Constant light influences the circadian oscillations of circulatory lipid peroxidation, antioxidants and some biochemical variables in rats

Temporal oscillations of circulatory thiobarbituric acid reactive substances (TBARS), antioxidants such as reduced glutathione (GSH), superoxide dismutase (SOD), and catalase and glucose, cholesterol, total protein and aspartate transaminase (AST) were studied under LD (12:12 h) and constant light (LL) (500 lux) conditions after exposing the animal for 21 days. Advances in the acrophase of GSH, SOD, catalase, glucose, total protein and (AST) rhythms and delays in TBARS and cholesterol were found; amplitude and mesor values of these rhythms were found to be altered during constant light treatment. The above said circadian alterations during LL exposure may be due to (1) formation of photooxidants and stress mediated lipid peroxidation, suppression of melatonin (2) modulation of neuroendocrine and neurotransmitters rhythm (3) suppression of sleep - wake cycle (4) feeding and locomotion rhythm. The exact mechanism still remains to be explored and further research needed.     

Integration of LC/MS,NMR and Molecular Docking for Profiling of Bioactive Diterpenes from Euphorbia mauritanica L. with in Vitro Anti-SARS-CoV-2 Activity

In spite of tremendous efforts exerted in the management of COVID-19, the absence of specific treatments and the prevalence of delayed and long-term complications termed post-COVID syndrome still urged all concerned researchers to develop a potent inhibitor of SARS-Cov-2. The hydromethanolic extracts of different parts of E. mauritanica were in vitro screened for anti-SARS-Cov-2 activity. Then, using an integrated strategy of LC/MS/MS, molecular networking and NMR, the chemical profile of the active extract was determined. To determine the optimum target for these compounds, docking experiments of the active extract's identified compounds were conducted at several viral targets. The leaves extract showed the best inhibitory effect with IC₅₀ 8.231±0.04 μg/ml. The jatrophane diterpenes were provisionally annotated as the primary metabolites of the bioactive leaves extract based on multiplex of LC/MS/MS, molecular network, and NMR. In silico studies revealed the potentiality of the compounds in the most active extract to 3CLpro, where compound 20 showed the best binding affinity. Further attention should be paid to the isolation of various jatrophane diterpenes from Euphorbia and evaluating their effects on SARS-Cov-2 and its molecular targets.     

Secondary Metabolites Generated from Saussurea lappa and Ligusticum sinensis Essential Oils by Microwave-Assisted Hydrodistillation: in Silico Molecular Docking and in Vitro Antibacterial Efficacy

In the current study, both the essential oil composition and biological activity of Saussurea lappa and Ligusticum sinensis were investigated by means of microwave-assisted hydrodistillation (MAHD) and characterized by Gas chromatography/mass spectrometry (GC/MS), whereas the antimicrobial efficiency of MAHD essential oils was examined against four pathogens: Staphylococcus aureus, Escherichia coli, Aspergillus niger, and Candida albicans responsible for microbial infections. The goal was to spot synergy and a favorable method that gives essential oils to possibly use as alternatives to common antimicrobial agents for the treatment of bacterial infections using a microdilution assay. S. lappa's 21 compounds were characterized by MAHD extraction. Sesquiterpene lactones (39.7 % MAHD) represented the major components, followed by sesquiterpene dialdehyde (25.50 % MAHD), while L. sinensis's 14 compounds were identified by MAHD extraction. Tetrahydroisobenzofurans (72.94 % MAHD) was the predominant compound class. S. lappa essential oil collection showed the strongest antimicrobial activity with MIC values of 16 μg/ml against all pathogens tested, while L. sinensis showed strong antibacterial activity and moderate antifungal activity with MIC values of 32 μg/ml and 500 μg/ml, respectively. The principal components of both oils, (velleral, eremanthin and neocnidilide), were docked into the bacterial histidine kinase (HK) and the fungal heat shock protein 90 (Hsp90).     

