Decrease In Enzyme Activity Research Articles

Abstract 4138698: Association of ALDH2*2 Variant with Increased HDL-Cholesterol Levels in East Asian Populations

Background: Mitochondrial aldehyde dehydrogenase 2 (ALDH2) is responsible for acetaldehyde metabolism with alcohol consumption. ALDH2 deficiency is a common enzymopathy – afflicting ~540 million East Asians. The ALDH2*2 variant, a missense mutation, significantly decreases enzyme activity. Recent studies suggest a potential link between ALDH2 deficiency and increased cardiovascular disease (CVD) risk. High-Density Lipoprotein cholesterol (HDL-C) is inversely associated with CVD and is known to increase with alcohol consumption. However, the impact of ALDH2*2 on HDL-C levels in East Asians remain unclear. Methods: Using the NIH All of Us cohort, we assessed HDL-C levels and reported alcohol consumption habits (never, < once/week, > once/week) at enrollment, as well as ALDH2 variant status among East Asian participants. Differences in HDL-C values were analyzed with Mann-Whitney U-tests. Results: Among 3,289 US Asian adults (age 46.8 ± 16.1 years; 58.8% female), median HDL-C was 54mg/dL [IQR 45, 67]. Of these, 2809 (85.4%) had wildtype ALDH2, and 480 (14.6%) had ALDH2*2 . Individuals with ALDH2*2 reported lower alcohol consumption (Figure A) but exhibited higher HDL-C levels (p=0.0002). The association was similar regardless of sex (Figure B). Conclusion: The ALDH2*2 variant is associated with higher HDL-C levels, despite lower alcohol consumption, indicating a possible independent influence on HDL-C levels. In the context of previous studies linking ALDH2 deficiency to adverse CVD outcomes, this suggests that ALDH2 may have a role independent of HDL-C levels, or it could affect HDL function rather than the HDL-C level itself.

Increased exercise tolerance in humanized G6PD deficient mice

Glucose-6-phosphate dehydrogenase (G6PD) deficiency affects 500 million people globally, impacting red blood cell (RBC) antioxidant pathways and increasing susceptibility to hemolysis under oxidative stress. Despite the systemic generation of reactive oxygen species during exercise, the effects of exercise on individuals with G6PD deficiency remain poorly understood This study utilized humanized mouse models expressing the G6PD Mediterranean variant (S188F, with 10% enzymatic activity) to investigate exercise performance and molecular outcomes. Surprisingly, despite decreased enzyme activity, G6PD-deficient mice have faster critical speed (CS) compared to mice expressing human canonical G6PD. Post-exercise, deficient mice did not exhibit differences in RBC morphology or hemolysis, but had improved cardiac function, including cardiac output, stroke volume, sarcomere length and mitochondrial content. Proteomics analyses of cardiac and skeletal muscles (gastrocnemius, soleus) from G6PD deficient compared to sufficient mice revealed improvements in mitochondrial function and increased protein turnover via ubiquitination, especially for mitochondrial and structural myofibrillar proteins. Mass spectrometry-based metabolomics revealed alterations in energy metabolism and fatty acid oxidation. These findings challenge the traditional assumptions regarding hemolytic risk during exercise in G6PD deficiency, suggesting a potential metabolic advantage in exercise performance for individuals carrying non-canonical G6PD variants.

Cis-3-Indoleacrylic Acid: A Nematicidal Compound from Streptomyces youssoufiensis YMF3.862 as V-ATPase Inhibitor on Meloidogyne incognita.

The application of the bionematicides derived from microorganisms and their secondary metabolites represents a promising strategy for managing root-knot nematodes. In this study, a nematicidal compound, cis-3-indoleacrylic acid, was isolated from Streptomyces youssoufiensis YMF3.862. This compound caused Meloidogyne incognita juveniles to have swollen bodies with apparent cracks on the cuticle surface. The LC50 value of cis-3-indoleacrylic acid against juveniles was 16.31 μg/mL 24 h of post-treatment. Cis-3-indoleacrylic acid at 20 μg/mL significantly inhibited V-ATPase expression and remarkably decreased enzyme activity by 84.41%. As an inhibitor of V-ATPase, cis-3-indoleacrylic acid caused significant H+ accumulation in nematode bodies, resulting in lower intracellular pH values and higher extracellular pH values of M. incognita. Application of 50 μg/mL cis-3-indoleacrylic acid generated a 71.06% control efficiency against M. incognita on tomatoes. The combination results of this study indicated that cis-3-indoleacrylic acid can be developed as a natural nematicide for controlling M. incognita.

