CHF2819: pharmacological profile of a novel acetylcholinesterase inhibitor.
ABSTRACT CHF2819 is a novel orally active acetylcholinesterase inhibitor (AChEI) developed for the treatment of Alzheimer's disease (AD). CHF2819 is a selective inhibitor of AChE, it is 115 times more potent against this enzyme than against butyrylcholinesterase (BuChE). Moreover, CHF2819 is more selective for inhibition of central (brain) AChE than peripheral (heart) AChE. In vivo CHF2819, 0.5, 1.5, and 4.5 mg/kg p.o., significantly and in dose-dependent manner increased acetylcholine (ACh) levels in hippocampus of young adult rats. Moreover, aging animals, with lower basal ACh levels than young adult rats, also exhibit a marked increase in hippocampal levels of this neurotransmitter after administration of CHF2819. At 1.5 mg/kg p.o. CHF2819 attenuated scopolamine-induced amnesia in a passive avoidance task. Furthermore, it decreased dopamine (DA) levels and increased extracellular levels of 5-hydroxytryptamine (5-HT) in the hippocampus, without modifying norepinephrine (NE) levels. By oral administration to young adult rats CHF2819 did not affect extracellular hippocampal levels of glutamate (Glu), aspartate (Asp), gamma-aminobutyric acid (GABA), taurine (Tau), arginine (Arg) or citrulline (Cit). Functional observational battery (FOB) screening demonstrated that CHF2819 (1.5 and 4.5 mg/kg p.o.) does not affect activity, excitability, autonomic, neuromuscular, and sensorimotor domains, as well as physiological endpoints (body weight and temperature). CHF2819 induced, however, involuntary motor movements (ranging from mild tremors to myoclonic jerks) in a dose-dependent manner. The neurochemical and behavioral profiles of CHF2819 suggest that this orally active novel AChEI could be of clinical interest for the treatment of Alzheimer-type dementia associated with multiple neurotransmitter abnormalities in the brain. In particular, CHF2819 might be a useful therapeutic drug for AD patients with cognitive impairment accompanied by depression.
- SourceAvailable from: Sibhghatulla Shaikh[Show abstract] [Hide abstract]
ABSTRACT: This review presents a concise update on the inhibitors of the neuroenzyme, Acetylcholinesterase (AChE; EC 126.96.36.199). AChE is a serine protease, which hydrolyses Acetylcholine neurotransmitter into Acetate & Choline & hence, terminates neurotransmission. Molecular interactions (mode of binding to the target enzyme), clinical applications and limitations have been summarized for each of the inhibitors discussed. Traditional inhibitors (e.g. Physostigmine, Tacrine, Donepezil, Rivastigmine etc.) as well as novel inhibitors like various Physostigmine-derivatives have been covered. This is followed by a short glimpse on inhibitors derived from nature (e.g. Huperzine A & B, Galangin). Also, a discussion on 'hybrids of pre existing drugs' has been incorporated. Furthermore, current status of therapeutic applications of AChE-inhibitors has also been summarized.CNS & neurological disorders drug targets 01/2014; 13(3):391-401. · 3.57 Impact Factor
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ABSTRACT: The therapeutic approach for improving the cognitive function in patients with Alzheimer's disease (AD) is mainly based on the potentiation of central cholinergic activity and is achieved clinically by the use of acetylcholinesterase (AChE) inhibitors such as tacrine, donepezil, rivastigmine, galantamine and other drugs currently in clinical trials. These are, by their pharmacology, only symptomatic drugs yet recently these molecules have shown some potential also in the modulation of amyloid precursor protein (APP) processing. We explore in this review the experimental evidence that suggests a role for AChEIs in APP processing and point to multiple complex mechanisms involving either a cholinergic agonist effect, coupled to multiple signal transduction pathways, or post-transcriptional effects that modulate the expression of cellular APP.Pharmacological Research 11/2004; 50(4):441-51. · 4.35 Impact Factor
- Journal of the College of Physicians and Surgeons--Pakistan : JCPSP. 07/2012; 22(7):476-7.
CHF2819: Pharmacological Profile
of a Novel Acetylcholinesterase Inhibitor
Luigia Trabace, Tommaso Cassano, Antonia Loverre,
Luca Steardo1, and Vincenzo Cuomo
Department of Pharmacology and Human Physiology, University of Bari, Bari, Italy;
1Department of Pharmacological Sciences, University of Palermo, Palermo, Italy
Key Words: Acetylcholinesterase inhibitors—Alzheimer’s disease—Amino acids—CHF2819—
CHF2819 is a novel orally active acetylcholinesterase inhibitor (AChEI) developed for
the treatment of Alzheimer’s disease (AD). CHF2819 is a selective inhibitor of AChE, it is
115 times more potent against this enzyme than against butyrylcholinesterase (BuChE).
