Rivastigmine-loaded in situ gelling nanostructured lipid carriers for nose to brain delivery.

In the current research work, rivastigmine (RV)-loaded in situ gelling nanostructured lipid carriers (NLCs) were developed for nose to brain delivery. NLCs were fabricated by ethanol injection method using glyceryl monosterate, Capmul MCM C8, Lecithin and Tween 80. NLCs showed average particle size of 123.2 ± 2.3 nm with entrapment efficiency of 68.34 ± 3.4%. DSC, XRD and IR studies showed complete amorphization and incorporation of the drug into nanoparticles. NLCs were incorporated into an in situ gelling system using 0.8% gellan gum and 15% Lutrol F 127. RV in situ gel showed excellent elasticity, rheology, mucoadhesion and adhesiveness to facilitate its adhesion to the upper nasal mucosa. NLC-based in situ gel showed a 2-fold increase in nasal permeation of the drug over plain RV solution. In situ gelling NLCs showed a 3-fold increase in enzyme inhibition efficacy.

Morphological and physiological changes in esterase and lipid peroxidation of two bean cultivars pre-soaked with potassium nitrate under salt stress.

Two broad bean cultivars (Vicia faba CV Nobaria3 and Vicia faba CV Sakha3) were obtained from Mallwi Agriculture Research Center, El Minia Governorate, Egypt. The seeds were divided into two groups, the first group soaked with distilled water, while the second group were soaked with 3 mM KNO3, respectively, for 4 hours. Seeds were sown and left to grow for 3 weeks then treated with different concentrations of NaCl (0.0, 40, 80, 120 and 160 mM) by top irrigation, then they left to grow further for 65 days from sowing. Plant samples were collected for some measurements: leaf area, plant height, root length, fresh and dry weight, photosynthetic pigments, carotenoids, soluble sugars, soluble proteins, total free amino acids, esterase enzyme, as well as MDA (malondialdehyde) content. Salinity reduced both fresh and dry weight in two broad bean cultivars, this reduction were more pronounced in Sakha3 than Nobaria3. Seed pre-soaking with KNO3resulted in enhancement of fresh and dry weight production in both cultivars especially at 40 mM NaCl. Photosynthetic pigments were substantially affected by salt treatment while the carotenoids were increased, seed pre-soaking with KNO3improved these components. The soluble sugars, amino acids as well as soluble proteins showed various responses with increasing salinity in the cultivars, seed pre-soaking with KNO3has improved these parameters to some extent. The shoots of two cultivars exhibited significant accumulation of MDA, compared to roots exposed to the highest salinity levels. Pre-soaking seeds with KNO3did not improve MDA in shoots but enhanced it in roots, however, in most cases still lower than the absolute control. The assessment of the esterase isozyme profiles on 7.5% native polyacrylamide gel revealed the presence of 13 isoforms in two faba bean plants in response to KNO3pre-soaking and treatments with different concentrations of NaCl.

Development of Rhizophora mangle (Rhizophoraceae) and Avicennia schaueriana (Avicenniaceae) in the presence of a hydrocarbon-degrading bacterial consortium and marine diesel oil.

The development of Rhizophora mangle and Avicennia schaueriana seedlings impacted by marine diesel oil (MDO) was evaluated in the presence or absence of a hydrocarbon-degrading bacterial consortium (HBC). The bioassays were conducted in a greenhouse during 6 months and consisted of three different treatments (control, MDO only and MDO + HBC). The bacterial consortium was mainly composed of Bacillus spp. (73%), but Rhizobium spp., Pseudomonas spp., Ochrobactrum spp., and Brevundimonas spp. were also present. After 6 months, A. schaueriana seedlings showed higher mortality compared to those of R. mangle; R. mangle exhibited 68% (control), 44% (MDO alone) and 50% (MDO + HBC) seedlings survivorship compared to 42% (control), 0% (MDO alone) and 4% (MDO + HBC) for A. schaueriana. This variability may be due to differences in species physiology. Stem growth, diameter and number of leaves remained constant during the 6 months of the experiment with marine diesel oil and hydrocarbon-degrading bacterial consortium (MDO + BBC). For both mangrove species, bacterial enzymatic activity in the sediments was sufficient to maintain cell counts of 107 cells cm-3 in the rhizospheric soil and possibly synthetize the extracellular polymeric substances (EPS) that may emulsify and solubilize oil products.

