Modeling and optimizing concentration of exogenous application of γ-aminobutyric acid on NaCl-stressed pineapple mint (Mentha suaveolens) using response surface methodology: an investigation into secondary metabolites and physiological parameters.

Salinity, a severe worldwide issue, compromises the economic production of medicinal plants including mints and causes drug-yield decline. γ-Aminobutyric acid (GABA) is a tolerance-inducing signaling bio-molecule in various plant physiological processes. Pineapple mint (Mentha suaveolens Ehrh.) is a valuable medicinal herb with an exhilarating scent of citrus fruit. Piperitenone oxide is the major bioactive constituent of its essential oil, having significant demand by pharmaceutical industries. Nonetheless, modeling and optimizing the effective concentration of GABA remain within twin foci of interest. Therefore, a two factor-five level (NaCl 0-150 mM and GABA 0-2.4 mM) central composite design was conducted to model and optimize drug yield and physiological responses of M. suaveolens. Based on the design of experiments (DoE) approach, different linear, quadratic, cubic, and quartic models were assigned to the response variables. Change trends of shoot and root dry weights followed a simple linear model, whereas sophisticated models (i.e., multiple polynomial regression) were fitted to the other traits. NaCl stress inevitably reduced root and shoot dry weight, piperitenone oxide content, relative water content, pigments content, and maximum quantum yield of PSII. However, content of malondialdehyde (MDA) and total flavonoid, and DPPH radical scavenging activity were increased under salinity. Under severe NaCl stress (150 mM), the essential oil content (0.53%) was increased three times in comparison with control (0.18%). Optimization analysis demonstrated that the highest amount of essential oil (0.6%) and piperitenone oxide (81%) as a drug yield-determining component would be achievable by application of 0.1-0.2 mM GABA under 100 mM NaCl. The highest dry weight of root and shoot was predicted to be achieved at 2.4 mM GABA. Overall, extremely severe NaCl stress (i.e., more than 100 mM) in which a sharp drop in yield components value was observed seemed to be out of M. suaveolens salinity tolerance range. Hence, it is rationale to compensate the decrease of drug yield by foliar application of a dilute GABA solution (i.e., 0.1-0.2 mM) under 100 mM NaCl stress or lower levels.

Delivery of miR-3529-3p using MnO2 -SiO2 -APTES nanoparticles combined with phototherapy suppresses lung adenocarcinoma progression by targeting HIGD1A.

BACKGROUND: The present study aimed to investigate the function of miR-3529-3p in lung adenocarcinoma and MnO2 -SiO2 -APTES (MSA) as a promising multifunctional delivery agent for lung adenocarcinoma therapy. METHODS: Expression levels of miR-3529-3p were evaluated in lung carcinoma cells and tissues by qRT-PCR. The effects of miR-3529-3p on apoptosis, proliferation, metastasis and neovascularization were assessed by CCK-8, FACS, transwell and wound healing assays, tube formation and xenografts experiments. Luciferase reporter assays, western blot, qRT-PCR and mitochondrial complex assay were used to determine the targeting relationship between miR-3529-3p and hypoxia-inducible gene domain family member 1A (HIGD1A). MSA was fabricated using MnO2 nanoflowers, and its heating curves, temperature curves, IC50, and delivery efficiency were examined. The hypoxia and reactive oxygen species (ROS) production was investigated by nitro reductase probing, DCFH-DA staining and FACS. RESULTS: MiR-3529-3p expression was reduced in lung carcinoma tissues and cells. Transfection of miR-3529-3p could promote apoptosis and suppress cell proliferation, migration and angiogenesis. As a target of miR-3529-3p, HIGD1A expression was downregulated, through which miR-3529-3p could disrupt the activities of complexes III and IV of the respiratory chain. The multifunctional nanoparticle MSA could not only efficiently deliver miR-3529-3p into cells, but also enhance the antitumor function of miR-3529-3p. The underlying mechanism may be that MSA alleviates hypoxia and has synergistic effects in cellular ROS promotion with miR-3529-3p. CONCLUSIONS: Our results establish the antioncogenic role of miR-3529-3p, and demonstrate that miR-3529-3p delivered by MSA has enhanced tumor suppressive effects, probably through elevating ROS production and thermogenesis.

