LOW- DOSE LITHIUM FOR THE TREATMENT OF NEURODEGENERATIVE DISORDERS
FIELD OF THE INVENTION
The present invention relates a method for treating neurodegenerative or related disorders by administering low doses of lithium. The invention also relates to pharmaceutical or dietary compositions comprising low content of lithium and uses thereof. BACKGROUND OF THE INVENTION
Lithium (Li) is the lightest metal and the less dense solid element. Lithium is one of the primordial elements produced in Big Bang nucleosynthesis, so is widely distributed on Earth but does not naturally occur in elemental form due to its reactivity. It is used in various applications: batteries, metal alloys, glass manufacture and clinical use (see below).
Lithium extraction takes place mainly in North and South America from rocks and brines associated with volcanic activity and aridity. Only less than 1% of the production is used in medicine (Birch and Jenner, 1973).
Lithium occurs naturally in biological tissues and hence is incorporated into foodstuffs. It occurs widely in drinking water, usually at low concentrations.
In medicine, lithium is a classic mood stabilizer and it was the first drug approved by the Food and Drug Administration (FDA) in 1971 for maintenance treatment of bipolar illness. It has acute antimanic and antidepressant effects and long term prophylactic effects (Marmol, 2008). Lithium exhibits a narrow therapeutic window, even at the therapeutic blood concentration, between 0.5-1.5 mEq Li/L, first various side effects commonly appear, necessitating close monitoring of the patients and repeated blood dosage of the lithium (Berthaud et al, 2000). Various orally administered formulations as well as transdermal delivery systems, such as dermal patch (see US 6,375,990), comprising lithium have been proposed or developed as to overcome or at least reduce said side effects.
Other data dealing with the nutritional aspect of lithium suggest effects of dietary lithium upon mood and behaviour (Schrauzer and de Vroey, 1994; Schrauzer and Shrestha, 1990; Fierro, 1988. ..).
Lithium in the bipolar disorder treatment
The main activity of lithium is the mood regulation. It was studied in in vitro or animal's models for fifty years and more than 600 publications are available (PubMed source).
The basis of Lithium therapeutic action remains unresolved, but accumulating evidences suggest that biochemical and biological effects of lithium in the brain include (Gould et al, 2004 ; Quiroz et al, 2004):
• interaction with Glycogen Synthase Kinase-3 (GSK-3) signalling and ion dysregulation,
• effects on neurotransmitter signalling like dopamine or serotonin,
• interaction with the adenylyl cyclase system,
• inositol phosphate and protein kinase C signalling,
• possible effects on arachidonic acid metabolism.
Among these, down regulation of GSK-3 activity suggests a prevention of apoptosis- dependent cellular death. Other results demonstrated that lithium works against the deleterious excitotoxic effects of glutamate and N-Methyl-D-Aspartic acid (NMD A) receptor activation and enhances the neuroprotective Bcl-2 and Brain-Derived Neurotrophic Factor (BDNF) level expression.
In order to exhibit a therapeutic effect, the lithium blood concentrations must be between 0.5 to 1.5 mEq Li/L (recommended starting dose around 150 mg Li/d). Unless otherwise specified, the letter d stands for day in the present document. Even within this therapeutic range, mild neurological side effects such as hand tremor are common, and progressive toxicity to marked neurological impairment correlates with increasing serum levels above 1.5 mEq Li/L. Numerous patients present moderate nephrogenic diabetes insipidus (25%), fine hand tremor (15%), weight gain (10-20%>), increase TSH value (5-10%), hypothyreosis (5%) and diarrhoea (5%). Mild toxic effects appear at blood concentration equal or higher to 1.5 mEq Li/L, just above the therapeutic window. The common toxic effects of lithium are renal toxicity, from common polyuria-polydipsia to renal insufficiency; neurotoxicity as tremor, lethargy, irritability, muscle weakness and slurred speech; hypothyroidism; gastrointestinal effects as vomiting, diarrhoea (see Tables 1 and 2 below).
Lithium is almost completely absorbed by gastrointestinal tract after oral administration and is not metabolized. It has a volume of distribution equivalent to sodium, corresponding to the total body water volume. The half-life of lithium elimination increases with use: from 24 hours to 58 hours after 1-year treatment. Elimination is principally renal (95%), with significant reabsorption (about 80%) in proximal renal tubili, closely associated to sodium homeostasis. The alteration in sodium balance or renal affection could increase the blood lithium concentration and lead to toxic effect.
Lithium in neuroprotective treatment
Lithium and Huntington's disease
Huntington's disease (HD), also named Huntington's chorea, is a genetic disorder with autosomal dominant inheritance. The disease occurs mainly in midlife and is invariably fatal 15-20 years after the onset of the first symptoms. The clinical symptoms are characterized by progressive motor impairment (involuntary movements, chorea, dyskinesia, dystonia), psychiatric disturbances (change in mood, depression...) and cognitive decline (memory loss, slowed thinking, speech disturbance, overall decline in executive functions,...) (Walker, 2007; Warby et al, 2007).
The pathological hallmark of HD is the gradual atrophy of the striatum (caudate nucleus and putamen). GABAergic projection medium-sized spiny neurons (MSNs), which correspond to
95% of the striatal neuronal population, are most severely affected. Other areas affected include the substantia nigra, layers 3, 5 and 6 of the cerebral cortex, hippocampus, purkinje cells in the cerebellum, lateral tuberal nuclei of the hypothalamus and parts of the thalamus.
Dysfunction and/or death of these specific neuronal types and brain regions caused the neuropsychiatric changes described above (Walker, 2007; Warby et al, 2007).
At the present time, symptomatic treatments are the only options available. Effective therapies are still necessary.
With respect to lithium in the Huntington's disease, various studies were performed in vitro, non mammalian and mammalian models during the last 10 years by independent investigators (Tables 3 and 4). It has been demonstrated that lithium decreases protein aggregates (Carmichael et al., 2002; Sarkar et al, 2008). In non mammalian models, lithium shows a
neuroprotective effect promoting rhabdomeres in a drosophilia transgenic model (Berger et ai, 2005; Sarkar et ai, 2008) or neuronal survival in a C. Elegans transgenic model (Voisine et aL, 2007).