The Impact of Heavy Metal Ions on Arginase Produced from Pseudomonas aeruginosa Isolated from Sewage

Background: Researchers remain captivated by the impact of heavy metal ions, commonly found in sewage, on arginase synthesis. Objective: The study examines the presence and characteristics of Pseudomonas aeruginosa in 24 sewage samples, identifying 18 isolates (75%). It assesses DNA concentration and purity, utilizes PCR-based methods for subtype analysis and investigates the inhibitory effects of heavy metals on purified enzymes. Methods: Between November 2022 and April 2023, 52 samples were collected from various sewage sites in Baghdad, Iraq. These samples were cultured in brain heart infusion broth and on nutrient agar plates. The isolates were then subjected to laboratory procedures, including biochemical tests, analysis with the Vitek2 system and PCR to identify Pseudomonas aeruginosa. Biochemical testing specifically focused on Pseudomonas aeruginosa. DNA extraction was performed on P.aeruginosa isolates from sewage, which had already been identified through morphological and biochemical tests as P.aeruginosa. This was accomplished by screening for the presence of the 16SrRNA gene using PCR. Result: Metal ion effects on L-arginase were tested at various concentrations (100mM, 50mM, 25mM, 12.5 mM). Metal ions were obtained via the cutting method and added 15 minutes before the substrate. Enzyme activity was measured and the activity ratio (enzyme activity with and without metal ions) calculated. Activity was assessed in the absence of 100% metal ions.Arginase isolated and purified from Pseudomonas aeruginosa from sewage, heavy metals (mercury, cadmium, cobalt) has effect on arginase, mercuric chloride and cadmium chloride inhibit and decrease enzyme activity, while Cobalt chloride increases enzyme activity.

B-237 Engineered Reverse Transcriptases and Taq DNA Polymerases deliver robust yield in the presence of clinically relevant inhibitors

Abstract Background The past five years has seen explosive growth in molecular diagnostic assays that rely on sensitive and accurate detection of nucleic acids across a wide range of sample types. As the assays are required to become increasingly sensitive, the need for highly functional and purpose-built enzymatic tools has grown. Reverse transcriptase (RT) and Taq DNA Polymerase (Taq DNAP) are commonly used to detect RNA and/or DNA viruses in patient samples for point of care (POC) diagnostics. However, crude patient samples introduce inhibitors that decrease enzyme activity and increase false negative results in POC testing. In addition, there is a need for faster turn-around time for patient diagnosis which can be enabled by engineering more active and sensitive Taq variants. Herein, we present on our engineered RT and Taq DNAP enzymes that were developed to confer greater activity, thermostability, inhibitor tolerance and/or sensitivity. Methods We take a 3-pronged approach to protein engineering: rational design, computational design and directed evolution. Using these techniques, we identified and characterized many RT and Taq DNAP variants. We deeply characterized each RT variant by measuring processivity, inhibitor tolerance and thermostability. First strand synthesis was done at temperatures from 42-65°C in the presence and absence of various clinically relevant inhibitors followed by qPCR to assess cDNA yield. Next, we characterized the inhibitor tolerance of the Taq variants by performing qPCR reactions in the presence of inhibitors. To determine if the Taq variant would be an appropriate fit for fast PCR, the polymerization activity of the Taq DNAP variants were characterized using a primer extension assay. Results Reverse transcriptases termed; StellarScript, StellarScript HT and StellarScript HT+ exhibit high processivity at 42°C. StellarScript HT+ exhibited the highest inhibitor tolerance, processivity and thermostability at temperatures up to 65°C thus making StellarScript HT+ well suited to produce high yields with clinical samples. Taq Pol variants were identified that efficiently amplify DNA in the presence of inhibitors. Conclusions Based on the increased polymerase activity and inhibitor tolerance, WMG Taq variants are well suited to give robust DNA yields with clinical samples. We were successful in engineering RT and Taq DNAP variants that are highly thermostable, active and inhibitor tolerant and thus will enable breakthroughs in existing POC diagnostics.