Effects of Long-Term Dietary Zinc Oxide Nanoparticle on Liver Function, Deposition, and Absorption of Trace Minerals in Intrauterine Growth Retardation Pigs.

To investigate the long-term effects of dietary zinc oxide nanoparticle (Nano-ZnO, 20-40 nm) on the relative organ weight, liver function, deposition, and absorption of trace minerals in intrauterine growth retardation (IUGR) pigs, piglets were allocated to NBW (6 normal birth weight piglets fed basal diets), IUGR (6 IUGR piglets fed basal diets) and IUGR+NZ (6 IUGR piglets fed basal diets + 600 mg Zn/kg from Nano-ZnO) groups at weaning (21 days of age), which were sampled at 163 days of age. There were no noteworthy changes in the relative weight of organs, hepatic histomorphology, serum alkaline phosphatase, glutamic pyruvic transaminase and glutamic oxalacetic transaminase activities, and Mn, Cu, and Fe concentrations in leg muscle, the liver, the tibia, and feces among the IUGR, NBW, and IUGR+NZ groups (P>0.05), and no intact Nano-ZnO in the jejunum, liver, and muscle was observed, while dietary Nano-ZnO increased the Zn concentrations in the tibia, the liver, serum, and feces (P<0.05) and mRNA expression of metallothionein (MT) 1A, MT2A, solute carrier family 39 member (ZIP) 4, ZIP14, ZIP8, divalent metal transporter 1, solute carrier family 30 member (ZnT) 1, ZnT4 and metal regulatory transcription factor 1, and ZIP8 protein expression in jejunal mucosa (P<0.05). Immunohistochemistry showed that dietary Nano-ZnO increased the relative optical density of ZIP8 (mainly expressed in cells of brush border) and MT2A (mainly expressed in villus lamina propria and gland/crypt) (P<0.05). In conclusion, long-term dietary Nano-ZnO showed no obvious side effects on the development of the major organs, liver function, and metabolism of Cu, Fe, and Mn in IUGR pigs, while it increased the Zn absorption and deposition via enhancing the expression of transporters (MT, ZIP, and ZnT families) in the jejunum, rather than via endocytosis as the form of intact nanoparticles.

Combinatorial Effect of Arsenic and Herbal Compounds in Telomerase-Mediated Apoptosis Induction in Liver Cancer.

Tumour illness and its resistance against existing anticancer therapies pose a serious health concern globally despite the progressive advancement of therapeutic options. The prevailing treatment of HCC using numerous antitumor agents has inflated long-lived complete remissions, but a percentage of individuals still die due to disease recurrence, indicating a need for further exploration of possible anti-tumour regimes. We aim to boost the effectiveness of the HCC treatment by conducting current investigations evaluating the effect of arsenic trioxide (ATO) with different herbal compounds like quercetin and aloe-emodin against liver tumour via inhibition of telomerase, a pro-cancer enzyme. The anticancer activity of ATO with herbal compounds was investigated in human control liver cell line (Wrl-68) and cancer liver cell line (HepG2) at different time intervals. Viability and cytotoxicity in response to combinatorial drugs were assessed in vitro by trypan blue dye exclusion assay and MTT and WST assay. Apoptosis was analysed by annexin V/PI assay, and the expression of telomerase and apoptosis-regulating proteins was evaluated by immunoblotting and qRT-PCR. Arsenic trioxide in combination with quercetin and aloe-emodin reduced cell viability in cancerous cells compared to normal cells by inducing apoptosis, downregulating telomerase and Bcl-2 (anti-apoptotic protein) and upregulating the expression of Bax (pro-apoptotic protein). ATO exhibited significant anticancer effects due to the synergistic effects of quercetin and aloe-emodin in liver tumour cells. The current study data collectively suggest that a successful inhibition of cancer growth by the combination of ATO and tested herbal medicines against liver tumour growth is via the inhibition of telomerase activity.

Functional brain-wide network mapping during acute stress exposure in rats: Interaction between the lateral habenula and cortical, amygdalar, hypothalamic and monoaminergic regions.