The neuroprotective effect of lithium is confirmed in mammalian models, decreasing induced lesion in a chemical model of HD in rat (Senatorov et al, 2004; Wei et al., 2001) or decreasing the course of the disease in a transgenic mouse model (Wood and Morton, 2003). In this last study, authors described toxic effects of a long term lithium treatment: some animals presented a weight loss (anorexic effect of lithium) inducing premature death. It is interesting to note that transgenic animals were more sensitive to lithium toxicity than wild type animals.
In these publications various mechanisms of actions were studied and some were correlated to the neuroprotective activity of lithium as the inhibition of GSK3B, the increase of autophagy, the increase of Bcl-2 protein levels, the inhibition of apoptosis and the stimulation of the neuronal and astroglial progenitor proliferation.
Due to the occurrence of side effects after a long term treatment and toxic effects hazard, the lithium treatment is not lauded by medical doctors as a neuroprotective treatment, according to the beneficial/ risk ratio. Lithium and Multiple Sclerosis
Multiple Sclerosis is a chronic inflammatory disease of the brain and spinal cord, which leads to multifocal lesions in the white and grey matter with focal lymphocytic infiltrations leading to damage of myelin and axons (Compston and Coles, 2008).
Multiple Sclerosis (MS) is characterised by multiple inflammatory lesions affecting preferentially white matter in the central nervous system (CNS), rich in myelin. Myelin has the role of facilitating nerve conductivity by forming an isolating cover around axons. It is destroyed by immune cells (principally macrophages and T lymphocytes) infiltrating the CNS, which is followed by formation of plaques, which in early stages of the disease form scars without subsequent loss of nerve function. Most often, the dissemination of these plaques throughout the CNS over time allows a clinical diagnostic of the disease. For ten years, it is known that these lesions lead to a diffuse loss in function of nerve function (preferentially that of axons). This nerve damage, or neurodegeneration, is responsible for the permanent neurological handicap observed in certain forms of the disease.
From a clinical point of view, in the majority of cases, the disease evolves initially in spurts (acute phases) during which one or more types of temporary central neurodeficiency can be observed, lasting from a few days to a few months. A remission phase follows each acute phase allowing recovery of neurological function. However, over several years, the remission periods become only partial and the disease enters into a chronic phase leading to growing invalidity and finally total handicap. The acute phase frequency and the nature of the evolution of the disease vary between individuals considerably. Some forms have a little impact for a significant period of time, whereas some forms become rapidly handicapping. In general (70% of cases), the first acute phase appears between 20 and 40 years of age and in the majority of cases in women (66% of cases).
There are four main forms of MS:
- Benign form: one or more acute events without resulting invalidity.
- Remittent form (the most frequent form): a succession of acute events and remissions; with incomplete remissions after a certain period of time. A progressive invalidity is manifested. - Progressive remittent form: acute phase events overlying a slow evolution of the chronic phase.
- Progressive form: continuous and progressive aggravation without acute events.
The clinical signs of the disease are varied: pyramidal syndrome, optical neuritis, hypoesthesia, trembling, cerebella disorders, etc.
The prescribed treatments for MS are i) relatively inefficacious for the progressive forms of the disease, ii) susceptible to provoke major perturbations within the immune system with severe associated side effects. The majority of MS related experimental studies relies on the model of Experimental Autoimmune Encephalomyelitis (EAE). This model reflects the clinical, immunological and neuropathological features.
The neuroprotective effect of lithium was demonstrated in an induced model of EAE (De sarno et al, 2008) at dose commonly used to treat bipolar disorders. Pretreatment suppressed the clinical symptoms induced by Myelin Oligodendrocyte Glycoprotein (MOG) peptide immunization and greatly reduced microglia activation, demyelination and leukocytes infiltration in the spinal cord. Administrated postimmunization, after disease onset, lithium
reduced disease severity and facilitated partial recovery. Furthermore, lithium administration was shown to control relapsing EAE.
Lithium and other neurodegenerative diseases
Amyotrophic Lateral Sclerosis (ALS) is characterized by loss of motor neurons in the spinal cord, brainstem, and motor cortex leading to a progressive and ultimately fatal loss of function, resulting in death typically within 3 to 5 years of diagnosis. The disease starts with a focal centre of weakness, such as one limb, and appears to spread to other parts of the body (Ince et al, 1998). The cause of the disease is still not known, increasing evidence suggesting that ALS is a multifactorial disease. Approximately 10-20% of all ALS cases are familial. Mutations in superoxide dismutase 1 (SODl) are known to cause disease and it is generally accepted they lead to pathology not by loss of enzymatic activity but by gain of some unknown toxic function(s). For example, it has been recently shown that lithium carbonate, given to presymptomatic SODl G93A transgenic mice, was able to remarkably increase their lifespan (+35%) with a modest effect in delaying symptoms onset (+8%) (Fornay et al, 2008). The neuroprotective effect lithium was confirmed by two other studies (Shin et al, 2007; Feng et al, 2008).
Alzheimer's disease (AD) is a neurodegenerative brain disorder causing neuronal dysfunction and ultimately cell death, giving rise to dementia.
It is characterized by the presence of two types of abnormal protein deposits: amyloid or senile plaques and neurofibrillary tangles. Senile plaques are extracellular and mainly composed of the amyloid (Αβ ϋ peptides as the major components) (Hardy and Higgins, 1992), whereas neurofibrillary tangles (NFT) are intracellular aggregates of fibrils mainly composed by the microtubule-associated protein tau in hyperphosphorylated form (Grundke- Iqbal et al, 1986). In vivo studies in different transgenic mice models, showed that lithium, as a potent inhibitor of GSK-3, a protein kinase implicated in the pathogenesis of AD, could be a combined therapeutic agent, inhibiting the phosphorylation of tau and/or the production of Αβ peptides (Ghosal et al, 2009; Caccamo et al, 2007; Rockenstein et al, 2007...). Furthermore, conflicting results were shown in clinical trials.