GhCASPL1 regulates secondary cell wall thickening in cotton fibers by stabilizing the cellulose synthase complex on the plasma membrane.

Cotton (Gossypium hirsutum) fibers are elongated single cells that rapidly accumulate cellulose during secondary cell wall (SCW) thickening, which requires cellulose synthase complex (CSC) activity. Here, we describe the CSC-interacting factor CASPARIAN STRIP MEMBRANE DOMAIN-LIKE1 (GhCASPL1), which contributes to SCW thickening by influencing CSC stability on the plasma membrane. GhCASPL1 is preferentially expressed in fiber cells during SCW biosynthesis and encodes a MARVEL domain protein. The ghcaspl1 ghcaspl2 mutant exhibited reduced plant height and produced mature fibers with fewer natural twists, lower tensile strength, and a thinner SCW compared to the wild type. Similarly, the Arabidopsis (Arabidopsis thaliana) caspl1 caspl2 double mutant showed a lower cellulose content and thinner cell walls in the stem vasculature than the wild type but normal plant morphology. Introducing the cotton gene GhCASPL1 successfully restored the reduced cellulose content of the Arabidopsis caspl1 caspl2 mutant. Detergent treatments, ultracentrifugation assays, and enzymatic assays showed that the CSC in the ghcaspl1 ghcaspl2 double mutant showed reduced membrane binding and decreased enzyme activity compared to the wild type. GhCASPL1 binds strongly to phosphatidic acid (PA), which is present in much higher amounts in thickening fiber cells compared to ovules and leaves. Mutating the PA-binding site in GhCASPL1 resulted in the loss of its colocalization with GhCesA8, and it failed to localize to the plasma membrane. PA may alter membrane structure to facilitate protein-protein interactions, suggesting that GhCASPL1 and PA collaboratively stabilize the CSC. Our findings shed light on CASPL functions and the molecular machinery behind SCW biosynthesis in cotton fibers.

Unraveling the Liver-Brain Axis: Resveratrol's Modulation of Key Enzymes in Stress-Related Anxiety.

Stress-related anxiety disorders and anxiety-like behavior in post-traumatic stress disorder (PTSD) are associated with altered neurocircuitry pathways, neurotransmitter systems, and the activities of monoamine and glucocorticoid-metabolizing enzymes. Resveratrol, a natural polyphenol, is recognized for its antioxidant, anti-inflammatory, and antipsychiatric properties. Previous studies suggest that resveratrol reduces anxiety-like behavior in animal PTSD models by downregulating key enzymes such as 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD-1) and monoamine oxidases (MAOs). However, the underlying mechanisms remain unclear. In this study, we explored the efficacy of resveratrol in treating stress-induced anxiety using a chronic predator stress model in rats. Resveratrol was administered intraperitoneally at 100 mg/kg following a 10-day stress exposure, and anxiety behavior was assessed with an elevated plus maze. Our results indicated that stress-related anxiety correlated with increased activities of brain MAO-A, MAO-B, and hepatic 11β-HSD-1, alongside elevated oxidative stress markers in the brain and liver. Resveratrol treatment improved anxiety behavior and decreased enzyme activities, oxidative stress, and hepatic damage. We demonstrate that resveratrol exerts antianxiogenic effects by modulating glucocorticoid and monoamine metabolism in the brain and liver. These findings suggest resveratrol's potential as a therapeutic agent for anxiety disorders, warranting further clinical investigation.

Bacterial Volatile Organic Compounds as a Strategy to Increase Drought Tolerance in Maize (Zea mays L.): Influence on Plant Biochemistry.

Maize is highly susceptible to drought, which affects growth and yield. This study investigated how bacterial volatile organic compounds (BVOCs) affect maize drought tolerance. Drought reduced shoot size but increased root length, an adaptation for accessing deeper soil moisture. BVOCs from strain D12 significantly increased root length and shoot growth under drought conditions. Drought also altered root biochemistry, decreasing enzyme activity, and increased osmolyte levels. BVOCs from strains F11 and FS4-14 further increased osmolyte levels but did not protect membranes from oxidative damage, while BVOCs from strains D12 and D7 strains reduced osmolyte levels and cell damage. In shoots, drought increased the levels of osmolytes and oxidative stress markers. BVOCs from FS4-14 had minimal effects on shoot biochemistry. BVOCs from D12 and F11 partially restored metabolic activity but did not reduce cell damage. BVOCs from D7 reduced metabolic activity and cell damage. These results suggest that BVOCs can modulate the biochemical response of maize to drought, with some strains evidencing the potential to enhance drought tolerance.