Upon stress exposure, a broad network of structures comes into play in order to provide adequate responses and restore homeostasis. It has been known for decades that the main structures engaged during the stress response are the medial prefrontal cortex, the amygdala, the hippocampus, the hypothalamus, the monoaminergic systems (noradrenaline, dopamine and serotonin) and the periaqueductal gray. The lateral habenula (LHb) is an epithalamic structure directly connected to prefrontal cortical areas and to the amygdala, whereas it functionally interacts with the hippocampus. Also, it is a main modulator of monoaminergic systems. The LHb is activated upon exposure to basically all types of stressors, suggesting it is also involved in the stress response. However, it remains unknown if and how the LHb functionally interacts with the broad stress response network. In the current study we performed in rats a restraint stress procedure followed by immunohistochemical staining of the c-Fos protein throughout the brain. Using graph theory-based functional connectivity analyses, we confirm the principal hubs of the stress network (e.g., prefrontal cortex, amygdala and periventricular hypothalamus) and show that the LHb is engaged during stress exposure in close interaction with the medial prefrontal cortex, the lateral septum and the medial habenula. In addition, we performed DREADD-induced LHb inactivation during the same restraint paradigm in order to explore its consequences on the stress response network. This last experiment gave contrasting results as the DREADD ligand alone, clozapine-N-oxide, was able to modify the network.

Light synergistically promotes the tea green leafhopper infestation-induced accumulation of linalool oxides and their glucosides in tea (Camellia sinensis).

Linalool, which is one of the most representative aroma substances in tea, is transformed into other aroma-related compounds, including linalool 3,6-oxides and linalool 3,7-oxides. The objective of this study was to elucidate the linalool oxide synthesis pathway and its response to stress in tea. By feeding experiment, chemical synthesis, and compound analysis, it was found that linalool can be transformed to linalool oxides via 6,7-epoxylinalool. The conversion rate from 6,7-epoxylinalool to linalool oxides was relatively high under acidic conditions. Four linalool oxide glucosides obtained from tea were structurally characterized. Additionally, tea green leafhopper infestation was observed to activate the whole metabolic flow from linalool into linalool oxides and their glucosides (p < 0.01). Moreover, light treatments further increased the accumulation of linalool oxides and their glucosides (p < 0.05). These results will be useful for elucidating the mechanism mediating linalool oxides content changes in response to stress in tea.

MnO2 nanoparticles as a minimalist multimode vaccine adjuvant/delivery system to regulate antigen presenting cells for tumor immunotherapy.

In the field of tumor immunotherapy, tumor vaccines have unique advantages including fewer side effects, tumor-specificity and immune memory, and hence attract more and more attention. In the development of tumor vaccines, a critical challenge lies in the exploitation of appropriate vaccine adjuvants/delivery systems that need to meet multiple requirements to achieve potent cellular immunity while simultaneously requiring single composition to simplify the clinical translation process. Among numerous materials, only manganese dioxide (MnO2) nanoparticles with rare physicochemical properties seem to meet the demanding criteria of simplicity and multifunctionality. However, the potential of MnO2 nanoparticles as vaccine adjuvants/delivery systems has not been well exploited, despite their widespread applications in the biomedical field. In this study, the mechanism and efficacy of single MnO2 nanoparticles as a minimalist multi-mode tumor vaccine adjuvant/delivery system were fully investigated by using a model antigen ovalbumin (OVA) to construct tumor vaccines OVA/MnO2. The obtained results show that MnO2 nanoparticles act as an ideal delivery system by multiple modes to deliver the antigen to the cytoplasm of dendritic cells to induce cellular immune response. Moreover, MnO2 nanoparticles also act as a superior adjuvant depot to sustainably release Mn2+ to enhance the immune response through a STING pathway in dendritic cells. Both the delivery function and the adjuvant effect of MnO2 nanoparticles contribute to improved cellular immunity and anti-tumor efficacy of tumor vaccines OVA/MnO2. From the results, MnO2 nanoparticles are found to be a promising minimalist multi-mode vaccine adjuvant/delivery system for the development of practical tumor vaccines.

Biological applications of green synthesized lanthanum oxide nanoparticles via Couroupita guianensis abul leaves extract.

In this work, extract from leaves of Couroupita guianensis (C.guianensis) abul was used as a potential reducing agent for the synthesis of lanthanum oxide (La2O3) nanoparticles (NPs). In addition, the morphology and several physicochemical properties of the La2O3 NPs were improved by introducing the ionic liquid of 1-butyl 3-methyl imidazolium tetra fluoroborate (BMIM BF4) as a stabilizing agent. The structure of the La2O3 (without ionic liquid) and IL-La2O3 (with ionic liquid) NPs were analyzed by X-ray diffraction (XRD). The chemical composition of the synthesized NPs was analyzed using the energy dispersive X-ray (EDX) and X-ray photoelectron spectroscopy (XPS) studies. Optical and morphological studies were also performed. The antibacterial, antioxidant, anti-inflammatory, anti-diabetic and anticancer properties of the La2O3 and IL-La2O3 NPs were evaluated.

