Geissoschizine methyl ether (1), a newly discovered strong acetylcholinesterase (AChE) inhibitor, along with six weakly active alkaloids, vallesiachotamine (2), hisuteine (3), hirsutine (4), isorhynchophylline (5), cisocorynoxeine (6) and corynoxeine (7) have been isolated from Uncaria rhynchophylla. Geissoschizine methyl ether (1) inhibited 50% of AChE activity at concentrations of 3.7 ± 0.3 µ...

This report describes the isolation and identification of a potent acetylcholinesterase (AChE) inhibitor-producing yeasts. Of 731 species of yeast strain, the S-3 strain was selected as a potent producer of AChE inhibitor. The selected S-3 strain was investigated for its microbiological characteristics. The S-3 strain was found to be short-oval yeast that did not form an ascospore. The strain f...

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that has no cure because its etiology still unknown, and main treatment the administration of acetylcholinesterase (AChE) inhibitors. The study mechanism action this family compounds critical for design new more potent specific In work, we molecular basis an uncompetitive inhibitor (compound 1, 2β, 3α-dihydroxy-5α-cholestan-6-...

Rivastigmine, which has been approved by the US Food and Drugs Administration for the treatment of Alzheimer's disease, is a non-competitive reversible inhibitor of acetylcholinesterase. We present a case of rivastigmine toxicity at a dose of 90 mg, with evidence of respiratory depression. To our knowledge, this case report provides evidence of the highest rivastigmine ingestion recorded (90 mg...

BACKGROUND Zebrafish is an important model organism for human neurobehavioural studies and compound screening for neurodegenerative disorders like Alzheimer's disease and dementia. PURPOSE We wanted to analyse the rapid neurobehavioural effects based on acetylcholinesterase inhibitors from Tephrosia purpurea in zebrafish. METHODS Tephrosia purpurea (a herbal neuroactive molecule) extract wa...

Autoradiographic and histochemical techniques have been used to characterize further the pharmacology of transmission at the Mauthner fiber giant synapse of the South American hatchetfish. [125I]alpha-Bungarotoxin was applied to hatchetfish medullae and a standard autoradiographic procedure was carried out on 3- to 4-microns sections of glutaraldehyde-fixed tissue. All Mauthner fiber giant syna...

Amnestic mild cognitive impairment (MCI) can be considered as a state with a high risk of developing Alzheimer's disease within 5 years, or as a prodromal stage of this condition. Randomized clinical trials comparing the acetylcholinesterase inhibitor donepezil with placebo have shown some symptomatic benefit on (i) cognition in one short-term (6-month) study; and (ii)conversion to dementia in ...

In vivo enzymology is not widely studied due to the lack of a well-adapted technology. We have developed a system that allows local and long-term spectrophotometric assays in brain tissue of live animals. It utilizes a miniaturized optical probe consisting of a multibarrel micropipette for reagent injections and optical fibers for light absorption measurements. We have applied this system to th...

Hypertrichosis is the excessive hair growth in any area of the skin surface. Acquired localized hypertrichosis may be secondary to multiple causes and there is a secondary form due to several drugs, which is usually reversible with discontinuation of the causative agent. Rivastigmine is a reversible and competitive inhibitor of acetylcholinesterase and butyrylcholinesterase used for symptomatic...