Bioactive sulfonyl hydrazones with alkyl derivative: Characterization, ADME properties, molecular docking studies and investigation of inhibition on choline esterase enzymes for the diagnosis of Alzheimer's disease.

In this work, new sulfonylhydrazone compounds with alkyl derivatives (SH1- SH4 series) were synthesized via a green chemistry method, and their inhibition effects on acetylcholinesterase and butyrylcholinesterase (AChE, BChE) were determined in vitro. This work was designed in two stages; in the first stage, using compounds that contain both sulfonamide and hydrazine groups which have important pharmacological properties, a series of sulfonyl hydrazone with alkyl derivatives (SH1- SH4) were synthesized with a method that is less time-consuming and more environmentalist that was by using different substitute groups containing aldehyde and ketone compounds. The structures of the synthesized compounds were characterized by elemental analyses, 1H NMR, 13C NMR, FT-IR methods. In the second stage, the effects of the synthesized sulfonyl hydrazones with alkyl derivatives on acetylcholinesterase and butyrylcholinesterase enzymes were examined. According to the results, all the synthesized compounds inhibited AChE and BChE enzymes. When the IC50 values were compared, SH2-3 (IC50 = 5.27 ± 0.05 µM) and SH3-3 (IC50 = 12.29 ± 1.47 µM) compounds which are containing the butyl group have the best inhibition effect on the AChE enzyme and BChE enzyme, respectively. In addition, the predictive properties of all compounds in terms of drug similarity were scanned using five Lipinski rules and ADME estimations. In silico ADME studies play an important role in improving and predicting drug compounds. In the ADME study; The absorption, distribution, metabolism, elimination, and properties of the molecules given below were theoretically calculated. Also, to evaluate the binding interactions between the sulfonylhydrazone compounds and enzymes, molecular docking studies were performed and the compounds with the best inhibition effect SH2-3 (for AChE enzyme) and SH3-3 (for BChE enzyme) were tested. Both in vitro and silico the results showed that two compounds could act as potent inhibitors of AChE, BChE.

Impact of dietary lipid level on esterase enzyme activities in the non-target freshwater shrimp Macrobrachium borellii exposed to chlorpyrifos.

This study increases our understanding of how diet-driven phenotypic plasticity can help non-target aquatic invertebrates deal with chlorpyrifos (CPO) exposure. A bioassay was performed over 6 days with the freshwater shrimp Macrobrachium borellii. Experimental treatments included CPO-treated shrimps (10 µg L-1) were fed with (i) a lipid-rich diet, (ii) a lipid-medium diet, or (iii) a lipid-poor diet. Control shrimps (no CPO exposure) received the same diets as detailed above. Cholinesterases and carboxylesterases were determined as an indicator of CPO exposure. Results showed that diets with a medium-to-high lipid content were important inducers of esterase activity, while shrimps exposed to CPO under a lipid-poor diet showed a significant enzymatic inhibition. This diet-dependent esterase induction suggests that the intake of fatty dietary items mitigates the esterase enzyme inhibition caused by CPO exposure.

Pyramiding of cry toxins and methanol producing genes to increase insect resistance in cotton.