Biodegradable flower-like manganese for synergistic photothermal and photodynamic therapy applications.

A flower-like nanostructured MnO2 with near-infrared (NIR) light-triggered high photothermal conversion capability of 30% and reactive oxygen species (ROS) generation ability was successfully developed. Different from the reported MnO2 nanomaterials those were used in the nanomedicine field for only relieving tumor hypoxia and/or imaging, the flower-like MnO2 inherently acts as a competent agent for simultaneously enhanced photothermal and photodynamic therapy. A flower-like nanostructured MnO2 with near-infrared (NIR) light triggered high photothermal conversion capability of 30% and reactive oxygen species (ROS) generation ability was successfully developed.

A Smart Theranostic Nanocapsule for Spatiotemporally Programmable Photo-Gene Therapy.

The therapeutic performance of DNAzyme-involved gene silencing is significantly constrained by inefficient conditional activation and insufficient cofactor supply. Herein, a self-sufficient therapeutic nanosystem was realized through the delicate design of DNAzyme prodrugs and MnO2 into a biocompatible nanocapsule with tumor-specific recognition/activation features. The indocyanine green (ICG)-modified DNA prodrugs are designed by splitting the DNAzyme and then reconstituted into the exquisite catalyzed hairpin assembly (CHA) amplification circuit. Based on the photothermal activation of ICG, the nanocapsule was disassembled to expose the MnO2 ingredient which was immediately decomposed into Mn2+ ions to supplement an indispensable DNAzyme cofactor on-demand with a concomitant O2 generation for enhancing the auxiliary phototherapy. The endogenous microRNA catalyzes the amplified assembly of DNA prodrugs via an exquisite CHA principle, leading to the DNAzyme-mediated simultaneous silencing of two key tumor-involved mRNAs. This self-activated theranostic nanocapsule could substantially expand the toolbox for accurate diagnosis and programmable therapeutics.

Discovery of 1,2,3-triazole based quinoxaline-1,4-di-N-oxide derivatives as potential anti-tubercular agents.

A series of thirty one novel 2-(((1-(substituted phenyl)-1H-1,2,3-triazol-4-yl)methoxy)carbonyl)-3-methylquinoxaline-1,4-dioxide (7a-l), 3-(((1-(substituted phenyl)-1H-1,2,3-triazol-4-yl)methoxy)carbonyl)-6-chloro-2-methylquinoxaline-1,4-dioxide (8a-l) and 2-(((1-(substituted phenyl)-1H-1,2,3-triazol-4-yl)methoxy)carbonyl)-6,7-dichloro-3-methylquinoxaline-1,4-dioxide (9a-g) analogues were synthesized, characterized using various analytical techniques and single crystal was developed for the compounds 8 g and 9f. Synthesized compounds were evaluated for in vitro anti-tubercular activity against Mycobacterium tuberculosis H37Rv strain and two clinical isolates Spec. 210 and Spec. 192. The titled compounds exhibited minimum inhibitory concentration (MIC) ranging from 30.35 to 252.00 µM. Among the tested compounds, 8e, 8 l, 9c and 9d exhibited moderate activity (MIC = 47.6 - 52.0 µM) and 8a exhibited significant anti-tubercular activity (MIC = 30.35 µM). Furthermore, 8e, 8 l, and 9d were found to be less toxic against human embryonic kidney, HEK 293 cell lines. Finally, a docking study was also performed using MTB DNA Gyrase (PDB ID: 5BS8) for the significantly active compound 8a to know the exact binding pattern within the active site of the target enzyme.

Research Note: Evaluation of manganese hydroxychloride in 45-wk-old white leghorn layers using yolk and shell manganese content.

