Effect of Donepezil, Tacrine, Galantamine and Rivastigmine on Acetylcholinesterase Inhibition in Dugesia tigrina

Abstract

Dugesia tigrina is a non-parasitic platyhelminth, which has been recently utilized in pharmacological models, regarding the nervous system, as it presents a wide sensitivity to drugs. Our trials aimed to propose a model for an in vivo screening of substances with inhibitory activity of the enzyme acetylcholinesterase. Trials were performed with four drugs commercialized in Brazil: donepezil, tacrine, galantamine and rivastigmine, utilized in the control of Alzheimer's disease, to inhibit the activity of acetylcholinesterase. We tested five concentrations of the drugs, with an exposure of 24 h, and the mortality and the inhibition of acetylcholinesterase planarian seizure-like activity (pSLA) and planarian locomotor velocity (pLMV) were measured. Galantamine showed high anticholinesterasic activity when compared to the other drugs, with a reduction of 0.05 µmol¨min´1 and 63% of convulsant activity, presenting screw-like movement and hypokinesia, with pLMV of 65 crossed lines during 5 min. Our results showed for the first time the anticholinesterasic and convulsant effect, in addition to the decrease in locomotion induced by those drugs in a model of invertebrates. The experimental model proposed is simple and low cost and could be utilized in the screening of substances with anticholinesterasic action.

Chemical composition, insecticidal and biochemical effects of Melaleuca alternifolia essential oil on the Helicoverpa armigera

“…Many plants contain various bioactive secondary metabolites, such as terpenes (Chen et al., ), flavonoids (Sharififar et al., ) and alkaloids (Jarmusch et al., ), which are natural pesticides source. To cope with bioactive secondary metabolites, the insects can decrease the sensitivity of the target site of pesticides, such as the nerve conduction enzyme acetylcholinesterase (AChE) (Bezerra da Silva et al., ). Or, the insects can utilize a variety of detoxifying enzymes, including glutathione S‐transferase (GST) (Li et al., ).…”

Measuring functional brain recovery in regenerating planarians by assessing the behavioral response to the cholinergic compound cytisine

“…This behavioral response has also been referred to as a C-like hyperkinesia (Palladini et al, 1996;Pagán et al, 2008) and is expressed as a series of sudden contractions/twitches of the anterior section while the tail is usually anchored to the bottom of the container, as opposed to the passive gliding that these animals normally display (please see Supplementary Video 1). pSLMs are easily quantified visually, are concentration-dependent, and have been used to document the behavioral effects of a variety of psychoactive agents, including cocaine, nicotine, and opiates, among other compounds (Bach et al, 2016;Bezerra da Silva et al, 2016;Pagán et al, 2008Pagán et al, , 2012Pagán et al, , 2013Pagán et al, , 2015Raffa and Rawls, 2008;Ramakrishnan and Desaer, 2011;Ramakrishnan et al, 2013;Ramoz et al, 2012, Rawls et al, 2009Tallarida et al, 2014).…”

Anti-Amyloid Aggregation Activity of Black Sesame Pigment: Toward a Novel Alzheimer’s Disease Preventive Agent

“…Synaptic dysfunction, tau protein hyperphosphorylation and aggregation, neuroinflammation, and oxidative stress would then follow, leading eventually to neuronal death and neurotransmitter deficits [ 8 , 9 ]. The first and so far sole marketed anti-Alzheimer drugs are the AChE inhibitors donepezil, rivastigmine, and galantamine, which increase the ACh levels [ 10 ]; these drugs, however, are effective only for symptomatic treatment of AD, since they are not able to prevent the progression of the disease. Other drugs, such as memantine, have proved to be effective in the treatment of both mild and moderate-to-severe AD by reducing excitotoxicity [ 11 ].…”