Lithium efficacy in others neurodegenerative diseases such as Ataxia, Parkinson's disease (PD) and Prion diseases were the subject of others studies (Watase et al, 2007; Heiseke et al, 2009; Youdim and Arraf, 2004...).
Tables 1-6 are general tables summarizing lithium toxicity and studies dealing with lithium in cell lines, non-mammalian or mammalian models for neurodegenerative disorders.
There is currently a renewed interest in lithium not only for treatment of bipolar disorder but also for treatment of neurodegenerative disorders, such as Huntington's disease, Amyotrophic Lateral Sclerosis, Alzheimer disease, Parkinson's disease, Prion diseases, Ataxia or neurodegenerative related disorders, such as Multiple Sclerosis. This renewed interest is mainly due to in vitro and in vivo studies supporting the notion that lithium has neuroprotective effects provided through multiple intersecting mechanisms.
These results suggest that one of the oldest psychiatric treatments may be of considerable interest in the treatment of chronic neurodegenerative disorders. However, because lithium is quite toxic at a serum level which is not much higher than the level needed to reach the "therapeutic range", its clinical use has been limited so far to the treatment of bipolar disorders.
The present invention relates to the possibility of increasing the beneficial/risk ratio of lithium, making its use possible for the treatment of neurodegenerative diseases or related diseases.
Indeed, the inventor discovered that lithium has a neuroprotective effect in animal models using doses from 250 to around 400 times lower than those previously reported in the literature. Consequently, toxicity commonly associated with lithium can be vastly reduced by using doses lower than those conceivable or suggested by the literature to be efficient in the treatment of neurodegenerative diseases or related diseases.
Acute toxicity LD50 in rat and rabbit = 13.5 to 20 mEq/ kg
Symptoms of acute toxicity: salivation, diarrhoea, gastro-enteritis, decrease in food and water consumption, anuria, ataxia and depression
Chronic toxicity After chronic exposure in rat: lithium accumulation and irreversible (5 mEq Li/kg) or reversible (3 mEq Li/kg) deterioration of renal function
No morphological change in brain
Mutagenicity Lack of mutagenicity at therapeutic dose (0.6 to 1.5 mEq Li/ kg)
Teratogenicity Lithium is teratogenic (passing the placenta) at therapeutic dose (0.6 to 1.5 mEq Li/ kg) inducing cardiovascular malformation
Cancerogenicity Lack of cancerogenicity at therapeutic dose (0.6 to 1.5 mEq Li/ kg)
Toxicokinetics of lithium The lithium reabsorption in the proximal renal tubuli is closely associated to sodium homeostasis: alteration in sodium balance or renal affection could increase the blood lithium concentration and lead to toxic effect
Table 1 : Lithium toxicity in animal, from Berthaud et al., 2000; Lagerkvist and Lindell, 2002
Acute toxicity Clinical symptoms of toxicity appear at 4mEq Li/ L serum level. Symptoms: diarrhoea, vomiting
Chronic toxicity Serum Li concentrations defining intoxication levels:
1.5 to 2 mEq Li/ L = mild
2 to 2.5 mEq Li/L = moderate
> 2.5 mEq Li/L = severe
Common toxic effects:
Renal toxicity: from common polyuria-polydipsia to renal insufficiency
Neurotoxicity: tremor, lethargy, irritability, muscle weakness and slurred speech
Gastrointestinal effects: vomiting, diarrhoea
Mutagenicity Lack of mutagenicity at therapeutic dose
(< 1.5 mEq Li/ L serum level)
Teratogenicity Low risk of teratogenic effects (foetal cardiovascular malformation) at therapeutic dose (<1.5 mEq Li/L serum level)
Cancerogenicity Lack of cancerogenicity at therapeutic dose (<1.5 mEq Li/ L serum level)
Side effects and prevalence At 0.5 to 0.8 mEq Li/L serum level: Moderate nephrogenic diadetes insipidus (25%), fine hand tremor (15%o), weight gain
(10-20%o), increase TSH value (5-10%o), hypothyreosis (5%>) and diarrhoea (5%>)
Local toxicity Corrosive to mucosa of respiratory tract and eyes and to the skin due to alkalinity
Table 2: Lithium toxicity in human, from Berthaud et al., 2000; Lagerkvist and Lindell, 2002
STUDY (CARMICHAEL ET AL.,
REFERENCE (BERGER ET AL., 2005) (VOISINE ET AL., 2007) (SARKAR ET AL., 2008)
African green monkey Drosophilia model of HD C. Elegans model of Mouse embryonic Drosophilia model of HD species
kidney cells (COS-7) and (gmr-httQ120) HD (Htn-Q150(rtIsl l)) fibroblasts (MEFs) and (gmr-httQ120) human neuroblastoma cells african green monkey
(SKNSH) kidney cells (COS-7)
300-400 cells/ experiment, -900 flies / / /
Transfection with HD exon Transgenic: expression of Transgenic Transfection with HD Transgenic: expression of 1 the N-terminal part of exon 1 fragment the N-terminal part of mutant huntingtin mutant huntingtin
2.5 or 5 mM LiCl in 0.5-1.5 mM LiCl in fly 10-100 mM LiCl in 10 mM LiCl in medium 4.2 mM lithium in fly food medium food food
Pretreatment (3 days prior Larval and adult stages 3 to 7 days 24 hours Larval and adult stages duration
transfection) and during
experimental period (48
nuclear fragmentation † of visible rhabdomeres † of neuronal survival †level of LC3-II † of visible rhabdomeres (effects) Ί
(Compared to Ί inclusion formation † of p70S6K
Lithium protects against Lithium attenuates toxicity Neuroprotective effect Lithium protects against Neuroprotective effect of polyglutamine toxicity of polyglutamine protein of lithium, dose polyglutamine toxicity lithium
aggregate, passing by dependent effect increasing autophagy
(association with inhibition of GSK3B
rapamycin increase effect)
Toxicity / / > 100 mM: death / /
Table 3: Overview of lithium efficacy in cell lines and non mammalian models of Huntington's disease. (-1 is reduction;† is increase)
STUDY REFERENCE (WEI ET AL., 2001) (WOOD AND MORTON 2003) (SENATOROV ET AL., 2004
Species, breed Sprague Dawley rats Transgenic mice model of HD (R6/2) Sprague Dawley rats
HD induction Chemical rat model of HD Chemical rat model of HD
(intrastriatal injection of Transgenic mice model of HD (R6/2) (intrastriatal injection of quinoli quinolinic acid) acid)
Daily dose LiCl at : 1.5 (day 1-4), 2.3 (day 5- LiCl at 0.5; 1; 2 or 3 mEq Li/kg
LiCl at 1.5 (first day) and 2.3 (following days) mEq Li/ kg
11) or 3 mEq Li/kg (day 12-16)
Dosing duration daily for 16 days prior to QA Pre-symptomatic: daily from 5.5 Post-symptomatic : daily from 10 24 hours prior to QA injection injection weeks of age until death weeks of age until death + 1 hour after QA injection
Route s.c. s.c. s.c.
