The impact of hydroquinone on acetylcholine esterase and certain human carbonic anhydrase isoenzymes (hCA I, II, IX, and XII).

AbstractCarbonic anhydrases (CAs) are widespread and the most studied members of a great family of metalloenzymes in higher vertebrates including humans. CAs were investigated for their inhibition of all of the catalytically active mammalian isozymes of the Zn2+-containing CA, (CA, EC 4.2.1.1). On the other hand, acetylcholinesterase (AChE. EC 3.1.1.7), a serine protease, is responsible for ACh hydrolysis and plays a fundamental role in impulse transmission by terminating the action of the neurotransmitter ACh at the cholinergic synapses and neuromuscular junction. In the present study, the inhibition effect of the hydroquinone (benzene-1,4-diol) on AChE activity was evaluated and effectively inhibited AChE with Ki of 1.22 nM. Also, hydroquinone strongly inhibited some human cytosolic CA isoenzymes (hCA I and II) and tumour-associated transmembrane isoforms (hCA IX, and XII), with Kis in the range between micromolar (415.81 μM) and nanomolar (706.79 nM). The best inhibition was observed in cytosolic CA II

The effects of some avermectins on bovine carbonic anhydrase enzyme

Avermectins are effective agricultural pesticides and antiparasitic agents that are widely employed in the agricultural, veterinary and medical fields. The aim of this study was to investigate the inhibitory effects of selected avermectins including abamectin, doramectin, emamectin, eprinomectin, ivermectin and moxidectin that are used as drugs against a wide variety of internal and external mammalian parasites, on the carbonic anhydrase enzyme (CA, EC 4.2.1.1.) purified from fresh bovine erythrocyte. CA catalyses the rapid interconversion of carbon dioxide (CO2) and water (H2O) to bicarbonate ([Formula: see text]) and protons (H(+)) and regulate the acidity of the local tissues. Bovine erythrocyte CA (bCA) enzyme was purified by Sepharose-4B affinity chromatography with a yield of 21.96% and 262.7-fold purification. The inhibition results obtained from this study showed Ki values of 9.73, 17.39, 20.43, 13.39, 16.44 and 17.73 nM for abamectin, doramectin, emamectin, eprinomectin, ivermectin and moxidectin, respectively. However, acetazolamide, well-known clinically established CA inhibitor, possessed a Ki value of 27.68 nM

The effect of caffeic acid phenethyl ester (CAPE) on metabolic enzymes including acetylcholinesterase, butyrylcholinesterase, glutathione S-transferase, lactoperoxidase, and carbonic anhydrase isoenzymes I, II, IX, and XII.

This work was financed in part by two EU projects of the 7th FP, Metoxia and Dynano. Also, IG and SE would like to extend his sincere appreciation to the Research Chairs Program at King Saud University for providing funding to this research

Synthesis and inhibitory properties of some carbamates on carbonic anhydrase and acetylcholine esterase

A series of carbamate derivatives were synthesized and their carbonic anhydrase I and II isoenzymes and acetylcholinesterase enzyme (AChE) inhibitory effects were investigated. All carbamates were synthesized from the corresponding carboxylic acids via the Curtius reactions of the acids with diphenyl phosphoryl azide followed by addition of benzyl alcohol. The carbamates were determined to be very good inhibitors against for AChE and hCA I, and II isoenzymes. AChE inhibition was determined in the range 0.209-0.291 nM. On the other hand, tacrine, which is used in the treatment of Alzheimer's disease possessed lower inhibition effect (Ki: 0.398 nM). Also, hCA I and II isoenzymes were effectively inhibited by the carbamates, with inhibition constants (Ki) in the range of 4.49-5.61 nM for hCA I, and 4.94-7.66 nM for hCA II, respectively. Acetazolamide, which was clinically used carbonic anhydrase (CA) inhibitor demonstrated Ki values of 281.33 nM for hCA I and 9.07 nM for hCA II. The results clearly showed that AChE and both CA isoenzymes were effectively inhibited by carbamates at the low nanomolar levels

Rosmarinic acid inhibits some metabolic enzymes including glutathione S-transferase, lactoperoxidase, acetylcholinesterase, butyrylcholinesterase and carbonic anhydrase isoenzymes