Moreover, CHF2819 is more selective for inhibition of central (brain) AChE than pe-
ripheral (heart) AChE. In vivo CHF2819, 0.5, 1.5, and 4.5 mg?kg p.o., significantly and in
dose-dependent manner increased acetylcholine (ACh) levels in hippocampus of young
adult rats. Moreover, aging animals, with lower basal ACh levels than young adult rats,
also exhibit a marked increase in hippocampal levels of this neurotransmitter after admi-
nistration of CHF2819. At 1.5 mg?kg p.o. CHF2819 attenuated scopolamine-induced am-
nesia in a passive avoidance task. Furthermore, it decreased dopamine (DA) levels and in-
creased extracellular levels of 5-hydroxytryptamine (5-HT) in the hippocampus, without
modifying norepinephrine (NE) levels. By oral administration to young adult rats
CHF2819 did not affect extracellular hippocampal levels of glutamate (Glu), aspartate
(Asp), ã-aminobutyric acid (GABA), taurine (Tau), arginine (Arg) or citrulline (Cit).
Functional observational battery (FOB) screening demonstrated that CHF2819 (1.5 and
4.5 mg?kg p.o.) does not affect activity, excitability, autonomic, neuromuscular, and sen-
sorimotor domains, as well as physiological endpoints (body weight and temperature).
CHF2819 induced, however, involuntary motor movements (ranging from mild tremors to
myoclonic jerks) in a dose-dependent manner.
The neurochemical and behavioral profiles of CHF2819 suggest that this orally active
novel AChEI could be of clinical interest for the treatment of Alzheimer-type dementia as-
CNS Drug Reviews
Vol. 8, No.1, pp. 53–69
© 2002 Neva Press, Branford, Connecticut
Address correspondence and reprint requests to: Luigia Trabace, Ph. D., Dept. of Pharmacology and Human
Physiology, Medical School, University of Bari, Policlinico. Piazza Giulio Cesare 11, 70124 Bari, Italy.
Tel.: +39 (080) 547-8439; Fax: +39 (080) 547-8444; E-mail: firstname.lastname@example.org
sociated with multiple neurotransmitter abnormalities in the brain. In particular, CHF2819
might be a useful therapeutic drug for AD patients with cognitive impairment accom-
panied by depression.
Alzheimer’s disease (AD), the main cause of senile dementia, is a progressive neuro-
degenerative disorder the incidence of which increased steadily over the last decades. This
disease attacks the brain resulting in demented patients with cognitive impairment, dis-
ability in daily living skills and, often, behavioral consequences. Some of the important
clinical features of dementia are impairments in short-term and long-term memory, ab-
stract thinking and judgement, disturbances of the cortical and hippocampal functions and
personality changes. The high prevalence, the degenerative component of the disease, as
well as its social and familial implications, suggest that the economic impact of the
disease may be dramatic for society, health insurance systems, patients and their families.
The pathogenesis and the etiology of AD remain unknown, although it has been sug-
gested that “cholinergic deficit” contributes to the progress of the disease (49). In fact,
among multiple transmitter deficits in AD, one of the most specific and consistent features
is an early and severe degeneration of the forebrain cholinergic system. This degeneration
has been revealed by the correlation that exists between the cholinergic pathology and de-
mentia (17). Therefore, the enhancement of brain cholinergic transmission in AD remains
a major goal for many putative therapeutic agents that are in use or under development.
Acetylcholinesterase inhibitors (AChEIs) are, so far, the only drugs demonstrating cli-
nical efficacy in the treatment of AD. In this regard, AChE has long been an attractive
target for the rational design of mechanism-based inhibitors due to the pivotal role it plays
in the central nervous system (CNS). By reducing ACh hydrolysis AChE inhibition en-
hances the function of central cholinergic neurons by permitting acetylcholine (ACh) to
remain in the synaptic cleft longer. Currently, only the AChE inhibition approach seems to
produce encouraging symptomatic improvements in clinical trials. In fact, the resulting in-
crease in extracellular ACh concentrations might reverse central cholinergic hypofunction
and improve cognitive functions in AD (30). However, the clinical usefulness of AChEIs
has been limited by either an extremely short or excessively long half-life, hepatotoxicity
or severe peripheral cholinergic side effects of the available compounds (18,30). For these
reasons, much effort is being directed to the development of novel AChEIs which enter
the CNS in sufficiently high concentrations to produce a therapeutic effect, have adequate
duration of action, but cause less peripheral cholinergic side effects than currently avai-
It has been demonstrated that AD is characterized by a heterogeneous etiopathogenesis.