Results (effects) ^ of lesion size in striatum 7 days Ί of body weight † of body weight in some animals Ί of lesion area in striatum
(Compared to after QA injection
No effect on survival Ί of survival in lighter animals Ί of neuronal damage in striatu untreated) Ί of neuronal damage in striatum
No effect on rotarod performances † of motor performances Ί of caspase-3 activation
† Bcl-2 protein levels at any speed
Conclusion Neuroprotective effect of lithium 2 effects of chronic lithium = beneficial (improve of motor performances) Neuroprotective effect of lithiu pre-treatment in striatum detrimental (weight loss) striatum: inhibition of apoptosis stimulation of neuronal and astr
Neuroprotection associated to R6/2 mice are more sensitive to lithium than wild type animals progenitor proliferation increase in Bcl-2 protein levels
Mice are more sensitive than rats
Toxicity No effect on body weight = therapeutic concentration of bipolar disorder but lower dose (<3mEq) to None
avoid possibility of renal toxicity
2 effects of chronic lithium = beneficial and detrimental: mice more sensitive
to lithium than rats
Table 4: Overview of lithium efficacy in mammalian model of Huntington's disease (I is reduction;† is increase; sc is subcutaneous; QA is quinolei acid)
STUDY REFERENCE (SHIN ET AL., 2007) (FORNAY ET AL, 2008) (FENG ET AL., 2008)
Species, breed Transgenic mice model (G93A) Transgenic mice model (G93A) Transgenic mice model (G93A)
Daily dose Li2C03 at 5.3 mEq Li/kg/d Li2C03 at 1 mEq Li/kg/d LiCl at 2.8 mEq Li/kg/d
Dosing duration Daily from 8 weeks of age Daily from 75 days of age Daily from 30 days of age
Route p.o. (food) i.p. i.p.
Results (effects) No effect on oxidative stress at † of motor performances and survival † of motor performances and survival
(Compared to Ί of motor neuron loss
untreated) Ί of neuronal apoptosis
† of motor performances and
Ί of motor neuron loss (58%)
Conclusion Neuroprotective effect of lithium: Neuroprotective effect of lithium Neuroprotective effect of lithium
inhibition of apoptosis
Table 5: Overview of lithium efficacy in mammalian model of Amyotrophic Lateral Sclerosis. (-1 is reduction;† is increase; i.p. is intraperitonea p.o. is per os)
STUDY REFERENCE (CACCAMO ET AL., 2007) (ROCKENSTEIN ET AL., 2007) (GHOSAL ET AL., 2009)
Species, breed Transgenic mice model (3xTG- Transgenic mice model (hAPP) expressing Transgenic mice model (FeCy25 expressing
AD) expressing plaques and plaques APP intracellular domain)
Daily dose LiCl at =1.5 mEq Li/kg/d LiCl at =3 mEq Li/kg/d Li2C03 at 2.4g/kg of diet/d
Dosing duration Daily from 15 months of age Daily from 3 months of age until 6 months Daily from 7-8 months of age
Route i.p. i.p. p.o. (food)
Results (effects) No rescue of working memory Ί of Water Maze performance deficit † working memory
(Compared to Ί of Αβ protein pecusor production
untreated) Ί of Tau Phosphorylation
No effect on Αβ load
Conclusion Neuroprotective effect of lithium Neuroprotective effect of lithium Neuroprotective effect of lithium
at early stage of AD
Table 6: Overview of lithium efficacy in mammalian model of Alzheimer disease. (-1 is reduction;† is increase; i.p. is intraperitoneal; p.o. is per os)
SUMMARY OF THE INVENTION
The applicant has surprisingly found that lithium used in a low amount is efficient in treating neurodegenerative diseases or related disorders. The side effects and toxicity commonly associated with lithium are thus advantageously reduced or eliminated by using lower doses.
The present invention includes methods of treatment of neurodegenerative diseases or related disorders, comprising administering to a subject in need of such treatment lithium in a daily dose range from 100 to 10000 μg Li (i.e., from 14.4 to 1440 μΈq Li/d), preferably from 400 to 2400 μg Li (i.e., from 57.6 to 345.8 μΈq Li/d) and more preferably from 800 to 1200 μg Li (i.e., from 115.2 μEq Li d to 172.9 μEq Li/d).
Another aspect of the present invention is an article of manufacture that comprises a container, a pharmaceutical composition comprising lithium within the container and instructions to administer the pharmaceutical composition at a daily dose which is from 100 to 10000 μg Li (i.e., from 14.4 to 1440 μEq Li/d), preferably from 400 to 2400 μg Li (i.e., from 57.6 to 345.8 μΈq Li/d) and more preferably from 800 to 1200 μg Li (i.e., from 115.2 μΈq Li/d to 172.9 μΕ Li/d).