Misprogramming of glucose metabolism impairs recovery of hippocampal slices from neuronal GLT-1 knockout mice and contributes to excitotoxic injury through mitochondrial superoxide production.

We have previously reported a failure of recovery of synaptic function in the CA1 region of acute hippocampal slices from mice with a conditional neuronal knockout (KO) of GLT-1 (EAAT2, Slc1A2) driven by synapsin-Cre (synGLT-1 KO). The failure of recovery of synaptic function is due to excitotoxic injury. We hypothesized that changes in mitochondrial metabolism contribute to the heightened vulnerability to excitotoxicity in the synGLT-1 KO mice. We found impaired flux of carbon from 13C-glucose into the tricarboxylic acid cycle in synGLT-1 KO cortical and hippocampal slices compared with wild-type (WT) slices. In addition, we found downregulation of the neuronal glucose transporter GLUT3 in both genotypes. Flux of carbon from [1,2-13C]acetate, thought to be astrocyte-specific, was increased in the synGLT-KO hippocampal slices but not cortical slices. Glycogen stores, predominantly localized to astrocytes, are rapidly depleted in slices after cutting, and are replenished during exvivo incubation. In the synGLT-1 KO, replenishment of glycogen stores during exvivo incubation was compromised. These results suggest both neuronal and astrocytic metabolic perturbations in the synGLT-1 KO slices. Supplementing incubation medium during recovery with 20 mM D-glucose normalized glycogen replenishment but had no effect on recovery of synaptic function. In contrast, 20 mM non-metabolizable L-glucose substantially improved recovery of synaptic function, suggesting that D-glucose metabolism contributes to the excitotoxic injury in the synGLT-1 KO slices. L-lactate substitution for D-glucose did not promote recovery of synaptic function, implicating mitochondrial metabolism. Consistent with this hypothesis, phosphorylation of pyruvate dehydrogenase, which decreases enzyme activity, was increased in WT slices during the recovery period, but not in synGLT-1 KO slices. Since metabolism of glucose by the mitochondrial electron transport chain is associated with superoxide production, we tested the effect of drugs that scavenge and prevent superoxide production. The superoxide dismutase/catalase mimic EUK-134 conferred complete protection and full recovery of synaptic function. A site-specific inhibitor of complex III superoxide production, S3QEL-2, was also protective, but inhibitors of NADPH oxidase were not. In summary, we find that the failure of recovery of synaptic function in hippocampal slices from the synGLT-1 KO mouse, previously shown to be due to excitotoxic injury, is caused by production of superoxide by mitochondrial metabolism.

Investigation of Enzyme Immobilization and Clogging Mechanisms in the Enzymatic Synthesis of Amoxicillin.

This study investigated the blocking mechanism of immobilized penicillin G acylase (PGA) during the enzymatic synthesis of amoxicillin. Laboratory observations revealed that the primary cause of clogging was the crystallization of the substrate and product on the enzyme surface. Adjusting key parameters can significantly reduce clogging and improve catalytic efficiency. Methanol can decrease enzyme activity, but isopropyl alcohol cleaners can effectively remove clogs and protect enzyme activity. These findings provide an experimental foundation for optimizing the PGA immobilization process, which is crucial for achieving high efficiency and sustainability in industrial production.

Influence of Selected Natural Antioxidants on Iron-Induced Enzymatic Alterations Related to Oxidative Stress

Iron is required in various biological processes of the cell, but excess iron causes oxidative stress. Oxidative stress can be prevented by antioxidants with free radical scavenging properties. Tannic acid and gallic acid are phenolic compounds with antioxidant properties found naturally in plants. In this study, the effects of gallic acid and tannic acid on iron-induced oxidative stress parameters were investigated in a fruit fly model. Effect of the compounds against iron-induced oxidative stress were evaluated by determining spectrophotometrically superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and acetylcholinesterase (AChE) enzyme activities, and levels of reduced glutathione (GSH) and malondialdehyde (MDA) in larvae (n: 10) and adults (n: 20) of wild type Oregon R strain of Drosophila melanogaster. Iron treatment decreased enzyme activities and GSH levels, but increased MDA levels. Co-treatment of these compounds with iron ameliorated iron-induced changes, especially in larvae. On the other hand, iron-induced decrease in AChE activity was increased in adults by treatment of these compounds with iron. The results showed that natural phenolic compounds have the potential to ameliorate iron-induced changes in oxidative stress parameters.