A New Method for Mercury Removal

A method is desibed for the removal of mercury from solution by using the off-gas produced from aerobic cultures of Klebsiella pneumoniae M426. Cells growing in Hg-supplemented medium produced a black precipitate containing mercury and sulphur. The ratio of Hg:S was determined as ~1:1 by analysis using proton-induced X-ray emission, suggesting precipitation of HgS within the culture. The outlet gases produced by a mercury-unsupplemented aerated culture were bubbled into an external chamber supplemented with up to 10 mg HgCl₂/ml. A yellowish-white precipitate formed, corresponding to 99% removal of the mercury from solution within 120 min. Energy dispersive X-ray microanalysis showed that this metal precipitate consisted of mercury, carbon and sulphur. Formation of mercury carbonate was discounted since similar precipitation occurred at pH 2 and no oxygen was detected in the solid, which gave an X-ray powder pattern suggesting an amorphous material, with no evidence of HgS. Precipitation of mercury with a volatile organosulphur compound is suggested. Bio-precipitation of heavy metals by using culture off-gas is a useful approach because it can be used with concentrated or physiologically incompatible solutions. Since the metal precipitate is kept separate from the bacterial biomass, it can be managed independently.     

Temporal variations of lipid peroxidation products, antioxidants and liver marker enzymes in experimental hyperammonemic rats

Circadian variations of lipid peroxidation products: thiobarbituric acid and reactive substances (TBARS), antioxidants: reduced glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and liver marker enzymes such as transaminases (aspartate transaminase (AST) and alanine transaminase (ALT), alkaline phosphatase (ALP) and γ-Glutamyl transpeptidase (GGT) in circulation were analysed in control and ammonium chloride (AC) induced (100 mg/kg bodyweight) hyperammonemic rats. Elevated lipid peroxidation and liver marker enzymes (increased mesor of TBARS, AST, ALT, ALP and GGT) associated with decreased activities of antioxidants (decreased mesor of GPx, GSH, SOD and CAT) were found in hyperammonemic rats. Variations in acrophase, amplitude and r values were also found in between the control and hyperammonemic rats. These alterations clearly indicate that temporal liver marker enzymes and redox status are modulated during hyperammonemic conditions, which may also play a crucial role in disease development.     

Influences of Chronic Mild Stress Exposure on Motor,Non-Motor Impairments and Neurochemical Variables in Specific Brain Areas of MPTP/Probenecid Induced Neurotoxicity in Mice

Parkinson''s disease (PD) is regarded as a movement disorder mainly affecting the elderly population and occurs due to progressive loss of dopaminergic (DAergic) neurons in nigrostriatal pathway. Patients suffer from non-motor symptoms (NMS) such as depression, anxiety, fatigue and sleep disorders, which are not well focussed in PD research. Depression in PD is a predominant /complex symptom and its pathology lies exterior to the nigrostriatal system. The main aim of this study is to explore the causative or progressive effect of chronic mild stress (CMS), a paradigm developed as an animal model of depression in1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (25 mg/kg. body wt.) with probenecid (250 mg/kg, s.c.) (MPTP/p) induced mice model of PD. After ten i.p. injections (once in 3.5 days for 5 weeks) of MPTP/p or exposure to CMS for 4 weeks, the behavioural (motor and non-motor) impairments, levels and expressions of dopamine (DA), serotonin (5-HT), DAergic markers such as tyrosine hydroxylase (TH), dopamine transporter (DAT), vesicular monoamine transporters—2 (VMAT 2) and α-synuclein in nigrostriatal (striatum (ST) and substantia nigra (SN)) and extra-nigrostriatal (hippocampus, cortex and cerebellum) tissues were analysed. Significantly decreased DA and 5-HT levels, TH, DAT and VMAT 2 expressions and increased motor deficits, anhedonia-like behaviour and α-synuclein expression were found in MPTP/p treated mice. Pre and/or post exposure of CMS to MPTP/p mice further enhanced the MPTP/p induced DA and 5-HT depletion, behaviour abnormalities and protein expressions. Our results could strongly confirm that the exposure of stress after MPTP/p injections worsens the symptoms and neurochemicals status of PD.     

Application of Box-Behnken Design to Hybrid Electrokinetic-Adsorption Removal of Mercury from Contaminated Saline-Sodic Clay Soil