Typically, the amount of lithium administered daily will be from 100 to 10000 μg Li, dosed, preferably from 400 to 2400 μg Li, still more preferably from 800 to 1200 μg of Li.
The present invention also deals with lithium or a pharmaceutical or dietary composition comprising lithium for a use in the treatment of neurodegenerative diseases or related disorders as set out for the method of the invention.
According to a preferred embodiment, lithium is the sole active ingredient or therapy administered to a subject in need of such treatment.
Further aspects of the present invention provide use of lithium for the manufacture of a medicament for the treatment of neurodegenerative diseases or related disorders as set out for the method of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention includes methods of treatment of neurodegenerative diseases or related disorders, comprising administering to a subject in need of such treatment lithium in a daily dose range from 100 to 10000 μg Li, preferably from 400 to 2400 μg Li and more preferably from 800 to 1200 μg Li.
The invention also concerns lithium or composition comprising lithium for a use in the treatment of neurodegenerative diseases or related disorders, wherein lithium is administered at dose range from 100 to 10000 μg Li/d (from 14.4 to 1440 μΕ Li/d), preferably from 400 to 2400 μg Li/d (i.e., from 57.6 to 345.8 μEq Li d) and more preferably from 800 to 1200 μg Li/d (i.e., from 115.2 μEq Li/d to 172.9 μEq Li/d).
The present invention further includes the use of lithium for the manufacture of a medicament for the treatment of neurodegenerative diseases or related disorders as set out for the method of the invention.
The source of lithium is preferably a lithium derivative. By way of examples, particularly useful lithium derivatives according to the invention are selected from sulphate, hydrate, halide, in particular chloride, citrate, carbonate, acetate, gluconate, succinate, any other water- soluble lithium salt, and mixture thereof. Typically, the lithium salt is citrate or carbonate. It is also possible to use ammonium salts, methoxide of alkali metals or alkaline earth metals which can be dissolved in water or sometimes in alcohols. However water-soluble salts are preferred.
Preferably, the lithium according to the invention is not included in the composition in a micellar system.
An object of the invention concerns a pharmaceutical or dietary composition comprising lithium salt and at least a physiologically acceptable carrier, excipient or support.
According to the invention, lithium is included in a pharmaceutical or dietary composition. The pharmaceutical or dietary composition of the invention may be liquid, semi liquid, semi solid or solid. The pharmaceutical or dietary composition according to the invention comprises an efficient amount of lithium salt or derivative adapted to the dose range to be
administered daily as specified above. By way of examples, the pharmaceutical or dietary composition according to the invention comprises from 100 to 10000 μg of Li (from 14.4 to 1440 μEq Li), or from 600 to 1200 μg of Li (from 86.4 to 172.9 μEq Li), or from 50 to 500 μg Li (from 7.2 to 72.0 μEq Li) or from 25 to 300 μg Li (3.6 to 43.2 μΈq Li).
According to the invention, lithium or composition of the invention is administered in different ways and in different forms. For instance, they may be administered by the oral or systemic route, such as for example by the intravenous, intramuscular, subcutaneous, transdermal, permuqueous, intra-arterial route, etc. Preferably, lithium or composition of the invention is administered orally or applied topically onto the skin. These pharmaceutical forms are prepared using methods, which are routinely used by pharmacists. Lithium of the present invention can be administered using any physiologically, or more specifically pharmaceutically, acceptable dosage form known in the art for such administration. The vehicle may be any solution, suspension, powder, gel, etc., including isotonic solution, buffered and saline solutions, such as syrups or aqueous suspensions, etc.
The pharmaceutical or dietary composition of the invention is more convenient to an oral administration.
According to particular embodiments, the pharmaceutical or dietary composition is in the form of a capsule, a tablet, a caplet, an aerosol, a spray, a solution or a soft elastic gelatin capsule.
According to another particular embodiment, the lithium or composition comprising the same is in form of a patch. The patch can be applied onto the skin of a subject in need of such treatment. The topically applied patch according to said embodiment comprises an adhesive and a reservoir system comprising an efficient amount of lithium salt adapted to the dose range to be administered daily as specified above.
The terms "neurodegenerative disease", "neurodegenerative disorder" and related disorder or disease are used in the broadest sense to include all disorders the pathology of which involves neuronal degeneration and/or dysfunction, including, without limitation, peripheral neuropathies; motomeuron disorders, such as Amyotrophic Lateral Sclerosis, Bell's palsy, and various conditions involving spinal muscular atrophy or paralysis ; and other human neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Multiple Sclerosis, Huntington's chorea, dementia, Prion diseases, Meniere's disease and Ataxia.
"Peripheral neuropathy" is a neurodegenerative disorder that affects the peripheral nerves, most often manifested as one or a combination of motor, sensory, sensorimotor, or autonomic dysfunction. Peripheral neuropathies may, for example, be genetically acquired, can result from a systemic disease, or can be induced by a toxic agent, such as a neurotoxic drug, e. g. an antineoplastic agent, or industrial or environmental pollutant.
The invention relates more preferably to neurodegenerative disorders selected from Huntington's disease, Amyotrophic Lateral Sclerosis, Parkinson's disease, Multiple Sclerosis, dementia, Prion diseases, and Alzheimer's disease, and more specifically neurodegenerative disorders selected from Huntington's disease and Multiple Sclerosis.
The administration of lithium according to the invention can be repeated as determined by methods known in the art. The dosage regimen must be determined based on the individual circumstances.
In a particular embodiment, the administration to the subject is repeated at least one (e.g.: one, two or three) time, preferably only one time, a day, for one or several weeks, months or years, more specifically for a duration of at least two, three, four, or more years. It may be administered more specifically permanently.
"Subject" refers to an organism to which the metal ion of the invention can be administered, including human being or any animal. The subject is more particularly a non-rodent animal, preferably pets (such as dogs and cats) or human subjects. The preferred subject is a human subject.
