplikace a dávkování   farmakokinetika   toxicita   MeSH
• tkáňová distribuce MeSH
• viabilita buněk účinky léků   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Costunolide, a natural sesquiterpene lactone, has multiple pharmacological activities such as neuroprotection or induction of apoptosis and eryptosis. However, the effects of costunolide on pro-survival factors and enzymes in human erythrocytes, e.g. glutathione and glucose-6-phosphate dehydrogenase (G6PDH) respectively, have not been studied yet. Our aim was to determine the mechanisms underlying costunolide-induced eryptosis and to reverse this process. Phosphatidylserine exposure was estimated from annexin-V-binding, cell volume from forward scatter in flow cytometry, and intracellular glutathione [GSH]i from high performance liquid chromatography. The oxidized status of intracellular glutathione and enzyme activities were measured by spectrophotometry. Treatment of erythrocytes with costunolide dose-dependently enhanced the percentage of annexin-V-binding cells, decreased the cell volume, depleted [GSH]i and completely inhibited G6PDH activity. The effects of costunolide on annexin-V-binding and cell volume were significantly reversed by pre-treatment of erythrocytes with the specific PKC-α inhibitor chelerythrine. The latter, however, had no effect on costunolide-induced GSH depletion. Costunolide induces eryptosis, depletes [GSH]i and inactivates G6PDH activity. Furthermore, our study reveals an inhibitory effect of chelerythrine on costunolide-induced eryptosis, indicating a relationship between costunolide and PKC-α. In addition, chelerythrine acts independently of the GSH depletion. Understanding the mechanisms of G6PDH inhibition accompanied by GSH depletion should be useful for development of anti-malarial therapeutic strategies or for synthetic lethality-based approaches to escalate oxidative stress in cancer cells for their sensitization to chemotherapy and radiotherapy.

• MeSH
• apoptóza účinky léků   MeSH
• benzofenantridiny farmakologie   MeSH
• eryptóza účinky léků   genetika   MeSH
• erytrocyty účinky léků   patologie   MeSH
• glukosa-6-fosfátdehydrogenasa antagonisté a inhibitory   genetika   MeSH
• glutathion genetika   MeSH
• inhibitory enzymů farmakologie   MeSH
• lidé MeSH
• oxidační stres účinky léků   MeSH
• proteinkinasa C-alfa antagonisté a inhibitory   genetika   MeSH
• reaktivní formy kyslíku MeSH
• seskviterpeny farmakologie   MeSH
• vápník metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Candida albicans has several virulence factors at its disposal, including yeast-hyphal transition associated with biofilm formation, phospholipases, proteases and hemolytic activity, all of which contribute to its pathogenesis. We used synthetic derivative LL-III/43 of antimicrobial peptide lasioglossin LL-III to enhance effect of azoles on attenuation of C. albicans virulence factors. LL-III/43 was able to inhibit initial adhesion or biofilm formation of C. albicans strains at 50 µM. Azoles, however, were ineffective at this concentration. Using fluorescently labeled LL-III/43, we observed that peptide covered C. albicans cells, partially penetrated through their membranes and then accumulated inside cells. LL-III/43 (25 µM) in combination with clotrimazole prevented biofilm formation already at 3.1 µM clotrimazole. Neither LL-III/43 nor azoles were able to significantly inhibit phospholipases, proteases, or hemolytic activity of C. albicans. LL-III/43 (25 µM) and clotrimazole (50 µM) in combination decreased production of these virulence factors, and it completely attenuated its hemolytic activity. Scanning electron microscopy showed that LL-III/43 (50 µM) prevented C. albicans biofilm formation on Ti-6Al-4 V alloy used in orthopedic surgeries and combination of LL-III/43 (25 µM) with clotrimazole (3.1 µM) prevented biofilm formation on urinary catheters. Therefore, mixture of LL-III/43 and clotrimazole is suitable candidate for future pharmaceutical research.