The idea of enhanced methanol production from cell wall by pectin methyl esterase enzymes (PME) combined with expression of cry genes from Bacillus thuringiensis as a strategy to improve insect pest control in cotton is presented. We constructed a cassette containing two cry genes (cry1Fa and Cry32Aa) and two pme genes, one from Arabidopsis thaliana (AtPME), and other from Aspergillus. niger (AnPME) in pCAMBIA1301 plant expression vector using CAMV-35S promoter. This construction was transformed in Eagle-2 cotton variety by using shoot apex-cut Agrobacterium-mediated transformation. Expression of cry genes and pme genes was confirmed by qPCR. Methanol production was measured in control and in the cry and pme transformed plants showing methanol production only in transformed plants, in contrast to the non-transgenic cotton plants. Finally, insect bioassays performed with transgenic plants expressing cry and pme genes showed 100% mortality for Helicoverpa armigera (cotton bollworm) larvae, 70% mortality for Pectinophora gossypiella (pink bollworm) larvae and 95% mortality of Earias fabia, (spotted bollworm) larvae, that was higher than the transgenic plants expressing only cry genes that showed 84%, 49% and 79% mortality, respectively. These results demonstrate that Bt. cry-genes coupled with pme genes are an effective strategy to improve the control of different insect pests.

Insight Into Microbial Applications for the Biodegradation of Pyrethroid Insecticides.

Pyrethroids are broad-spectrum insecticides and presence of chiral carbon differentiates among various forms of pyrethroids. Microbial approaches have emerged as a popular solution to counter pyrethroid toxicity to marine life and mammals. Bacterial and fungal strains can effectively degrade pyrethroids into non-toxic compounds. Different strains of bacteria and fungi such as Bacillus spp., Raoultella ornithinolytica, Psudomonas flourescens, Brevibacterium sp., Acinetobactor sp., Aspergillus sp., Candida sp., Trichoderma sp., and Candia spp., are used for the biodegradation of pyrethroids. Hydrolysis of ester bond by enzyme esterase/carboxyl esterase is the initial step in pyrethroid biodegradation. Esterase is found in bacteria, fungi, insect and mammalian liver microsome cells that indicates its hydrolysis ability in living cells. Biodegradation pattern and detected metabolites reveal microbial consumption of pyrethroids as carbon and nitrogen source. In this review, we aim to explore pyrethroid degrading strains, enzymes and metabolites produced by microbial strains. This review paper covers in-depth knowledge of pyrethroids and recommends possible solutions to minimize their environmental toxicity.

Acetylcholine esterase enzyme doped multiwalled carbon nanotubes for the detection of organophosphorus pesticide using cyclic voltammetry.

Use of immobilized acetylcholine esterase (AChE) for detecting organophosphorus pesticides in water sources and body fluids can bring down the detection costs dramatically. In the present study, AChE was directly doped on multiwalled carbon nanotube (MWCNT) surface modified with carboxylic groups through amide bond and used for organophosphorus pesticide detection. Amide bond formation between MWCNTs and the enzyme molecules avoid use of any intermediate membranes, cross-linkers or binding materials. This strategy overcomes the hindrance to electron transfer posed by membranes or cross-linkers and increases the sensitivity of detection. MWCNTs carrying carboxyl groups were deposited on glassy carbon electrode and were subsequently immobilized with AChE. The activity of AChE was monitored by cyclic voltammetry after immobilization. Scanning electron microscopy and atomic force microscopy were used to characterize the electrode surface. FT-IR spectra were taken to characterize enzyme-MWCNT complex. Under optimized parameters, the electrode showed linear range between 10 and 50 nM, which is promising for detection of trace amounts of the pesticide. The lower and higher detection limits of the sensor are 0.1 nM and 500 nM respectively. The stability and reusability of the electrode were determined. Finally, successful detection of organophosphorus compounds in real samples established it as reliable for sensor applications.

The effect of esterase enzyme on aging dental composites.