As used herein, "treatment" is an approach for obtaining beneficial or desired clinical results. For purposes of this invention, beneficial or desired clinical results include, but are not limited to, alleviation of symptoms, diminishment of extent of disease, stabilized (i.e., not worsening) state of disease, delay or slowing of disease progression, amelioration or palliation of the disease state, and remission (whether partial or total), whether detectable or undetectable. "Treatment" can also mean prolonging survival as compared to expected survival if not
receiving treatment. "Treatment" is an intervention performed with the intention of preventing the development or altering the pathology of a disorder. Accordingly, "treatment" refers to both therapeutic treatment and prophylactic or preventative measures. Those in need of treatment include those already with the disorder as well as those in which the disorder is to be prevented. Specifically, the treatment may directly prevent, slow down or otherwise decrease neurodegenerative or related disorder, in particular pathology of cellular degeneration or damage, such as the pathology of nerve cells, or may render the cells, e. g. neurons, more susceptible to treatment by other therapeutic agents. In a preferred embodiment, the treatment reduces or slows down the decline and/or stimulates the restoration of the function of target neurons. For instance, the present invention relates to lithium for the treatment of patients who have, or in preventing patients from developing, a disease or condition of neurodegenerative disease, for helping to prevent or delay the onset of neurodegenerative disease, or for helping to slow the progression of neurodegenerative disease.
The invention relates more particularly to the treatment of motor and/or cognitive impairments related to neurodegenerative disorders. The progressive motor impairments related to neurodegenerative disorders, more specifically to Huntington disease, are selected from the group consisting of involuntary movements, chorea, dyskinesia, dystonia, and a mixture thereof. The cognitive impairments (or decline) related to neurodegenerative disorders, more specifically to Huntington disease, are selected from the group consisting of slowed thinking, speech disturbance, overall decline in executive functions, and a mixture thereof. According to a particular embodiment, the invention concerns the use of lithium at daily doses as specified above as to maintain or enhance motor coordination, to maintain or improve motor and/or cognitive performance.
According to a particular embodiment, the invention relates more particularly to the treatment of neurodegenerative disorders, more specifically multiple sclerosis, by slowing down or preventing the apparition of clinical signs during the acute phase of a neurodegenerative disease, more specifically multiple sclerosis, and/or facilitates partial recovery during the chronic phase of the disease.
In the context of prophylactic or preventative measures, the dietary composition as defined above is more particularly suitable; it is more specifically useful to ensure maintenance of
good health, in particular for helping to prevent or delay the onset of neurodegenerative disease, or for helping to slow the progression of neurodegenerative disease.
In another aspect, the invention contemplates an article of manufacture containing materials useful for the treatment of neurodegenerative or related disorder. The article of manufacture comprises a container and a label or package insert on or associated with the container. Suitable containers include, for example, bottles, vials, syringes etc. The containers may be formed from a variety of materials such as glass and plastic. The container holds a composition comprising lithium as described above and the label or package insert indicates that the composition is to be administered in a dose of between 100 and 10000 μg Li/d (from 14.4 to 1440 μEq Li/d), preferably from 400 to 2400 μg Li d (i.e., from 57.6 to 345.8 μEq Li/d) and more preferably from 800 to 1200 μg Li/d (i.e., from 115.2 μΈq Li/d to 172.9 μΈq Li/d). Optionally, the label may also indicate that the composition is useful for the treatment of neurodegenerative or related disorders.
LEGENDS TO THE FIGURES
Figure 1: In vivo evaluation of efficacy of lithium solutions on EAE clinical scores.
Figure 2: In vivo evaluation of efficacy of lithium solutions on R6/2 motor coordination
Figure 3: In vivo evaluation of efficacy of lithium solutions on R6/2 motor performances
(swimming tank test).
Figure 4: In vivo evaluation of efficacy of lithium solutions on R6/2 cognitive performances
(2 choice tests).
Figure 5: In vivo evaluation of efficacy of lithium solutions on R6/2 survival.
The following examples are intended to exemplify the operation of the present invention but not to limit its scope.
Example 1: Evaluation of in vivo efficacy of lithium solutions in EAE mice model of Multiple Sclerosis
Multiple Sclerosis is the most common autoimmune inflammatory disease in the CNS. It is characterized by immune mediated demyelinisation and neurodegeneration of the CNS.
Experimental Autoimmune Encephalomyelitis (EAE) is a standard widely used experimental model of the clinical, immunological and neuropatho logical features of Multiple Sclerosis. The aim of this study was to evaluate in a chronic EAE model induced in mice the neuroprotective efficacy of lithium at high dose and at lower dose than previously described in the literature (De sarno, 2008).
- Sample A: solution of lithium citrate at 0.150 μg Li/ml, delivered in drinking water from DO to D50
- Sample B: solution of lithium citrate at 150 μg Li/ml, delivered in drinking water from DO to D50
To induce EAE, C57bl/6 were injected subcutaneously on days 0 and 7 with 150 μg of MOG peptide emulsified in complete Freund's adjuvant (Difco laboratories) supplemented with Mycobacterium tuberculosis H37 RA (Difco laboratories) at a final concentration of 5 mg/ml. In addition, on days 0 and 2 post-immunization (p.i.), mice were given 500 ng pertussis toxin (Sigma Aldrich Corporation) intraperitonally.
These mice (8 mice per group) were treated daily by lithium in drinking water at around 40 μg Li/kg (5.8 μEq Li/kg) (sample A) and 40 mg Li/kg (5.8 mEq Li/kg) (sample B) from DO to D50 post immunization. Untreated EAE mice were used as control (8 mice per group).
Animals were weighed and scored for clinical signs of disease from D10 post-immunization until D50 (week-ends excluded). Clinical assessment of EAE was performed daily according to the following criteria: 0 = no disease signs, 1 = tail weakness, 2 = tail paralysis, 3 = incomplete paralysis of one or two hind legs, 4 = complete hind limb paralysis, 5 = moribund, 6 = death. Animals were sacrificed on D50.