Rosmarinic acid (RA) is a natural polyphenol contained in many aromatic plants with promising biological activities. Carbonic anhydrases (CAs, EC 4.2.1.1) are widespread and intensively studied metalloenzymes present in higher vertebrates. Acetylcholinesterase (AChE, E.C. 3.1.1.7) is intimately associated with the normal neurotransmission by catalysing the hydrolysis of acetylcholine to acetate and choline and acts in combination with butyrylcholinesterase (BChE) to remove acetylcholine from the synaptic cleft. Lactoperoxidase (LPO) is an enzyme involved in fighting pathogenic microorganisms, whereas glutathione S-transferases (GSTs) are dimeric proteins present both in prokaryotic and in eukaryotic organisms and involved in cellular detoxification mechanisms. In the present study, the inhibition effects of rosmarinic acid on tumour-associated carbonic anhydrase IX and XII isoenzymes, AChE, BChE, LPO and GST enzymes were evaluated. Rosmarinic acid inhibited these enzymes with K(i)s in the range between micromolar to picomolar. The best inhibitory effect of rosmarinic acid was observed against both AChE and BChE

Synthesis of 4,5-disubstituted-2-thioxo-1,2,3,4-tetrahydropyrimidines and investigation of their acetylcholinesterase, butyrylcholinesterase, carbonic anhydrase I/II inhibitory and antioxidant activities.

A series of tetrahydropyrimidinethiones were synthesized from thiourea, β-diketones and aromatic aldehydes, such as p-tolualdehyde, p-anisaldehyde, o-tolualdehyde, salicylaldehyde and benzaldehyde. These cyclic thioureas showed good inhibitory action against acetylcholine esterase (AChE), butyrylcholine esterase (BChE), and human (h) carbonic anhydrase (CA) isoforms I and II. AChE and BChE inhibitions were in the range of 6.11-16.13 and 6.76-15.68 nM, respectively. hCA I and II were effectively inhibited by these compounds, with Ki values in the range of 47.40-76.06 nM for hCA I, and of 30.63-76.06 nM for hCA II, respectively. The antioxidant activity of the cyclic thioureas was investigated by using different in vitro antioxidant assays, including 1,1-diphenyl-2-picrylhydrazyl (DPPH·) radical scavenging, Cu2+ and Fe3+ reducing, and Fe2+ chelating activities

PCOS and inositols: controversial results and necessary clarifications. Basic differences between D-chiro and myo-inositol

Myo-Inositol (myo-Ins) and its phosphate derivatives—including inositol phosphates (InsPs), inositol pyrophosphates (IPPs) and phosphatidyl-inositol phosphate (PtdIns)—are credited to act as second messengers, which accumulate rapidly and transiently in response to external or endocrine signals, a phenomenon that allows signaling to be discrete and regulated (1, 2). Noticeably, inositol is involved in the transduction of several endocrine signals, including insulin (3, 4), thyroid hormones (5), gonadotropins (6), lipids with hormone-like activity (as prostaglandins) (7), and many other endocrine systems (8). Namely, in the last decade, a growing body of clinical and experimental research provided robust evidence about the efficiency of inositol in reversing a few clinical, metabolic, and endocrine features of the Polycystic Ovary Syndrome (PCOS). Myo-inositol, alone or in combination with its isomer D-Chiro-Inositol (D-Chiro-Ins), showed to exert a variable—albeit significant—effect in improving both symptoms and outcome in PCOS patients (9). Experimental and pilot clinical studies pointed out that a combination of both isomers could provide a reliable rationale for establishing a proper treatment strategy, as first suggested by Beemster’s seminal study (10, 11). However, the proper formula—i.e., the respective percentage of myo-Ins and D-Chiro-Ins—is still a matter of debate. In several cases, no conclusive insights can be obtained from clinical trials based on unclear rational design, limited number of recruited patients and variable formula composition and dosage(s). First, it is improper to compare clinical results from studies in which commercial nutraceutical formulas involve a wide range of concentrations (Table 1), with the myo-Ins/D-Chiro-Ins ratio varying implausibly from 0.4:1 to 104:1. Current commercial preparations also contain D-Chiro-Ins alone at concentrations reaching 600 mg that can be administered once or twice a day. Therefore, the daily dose of D-chiro-Ins, alone or with myo-Ins, ranges from low (less than 300 mg/die), medium (300–600 mg/die) and high (600–1,200 mg/die)

High-fat diet-induced aggravation of cardiovascular impairment in permethrin-treated Wistar rats.