The objective of the current study was to evaluate increasing levels of manganese hydroxychloride (MHC) in 45-wk-old white leghorn laying hens, using yolk and shell manganese (Mn) content as a potential marker for Mn concentration. A total of 80, 45-wk-old white leghorns were assigned to 6 dietary treatments, each consisting of 14 individually caged laying hens, with the exception of the reference diet containing 10 individually caged laying hens. The experiment consisted of a reference diet that contained 70 ppm of supplemental inorganic Mn in the form of Mn oxide and 5 experimental treatments each containing 0, 15, 30, 60, and 90 ppm supplemental MHC. Experimental birds were subjected to a 21 D depletion phase in which no supplemental Mn was included in the diet; however, during this time reference fed birds were fed the control diet (70 ppm Mn). After the 21 D depletion phase, the depleted birds were fed experimental diets for a 35 D evaluation period. Yolk and shell Mn content were analyzed at the end of the depletion phase and during the experimental phase on day 5, 10, 15, 25, and 35. During the experimental phase, Mn was replenished in the yolk and shell in all experimental treatments containing supplemental Mn; however, dose and time impacted the rate of replenishment. The yolk tended to be more sensitive to variations in Mn level as increases in Mn inclusion significantly (P < 0.05) increased concentration. These data demonstrate the ability to deplete and replenish Mn, and the use of egg yolk Mn concentration as measurement for determining changes in dietary Mn. At the conclusion of the experiment at 35 D, 60 ppm of Mn hydroxychloride seemed to be adequate in replenishing Mn to the level of the reference.

[Primary hyperoxaluria: case report and therapeutic perspectives].

Primary hyperoxaluria (PH) is a rare genetic disorder with autosomal recessive transmission, characterized by high endogenous production and markedly excessive urinary excretion of oxalate (Ox). It causes the accumulation of calcium oxide crystals in organs and tissues including bones, heart, arteries, skin and kidneys, where it may cause oxalo-calcic nephrolithiasis, nephrocalcinosis and chronic renal failure. Some forms are secondary to enteric diseases, drugs or dietetic substances, while three primitive forms, caused by various enzymatic defects, are currently known: PH1, PH2 and PH3. An early diagnosis, with the aid of biochemical and genetic investigations, helps prevent complications and establish a therapeutic strategy that often includes liver and liver-kidney transplantation, improving the prognosis of these patients. In this work we describe the clinical case of a patient with PH1 undergoing extracorporeal hemodialysis treatment and we report the latest research results that could change the life of patients with PH.

Use of chlorine dioxide to sterilize medium for tissue culture of potato.

In vitro cultured seedlings or microtubers are the major starting materials for the production of potato. Currently, seedlings are cultured in media sterilized by autoclaving, which, however, consumes more electricity and takes longer for sterilization, and also requires high temperature-tolerant vessel materials. In order to identify alternative methods of sterilizing culture conditions, the disinfection effects of chlorine dioxide (CD) at 88.0, 29.3, 17.6, 12.6 and 8.8 µM were evaluated in potato medium and vessels. The ≥12.6 µM gaseous CD effectively disinfected vessel through a 30-min fumigation process, and its aqueous solution disinfected potato medium efficiently as well. In presence of 12.6 µM CD in the medium, the potato seedlings had similar morphological features as those grown on autoclaved medium, with some exceptions. The use of 12.6-29.3 µM aqueous CD to sterilize the medium increased antioxidant enzyme activities in potato seedlings, while the use of higher concentration decreased antioxidant enzyme activity levels. SSR analysis did not reveal significant molecular differences in potato seedlings cultured between autoclaved and CD-sterilized medium. In addition to this, CD-sterilized medium induced potato microtuber formation at a similar rate as autoclaved medium. In summary, using CD to sterilize potato medium and vessels did not compromise the growth of seedlings and microtuber induction. This study provides an economical and simplified sterilization method for media used to culture potato plantlets, and this can improve energy use of the large-scale tissue culture industry.

Microwave heating extraction of pectin from lime peel: Characterization and properties compared with the conventional heating method.

Microwave and conventional heating methods were used to extract pectin from lime peel waste using different acid extractants (hydrochloric or citric acid) and peel-to-extractant ratios (1:20 or 1:40). Hydrochloric acid as the extractant resulted in a higher yield of pectin with both methods. The methoxyl content and galacturonic acid content of lime peel pectin were in the range 8.74-10.51% and 79.29-95.93%, respectively. The intense band around 1730 cm-1 corresponded to methyl esterified uronic carboxyl groups and confirmed the higher equivalent weight and degree of esterification for the microwave-extracted pectin than that from conventional extraction. Lime peel pectin could be classified as high methoxyl pectin having a rapid-set gel formation. The viscosity and viscoelastic properties of the pectin solution from both heating methods enhanced with increasing solid concentration. Hence, microwave heating can be a short processing time for pectin extraction from lime peel waste with suitable pectin properties.