Results of clinical scores are shown in figure 1 which clearly demonstrates that treatment with 40 mg Li/kg (sample B) is toxic for these mice which quickly die after 2 or 3 weeks of
treatment. In contrast, at very low dose, 40 μg Li/kg (sample A), lithium is effective at preventing the apparition of clinical signs during the acute phase of the disease and facilitates partial recovery during the chronic phase of the disease.
This experiment shows that lithium can be used, without risk of toxicity, for the treatment of inflammatory disease linked to degeneration of the CNS at very lower dose than previously reported in the literature for this model (sample A).
Example 2: Evaluation of in vivo efficacy of lithium solutions in the R6/2 mice model of Huntington disease
Huntington disease (HD) is an inherited fatal neurologic disorder caused by an expansion of a CAG repeat in exon 1 of the huntingtin gene. The selective loss of a subset of brain cells (neurons) involves psychiatric, motor and cognitive disturbances.
R6/2 mice (Jackson Laboratory) are a transgenic model widely used as Huntington's disease model. They express human HD gene carrying approximately 120 +/- 5 (CAG) repeat expansions. Transgenic mice exhibit a progressive neurological phenotype that mimics many of the features of HD, including deficits of motor coordination, altered locomotor activity, impaired cognitive performance and seizures.
The aim of this study was to evaluate in R6/2 mice, by a standardized battery of analysis, the neuroprotective effect of lithium solution at very low dose (sample C) and at dose normally used for the treatment of bipolar disorders (sample D). Motor coordination and balance were evaluated by rotarod test and swimming tank test. Cognitive performances were evaluated by 2 choice tests. Survival was also evaluated.
- Sample C: lithium citrate in solution at 8 μg Li/ml, delivered at 5 ml/kg/d by oral route (gavage) until death
- Sample D: lithium citrate in solution at 3.2 mg Li/ml, delivered at 5 ml/kg/d by oral route (gavage) until death
As described below, R6/2 mice at 8-9 weeks old (apparition of the first clinical signs) were treated 5 days a week until death by gavage at 40 μg Li/kg (5.8 μΈq Li/kg) (sample C) (group
1, 10 mice per group) or 16 mg Li/kg (2.3 mEq Li/kg) (sample D) (group 2, 10 mice per group) using a plastic syringe fitted with a metal curved gavage tube. Untreated R6/2 mice (group 3, 8 mice per group) or untreated wild type mice (group 4, 6 mice per group) were used as controls.
Rotarod tests were performed before and after 3 weeks of treatment using a Rota Rod apparatus (UGO Basile 47600, rotating rod diameter 3 cm). After an acclimation test of 15 minutes, mice performed 2 trials at 5 rpm. The latency at which each mouse falls of the rod was recorded. Swimming test was performed using a tank filled to a depth of 20 cm with water. For the 2 choice test, a visible escape platform was located at the end of one tank side in the same apparatus. During the 5th week of treatment, the latency to reach the platform and the swimming speed were recorded 5 times per day during 5 consecutive days.
Results of rotarod test are shown in figure 2 which demonstrates that both solutions of lithium (samples C and D) maintain motor coordination of R6/2 mice.
Results of swimming speed shown in figure 3 confirm that the R6/2 mice treated with both doses of lithium (samples C and D) have better motor performances than untreated R6/2 mice. Results of cognitive performance are shown in figure 4 which demonstrates that whatever the dose (samples C and D), lithium in solution maintains the capacity of R6/2 to learn a simple task: choose the good direction to reach the platform.
Figure 5 demonstrates an increase of survival of R6/2 mice treated with lithium at very low dose (sample C).
All these experiments demonstrate the neuroprotective efficacy of sample C, delivering lithium at dose 250 to 400 lower than those previously reported in the literature for this mouse model of Huntington's disease (Wood and Morton, 2003). The side effects and toxicity commonly associated with lithium are likely to be vastly reduced or eliminated using these lower dose.
Berger, Z., Ttofi, E. K., Michel, C. H., Pasco, M. Y., Tenant, S., Rubinsztein, D. C, and O'Kane, C. J. (2005). Lithium rescues toxicity of aggregate-prone proteins in Drosophila by perturbing Wnt pathway. Hum Mol Genet 14, 3003-11.
Berthaud, S., Chareyre, S., Descotes, J., Frantz, P., Guerrier, F., Meram, D., Pulce, C, Sapori, J. M., Testud, F., and Vial, T. (2000). Lithium Carbonate. INCHEM, Chemical Safety Information from Intergovernmental Organizations.
Birch, N. J., and Jenner, F. A. (1973). The distribution of lithium and its effects on the distribution and excretion of other ions in the rat. Br J Pharmacol 47, 586-94.
Caccamo, A., Oddo, S., Tran, L.X. and LaFerla, F.M. (2007). Lithium reduces Tau phosphorylation but no t Αβ or working memory deficits in a transgenic model with both plaques and tangles. Am J Pathol. May; 170(5): 1669-75
Carmichael, J., Sugars, K. L., Bao, Y. P., and Rubinsztein, D. C. (2002). Glycogen synthase kinase- 3beta inhibitors prevent cellular polyglutamine toxicity caused by the Huntington's disease mutation. J Biol Chem 277, 33791-8.
Compston, A., and Coles, A. (2008). Multiple sclerosis. Lancet 312, 1502-17.
De Sarno, P., Axtell, R.C., Raman, C, Roth, K.A., Alessi, D.R., and Jope, R.S. (2008). Lithium prevents and ameliorates experimental autoimmune encephalomyelitis. J Immunol.; l,:338-45.
Feng, H.L., Leng, Y., Ma, C.H., Zhang, J., Ren, M., and Chuang, D.M.. (2008). "Combined lithium and valproate treatment delays disease onset, reduces neurological deficits and prolongs survival in an amyotrophic lateral sclerosis mouse model. Neuroscience 155(3): 567-72.