Episodic Hyponatremia in Acute Intermittent Porphyria: A Case Report

Background: Acute intermittent porphyria (AIP) is an uncommon, ubiquitously distributed autosomal dominant disorder with low penetrance characterized by decreased enzyme activity of hydroxymethylbilane synthase (HMBS) an enzyme of heme synthesis pathway. It is often an elusive diagnosis due to rarity and non-specific signs and symptoms. Case report: A 28 years old female from Nawalparasi (district in central Nepal) presented with history of recurrent episodes of abdominal pain and vomiting. Her current episode began two weeks before presentation to our center. Abdominal pain was diffuse, colicky in nature without exacerbating or relieving factor. There was no postural or diurnal variation. On examination, there was no tenderness and abdominal examination findings were unremarkable. Her biochemical investigations were unremarkable except for severe hyponatremia (S. Na of 100mmol/L) which was SIADH/SIADH like presentation (Table 1 and Table 2). Severe episodic hyponatremia, port-wine color of urine, gastrointestinal symptoms and previous hospital stay two years back with similar episode of hyponatremia and abdominal pain were valuable clues for suspicion of acute porphyria. On further evaluation, patient was found to have presence of porphyrogenic precursors in urine and diagnosis of acute intermittent porphyria was confirmed. After diagnosis, she was managed conservatively with carbohydrate loading with intravenous dextrose, opioids and pregabalin as analgesics. Her symptoms gradually improved, hyponatremia subsided and was discharged in normal condition. Conclusion: Acute intermittent porphyria has signs and symptoms common to several clinical, neurological, psychiatric and gastroenterological pathologies, which complicate diagnosis. In young patients with hyponatremia (with SIADH –like picture), AIP should be considered in differential diagnosis.

Effects of Dietary Supplementation of Bile Acids on Growth, Glucose Metabolism, and Intestinal Health of Spotted Seabass (Lateolabrax maculatus).

An 8-week feeding trial was performed to investigate the effects of dietary bile acids on growth, glucose metabolism, and intestinal health in spotted seabass (Lateolabrax maculatus) reared at high temperatures (33 °C). The fish (20.09 ± 1.12 g) were fed diets supplemented with bile acids: 0 (Con), 400 (BA400), 800 (BA800), and 1200 (BA1200) mg/kg, respectively. The results showed that the growth was promoted in fish at the BA800 treatment compared with the control (p < 0.05). Increased enzyme activities and transcripts of gluconeogenesis in the liver were observed, whereas decreased enzyme activities and transcripts of glycolysis, as well as glycogen content, were shown in the BA800 treatment (p < 0.05). The transcripts of bile acid receptors fxr in the liver were up-regulated in the BA800 treatment (p < 0.05). A bile acid supplementation of 800 mg/kg improved the morphological structure in the intestine. Meanwhile, intestinal antioxidant physiology and activities of lipase and trypsin were enhanced in the BA800 treatment. The transcripts of genes and immunofluorescence intensity related to pro-inflammation cytokines (il-1β, il-8, and tnf-α) were inhibited, while those of genes related to anti-inflammation (il-10 and tgf-β) were induced in the BA800 treatment. Furthermore, transcripts of genes related to the NF-κB pathway in the intestine (nfκb, ikkα, ikkβ, and ikbα1) were down-regulated in the BA800 treatment. This study demonstrates that a dietary bile acid supplementation of 800 mg/kg could promote growth, improve glucose metabolism in the liver, and enhance intestinal health by increasing digestive enzyme activity and antioxidant capacity and inhibiting inflammatory response in L. maculatus.

The combination of Schisandrin C and Luteolin synergistically attenuates hepatitis B virus infection via repressing HBV replication and promoting cGAS-STING pathway activation in macrophages.

