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Assessment of 8-hydroxy-2-deoxyguanosine activity, apoptosis, acetylcholinesterase and antioxidant enzyme activity in Capoeta umbla brain exposed to chlorpyrifos

Kirici Mahinur

Oceanological and Hydrobiological Studies

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2022

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Vol. 51, No. 2

167--177

EN

In this study, neurotoxic responses to exposure to chlorpyrifos (CPF) at different doses (55 and 110 μg l-1) and at different time intervals (24 and 96 h) were investigated in Siraz fish (Capoeta umbla) using 8-hydroxy 2-deoxyguanosine (8-OHdG) activity, caspase-3, acetylcholinesterase (AChE) and oxidative stress parameters [malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione reductase (GR)]. In this study, the LC50 value of CPF was deterined for the first time for C. umbla and calculated as 440 μg l-1. In this study, 12.5% (55 μg l-1) and 25% (110 μg l-1) of the LC50 value were used. The obtained data indicate a significant increase in the MDA level and inhibition of antioxidant enzymes in the brain (p < 0.05). Considering DNA damage and the apoptotic process, no significant changes were found in 8-OHdG and caspase-3 activity at both doses exposed for 24 h, but a significant increase was detected in both markers at 96 hours compared to the control group (p < 0.05). In the case of AChE activity, which is one of the neurotoxic markers in the brain, while inhibition was determined only at the high concentration (110 μg l-1) at the end of 24 hours, a decrease in enzyme activity was observed at the end of 96 hours in both concentration groups. In the light of all these results, we can say that CPF showed inhibitory effects on enzyme activity and inducing effects on MDA, caspase-3 and 8-OHdG levels. Based on these results, it can be concluded that CPF contributes to oxidative stress in fish and may have neurotoxic effects.

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Neurotoxicity of cyanobacterial toxins

Florczyk M., Łakomiak A., Woźny M., Brzuzan P.

Environmental Biotechnology

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2014

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Vol. 10, No. 1

26--43

EN

Eutrophication of marine and fresh waters can lead to excessive development of cyanobacterial blooms, which may contain strains that produce toxins. These toxins are secondary metabolites which can accumulate in the food chain and contaminate drinking water, thus posing a potential threat to the health of humans and aquatic organisms. These toxins include a variety of compounds with different mechanisms; this review focuses on the neurotoxicity of microcystin and other cyanotoxins. Although the hepatotoxic action of microcystins is commonly known, its neurotoxic effects have also been described, e.g. oxidative stress, cytoskeletal changes and changes in protein phosphatase activity. These effects have been partially explained by the discovery in the blood brain barrier of the same membrane transporters involved in microcystins hepatotoxic mechanisms. Additionally, this paper reviews other cyanotoxins that are known or suspected to target cholinergic synapses and voltage gated channels, including anatoxin a, anatoxin a(s), antillatoxins, cylindrospermopsin, homoanatoxin a, jamaicamide, kalkitoxin and saxitoxins. The neurotoxic and cytotoxic effects of the cyanotoxins discussed here are of particular interest because of their pharmacological potential. This review also discusses the potential of these compounds to serve as drugs for cancer and central nervous system failure.

3

A beta peptide oligomers - potential neurotoxic agents in Alzheimer's disease

Jabłonowska A., Dadlez M.

Polimery

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2003

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T. 48, nr 1

35-43

EN

Amyloid beta peptide (Abeta) is recognized as the main constituent of the extracellular amyloid plaques, the major neuropathological hallmark of Alzheimer's disease (AD). Abeta is a small peptide present in normal cells, not toxic in the monomeric form but aggregated Abeta is assumed to be the main if not the only factor causing Alzheimer's disease. Interestingly, the new reports suggest neurotoxicity of soluble Abeta oligomers rather then amyloid fibrils. Due to the fact that fibrils were thought to be the main toxic species in AD, early structural studies focused on fibrils themselves and Abeta monomers, as their building blocks, while there is practically no data on oligomer structure and mechanism of neurotoxicity. Thus a new area of research opened, focusing on Abeta soluble oligomers and the results of the studies will be reviewed here.

PL

Peptyd beta amyloidu (Ap) jest głównym składnikiem włókien amyloidowych budujących zewnątrzkomórkowe płytki starcze, będące cechą charakterystyczną choroby Alz-heimera (AD). A(3 jest małym peptydem konstytutywnie wydzielanym przez komórki ssaków. Peptyd ten w postaci monomeru nie jest toksyczny, lecz jego zagregowana forma była uważana za główny, jeżeli nie jedyny, czynnik wywołujący chorobę Alzheimera. Z tego powodu wszystkie prowadzone dotychczas badania koncentrowały się głównie na poznaniu struktury i właściwości włókien amyloidowych oraz monomeru Ap jako ich głównej jednostki budulcowej. Prowadzone obecnie prace sugerują, że neurotoksyczność wiąże się raczej z rozpuszczalnymi oligomerami AP, a nie z nierozpuszczalnymi włóknami amyloidowymi. Odkrycie, że to rozpuszczalne oligomery AP mogą stanowić główny czynnik neurotoksycz-ny w chorobie Alzheimera stworzyło nowy obszar badań rozwijający się prężnie w ciągu ostatnich pięciu lat. Uzyskane w tej dziedzinie wyniki zostały podsumowane w niniejszym artykule. Zarysowano w nim główne cechy struktury monomeru i fibryli jako najlepiej zbadanych form peptydu Ap, a następnie szczegółowo przedstawiono dane dotyczące struktury postaci oligomerycznych: małych oligomerów obejmujących dimery do tetramerów, oligomerów o ciężarze cząsteczkowym 20-40 kD (ADDL - ang. Ap-derróed diffusible li-gands) oraz metastabilnych form przejściowych - protofibryli. W odniesieniu do każdej z opisanych struktur oligomerycznych omówiono jej potencjalną neurotoksyczność.