Fierro, A. A. (1988). Natural low dose lithium supplementation in manic-depressive disease. Nutr Persepectives : 10-11.
Fornai, F., Longone, P., Cafaro, L., Kastsiuchenka, O., Ferrucci, M., Manca, M.L., Lazzeri, G., Spalloni, A., Bellio, N., Lenzi, P., Modugno, N., Siciliano, G., Isidoro, C, Murri,L. Ruggieri, S., and Paparelli, A. (2008). Lithium delays progression of amyotrophic lateral sclerosis. Proc Natl Acad Sci USA 105(6): 2052-7.
Ghosal, K., Vogt, D.L., Liang, M., Shen, Y., Lamb, B.T., Pimplikar, S.W. (2009). Alzheimer's disease-like pathological feautures in transgenic mice expressing the APP intracellular domain. Proc Natl Acad Sci USA 106(43): 18367-12.
Gould, T. D., Quiroz, J. A., Singh, J., Zarate, C. A., and Manji, H. K. (2004). Emerging experimental therapeutics for bipolar disorder: insights from the molecular and cellular actions of current mood stabilizers. Mol Psychiatry 9, 734-55.
Grounkde-Iqbal, I., Iqbal, K., Tung, Y.C., Quinlan, M., Wisniewski, H.M., and Binder, L.I. (1986). Abnormal phosphorylation of the microtubule-associated protein tau (tau) in Alzheimer cytoskeletal pathology. Proc Natl Acad Sci USA 83 (13): 4913-7.
Hardy, J.A., and Higgins, G.A. (1992). Alzheimer's disease: the amyloid cascade hypothesis. Science 256 (5054): 184-5
Heiseke, A., Aguib, Y., Riemer, C, Baier, M. and Schatzl, H.M. (2009). Lithium induces clearance of protease resistant prion protein in prion-infected cells by induction of autophagy. J Neurochem. 109(l):25-34
Ince P.G., Lowe, J., and Shaw, P.J. (1998). Amyotrophic lateral sclerosis: current issues in classification, pathogenesis and molecular pathology. Neuropathol Appl Neurobiol 24: 104-117.
Lagerkvist, B. J., and Lindell, B. (2002). Lithium and Lithium compounds. The Nordic Expert Group for Criteria Documentation of Health Risks fron Chemicals.
Marmol, F. (2008). Lithium: bipolar disorder and neurodegenerative diseases Possible cellular mechanisms of the therapeutic effects of lithium. Prog Neuropsychopharmacol Biol Psychiatry 32, 1761-71.
Quiroz, J. A., Gould, T. D., and Manji, H. K. (2004). Molecular effects of lithium. Mol Interv 4, 259- 72.
Rockenstein, E., Torrance, M., Adame, A., Mante, M., Bar-on, P., Bose, J.B., Crews, L. and Masliah, E. (2007). Neuroprotective effect of regulators of the glycogen synthase kinase-3P signalling pathway in a transgenic model of Alzheimer disease are associated with reduced amyloid precursor protein phosphorylation. JNeurosci Feb 21;27(8): 1981-91.
Sarkar, S., Krishna, G., Imarisio, S., Saiki, S., O'Kane, C. J., and Rubinsztein, D. C. (2008). A rational mechanism for combination treatment of Huntington's disease using lithium and rapamycin. Hum Mol Genet 17, 170-8.
Schrauzer G.N., and de Vroey E. (1994). Effects of nutritional lithium supplementation on mood. Biol. Trace El. Res 40, 89-101.
Schrauzer G.N., and Shrestha K.P. (1990). Lithium in drinking water and the incidences of crimes, suicides, and arrests related to drug addictions. Biol Trace El Res 25, 105-113.
Senatorov, V. V., Ren, M., Kanai, H., Wei, H., and Chuang, D. M. (2004). Short-term lithium treatment promotes neuronal survival and proliferation in rat striatum infused with quinolinic acid, an excitotoxic model of Huntington's disease. Mol Psychiatry 9, 371-85.
Shin, J.H., Cho, S.I., Lim, H.R., Lee, J.K., Lee, Y.A., Noh, J.S., Joo, I.S., Kim, K.W., and Gwag, B.J. (2007). "Concurrent administration of Neu2000 and lithium produces marked improvement of motor neuron survival, motor function, and mortality in a mouse model of amyotrophic lateral sclerosis." Mol Pharmacol 71(4): 965-75.
Voisine, C, Varma, H., Walker, N., Bates, E. A., Stockwell, B. R., and Hart, A. C. (2007). Identification of potential therapeutic drugs for huntington's disease using Caenorhabditis elegans. PLoS One 2, e504.
Walker, F. O. (2007). Huntington's disease. Lancet 369, 218-28.
Warby, S. C, Graham, R. K., and Hayden, M. R. (2007). Huntington disease. GeneReviews.
Watase, K., Gatchel, J.R., Sun, Y., Emamian, E., Atkinson, R., Richman, R., Mizusawa, H., Orr, H.T., Shaw, C, Zoghbi, H.Y. (2007) Lithium therapy improves neurological function and hippocampal dendritic arborization in a spinocerebellar ataxia type 1 mouse model. PLoS Med.;4(5):e\ 82.
Wei, H., Qin, Z. H., Senatorov, V. V., Wei, W., Wang, Y., Qian, Y., and Chuang, D. M. (2001). Lithium suppresses excitotoxicity-induced striatal lesions in a rat model of Huntington's disease. Neuroscience 106, 603-12.
Wood, N. I., and Morton, A. J. (2003). Chronic lithium chloride treatment has variable effects on motor behaviour and survival of mice transgenic for the Huntington's disease mutation. Brain Res Bull 61, 375-83.
Youdim, M.B., and Arraf, Z. (2004). Prevention of MPTP (N-methyl-4-phenyl-l,2,3,6- tetrahydropyridine) dopaminergic neurotoxicity in mice by chronic lithium: involvements of Bcl-2 and Bax. Neuropharmacology. Jun;46(8): l 130-40.