The most prominent neuropathological hallmarks of AD are senile plaques, neurofibrillary
tangles (NFTs), amyloid deposition in neural tissues and vessels, synaptic loss and subse-
quent neuronal death (4). Furthermore, as demonstrated by both in vitro (35) and in vivo
studies (42), â-amyloid deposition in AD brain has been linked to AChE expression
through an AChE-â-amyloid cycle process. Indeed, it has been proposed that AChE co-
localizes with â-amyloid and accelerates â-amyloid formation and deposition in AD brain.
Reciprocally, â-amyloid protein regulates AChE expression, assembly and glycosylation.
CNS Drug Reviews, Vol. 8, No. 1, 2002
54 L. TRABACE ET AL.
As a result, AChE which is expressed around neuritic plaques influences â-amyloid for-
mation which in turn stimulates AChE formation. Inhibition of AChE may, therefore,
affect â-amyloid precursor protein (APP) processing and â-amyloid deposition. Another
feature of AChEIs is their ability to enhance the release of non-amyloidogenic soluble de-
rivatives of APP from cortex (42). Secretion of APP can be increased in the brain by acti-
vation of muscarinic receptors (type 1) and subsequent protein phosphorylation or through
direct activation of nicotinic receptors. By increasing ACh levels in brain cortex AChEIs
have been shown to increase basal release of non-amyloidogenic amino-terminal soluble
derivatives. This specific effect could concomitantly decrease the formation of amyloido-
genic compounds in AD brain (42). The same mechanism may also explain the stabilizing
effect on cognitive deterioration seen during the first 6 to 12 months of AChEI therapy (19).
Several neurochemical mechanisms may account for cell death and neurodegeneration
in AD, including neuroimmune dysfunction, free radical formation as well as neurotrans-
mitter deficits (4). In addition to cholinergic transmission deficits, non-cholinergic neuro-
chemical abnormalities have been identified in AD. These abnormalities may contribute to
the behavioral and cognitive disorders associated with AD (5,67). It is, therefore, likely
that the efficacy of AChEIs in the treatment of demented patients could be due not only to
cholinesterase inhibition, but also to other neurochemical effects of these drugs.
Moreover, there has been also considerable interest in the involvement of excitatory
amino acids in the pathogenesis of neurodegenerative diseases, such as AD (44). In fact,
in AD, cortical and hippocampal pyramidal neurons, which are particularly affected by
NFTs and neuronal degeneration, use glutamate (Glu) or aspartate (Asp) as neurotrans-
mitters (38). It has been shown that the distribution of senile plaques in the AD brain cor-
relates with the distribution of glutaminergic synapses (55). Glu signal transduction at the
postsynaptic terminals is initiated by stimulation of Glu receptors, especially of N-methyl-
D-aspartate (NMDA) subtype. In the case of hyperactivity of Glu neurotransmission (44),
that is likely to occur in AD, the excessive intracellular calcium accumulation leads to
an abnormal activation of calcium-dependent enzymes, such as neuronal nitric oxide
synthase (nNOS). This enzyme catalyzes the formation of nitric oxide (NO) and citrulline
(Cit) from L-arginine (Arg). It has been suggested that taurine (Tau)-containing neurons
could also be involved in this pathological process (34). Taken together, these data suggest
a role for amino acids in the clinical manifestation and pathogenesis of AD (44) as an al-
ternative (not necessarily exclusive) to the cholinergic hypothesis.
This review describes the biochemical and neurobehavioral profile of CHF2819
(ganstigmine, Fig. 1), a novel geneserine derivative with AChE inhibitory activity (50).
CNS Drug Reviews, Vol. 8, No. 1, 2002
Fig. 1. Chemical structure of CHF2819.
Geneserine is one of the major alkaloids found in Calabar beans and shows different de-
grees of AChE inhibitory activity. Geneserine was reported to be a weak AChEI in in vitro
studies, when compared to physostigmine (53), whereas a significant inhibition of plasma
AChE by this drug has been demonstrated in healthy volunteers (1). The in vitro inhibition
of the AChE by CHF2819 in human plasma and erythrocytes has been evaluated and the
ex vivo inhibition of rat brain and of peripheral AChE has been also studied (50).
CHF2819 was further characterized by in vivo microdialysis. The drug was administered
by either oral route or by local infusion using dialysis probe. The extracellular concentra-
tions of ACh were measured in hippocampus of freely moving young adult rats (59). This
study was followed by investigation of behavioral correlates of central cholinergic
function in young adult rats using scopolamine-induced amnesia in a passive avoidance
task (59). Since AChEIs, as well as other drugs acting on cholinergic neurons, (51,56,62)
are known to restore extracellular ACh levels in aging rats, the effects of CHF2819 on
extracellular ACh levels in the hippocampus of aging rats were evaluated (59). In addition,
the effects of CHF2819 on extracellular concentrations of dopamine (DA), 5-hydro-
xytryptamine (5-HT), norepinephrine (NE), Glu, Asp, ã-aminobutyric acid (GABA), Tau,
Arg, and Cit in the hippocampus of young adult rats were studied (59,61). Finally, a func-
tional observational battery (FOB) of tests was used to assess functional domains (sensory,
motor and autonomic) in young adult rats in order to investigate potential neurotoxic ef-
fects of CHF2819 (59).