• MeSH
• antifungální látky farmakologie   MeSH
• azoly farmakologie   MeSH
• biofilmy účinky léků   růst a vývoj   MeSH
• Candida albicans účinky léků   MeSH
• erytrocyty účinky léků   MeSH
• faktory virulence MeSH
• fosfolipasy antagonisté a inhibitory   MeSH
• hemolýza účinky léků   MeSH
• hydrofobní a hydrofilní interakce účinky léků   MeSH
• kationické antimikrobiální peptidy chemická syntéza   farmakokinetika   MeSH
• lidé MeSH
• proteasy metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Aluminum accumulation, glutathione (GSH) and malondialdehyde (MDA) concentrations as well as catalase (CAT) and superoxide dismutase (SOD) activities were determined in erythrocytes and brain and liver homogenates of BALB/c mice treated with Al3+ (7.5 mg/kg/day (0.15 LD50) as AlCl3 (37.08 mg/kg/day), whereas HCl (30.41 mg/kg/day) was used as Cl- control, the treatments were performed for 21 days, i.p., in the presence and absence of rosmarinic acid (0.2805 mg/kg/day (0.05 LD50), 21 days, i.g.) or carvacrol (0.0405 mg/kg/day (0.05 LD50), 21 days, i.g.). The treatment with AlCl3 increased GSH concentration in erythrocytes only slightly and had no effect on brain and liver homogenates. Rosmarinic acid and carvacrol strongly increased GSH concentration in erythrocytes but decreased it in brain and liver homogenates. However, AlCl3 treatment led to Al accumulation in mice blood, brain, and liver and induced oxidative stress, assessed based on MDA concentration in the brain and liver. Both rosmarinic acid and carvacrol were able to counteract the negative Al effect by decreasing its accumulation and protecting tissues from lipid peroxidation. AlCl3 treatment increased CAT activity in mice brain and liver homogenates, whereas the administration of either rosmarinic acid or carvacrol alone or in combination with AlCl3 had no significant effect on CAT activity. SOD activity remained unchanged after all the treatments in our study. We propose that natural herbal phenolic compounds rosmarinic acid and carvacrol could be used to protect brain and liver against aluminum induced oxidative stress leading to lipid peroxidation.

• MeSH
• antioxidancia farmakologie   MeSH
• biologické přípravky chemie   farmakologie   MeSH
• cinnamáty chemie   farmakologie   MeSH
• cymeny chemie   farmakologie   MeSH
• depsidy chemie   farmakologie   MeSH
• erytrocyty účinky léků   metabolismus   MeSH
• hliník škodlivé účinky   chemie   MeSH
• játra účinky léků   metabolismus   MeSH
• malondialdehyd metabolismus   MeSH
• mozek účinky léků   metabolismus   MeSH
• myši MeSH
• oxidační stres účinky léků   MeSH
• peroxidace lipidů účinky léků   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

It is generally believed that antibacterial essential oils have the potential to become one of the alternatives in preventing diarrheal diseases of monogastric animals. The disadvantage is their low efficiency per oral due to easy degradation during digestion in the stomach. This study compares the efficacy of chitosan, alginate-chitosan, guar gum-chitosan, xanthan gum-chitosan and pectin-chitosan nanocapsules to the synthesis of pH-responsive biopolymeric nanocapsule for Thymus vulgaris, Rosmarinus officinalis and Syzygium aromaticum essential oils. Using spectrophotometric approach and gas chromatography, release kinetics were determined in pH 3, 5.6 and 7.4. The growth rates of S. aureus and E. coli, as well as minimal inhibition concentration of essential oils were studied. The average encapsulation efficiency was 60%, and the loading efficiency was 70%. The size of the nanocapsules ranged from 100 nm to 500 nm. Results showed that chitosan-guar gum and chitosan-pectin nanocapsules released 30% of essential oils (EOs) at pH 3 and 80% at pH 7.4 during 3 h. Similar release kinetics were confirmed for thymol, eugenol and α-pinene. Minimal inhibition concentrations of Thymus vulgaris and Syzygium aromaticum essential oils ranged from 0.025 to 0.5%. Findings of this study suggest that the suitable pH-responsive nanocapsule for release, low toxicity and antibacterial activity is based on chitosan-guar gum structure.

• MeSH
• antibakteriální látky chemie   farmakologie   MeSH
• erytrocyty cytologie   účinky léků   MeSH
• Escherichia coli účinky léků   růst a vývoj   MeSH
• hemolýza účinky léků   MeSH
• koncentrace vodíkových iontů MeSH
• lidé MeSH
• mikrobiální testy citlivosti MeSH
• nanokapsle aplikace a dávkování   chemie   MeSH
• oleje prchavé chemie   farmakologie   MeSH
• polymery chemie   MeSH
• Staphylococcus aureus účinky léků   růst a vývoj   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Lectins are a group of ubiquitous proteins which specifically recognize and reversibly bind sugar moieties of glycoprotein and glycolipid constituents on cell surfaces. The mutagenesis approach is often employed to characterize lectin binding properties. As lectins are not enzymes, it is not easy to perform a rapid specificity screening of mutants using chromogenic substrates. It is necessary to use different binding assays such as isothermal titration calorimetry (ITC), surface plasmon resonance (SPR), microscale thermophoresis (MST), enzyme-linked lectin assays (ELLA), or glycan arrays for their characterization. These methods often require fluorescently labeled proteins (MST), highly purified proteins (SPR) or high protein concentrations (ITC). Mutant proteins may often exhibit problematic behaviour, such as poor solubility or low stability. Lectin-based cell agglutination is a simple and low-cost technique which can overcome most of these problems. In this work, a modified method of the agglutination of human erythrocytes and yeast cells with microscopy detection was successfully used for a specificity study of the newly prepared mutant lectin RS-IIL_A22S, which experimentally completed studies on sugar preferences of lectins in the PA-IIL family. Results showed that the sensitivity of this method is comparable with ITC, is able to determine subtle differences in lectin specificity, and works directly in cell lysates. The agglutination method with microscopy detection was validated by comparison of the results with results obtained by agglutination assay in standard 96-well microtiter plate format. In contrast to this assay, the microscopic method can clearly distinguish between hemagglutination and hemolysis. Therefore, this method is suitable for examination of lectins with known hemolytic activity as well as mutant or uncharacterized lectins, which could damage red blood cells. This is due to the experimental arrangement, which includes very short sample incubation time in combination with microscopic detection of agglutinates, that are easily observed by a small portable microscope.