HBV infection can result in severe liver diseases and is one of the primary causes of liver cell carcinoma-related mortality. Liuwei Wuling tablet (LWWL) is a traditional Chinese medicine formula, with a protecting liver and decreasing enzyme activity, usually used to treat chronic hepatitis B with NAs in clinic. However, its main active ingredients and mechanism of action have not been fully investigated. Hence, we aimed to screen the active ingredient and effective ingredient combinations from Liuwei Wuling tablet to explore the anti-herpatitis B virus activity and mechanism. Analysis and screening of effective antiviral components in LWWL by network pharmacology, luteolin (Lut) may be a compound with significant antiviral activity. The mechanism of antiviral action of Lut was also found by real-time PCR detection and western blotting. Meanwhile, we established a co-culture model to investigate the antiviral mechanism of Schisandrin C (SC), one of the main active components of Schisandra chinensis fructus (the sovereign drug of LWWL). Next, HBV-infected mice were established by tail vein injection of pAAV-HBV1.2 plasmid and administered continuously for 20days. And their antiviral capacity was evaluated by checking serum levels of HBsAg, HBeAg, levels of HBV DNA, and liver levels of HBcAg. In this study, we conducted network pharmacology analysis on LWWL, and through in vitro experimental validation and data analysis, we found that luteolin (Lut) possessed obviously anti-HBV activity, inhibiting HBV replication by downregulating hepatocyte nuclear factor 4α (HNF4α) via the ERK pathway. Additionally, we established a co-culture system and proved that SC promoted activation of cGAS-STINIG pathway and IFN-β production in THP-1 cells to inhibit HBV replication in HepG2.2.15 cells. Moreover, we found the combination of SC and Lut shows a greater effect in inhibiting HBV compared to SC or Lut alone in HBV-infected mice. Taken together, our study suggests that combination of SC and Lut may be potential candidate drug for the prevention and treatment of chronic hepatitis B.

Protective Effect of Salvia cadmica on Fibroblast Cells from t-bhp-induced Oxidative Damage

Background:: Salvia species known as "Sage" are among the important aromatic plants used in the world. This study, it was investigated the antioxidant capacity of Salvia cadmica and to investigate its protective effect on oxidative damage in t-BHP-induced fibroblast cells. Methods:: Antioxidant activity and phenolic characterization of the extract were evaluated using DPPH, TPC, TFC, FRAP, and HPLC, respectively.TAS, TOS, MDA and 8-oxo-guanine, CAT, SOD, and GPx values were examined using enzyme-linked immunosorbent assay (ELISA). The antiproliferative and apoptosis effects of Salvia cadmica ethanolic extract were determined using XTT assay and fluorescent probes in fibroblast cells. Results:: As a result of GC-MS analysis of Salvia cadmica ethanolic extract, carvacrol content was found to be high. The IC50 value of the DPPH antioxidant assay of the Salvia cadmica ethanolic extract was 80 ± 0.51 μg/mL. TPC, TFC, and FRAP values were found to be 18.25 ± 0.64 (mg gallic acid/g powder), 1.691±0.314 (mg quercetin /g powder), 31.5 ± 0.10 (mg Trolox/g powder), respectively. Total antioxidant and TOS values were found to be 0.383±0.033 (mmol Trolox Equ L-1), 16.31±0.71 (μmol H2O2 L-1) for 0.25 mg/mL, and 0.725±0.05 (mmol Trolox Equ L-1), 12.02 ±0.56 (μmol H2O2 L-1) for 0.5 mg/mL. In addition, while CAT and GPx significantly decreased enzyme activities, no significant change was observed in SOD enzyme activity. Ethanolic Salvia cadmica extract exhibited apoptotic features compared to only the t-BHP group. Conclusion:: These results suggest that Salvica cadmica extract works through a free radical mechanism.