CHF2819 is a white to whitish crystalline powder. It was synthesized at Chiesi
Farmaceutici S.p.A. The chemical name of CHF2819 is (–)-(3aS,8aS,1S)-1,2,3,3a,8,8a-
hydrochloride (Fig. 1). This compound has a molecular weight of 417.93 and its empirical
formula is C22H27N3O3·HCl. It is sparingly soluble in water, freely soluble in ethanol, and
insoluble in ethyl acetate and toluene.
The inhibition of AChE by CHF2819 has been evaluated in vitro in human erythrocytes
and plasma. It inhibited AChE with IC50values at the ìM level. CHF2819 was 2.6-fold
less potent than physostigmine in inhibiting AChE and 1,041-fold less potent in inhibiting
BuChE. CHF2819 appeared to be a selective inhibitor of AChE, since it was 115 times
more potent against this enzyme than against BuChE (50).
AChE inhibition by CHF2819 has been also evaluated ex vivo in rat brain and heart.
The time course of ex vivo AChE inhibitory activity was investigated in rat brain after oral
administration of the compound at a dose equal to one-fifth of its LD50value. CHF2819
exhibited significant activity for up to 16 h after its administration; peak AChE inhibition
was 34%. To study the selectivity of this compound in inhibiting central rather than pe-
CNS Drug Reviews, Vol. 8, No. 1, 2002
56L. TRABACE ET AL.
ripheral AChE, dose-response curves for AChE inhibition were compared at the time of
peak effect on rat brain and heart homogenates. CHF2819 inhibited brain AChE, with an
ED50of 1.5 and 95% confidence limits of 0.4 to 3.7 mg?kg p.o. In the heart homogenates,
CHF2819 was almost inactive (50).
The above mentioned results of in vitro experiments can be discussed in relation to the
ex vivo data obtained in both rat brain and heart homogenates. CHF2819 was endowed
with a significant by longer duration of rat brain AChE inhibitory activity compared, than,
for example, with physostigmine. Indeed, the aryl substitution of the carbamoyl group of
physostigmine resulted in a compound with long-lasting inhibition of AChE. The pro-
totype of this class of compounds is phenserine (phenyl-physostigmine) that was reported
to inhibit rat brain and plasma AChE for 8 and 6 h after oral administration, respectively
(24). By contrast, the duration of action of physostigmine was significantly shorter. This
result is correlated with the low bioavailability of physostigmine and also with the fact
that the fast kinetics of carbamylation is counterbalanced by a rise of the decarbamylation
process (48). In this regard, further studies are necessary to elucidate the mechanistic in-
teractions between CHF2819 and AChE. The observed features of the kinetics of AChE
inhibition should have a relevant influence on the therapeutic action of this kind of
molecule, since strong and long-lasting inhibitory effects are required for AChEIs to be
suitable for AD therapy.
In addition to the kinetic profile, another important aspect of AChEIs is their selective
activity in inhibiting the enzyme in the brain, rather than in the peripheral organs. Such a
selective inhibition results in a decrease of the peripheral cholinergic effects and toxicity.
In this respect, CHF2819 appears to inhibit central (brain) more than peripheral (heart)
AChE. This activity might be correlated with its in vitro selective inhibition of AChE
rather than of BuChE.
Effects on Cholinergic System
The effects of CHF2819 on the extracellular ACh concentrations were investigated in
the conscious rat hippocampus using in vivo microdialysis. ACh concentrations were de-
termined by microbore high performance liquid chromatography (HPLC), as previously
The development of a novel AChEI, which is orally active, efficacious, well tolerated
and relatively safe, remains a major therapeutic goal in the treatment of AD and is im-
portant for further validation of the cholinergic deficit hypothesis of AD. The present
review suggests that the novel geneserine derivative, CHF2819, is, in this respect, an im-
portant candidate. Indeed, results have shown clearly that, in the hippocampus of both
young and aging rats, CHF2819, administered either systemically or by local infusion, po-
tently increases extracellular ACh levels. The highly sensitive detection methods used for
determining ACh concentrations in the microdialysis samples made it possible to de-
termine these effects without addition of other AChEIs. The use of such additional inhi-
bitors has often restricted interpretation of previous studies of ACh release. The addition
of neostigmine or physostigmine has been reported to alter ACh release profiles (13) and
CNS Drug Reviews, Vol. 8, No. 1, 2002