Response of the antioxidant enzymes of rats following oral administration of metal-oxide nanoparticles (Al2O3, CuO, TiO2).

Metal-oxide nanoparticles (NPs), as a new emerging technological compound, promise a wide range of usage areas and consequently have the potential to cause environmental toxicology. In the present work, aluminum (Al2O3), copper (CuO), and titanium (TiO2) nanoparticles (NPs) were administered via oral gavage to mature female rats (Rattus norvegicus var. albinos) for 14 days with a dose series of 0 (control), 0.5, 5, and 50 (mg/kg b.w./day). Enzyme activities of the antioxidant system such as catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione S-transferase (GST), and glutathione reductase (GR) in the liver were measured. Transmission electron microscope (TEM) images of the liver were taken to demonstrate NP accumulation and distribution in liver tissue. Data showed that all NPs caused some significant (P > 0.05) alterations in the activities of antioxidant enzymes. CAT activity increased after CuO and TiO2 administrations, while SOD activity decreased after Al2O3 administration. The activities of enzymes associated with glutathione (GR, GPx, GST) metabolisms were also significantly altered by NPs. GPx activity increased in rats received Al2O3, CuO NPs, while GR activity increased only by Al2O3. However, there were increases (TiO2) and decreases (CuO) in GST activity in the liver of rats. TEM images of the liver demonstrated that all NPs accumulated in the liver, even at the lowest dose. This study indicated that the antioxidant enzymes in the liver of rats were affected by all NPs, suggesting the antioxidant system of rats suffered after NP administration.

Extremely Thermoacidophilic Metallosphaera Species Mediate Mobilization and Oxidation of Vanadium and Molybdenum Oxides.

Certain species from the extremely thermoacidophilic genus Metallosphaera directly oxidize Fe(II) to Fe(III), which in turn catalyzes abiotic solubilization of copper from chalcopyrite to facilitate recovery of this valuable metal. In this process, the redox status of copper does not change as it is mobilized. Metallosphaera species can also catalyze the release of metals from ores with a change in the metal's redox state. For example, Metallosphaera sedula catalyzes the mobilization of uranium from the solid oxide U3O8, concomitant with the generation of soluble U(VI). Here, the mobilization of metals from solid oxides (V2O3, Cu2O, FeO, MnO, CoO, SnO, MoO2, Cr2O3, Ti2O3, and Rh2O3) was examined for M. sedula and M. prunae at 70°C and pH 2.0. Of these oxides, only V and Mo were solubilized, a process accelerated in the presence of FeCl3 However, it was not clear whether the solubilization and oxidation of these metals could be attributed entirely to an Fe-mediated indirect mechanism. Transcriptomic analysis for growth on molybdenum and vanadium oxides revealed transcriptional patterns not previously observed for growth on other energetic substrates (i.e., iron, chalcopyrite, organic compounds, reduced sulfur compounds, and molecular hydrogen). Of particular interest was the upregulation of Msed_1191, which encodes a Rieske cytochrome b6 fusion protein (Rcbf, referred to here as V/MoxA) that was not transcriptomically responsive during iron biooxidation. These results suggest that direct oxidation of V and Mo occurs, in addition to Fe-mediated oxidation, such that both direct and indirect mechanisms are involved in the mobilization of redox-active metals by Metallosphaera species.IMPORTANCE In order to effectively leverage extremely thermoacidophilic archaea for the microbially based solubilization of solid-phase metal substrates (e.g., sulfides and oxides), understanding the mechanisms by which these archaea solubilize metals is important. Physiological analysis of Metallosphaera species growth in the presence of molybdenum and vanadium oxides revealed an indirect mode of metal mobilization, catalyzed by iron cycling. However, since the mobilized metals exist in more than one oxidation state, they could potentially serve directly as energetic substrates. Transcriptomic response to molybdenum and vanadium oxides provided evidence for new biomolecules participating in direct metal biooxidation. The findings expand the knowledge on the physiological versatility of these extremely thermoacidophilic archaea.

