Eggplant (Solanum spp) supplemented fruits diet modulated the activities of ectonucleoside triphosphate diphosphohydrolase (ENTPdase), monoamine oxidase (MAO), and cholinesterases (AChE/BChE) in the brain of diabetic Wistar male rats.

Type 2 diabetes mellitus is associated with complications such as Alzheimer disease (AD). Tropical eggplant (Solanum gilo, Solanum kumba, and Solanum aethiopicum) fruits have been extensively used for the treatment of different ailments. This study assesses the effect of an eggplant supplemented-diet on purinergic, monoaminergic, and cholinergic enzyme systems in diabetic male rats, besides determining the presence of alkaloids using GC-MS chromatography. Results from this study show that eggplant fruit diet modulates the activities of the enzymes in purinergic, monoaminergic, and cholinergic enzyme systems associated with AD-like symptoms. Solanum kumba-supplemented diet significantly (p < 0.05) reduced enzyme activities better than S. gilo and S. aethiopicum, which could be due to its rich phytochemical constituents. In conclusion, eggplant fruits could serve as a holistic measure in the prevention of diabetes-related complications such as neurodegenerative disease. PRACTICAL APPLICATIONS: The therapeutic management of diabetes fails to holistically address inflammatory response which likely contributes to type 2 diabetes mellitus (T2DM) occurrence by causing insulin resistance; this, in turn, is intensified in the presence of hyperglycemia to promote long-term complications such as neurodegenerative disorders. The health benefit of a tropical eggplant fruit diet inform a nutritional and therapeutic approach for the prevention and treatment of T2DM and its associated complications such as neurodegenerative disorders has been proved. The eggplant fruit-supplemented diet, which is cost-effective with little or no side effect, could substantially increase the antioxidant status and also modulate the activities of neuronal enzymes in a diabetic model with dementia, as well as Alzheimer's-like symptoms. This study, therefore, revealed more of the benefits of tropical eggplant fruits vis-à-vis their management in hyperglycemia-mediated neurodegeneration.

Effect of Salvia miltiorrhiza root extract on brain acetylcholinesterase and butyrylcholinesterase activities, their mRNA levels and memory evaluation in rats.

Salvia miltiorrhiza (Lamiaceae), one of the most important and popular plants of traditional medicine of Asia, is used for the prevention and treatment of cardiovascular diseases and in central nervous system disturbances. The main aim of this study was to assess the influence of subchronic (28-fold) administration of Salvia miltiorrhiza root extract (SE, 200mg/kg, p.o.) on behavioural activity and memory of rats and to evaluate the activities of cholinesterases (AChE and BuChE) and gene expression levels of AChE and BuChE as well as of beta-secretase (BACE1) in the hippocampus and frontal cortex in vivo. Huperzine A (HU, 0.5mg/kg b.w., p.o.) served as a positive control substance, whereas scopolamine (0.5mg/kg, i.p.) injection was used as a well-known model of memory impairment. The results showed that subchronic administration of SE led to an improvement of long-term memory of rats. Strong inhibition of AChE and BuChE mRNA transcription in the frontal cortex of rats treated with SE or HU was observed. The BACE1 transcript level was significantly decreased. AChE activity was statistically significantly inhibited in the frontal cortex and the hippocampus by SE (47% and 55%, respectively). Similar effects were observed in the case of HU. In summary, activity of SE provides evidence that the plant can be a source of drugs used in the treatment of Alzheimer disease.

Deleterious Effect of Butyrylcholinesterase K-Variant in Donepezil Treatment of Mild Cognitive Impairment.

BACKGROUND: Donepezil is an acetylcholinesterase inhibitor frequently prescribed for the treatment of mild cognitive impairment (MCI) though not approved by the Food and Drug Administration for this indication. In Alzheimer's disease, butyrylcholinesterase (BChE) activity increases with disease progression and may replace acetylcholinesterase function. The most frequent polymorphism of BChE is the K-variant, which is associated with lower acetylcholine-hydrolyzing activity. BChE-K polymorphism has been studied in Alzheimer's disease progression and donepezil therapy, and has led to contradictory results. OBJECTIVES: To determine whether BChE-K genotype predicts response to donepezil in MCI. METHODS: We examined the association between BChE-K genotype and changes in cognitive function using the data collected during the ADCS vitamin E/donepezil clinical trial in MCI. RESULTS: We found significant interactions between BChE-K genotype and the duration of donepezil treatment, with increased changes in MMSE and CDR-SB scores compared to the common allele in MCI subjects treated during the 3-year trial. We found faster MMSE decline and CDR-SB rise in BChE-K homozygous individuals treated with donepezil compared to the untreated. We observed similar interactions between BChE-K genotype and steeper changes in MMSE and CDR-SB scores in APOE4 carriers treated with donepezil compared to controls. CONCLUSION: BChE-K polymorphisms are associated with deleterious changes in cognitive decline in MCI patients treated with donepezil for 3 years. This indicates that BChE-K genotyping should be performed to help identify subsets of subjects at risk for donepezil therapy, like those carrying APOE4. BChE-K and APOE4 carriers should not be prescribed off-label donepezil therapy for MCI management.

In Silico Analysis of Green Tea Polyphenols as Inhibitors of AChE and BChE Enzymes in Alzheimer's Disease Treatment.

Alzheimer's disease (AD) is the most frequent cause of dementia, especially in the elderly. AD is the most common progressive neurodegenerative disorder, which involves the loss of structure and function of cholinergic neurons. Moreover, if these neuronal changes cannot be compensated, this may ultimately lead to neurodegenerative processes. Therefore, most of the drug therapies are based on the cholinergic hypothesis, which suggests that AD begins as a deficiency in the production of the neurotransmitter acetylcholine. In this context, many inhibitors play an important role in AD treatment among which acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) have more potential in the treatment process of AD. In this study, we selected tea polyphenols of green tea which are reported as AChE and BChE inhibitors used in the treatment of AD. The molecular docking results revealed that polyphenols exhibit interactions and inhibit by binding with AChE and BChE. The amount of energy to bind with AChE and BChE needed by Epigallocatechin-3-gallate was lowest at about -14.45 and -13.30 kcal/mol, respectively. All compounds showed binding energy values ranging between -14.45 to -9.75 kcal/mol for both types of enzymes. The present docking study suggests that tea polyphenols inhibit AChE as well as BChE and enhance the cholinergic neurotransmission by prolonging the time. However, AChE molecules remain in the synaptic cleft. In consideration to these findings, cholinesterase inhibitors are suggested as the standard drugs for the treatment of AD.

Detection of glycoalkaloids using disposable biosensors based on genetically modified enzymes.

In this work we present a rapid, selective, and highly sensitive detection of α-solanine and α-chaconine using cholinesterase-based sensors. The high sensitivity of the devices is brought by the use of a genetically modified acetylcholinesterase (AChE), combined with a one-step detection method based on the measurement of inhibition slope. The selectivity was obtained by using butyrylcholinesterase (BChE), an enzyme able to detect these two toxins with differential inhibition kinetics. The enzymes were immobilized via entrapment in PVA-AWP polymer directly on the working electrode surface. The analysis of the resulting inhibition slope was performed employing linear regression function included in Matlab. The high toxicity of α-chaconine compared to α-solanine due to a better affinity to the active site was proved. The inhibition of glycoalkaloids (GAs) mixture was performed over AChE enzyme wild-type AChE and BChE biosensors resulting in the detection of synergism effect. The developed method allows the detection of (GAs) at 50 ppb in potato matrix.

Effects of indirect exposure of mice pups to endosulfan via their dams during gestation and lactation periods and the ameliorative effect of vitamin E.

During gestation and lactation, the experimental mice dams received one of the following treatments: (a) diet free of pesticide; (b) diet enriched with endosulfan (END); 30.0 µg kg(-1); (c) diet free of pesticide + oral vitamin E (α-tocopherol; 200 mg kg(-1) per mouse); and (d) diet enriched with END (30.0 µg kg(-1)) + oral vitamin E (200 mg kg(-1) per mouse). At weaning, pups and dams were killed, and selected organs as well as blood samples were collected for analyses. Compared with the control results, END induced alteration in a number of biochemical and histopathological parameters either in the dams or their offspring. The ameliorative effect of vitamin E to superoxide dismutase based on the "ameliorative index (AI)" for mothers and pups was 0.84 and 0.72, respectively. The AI for malondialdehyde reached a maximum value of nearly equal to 1.0 for dams or pups. For butyryl cholinesterase, the AI was 0.90 and 0.94 for dams and pups, respectively. In conclusion, a dietary exposure during gestation and lactation to low dose of END caused significant changes in the mother but also in the weaned animals that had not been directly exposed to this pesticide. These biological and histological alterations could be reversed to a great extent by oral supplementation of vitamin E.