In vitro and in silico studies of the potential cytotoxic, antioxidant, and HMG CoA reductase inhibitory effects of chitin from Indonesia mangrove crab (Scylla serrata) shells

This study aimed to characterize chitin extracted from Indonesia mangrove crab (Scylla serrata) shells, as well as to assess its in vitro cytotoxic, antioxidant, and HMG CoA reductase inhibitory potentials. In silico molecular docking, molecular dynamic, and ADMET prediction analyses were also carried out. Chitin was extracted from mangrove crab shells using deproteination and demineralization processes, Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) characterization are then performed. The MTT method was further tested in a study of cell viability, while in vitro method was used to assess HMG CoA reductase inhibitory and antioxidant activities. The extracted chitin was found to have a moderate level of cytotoxic and antioxidant activities. In vitro studies showed that it has an IC50 of 36,65 ± 0,082 μg/mL as an HMG CoA reductase inhibitor, and decreased enzyme activity by 68.733 % at 100 μg/mL as a concentration. Furthermore, in the in silico study, chitin showed a strong affinity to several targets, including HMG CoA reductase, HMG synthase, LDL receptor, PPAR-alfa, and HCAR-2 with binding energies of −5.7; −5.8; −3.6; −5.6; −4.6 kcal/mol, respectively. Based on the ADMET properties, it had non-toxic molecules, which were absorbed and distributed across the blood-brain barrier. The molecular dynamics (MD) simulation also showed that it remained stable in the active sites of HMG CoA reductase receptor for 100 ns. These results indicated that chitin from Indonesian mangrove crab shells can be used to develop more potent HMG CoA reductase inhibitor with antioxidant and cytotoxic activities for effective dyslipidemia therapy.

The effect of chelating agents on the Zn-phytoextraction potential of hemp and soil microbial activity

BackgroundHemp (Cannabis sativa) is a crop with a wide range of uses, from the production of fiber and seeds to the secondary metabolites for medicinal purposes. In addition, it is characterized by high biomass yield and the ability to accumulate heavy metals, which makes this plant convenient for phytoremediation purposes. In this study, the effect of applying exogenous biodegradable chelating agents, citric acid (CA) and nitrilotriacetic acid (NTA), to zinc-contaminated soil on zinc (Zn) uptake by two industrial hemp varieties ‘Felina 32’ and ‘Monoica’ was studied. The effect of CA and NTA on available Zn in soils was investigated using an ‘in pot’ experiment under controlled conditions. The effect of both tested compounds on soil microbial activity was simultaneously evaluated.ResultsAfter the application of NTA at a concentration of 5 mmol L−1, a > threefold increased accumulation of Zn in the above-ground parts was recorded in the ‘Felina 32’ variety. In the ‘Monoica’ variety, the levels of Zn in the above-ground parts were increased > twofold. NTA affected the soil microbiome negatively, causing decreased enzyme activity (in ‘Monoica’ planted soil) and induced respiration (in ‘Monoica’ and especially in ‘Felina 32’ planted soil). On the other hand, CA application did not lead to significantly increased Zn levels in any of the studied hemp varieties. Together with CA’s negative effects on some soil enzymes, CA enhanced urease activity, dehydrogenase and several respiration types for the ‘Felina 32’ variety and exerted less detrimental effect on the soil microbiome. No toxic effects from increased Zn uptake and accumulation in experimental plants were detected, accounting for the unchanged physiological stress markers (levels of photosynthetic pigments and proline in leaves, chlorophyll fluorescence parameters) and selected growth traits of the above-ground organs and root system.ConclusionsFrom the studied varieties, ‘Felina 32’ seems to be more suitable for Zn-phytoextraction because of its higher tolerance to increased Zn levels, higher biomass production and Zn accumulation capacity. Our results indicate the potential of using the ‘Felina 32’ variety in NTA-assisted Zn phytoextraction from contaminated soils.Graphical

Investigation of inhibitory effect of sulfated chitosan oligomer on human heparanase enzyme: in silico and in vitro studies

Deaths from cancer are widespread worldwide and the numbers continue to increase day by day. During the disease progression of cancer in cells, many of its metabolic activities change. Increased heparanase enzyme release is just one example. Following heparanase enzyme activity, many molecules interact with the remodeling of glycosaminoglycan structures, which triggers the release of different enzymes, cytokines, and growth factors, including fibroblast growth factors (FGF1 and FGF2), vascular endothelial growth factor (VEGF), hepatocyte growth factor, transforming growth factor β and platelet-derived growth factor. These are the most important factors in metastasis due to the formation of new vascular structures caused by those elements. To reduce tumor growth and metastasis, various drugs have been designed by modifying chitosan and its derivatives. In this study, we used chitosan oligomer (A), sulfated chitosan oligomer (ShCsO) (B), heparin (C), phosphate monomer (D1) of PI-88 and sulfate monomer (D2) of PI-88 as heparanase inhibitors. We modified the chitosan oligomer with chlorosulfonic acid to synthesize ShCsO to investigate its inhibitory effects on human serum heparanase. Also examined were molecular docking; molecular dynamics (MD); adsorption, distribution, metabolism, elimination and toxicity (ADMET); and target prediction. ShCsO decreased enzyme activity at a concentration of 0.0001 mg/mL. The docking scores of A, B and C from in silico studies were −6.254, −6.936 and −6.980 kcal/mol, respectively, and the scores for the two different PI-88 monomers were −5.741 and −5.824 kcal/mol. These results show that ShCsO may be a potential drug candidate for treating cancer. Communicated by Ramaswamy H. Sarma