This study characterized the impact of post-weaning high-fat diet (HFD) and/or permethrin (PER) treatment on heart dysfunction and fibrosis, as well as atherogenic risk, in rats by investigating interactions between HFD and PER. Our results revealed that HFD and/or PER induced remarkable cardiotoxicity by promoting cardiac injury, biomarker leakage into the plasma and altering heart rate and electrocardiogram pattern, as well as plasma ion levels. HFD and/or PER increased plasma total cholesterol, triacylglycerols, and low-density lipoprotein (LDL) cholesterol levels but significantly reduced high-density lipoprotein (HDL) cholesterol. Cardiac content of peroxidation malonaldehyde, protein carbonyls, and reactive oxygen species were remarkably elevated, while glutathione levels and superoxide dismutase, catalase and glutathione peroxidase activities were inhibited in animals receiving a HFD and/or PER. Furthermore, cardiac DNA fragmentation and upregulation of Bax and caspase-3 gene expression supported the ability of HFD and/or PER to induce apoptosis and inflammation in rat hearts. High cardiac TGF-β1 expression explained the profibrotic effects of PER either with the standard diet or HFD. Masson's Trichrome staining clearly demonstrated that HFD and PER could cause cardiac fibrosis. Additionally, increased oxidized LDL and the presence of several lipid droplets in arterial tissues highlighted the atherogenic effects of HFD and/or PER in rats. Such PER-induced cardiac and vascular dysfunctions were aggravated by and associated with a HFD, implying that obese individuals may be more vulnerable to PER exposure. Collectively, post-weaning exposure to HFD and/or PER may promote heart failure and fibrosis, demonstrating the pleiotropic effects of exposure to environmental factors early in life

Inositol induces mesenchymal-epithelial reversion in breast cancer cells through cytoskeleton rearrangement

Inositol displays multi-targeted effects on many biochemical pathways involved in epithelial-mesenchymal transition (EMT). As Akt activation is inhibited by inositol, we investigated if such effect could hamper EMT in MDA-MB-231 breast cancer cells. In cancer cells treated with pharmacological doses of inositol E-cadherin was increased, β-catenin was redistributed behind cell membrane, and metalloproteinase-9 was significantly reduced, while motility and invading capacity were severely inhibited. Those changes were associated with a significant down-regulation of PI3K/Akt activity, leading to a decrease in downstream signaling effectors: NF-kB, COX-2, and SNAI1. Inositol-mediated inhibition of PS1 leads to lowered Notch 1 release, thus contributing in decreasing SNAI1 levels. Overall, these data indicated that inositol inhibits the principal molecular pathway supporting EMT. Similar results were obtained in ZR-75, a highly metastatic breast cancer line. These findings are coupled with significant changes on cytoskeleton. Inositol slowed-down vimentin expression in cells placed behind the wound-healing edge and stabilized cortical F-actin. Moreover, lamellipodia and filopodia, two specific membrane extensions enabling cell migration and invasiveness, were no longer detectable after inositol addiction. Additionally, fascin and cofilin, two mandatory required components for F-actin assembling within cell protrusions, were highly reduced. These data suggest that inositol may induce an EMT reversion in breast cancer cells, suppressing motility and invasiveness through cytoskeleton modifications

Glomerular filtration barrier in rat offspring exposed to maternal undernutrition

Poor diet during pregnancy can increase blood pressure in offspring of human and laboratory animals. The present study examined the effects of moderate intrauterine undernutrition on the ultrastructure of the glomerular filtration barrier in 20-day-old rat fetuses and six-month-old rat offspring. Pregnant rats were provided with either ad libitum food during pregnancy (control group, C) or restricted to 50% of ad libitum food until delivery (food-restricted group, FR). Both groups were given free access to food after birth. The kidneys of embryonic day 20 and six-month-old rats were harvested. Transmission electron micrographs in glomeruli from both groups were obtained to study the ultrastructure of the glomerular filtration barrier. Blood pressure and glomerular filtration rate were measured in six-month-old rats. In comparison to the control group, the FR group had smaller body and kidney weights in both ages. Systemic blood pressure was significantly elevated in the FR group. The glomerular filtration rate was similar in both groups. A study of the glomerular ultrastructure showed a remarkable retardation in the development of the podocyte foot process in the FR group at embryonic day 20. Micrographs also showed remarkable changes in the glomerular filtration barrier of six-month-old rats including an increase in the thickness of the glomerular basement membrane and an increase in the width of filtration slits. These results suggest that maternal food restriction disturbs the development of the glomerular filtration barrier, which may contribute to hypertension in adult rat offspring. The long-term exposure to hypertension and glomerular hyperfiltration may have contributed to the damages observed in the glomerular filtration barrier of six-month-old rats exposed to intrauterine food restriction