Anticonvulsant drug toxicity in rat brain cell aggregate cultures

A transcriptomics-based analysis of the toxicity mechanisms of gabapentin to zebrafish embryos at realistic environmental concentrations

Gabapentin (GPT) has become an emerging contaminant in aquatic environments due to its wide application in medical treatment all over the world. In this study, embryos of zebrafish were exposed to gabapentin at realistically environmental concentrations, 0.1 μg/L and 10 μg/L, so as to evaluate the ecotoxicity of this emergent contaminant. The transcriptomics profiling of deep sequencing was employed to illustrate the mechanisms. The zebrafish (Danio rerio) embryo were exposed to GPT from 12 hpf to 96 hpf resulting in 136 and 750 genes differentially expressed, respectively. The results of gene ontology (GO) analysis and the Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis illustrated that a large amount of differentially expressed genes (DEGs) were involved in the antioxidant system, the immune system and the nervous system. RT-qPCR was applied to validate the results of RNA-seq, which provided direct evidence that the selected genes involved in those systems mentioned above were all down-regulated. Acetylcholinesterase (AChE), lysozyme (LZM) and the content of C-reactive protein (CRP) were decreased at the end of exposure, which is consistent with the transcriptomics results. The overall results of this study demonstrate that GPT simultaneously affects various vital functionalities of zebrafish at early developmental stage, even at environmentally relevant concentrations.

Evaluation of acetylcholinesterase in an animal model of mania induced by D-amphetamine

The present study aims to investigate the effects of mood stabilizers, lithium (Li) and valproate (VPA), on acetylcholinesterase (AChE) activity in the brains of rats subjected to an animal model of mania induced by D-amphetamine (D-AMPH). In the reversal treatment, Wistar rats were first given D-AMPH or saline (Sal) for 14 days. Between days 8 and 14, the rats were treated with Li, VPA, or Sal. In the prevention treatment, rats were pretreated with Li, VPA, or Sal. AChE activity was measured in the brain structures (prefrontal cortex, hippocampus, and striatum). Li, alone in reversion and prevention treatments, increased AChE activity in the brains of rats. VPA, alone in prevention treatment, increased AChE activity in all brain regions evaluated; in the reversion, only in the prefrontal. However, D-AMPH decreased activity of AChE in the striatum of rats in both the reversion and prevention treatments. VPA was able to revert and prevent this AChE activity alteration in the rat striatum. Our findings further support the notion that the mechanisms of mood stabilizers also involve changes in AChE activity, thus reinforcing the need for more studies to better characterize the role of acetylcholine in bipolar disorder.

Ensaculin (KA-672 HCl): a multitransmitter approach to dementia treatment

Ensaculin, a novel benzopyranone substituted with a piperazine moiety, showed memory-enhancing effects in paradigms of passive and conditioned avoidance in both normal and artificially amnesic rodents. It exhibited neuroprotective activities in an NMDA toxicity model and neurotrophic effects in primary cultured rat brain cells. The compound could be characterized as a weak NMDA receptor-operated channel blocker. In receptor-binding studies, ensaculin was found to have high affinities to serotonergic 5-HT(1A) and 5-HT(7) receptors, adrenergic alpha(1), and dopaminergic D(2) and D(3) receptors. Due to its unique pharmacodynamic profile, ensaculin may have potential as an antidementia agent acting on various transmitter systems.