A colorimetric assay for acetylcholinesterase activity and inhibitor screening based on the thiocholine-induced inhibition of the oxidative power of MnO2 nanosheets on 3,3',5,5'-tetramethylbenzidine.

The authors describe a colorimetric method for the determination of the activity of acetylcholinesterase (AChE). Manganese dioxide (MnO2) nanosheets directly reacts with 3,3',5,5'-tetramethylbenzidine (TMB) in the absence of hydrogen peroxide (H2O2). This leads to the formation of a blue product (oxTMB) with an absorption peak at 652 nm. If AChE hydrolyzes its substrate acetylthiocholine chloride, thiocholine is formed which blocks the oxidative power of the MnO2 nanosheets. Hence, oxTMB will not be formed. The decreased absorbance is directly related to the AChE activity in the 0.01-1.0 mU·mL-1 range. The detection limit is 0.01 mU·mL-1 and the relative standard deviation is 1.2% (for n = 11 at 0.5 mU·mL-1). The method was also applied to screen for inhibitors of AChE. Graphical abstract Based on the oxidizing properties of manganese dioxide nanosheets (MnO2 nanosheets), we report a colorimetric method for determining acetylcholinesterase activity with the chromogenic substrate 3,3',5,5'-tetramethylbenzidine (TMB).

Evaluation of lipid peroxidation and the level of some elements in rat erythrocytes during separate and combined vanadium and magnesium administration.

The impact of vanadium (V) and magnesium (Mg) as sodium metavanadate (SMV, 0.125 mg V/ml) and magnesium sulfate (MS, 0.06 mg Mg/ml) on lipid peroxidation (LPO) and selected elements in the rat erythrocytes (RBCs) was investigated. Relationships between some indices determined in RBC were also studied. SMV alone (Group II) elevated the malondialdehyde level (MDARBC) (by 95% and 60%), compared with the control (Group I) and MS-supplemented rats (Group III), respectively, reduced the concentration of CuRBC (by 23.5%), in comparison with Group I, but did not change the levels of NaRBC, KRBC, and CaRBC, whereas MS alone (Group III) only reduced the CuRBC concentration (by 22%), compared with Group I. The SMV + MS combination (Group IV) reduced and elevated the CuRBC (by 24%) and CaRBC (by 111%) concentrations, respectively, in comparison with Groups I and III, and these changes were induced by the V-Mg antagonistic and synergistic interaction, respectively. The combined SMV + MS effect also enhanced the MDARBC level, compared with Groups I (by 79%) and III (by 47%) and slightly limited its concentration, compared with Group II, which, in turn, resulted from the distinct trend toward the V-Mg antagonistic interaction. We can conclude that V (as SMV) is able to stimulate LPO in rat RBCs and that V-Mg interactive effects are involved in changes in CuRBC, CaRBC, and MDARBC. Further studies are needed to elucidate the exact mechanisms of the V-Mg antagonistic/synergistic interactions and to provide insight into the biochemical mechanisms of changes in rats suffering from anemia [1], characterized by a disrupted antioxidant barrier in RBCs [2] and an intensified free radical process in these cells.

Interaction of low frequency external electric fields and pancreatic ß-cell: a mathematical modeling approach to identify the influence of excitation parameters.

PURPOSE: Although the effect of electromagnetic fields on biological systems has attracted attraction in recent years, there has not been any conclusive result concerning the effects of interaction and the underlying mechanisms involved. Besides the complexity of biological systems, the parameters of the applied electromagnetic field have not been estimated in most of the experiments. MATERIALS AND METHODS: In this study, we have used computational approach in order to find the excitation parameters of an external electric field which produces sensible effects in the function of insulin secretory machinery, whose failure triggers the diabetes disease. A mathematical model of the human ß-cell has been used and the effects of external electric fields with different amplitudes, frequencies and wave shapes have been studied. RESULTS: The results from our simulations show that the external electric field can influence the membrane electrical activity and perhaps the insulin secretion when its amplitude exceeds a threshold value. Furthermore, our simulations reveal that different waveforms have distinct effects on the ß-cell membrane electrical activity and the characteristic features of the excitation like frequency would change the interaction mechanism. CONCLUSION: The results could help the researchers to investigate the possible role of the environmental electromagnetic fields on the promotion of diabetes disease.