THE EFFECT OF CYP2D6 INHIBITORS ON THE THERAPEUTIC EFFICACY OF TAMOXIFENE: LITERATURE REVIEW

INTRODUCTION: Tamoxifen is a selective estrogen receptor modulator and is used to reduce the risk of recurrence of malignant breast cancer, which leads to greater survival in women with this disease. The use of tamoxifen as an adjuvant dramatically decreases the risk of cancer-specific recurrence and mortality. This medication is more accurate than traditional chemotherapies, as there are fewer side effects than other chemotherapeutics. The transformation of tamoxifen initially takes place via hepatic cytochrome P450 into active metabolites. It occurs through the CYP2D6 enzyme, being the main enzyme that participates in the bioactivation of tamoxifen. Endoxifene plasma indices are influenced by the CYP2D6 genotype and the use of drugs that affect CYP2D6 activity. CYP2D6 inhibitors are a broad spectrum of drugs that decrease enzyme activity. OBJECTIVE: The aim of this work is to elucidate, through a literature review, the main drugs that inhibit CYP2D6 and how they influence the therapeutic effect of tamoxifen. METHODS: This present work is a documental, quantitative and literature review research, and for its accomplishment, searches were carried out in electronic databases in Scientific Electronic Library Online (Scielo), MEDLINE, Pubmed, Web Of platforms Science, Science Direct, World Wide Science in a period of six months, using articles that were published during the years 2010 to 2020. RESULTS: The use of drugs that inhibit the CYP2D6 enzyme can be potentially harmful to patients who use tamoxifen in their treatment, causing a decrease in therapeutic efficacy and making it difficult to cure the disease. CONCLUSION: There are several drugs that affect therapeutic efficacy through inhibition of the CYP2D6 enzyme, requiring care and careful observation by health professionals, so that future errors can be avoided. Literature proves that interactions affect the quality of treatment of patients with breast cancer, being able to harm the health of these individuals.

In vitro inhibitory effect of five natural sweeteners on α-glucosidase and α-amylase.

A promising and efficacious approach to manage diabetes is inhibiting α-glucosidase and α-amylase activity. Therefore, the inhibitory activities of five natural sweeteners (mogrosides (Mog), stevioside (Ste), glycyrrhizinic acid (GA), crude trilobatin (CT), and crude rubusoside (CR)) against α-glucosidase and α-amylase and their interactions were evaluated in vitro using enzyme kinetics, fluorescence spectroscopy, Fourier infrared spectroscopy, and molecular docking. The inhibitor sequence was CT > GA > Ste, as GA competitively inhibited α-glycosidase activity while CT and Ste exhibited mixed inhibitory effects. Compared to a positive control acarbose, the inhibitory activity of CT was higher. For α-amylase, the mixed inhibitors CT, CR, and Mog and the competitive inhibitor Ste effectively inhibited the enzyme, with the following order: CT > CR > Ste > Mog; nevertheless, the inhibitors were slightly inferior to acarbose. Three-dimensional fluorescence spectra depicted that GA, CT, and CR bound to the hydrophobic cavity of α-glucosidase or α-amylase and changed the polarity of the hydrophobic amino acid-based microenvironment and structure of the polypeptide chain backbone. Infrared spectroscopy revealed that GA, CT, and CR could disrupt the secondary structure of α-glucosidase or α-amylase, which decreased enzyme activity. GA, trilobatin and rubusoside bound to amino acid residues through hydrogen bonds and hydrophobic interactions, changing the conformation of enzyme molecules to decrease the enzymatic activity. Thus, CT, CR and GA exhibit promising inhibitory effects against α-glucosidase and α-amylase.