• MeSH
• aglutinace účinky léků   MeSH
• aglutinační testy * metody   MeSH
• bakteriální proteiny farmakologie   MeSH
• erytrocyty cytologie   účinky léků   MeSH
• hemaglutinace účinky léků   MeSH
• hemolýza účinky léků   MeSH
• kvasinky cytologie   účinky léků   MeSH
• lektiny farmakologie   MeSH
• lidé MeSH
• mikroskopie MeSH
• povrchová plasmonová rezonance MeSH
• proteiny z Escherichia coli farmakologie   MeSH
• Saccharomyces cerevisiae cytologie   účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Malarial dipeptidyl aminopeptidases (DPAPs) are cysteine proteases important for parasite development thus making them attractive drug targets. In order to develop inhibitors specific to the parasite enzymes, it is necessary to map the determinants of substrate specificity of the parasite enzymes and its mammalian homologue cathepsin C (CatC). Here, we screened peptide-based libraries of substrates and covalent inhibitors to characterize the differences in specificity between parasite DPAPs and CatC, and used this information to develop highly selective DPAP1 and DPAP3 inhibitors. Interestingly, while the primary amino acid specificity of a protease is often used to develop potent inhibitors, we show that equally potent and highly specific inhibitors can be developed based on the sequences of nonoptimal peptide substrates. Finally, our homology modelling and docking studies provide potential structural explanations of the differences in specificity between DPAP1, DPAP3, and CatC, and between substrates and inhibitors in the case of DPAP3. Overall, this study illustrates that focusing the development of protease inhibitors solely on substrate specificity might overlook important structural features that can be exploited to develop highly potent and selective compounds.

• MeSH
• aminokyseliny chemie   MeSH
• dipeptidylpeptidasy a tripeptidylpeptidasy metabolismus   MeSH
• erytrocyty účinky léků   metabolismus   parazitologie   MeSH
• inhibitory proteas farmakologie   MeSH
• konformace proteinů MeSH
• lidé MeSH
• molekulární modely MeSH
• molekulární struktura MeSH
• peptidové fragmenty metabolismus   MeSH
• Plasmodium falciparum účinky léků   růst a vývoj   metabolismus   MeSH
• substrátová specifita MeSH
• tropická malárie farmakoterapie   metabolismus   parazitologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Cytolytic leukotoxins of the repeat in toxin (RTX) family are large proteins excreted by gram-negative bacterial pathogens through the type 1 secretion system (T1SS). Due to low yields and poor stability in cultures of the original pathogens, it is useful to purify recombinant fatty-acylated RTX cytolysins from inclusion bodies produced in E. coli. Such preparations are, however, typically contaminated by high amounts of E. coli lipopolysaccharide (LPS or endotoxin). We report a simple procedure for purification of large amounts of biologically active and endotoxin-free RTX toxins. It is based on the common feature of RTX cytolysins that are T1SS-excreted as unfolded polypeptides and fold into a biologically active toxin only upon binding of calcium ions outside of the bacterial cell. Mimicking this process, the RTX proteins are solubilized from inclusion bodies with buffered 8 M urea, bound onto a suitable chromatographic medium under denaturing conditions and the contaminating LPS is removed through extensive on-column washes with buffers containing 6 to 8 M urea and 1% Triton X-100 or Triton X-114. Extensive on-column rinsing with 8 M urea buffer removes residual detergent and the eluted highly active RTX protein preparations then contain only trace amounts of LPS. The procedure is exemplified using four prototypic RTX cytolysins, the Bordetella pertussis CyaA and the hemolysins of Escherichia coli (HlyA), Kingella kingae (RtxA), and Actinobacillus pleuropneumoniae (ApxIA).

• MeSH
• bakteriální proteiny izolace a purifikace   toxicita   MeSH
• cytotoxiny izolace a purifikace   toxicita   MeSH
• detergenty chemie   MeSH
• erytrocyty účinky léků   MeSH
• Escherichia coli metabolismus   MeSH
• hemolýza MeSH
• hemolyziny izolace a purifikace   toxicita   MeSH
• lidé MeSH
• lipopolysacharidy analýza   MeSH
• močovina chemie   MeSH
• nádorové buněčné linie MeSH
• oktoxynol chemie   MeSH
• ovce MeSH
• THP-1 buňky MeSH
• viabilita buněk účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH