The present study investigated the effects of Porphyra yezoensis enzyme degradation extract (PYEDE) on the brain injuries and neurodegenerative diseases due to oxidative stress. We used in vitro antioxidant systems to verify the antioxidant potential of PYEDE. The results indicated that the PYEDE alleviated weight loss and organ atrophy, reduced the levels of lipid peroxidation and protein carbonylation and elevated reduced glutathione (GSH) content in the serum and brains of the d-galactose-induced ageing model mice. The PYEDE also renewed the glutathione peroxidase (GSH-Px), superoxide dismutase and total antioxidant capability activities, down-regulated the inducible nitric oxide synthase activity and nitric oxide levels, normalised the hippocampal neurons and modulated multiple neurotransmitter systems by inhibiting the activities of acetylcholinesterase and monoamine oxidase in the up-regulation of acetylcholine, dopamine and noradrenaline levels. Overall, the PYEDE is a promising supplement for the alleviation of oxidative stress and age-associated brain diseases.

Previous studies have shown the anthelmintic efficacy of Senna alata, Senna alexandrina and Senna occidentalis on the zoonotic parasite Hymenolepis diminuta through microscopic studies on morphological structure. The present study is based on the light and confocal microscopic studies to understand if Senna extracts affect neurotransmitter activity of the parasites. A standard concentration (40 mg/mL) of the three leaf extracts and one set of 0.005 mg/mL concentration of the reference drug praziquantel were tested against the parasites, keeping another set of parasites in phosphate buffer saline as a control. Histochemical studies were carried out using acetylthiocholine iodide as the substrate and acetylcholinesterase as the marker enzyme for studying the expression of the neurotransmitter of the parasite and the staining intensity was observed under a light microscope. Immunohistochemical studies were carried out using anti serotonin primary antibody and fluorescence tagged secondary antibody and observed using confocal microscopy. Intensity of the stain decreases in treated parasites compared with the control which implies loss of activity of the neurotransmitters. These observations indicated that Senna have a strong anthelmintic effect on the parasite model and thus pose as a potential anthelmintic therapy.

Objective: Neuronal ceroid-lipofuscinoses are a heterogeneous group of inherited disorders in which abnormal lipopigments form lysosomal inclusion bodies in neurons. Kufs disease is rare, and clinical symptoms include seizures, progressive cognitive impairment, and myoclonus. Most cases of Kufs disease are autosomal recessive; however, there have been a few case reports of an autosomal dominant form linked to mutations within the DNAJC5 gene. Methods: We describe a family with Kufs disease in which the proband and three of her four children presented with cognitive impairment, seizures, and myoclonus. Results: Genetic testing of all four children was positive for a c.346_348delCTC(p.L116del) mutation in the DNAJC5 gene. The proband brain had an abundance of neuronal lipofuscin in the cerebral cortex, striatum, amygdala, hippocampus, substantia nigra, and cerebellum. There were no amyloid plaques or neurofibrillary tangles. Immunohistochemistry demonstrated that the cholinergic neurons and cholinergic projection fibers were spared, but there was a profound loss of choline acetyltransferase within the caudate, putamen, and basal forebrain. This suggests a loss of choline acetyltransferase as opposed to a loss of the neurons. Conclusions: This report describes the clinical history of autosomal dominant Kufs disease, the genetic mutation within the DNAJC5 gene, and the neuropathological findings demonstrating depletion of choline acetyltransferase in the brain.

Canine cognitive dysfunction (CCD) is an age-dependent neurodegenerative condition characterised by changes in decline in learning and memory patterns. The neurodegenerative features of CCD in ageing dogs and cats are similar to human ageing and Alzheimer's disease (AD). Discovering neuroprotective disease-modifying therapies against CCD and AD is a major challenge. Strong evidence supports the role of amyloid β peptide deposition and oxidative stress in the pathophysiology of CCD and AD. In both the human and canine brain, oxidative damage progressively increases with age. Dietary antioxidants from natural sources hold a great promise in halting the progression of CCD and AD. Withania somnifera (WS), an Ayurvedic tonic medicine, also known as ‘Indian ginseng’ or ashwagandha has a long history of use in memory-enhancing therapy but there is a dearth of studies on its neuroprotective effects. The objective of this study was to investigate whether WS extract can protect against Aβ peptide- and acrolein-induced toxicity. We demonstrated that treatment with WS extract significantly protected the human neuroblastoma cell line SK-N-SH against Aβ peptide and acrolein in various cell survival assays. Furthermore, treatment with WS extract significantly reduced the generation of reactive oxygen species in SK-N-SH cells. Finally, our results showed that WS extract is also a potent inhibitor of acetylcholinesterase activity. Thus, our initial findings indicate that WS extract may act as an antioxidant and cholinergic modulator and may have beneficial effects in CCD and AD therapy.

Flavonoids, a group of natural substances with variable phenolic structures, are found in fruits, vegetables, grains, bark, roots, stems, flowers, tea and wine. These natural products are well known for their beneficial effects on health and efforts are being made to isolate the ingredients so called flavonoids. Flavonoids are now considered as an indispensable component in a variety of nutraceutical, pharmaceutical, medicinal and cosmetic applications. This is attributed to their anti-oxidative, anti-inflammatory, anti-mutagenic and anti-carcinogenic properties coupled with their capacity to modulate key cellular enzyme function. Research on flavonoids received an added impulse with the discovery of the low cardiovascular mortality rate and also prevention of CHD. Information on the working mechanisms of flavonoids is still not understood properly. However, it has widely been known for centuries that derivatives of plant origin possess a broad spectrum of biological activity. Current trends of research and development activities on flavonoids relate to isolation, identification, characterisation and functions of flavonoids and finally their applications on health benefits. Molecular docking and knowledge of bioinformatics are also being used to predict potential applications and manufacturing by industry. In the present review, attempts have been made to discuss the current trends of research and development on flavonoids, working mechanisms of flavonoids, flavonoid functions and applications, prediction of flavonoids as potential drugs in preventing chronic diseases and future research directions.

Acetylcholinesterase (AChE), encoded by the ace gene, is a key enzyme of cholinergic neurotransmission. Insensitive acetylcholinesterase (AChE) has been shown to be responsible for resistance to OPs and CBs in a number of arthropod species, including the most important pest of olives trees, the olive fruit fly Bactrocera oleae. In this paper, the organization of the B. oleae ace locus, as well as the structural and functional features of the enzyme, are determined. The organization of the gene was deduced by comparison to the ace cDNA sequence of B. oleae and the organization of the locus in Drosophila melanogaster. A similar structure between insect ace gene has been found, with conserved exon-intron positions and junction sequences. The B. oleae ace locus extends for at least 75 kb, consists of ten exons with nine introns and is mapped to division 34 of the chromosome arm IIL. Moreover, according to bioinformatic analysis, the Bo AChE exhibits all the common features of the insect AChE. Such structural and functional similarity among closely related AChE enzymes may implicate similarities in insecticide resistance mechanisms.

Acetylcholinesterase (ACHE) is present in the muscle and on the tegument of schistosomes. Molecular forms of schistosome AChE were examined because particular AChEs are found in tissues of distinct function elsewhere. The dimeric globular form (G2) is the only form evident in adult Schistosoma haematobium: 32 % of the muscle AChE is hydrophilic and 61 % is membrane associated. A substantial amount of this enzyme is phosphatidylinositol (PI) anchored since it could be released by PI-specific phospholipase C from both muscle and tegumental membranes.

The inhibition of acetylcholinesterase secretion by male and female Heligmosomoides polygyrus was tested on worms taken from experimentally infected mice and maintained for 3 days in vitro in levamisole. The dose inhibiting 50% of enzyme secretion (ID 50) of male worms was twice the ID 50 for female worms. A similar difference was observed in vivo between the dose of levamisole removing 50% (LD 50) of male and female worms from the mouse. Acetylcholinesterase secretion by worms and ID 50 were tested in vitro at 3-weekly intervals from 3 to 21 weeks post infection (WPI). Acetylcholinesterase secretion was always significantly higher for male than for female worms. A decrease of ID 50, correlated with the age of the worms was observed: from 1·5 to 0·5 μg/ml for males and from 0·7 to 0·1 μg/ml for females. These results were confirmed in vivo by a higher efficacy of the anthelminthic at 21 than at 4 WPI.

The distribution of acetylcholinesterase (AChE) in the lateral eye and brain of the horseshoe crab was investigated with histochemical means using standard controls to eliminate butyrylcholinesterase and nonspecific staining. Intense staining was observed in the neural plexus of the lateral compound eye, in the lateral optic nerve, and in various neuropils of the brain. Nerve fibers with moderate to weak staining were widespread in the brain. No sornata were stained in either the lateral eye or the brain. The distribution of acetylcholinesterase in the supraesophageal ganglia and nerves of the giant barnacle was also investigated for comparison. Although both the median optic nerve of the barnacle and the lateral optic nerve of the horseshoe crab appear to contain the fibers of histaminergic neurons, only the lateral optic nerve of the horseshoe crab shows AChE staining. Other parts of the barnacle nervous system, however, showed intense AChE staining. These results along with the histochemical controls eliminate the possibility that some molecule found in histaminergic neurons accounted for the AChE staining but support the possibility that acetylcholine might be involved as a neurotransmitter in lateral inhibition in the horseshoe crab retina. Two reasonable neurotransmitter candidates for lateral inhibition, histamine and acetylcholine, must now be investigated.

Both Sitobion avenae (Fabricius) and Rhopalosiphum padi (Linnaeus) are the most important pests of wheat in China and usually coexist on the late period of wheat growth. Pirimicarb was introduced into China for wheat aphid control in early 1990s, and differential susceptibilities of Sitobion avenae (Fabricius) and Rhopalosiphum padi (Linnaeus) to pirimicarb have been observed. A bioassay exhibited that Rhopalosiphum padi possessed significantly higher susceptibility to pirimicarb than Sitobion avenae. The addition of synergists DEF, an esterase inhibitor, PBO, a cytochrome P450 monooxygenase inhibitor, and DEM, a glutathione S-transferase inhibitor, resulted in apparent reductions in the differential susceptibilities, suggesting the involvement of the above three detoxification enzymes in the differential susceptibility to pirimicarb between Sitobion avenae and Rhopalosiphum padi. A biochemical analysis showed that the activities of carboxylesterases and glutathione S-transferases were significantly higher in Sitobion avenae than in Rhopalosiphum padi, consistent with the results of synergism. Acetylcholinesterase is the target enzyme of pirimicarb and the sensitivity of acetylcholinesterase to pirimicarb was significantly higher in Rhopalosiphum padi than in Sitobion avenae. The combined results suggest that multiple mechanisms are likely to be responsible for differential susceptibilities to pirimicarb between Sitobion avenae and Rhopalosiphum padi. The results obtained from this study should be helpful in the rational applications of insecticides.

Acetylcholinesterase (AChE) is present in all stages of the life-cycle of schistosomes and is located in muscle and on the surface of the parasite. Metrifonate is a drug that inhibits AChE. We compared the AChEs from three schistosome species (Schistosoma mansoni, Schistosoma haematobium and Schistosoma bovis) that have different susceptibilities to metrifonate in vivo. Sensitivities to AChE inhibitors were similar. The subunits of AChE were 110 kDa and 76 kDa and the dominant molecular form of AChE was a G2 form in all three species. This was the major form on the tegument while additional molecular forms were associated with the internal tissues. Differences in relative amounts of AChE activity between these species were found in the adults but not in the schistosomula. At the adult stage the major difference between species lay in the relative amounts of AChE activity in their teguments. S. haematobium teguments carried 20 times and S. bovis 6·9 times the activity present on S. mansoni teguments. These quantitative differences associate with the relative sensitivities of these species to metrifonate.

Acetylcholinesterase (AChE) has been purified from the excretory/secretory (ES) products of Trichostrongylus colubriformis (using edrophonium chloride linked to epoxy-activated Sepharose) with yields of 40–50%. Purity was confirmed by polyacrylamide gel electrophoresis (using silver [protein] and Karnovsky [activity] stains) and measurement of specific AChE activity. Further analysis of the purified fractions by gel filtration and sucrose density gradient techniques revealed the existence of 2 forms of hydrophilic AChE (Mr 189 and 80 kDa). From the data we deduce these to be the globular monomer and dimer, G1 and G2 forms of AChE. Inhibition studies using BW284C51, iso-OMPA and excess substrate, along with substrate specificity studies, show both forms to be true acetylcholinesterases. We are currently assessing the protective immunogenicity of purified AChE in sheep.

Whole worm homogenates and excretory/secretory (E/S) products of adult Nippostrongylus brasiliensis significantly decreased the amplitude of contractions of segments of uninfected rat intestine maintained in an organ bath, with significantly larger volumes of E/S products being required to bring about a similar decrease to that caused by the whole worm homogenate. Boiled samples of homogenate and E/S products significantly decreased the amplitude of contractions of uninfected rat intestine, but larger volumes were needed than with unboiled samples. Frequency of contraction was unaltered by homogenates or E/S products. When electric eel AChE was injected into the lumen of segments of uninfected rat intestine maintained in an organ bath there was no significant decrease in the amplitude of contractions. These results suggest that substances present in the E/S products of N. brasiliensis significantly reduce the amplitude of contractions of uninfected rat intestine in vitro and that the biochemical holdfast responsible for this phenomenon may not be AChE.

The gilthead seabream is the most important Mediterranean aquacultured fish species. The main objective of this study was to investigate whether copper sulphate bath treatments used routinely in aquaculture have effects on important physiological functions of early life stages of the gilthead seabream (Sparus aurata). Fingerlings (80–90 days, 0.27 ± 0.06 g) were exposed to copper sulphate baths at 0, 0.25, 0.5 and 1.5 mg L−1 during 24 h. Effects on the central nervous function were evaluated analysing brain acetylcholinesterase activity (AChE). Oxidative stress was assessed by the quantification of lipid peroxidation (LP). Heat shock proteins (HSP70) were used as a general response to chemical stress, RNA/DNA ratio as an indicator of growth, and effects on detoxification function were estimated using glutathione–S-transferases activity (GST). Exposure of S. aurata fingerlings to copper sulphate induced increased lipid peroxidation. In contrast, there were no significant changes in AChE activity, HSP70 levels, RNA/DNA ratio or GST activity. Particularly, the absence of response in GST activity points towards a limited extent of the putative damage caused by the treatments at the highest doses (evidenced through the levels of peroxidation), since this enzyme is directly implicated in detoxification processes involving redox cyclic products. The results suggest that copper sulphate baths at the conditions tested are safe treatments for S. aurata fingerlings.

With an increasing incidence of cutaneous leishmaniasis in Sri Lanka, particularly in northern provinces, insecticide-mediated vector control is under consideration. Optimizing such a strategy requires the characterization of sand fly populations in target areas with regard to species composition and extant resistance, among other parameters. Sand flies were collected by human bait and cattle-baited net traps on Delft Island, used as an illegal transit location by many refugees returning to the north of Sri Lanka from southern India where leishmaniasis is endemic. For species identification, genomic DNA was extracted and a fragment of the ribosomal 18S gene amplified. The sequence from all flies analysed matched that of Phlebotomus argentipes Annandale & Brunetti, the primary vector in India and the most likely vector in Sri Lanka. Independent morphological analysis also identified P. argentipes. To establish the current susceptibility status of vector species, data were obtained at the biochemical level, from which potential cross-resistance to alternative insecticides can be predicted. The Delft Island collection was assayed for the activities of four enzyme systems involved in insecticide resistance (acetylcholinesterase, non-specific carboxylesterases, glutathione-S-transferases and cytochrome p450 monooxygenases), establishing baselines against which subsequent collections can be evaluated. There was preliminary evidence for elevated esterases and altered acetylcholinesterase in this population, the first report of these resistance mechanisms in sand flies to our knowledge, which probably arose from the malathion-based spraying regimes of the Anti-Malarial Campaign.

Acetylcholine (ACh) is one of an array of neurotransmitters used by invertebrates and, analogous to vertebrate nervous systems, acetylcholinesterase (AChE) regulates synaptic levels of this transmitter. Similar to other invertebrates, nematodes possess several AChE genes. This is in contrast to vertebrates, which have a single AChE gene, transcripts of which are alternatively spliced to produce different types of the enzyme which vary at their C-termini. Parasitic nematodes have a repertoire of AChE genes which include those encoding neuromuscular AChEs and those genes which code for secreted AChEs. The latter proteins exist as soluble monomers released by the parasite during infection and these AChE are distinct from those enzymes which the nematodes use for synaptic transmission in their neuromuscular system. Thus far, Dictyocaulus viviparus is the only animal-parasitic nematode for which distinct genes that encode both neuromuscular and secreted AChEs have been defined. Here, we describe the isolation and characterization of a cDNA encoding a putative neuromuscular AChE from D. viviparus which contains a tryptophan amphiphilic tetramerization (WAT) domain at its C-terminus analogous to the common ‘tailed’ AChE form found in the neuromuscular systems of vertebrates and in the ACE-1 AChE from Caenorhabditis elegans. This enzyme differs from the previously isolated, D. viviparus neuromuscular AChE (Dv-ACE-2), which is a glycosylphosphatidylinositol-anchored variant analogous to vertebrate ‘hydrophobic’ AChE.

Acetylcholine is the major excitatory neurotransmitter controlling motor activities in nematodes, and the enzyme which hydrolyses and inactivates acetylcholine, acetylcholinesterase, is thus essential for regulation of cholinergic transmission. Different forms of acetylcholinesterase are encoded by multiple genes in nematodes, and analysis of the pattern of expression of these genes in Caenorhabditis elegans suggests that they perform non-redundant functions. In addition, many parasitic species which colonise host mucosal surfaces secrete hydrophilic variants of acetylcholinesterase, although the function of these enzymes is still unclear. Acetylcholinesterases have a history as targets for therapeutic agents against helminth parasites, but anti-cholinesterases have been used much more extensively as pesticides, for example to control crop damage and ectoparasitic infestation of livestock. The toxicity associated with these compounds (generally organophosphates and carbamates) has led to legislation to withdraw them from the market or restrict their use in many countries. Nevertheless, acetylcholinesterases provide a good example of a neuromuscular target enzyme in helminth parasites, and it may yet be possible to develop more selective inhibitors. In this article, we describe what is known about the structure and function of vertebrate cholinesterases, illustrate the molecular diversity and tissue distribution of these enzymes in C. elegans, and discuss to what extent this may represent a paradigm for nematodes in general.