A hybrid electrokinetic-adsorption (HEKA) technique using uniform electric field and granular activated carbon (GAC) produced from date palm pits was investigated for the removal of mercury from natural saline-sodic clay heavily contaminated with heavy metals, phenol, and kerosene. Response surface methodology (RSM) was employed to model, optimize, and interpret the results obtained with the aid of Design Expert software. According to the Box-Behnken experimental design, 15 experiments were conducted each with residence time of three weeks. The effects of voltage gradient (0.2–1 V/cm), initial Hg concentration (mg/Kg), and polarity reversal interval (0-48 hours) on Hg removal efficiency and energy consumed for Hg removal were investigated. Respectively, the responses fitted reduced cubic (R² = 99.3%) and quadratic models (R² = 92.3%) with the overall relative contributions of the investigated parameters on the responses following the order: voltage gradient > initial Hg concentration > polarity reversal interval based on analysis of variance (ANOVA). The optimal conditions obtained with desirability of 90% aimed at maximizing Hg removal were 24 hours polarity reversal interval, 0.2 V/cm voltage gradient, and 100 mg/kg initial Hg concentration. This optimum operating condition yielded good removal of Hg (99.5%) at reduced energy consumption of 50.1kWh.m^?3mg^?1. Experimental validation of the models showed good prediction of Hg removal efficiency (0.0368% prediction error). The results presented herein suggest that HEKA technology could be utilized effectively for the removal of Hg from contaminated, low permeable soils under extreme soil and contamination conditions.     

Molecular Dynamics Analysis of a Novel β3 Pro189Ser Mutation in a Patient with Glanzmann Thrombasthenia Differentially Affecting αIIbβ3 and αvβ3 Expression

Mutations in ITGA2B and ITGB3 cause Glanzmann thrombasthenia, an inherited bleeding disorder in which platelets fail to aggregate when stimulated. Whereas an absence of expression or qualitative defects of αIIbβ3 mainly affect platelets and megakaryocytes, αvβ3 has a widespread tissue distribution. Little is known of how amino acid substitutions of β3 comparatively affect the expression and structure of both integrins. We now report computer modelling including molecular dynamics simulations of extracellular head domains of αIIbβ3 and αvβ3 to determine the role of a novel β3 Pro189Ser (P163S in the mature protein) substitution that abrogates αIIbβ3 expression in platelets while allowing synthesis of αvβ3. Transfection of wild-type and mutated integrins in CHO cells confirmed that only αvβ3 surface expression was maintained. Modeling initially confirmed that replacement of αIIb by αv in the dimer results in a significant decrease in surface contacts at the subunit interface. For αIIbβ3, the presence of β3S163 specifically displaces an α-helix starting at position 259 and interacting with β3R261 while there is a moderate 11% increase in intra-subunit H-bonds and a very weak decrease in the global H-bond network. In contrast, for αvβ3, S163 has different effects with β3R261 coming deeper into the propeller with a 43% increase in intra-subunit H-bonds but with little effect on the global H-bond network. Compared to the WT integrins, the P163S mutation induces a small increase in the inter-subunit fluctuations for αIIbβ3 but a more rigid structure for αvβ3. Overall, this mutation stabilizes αvβ3 despite preventing αIIbβ3 expression.     

Multiplexed echo planar imaging for sub-second whole brain FMRI and fast diffusion imaging

Echo planar imaging (EPI) is an MRI technique of particular value to neuroscience, with its use for virtually all functional MRI (fMRI) and diffusion imaging of fiber connections in the human brain. EPI generates a single 2D image in a fraction of a second; however, it requires 2-3 seconds to acquire multi-slice whole brain coverage for fMRI and even longer for diffusion imaging. Here we report on a large reduction in EPI whole brain scan time at 3 and 7 Tesla, without significantly sacrificing spatial resolution, and while gaining functional sensitivity. The multiplexed-EPI (M-EPI) pulse sequence combines two forms of multiplexing: temporal multiplexing (m) utilizing simultaneous echo refocused (SIR) EPI and spatial multiplexing (n) with multibanded RF pulses (MB) to achieve m×n images in an EPI echo train instead of the normal single image. This resulted in an unprecedented reduction in EPI scan time for whole brain fMRI performed at 3 Tesla, permitting TRs of 400 ms and 800 ms compared to a more conventional 2.5 sec TR, and 2-4 times reductions in scan time for HARDI imaging of neuronal fibertracks. The simultaneous SE refocusing of SIR imaging at 7 Tesla advantageously reduced SAR by using fewer RF refocusing pulses and by shifting fat signal out of the image plane so that fat suppression pulses were not required. In preliminary studies of resting state functional networks identified through independent component analysis, the 6-fold higher sampling rate increased the peak functional sensitivity by 60%. The novel M-EPI pulse sequence resulted in a significantly increased temporal resolution for whole brain fMRI, and as such, this new methodology can be used for studying non-stationarity in networks and generally for expanding and enriching the functional information.