We measured the push-out and diametral tensile strength of dental restorative composites following aging under environmental conditions relevant to the oral cavity; air (A), artificial saliva (AS), acidified (50 mM CH3 COOH, pH = 4.7) artificial saliva (AS + HAc), and AS with esterase enzyme (AS + ENZ). Cylindrical test specimens (6.3 mm diameter by 5.1 mm long) were prepared by placing 0.3 g of nanofilled composite in an epoxy ring and cured. Twenty samples were aged in each environment for 163-186 days at 37°C. The push-out strengths (mean ± standard error of the mean [SEM], in MPa) for specimens were: A-2.4 ± 0.2, AS-7.3 ± 0.5, AS + HAc-7.2 ± 0.9, and AS + ENZ-6.0 ± 0.6. Following the push-out test, the diametral tensile strength and elasticity were immediately determined. The diametral tensile strengths (mean ± SEM, in MPa) for specimens were: A-54.0 ± 1.6, AS-31.4 ± 1.3, AS + HAc-34.3 ± 1.2, and AS + ENZ-22.5 ± 0.7. The push-out strength was lowest for the A environment due to shrinkage of the composite. The push-out strength increased significantly as water diffused into the specimens (AS and AS + HAc) but decreased significantly in the enzyme environment (AS + ENZ). The diametral tensile strength was highest for specimens in the A environment, which was significantly higher than both the AS and AS + HAc specimens and > 2× higher than the AS + ENZ specimens. The results indicated that a water environment (with or without acid) caused a significant decrease in the mechanical properties of this composite, but the greatest decrease was seen in water with esterase. This is the first study to demonstrate that esterase enzymes affect the bulk strength of a commonly used commercial dental composite. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2178-2184, 2019.

Evaluating the effects of allelochemical ferulic acid on Microcystis aeruginosa by pulse-amplitude-modulated (PAM) fluorometry and flow cytometry.

We investigated the effects of allelochemical ferulic acid (FA) on a series of physiological and biochemical processes of blue-green algae Microcystis aeruginosa, in order to find sensitive diagnostic variables for allelopathic effects. Algal cell density was significantly suppressed by FA (0.31-5.17 mM) only after 48 h exposure. Inhibitions of photosynthetic parameters (F(v)/F(m) and F(v)'/F(m)') occurred more rapidly than cell growth, and the stimulation of non-photochemical quenching was observed as a feed-back mechanisms induced by photosystem II blockage, determining by PAM fluorometry. Inhibitions on esterase activity, membrane potential and integrity, as well as disturbance on cell size, were all detected by flow cytometry with specific fluorescent markers, although exhibiting varied sensitivities. Membrane potential and esterase activity were identified as the most sensitive parameters (with relatively lower EC50 values), and responded more rapidly (significantly inhibited only after 8 h exposure) than photosynthetic parameters and cell growth, thus may be the primary responses of cyanobacteria to FA exposure. The use of PAM fluorometry and flow cytometry for rapid assessment of those sensitive variables may contribute to future mechanistic studies of allolepathic effects on phytoplankton.

Clonación, expresión y caracterización de una nueva esterasa derivada de metagenomas de suelos agrícolas colombianos / Cloning, expression and characterization of a novel esterase derived from colombian agricultural soils metagenomes

El presente trabajo tuvo como objetivo la bioprospección de ADN metagenómico derivado de comunidades microbianas asociadas a un agroecosistema de importancia nacional. Este análisis permitió realizar la producción, expresión, purificación y caracterización de una enzima novedosa con actividad esterasa. Esta enzima, denominada LipM, había sido previamente identificada en clones metagenómicos derivados de suelos dedicados al cultivo de papa criolla (Solanum pureja), mediante secuencia de nueva generación y análisis bioinformáticos. La secuencia codificante de la enzima fue clonada en el vector pBADgiii y expresada en E. coli como sistema de expresión, lo que permitió optimizar el proceso de producción recombinante y su posterior purificación. Funcionalmente la enzima presentó una mayor afinidad por sustratos de p-nitrofenil con ácidos grasos de cadena corta (

The present work had as a main objective to bioprospect metagenomic DNA from microbial communities associated with an agro-ecosystem of national importance. This analysis allowed the production, expression, purification and characterization of a novel enzyme with esterase activity. This enzyme, named here as LipM, was previously identified in metagenomic clones derived from soils dedicated to creole potato (Solanum pureja) crops by means of next-generation sequencing and bioinformatics analyses. The coding sequence of the enzyme was cloned into pBADgiii vector and expressed in E. coli as an expression system, allowing to optimize its recombinant production process and its further purification. The enzyme functionally showed a greater affinity for p-nitrophenyl substrates with short-chain fatty acids (