Rosmarinus officinalis L. leaf extract improves memory impairment and affects acetylcholinesterase and butyrylcholinesterase activities in rat brain.

Rosmarinus officinalis L. leaf as part of a diet and medication can be a valuable proposal for the prevention and treatment of dementia. The aim of the study was to assess the effects of subchronic (28-fold) administration of a plant extract (RE) (200 mg/kg, p.o.) on behavioral and cognitive responses of rats linked with acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) activity and their mRNA expression level in the hippocampus and frontal cortex. The passive avoidance test results showed that RE improved long-term memory in scopolamine-induced rats. The extract inhibited the AChE activity and showed a stimulatory effect on BuChE in both parts of rat brain. Moreover, RE produced a lower mRNA BuChE expression in the cortex and simultaneously an increase in the hippocampus. The study suggests that RE led to improved long-term memory in rats, which can be partially explained by its inhibition of AChE activity in rat brain.

Identification and characterization of diarylimidazoles as hybrid inhibitors of butyrylcholinesterase and amyloid beta fibril formation.

In this contribution, a chemical collection of aromatic compounds was screened for inhibition on butyrylcholinesterase (BChE)'s hydrolase activity using Ellman's reaction. A set of diarylimidazoles was identified as highly selective inhibitors of BChE hydrolase activity and amyloid ß (Aß) fibril formation. New derivatives were synthesized resulting in several additional hits, from which the most active was 6c, 4-(3-ethylthiophenyl)-2-(3-thienyl)-1H-imidazole, an uncompetitive inhibitor of BChE hydrolase activity (IC50 BChE=0.10 µM; K(i)=0.073 ± 0.011 µM) acting also on Aß fibril formation (IC50=5.8 µM). With the aid of structure-activity relationship (SAR) studies, chemical motifs influencing the BChE inhibitory activity of these imidazoles were proposed. These bifunctional inhibitors represent good tools in basic studies of BChE and/or promising lead molecules for AD therapy.

Recent progress in protein drug design and discovery with a focus on novel approaches to the development of anti-cocaine medications.

Cocaine is highly addictive and no anti-cocaine medication is currently available. Accelerating cocaine metabolism, producing biologically inactive metabolites, is recognized as an ideal anti-cocaine medication strategy, especially for the treatment of acute cocaine toxicity. However, currently known wild-type enzymes have either too low a catalytic efficiency against the abused cocaine, in other words (-)-cocaine, or the in vivo half-life is too short. Novel computational strategies and design approaches have been developed recently to design and discover thermostable or high-activity mutants of enzymes based on detailed structures and catalytic/inactivation mechanisms. The structure- and mechanism-based computational design efforts have led to the discovery of high-activity mutants of butyrylcholinesterase and thermostable mutants of cocaine esterase as promising anti-cocaine therapeutics. The structure- and mechanism-based computational strategies and design approaches may be used to design high-activity and/or thermostable mutants of many other proteins that have clear therapeutic potentials and to design completely new therapeutic enzymes.

A mutation linked with autism reveals a common mechanism of endoplasmic reticulum retention for the alpha,beta-hydrolase fold protein family.

A mutation linked to autistic spectrum disorders encodes an Arg to Cys replacement in the C-terminal portion of the extracellular domain of neuroligin-3. The solvent-exposed Cys causes virtually complete retention of the protein in the endoplasmic reticulum when the protein is expressed in transfected cells. An identical Cys substitution was reported for butyrylcholinesterase through genotyping patients with post-succinylcholine apnea. Neuroligin, butyrylcholinesterase, and acetylcholinesterase are members of the alpha,beta-hydrolase fold family of proteins sharing sequence similarity and common tertiary structures. Although these proteins have distinct oligomeric assemblies and cellular dispositions, homologous Arg residues in neuroligin-3 (Arg-451), in butyrylcholinesterase (Arg-386), and in acetylcholinesterase (Arg-395) are conserved in all studied mammalian species. To examine whether an homologous Arg to Cys mutation affects related proteins similarly despite their differing capacities to oligomerize, we inserted homologous mutations in the acetylcholinesterase and butyrylcholinesterase cDNAs. Using confocal fluorescence microscopy and analysis of oligosaccharide processing, we find that the homologous Arg to Cys mutation also results in endoplasmic reticulum retention of the two cholinesterases. Small quantities of mutated acetylcholinesterase exported from the cell retain activity but show a greater K(m), a much smaller k(cat), and altered substrate inhibition. The nascent proteins associate with chaperones during processing, but the mutation presumably restricts processing through the endoplasmic reticulum and Golgi apparatus, because of local protein misfolding and inability to oligomerize. The mutation may alter the capacity of these proteins to dissociate from their chaperone prior to oligomerization and processing for export.

DNA sequence of butyrylcholinesterase from the rat: expression of the protein and characterization of the properties of rat butyrylcholinesterase.

The rat is the model animal for toxicity studies. Butyrylcholinesterase (BChE), being sensitive to inhibition by some organophosphorus and carbamate pesticides, is a biomarker of toxic exposure. The goal of this work was to characterize the purified rat BChE enzyme. The cDNA sequence showed eight amino acid differences between the active site gorge of rat and human BChE, six clustered around the acyl binding pocket and two below the active site serine. A prominent difference in rat was the substitution of arginine for leucine at position 286 in the acyl pocket. Wild-type rat BChE, the mutant R286L, wild-type human BChE, and the mutant L286R were expressed in CHO cells and purified. Arg286 was found responsible for the resistance of rat BChE to inhibition by Triton X-100. Replacement of Arg286 with leucine caused the affinity for Triton X-100 to increase 20-fold, making it as sensitive as human BChE to inhibition by Triton X-100. Wild-type rat BChE had an 8- to 9-fold higher K(m) for the positively charged substrates butyrylthiocholine, acetylthiocholine, propionylthiocholine, benzoylcholine, and cocaine compared with wild-type human BChE. Wild-type rat BChE catalyzed turnover 2- to 7-fold more rapidly than human BChE, showing the highest turnover with propionylthiocholine (201,000 min(-1)). Human BChE does not reactivate spontaneously after inhibition by echothiophate, but rat BChE reactivates with a half-life of 4.3hr. Human serum contains 5mg/L of BChE and 0.01mg/L of AChE. Male rat serum contains 0.2mg/L of BChE and approximately 0.2mg/L of AChE.

Determination of the DNA sequences of acetylcholinesterase and butyrylcholinesterase from cat and demonstration of the existence of both in cat plasma.

Cat serum contains 0.5 mg/L of butyrylcholinesterase (BChE, EC 3.1.1. 8) and 0.3 mg/L of acetylcholinesterase (AChE, EC 3.1.1.7); this can be compared with 5 mg/mL and < 0.01 mg/L, respectively, in human serum. Cat BChE differed from human BChE in the steady-state turnover of butyrylthiocholine, having a 3-fold higher k(cat) and 2-fold higher K(m) and K(ss) values. Sequencing of the cat BCHE cDNA revealed 70 amino acid differences between cat and human BChE, three of which could account for these kinetic differences. These amino acids, which were located in the region of the active site, were Phe398Ile, Pro285Leu, and Ala277Leu (where the first amino acid was found in human and the second in cat). Sequencing genomic DNA for cat and human ACHE demonstrated that there were 33 amino acid differences between the cat and human AChE enzymes, but that there were no differences in the active site region. In addition, a polymorphism in intron 3 of the human ACHE gene was detected, as well as a silent polymorphism at Y116 of the cat ACHE gene.

Polymorphism of acetylcholinesterase in discrete regions of the developing human fetal brain.

The molecular forms and membrane association of acetylcholinesterase (acetylcholine hydrolase, EC 3.1.1.7) and pseudocholinesterase (acylcholine acylhydrolase, EC 3.1.1.8) were determined in the presence of protease inhibitors in dissected regions of developing human fetal brain, as compared with parallel areas from mature brain. All areas contained substantial cholinesterase activities, of which acetylcholinesterase accounted for almost all the activity. Two major forms of acetylcholinesterase activity, sedimenting at 10-11S and 4-5S, respectively, were detected on sucrose gradients and possessed similar catalytic properties, as judged by their individual Km values toward [3H]acetylcholine (ca. 4 X 10(-4) M). The ratio between these forms varied by up to four- to fivefold, both between different areas and within particular areas at various developmental stages, but reached similar values (about 5:2) in all areas of mature brain. Acetylcholinesterase activity was ca. 35-50% low-salt-soluble and 45-65% detergent-soluble in various developmental stages and brain areas, with an increase during development of the detergent-soluble fraction of the light form. In contrast, pseudocholinesterase activity was mostly low-salt-soluble and sedimented as one component of 10-11S in all areas and developmental stages. Our findings suggest noncoordinate regulation of brain acetylcholinesterase and pseudocholinesterase, and indicate that the expression of acetylcholinesterase forms within embryonic brain areas depends both on cell type composition and on development.