Tetracyclic antidepressant; Adrenergic Receptor

Apoptosis is induced and HCC cells become more sensitive to sorafenib (2 μM) when exposed to maprotiline (10 μM) [2]. In HepG2 and Huh7 cells, maprotiline (0, 10 or 20 μM, 72 hours) suppresses the phosphorylation of SREBP2 by acting on the ERK pathway [2]. In HCC cells, maprotiline may regulate cholesterol production by targeting CRABP1 [2]. Test for cell invasion [2]

Neuropathic pain can be effectively reduced by combining the synthetic cannabinoid WIN 55,212-2 with maprotiline (3, 10, or 30 mg/kg; i.p.) [1]. Low toxicity to organs, immune system, and hematopoiesis is observed with maprotiline (0, 20, or 40 mg/kg); intraperitoneally; twice weekly; 3 weeks [2]. By blocking cholesterol production and interacting with CRABP1, maprotiline (0, 20, or 40 mg/kg; i.p.; twice weekly; 3 weeks) suppresses the development and metastasis of HCC cells [2].

Antidepressants are generally used for treatment of various mood and anxiety disorders. Several studies have shown the anti-tumor and cytotoxic activities of some antidepressants, but the underlying mechanisms were unclear. Maprotiline is a tetracyclic antidepressant and possesses a highly selective norepinephrine reuptake ability. We found that maprotiline decreased cell viability in a concentration- and time-dependent manner in Neuro-2a cells. Maprotiline induced apoptosis and increased caspase-3 activation. The activation of caspase-3 by maprotiline appears to depend on the activation of JNK and the inactivation of ERK. Maprotiline also induced [Ca(2+)](i) increases which involved the mobilization of intracellular Ca(2+) stored in the endoplasmic reticulum. Pretreatment with BAPTA/AM, a Ca(2+) chelator, suppressed maprotiline-induced ERK phosphorylation, enhanced caspase-3 activation and increased maprotiline-induced apoptosis. In conclusion, maprotiline induced apoptosis in Neuro-2a cells through activation of JNK-associated caspase-3 pathways. Maprotiline also evoked an anti-apoptotic response that was both Ca(2+)- and ERK-dependent.[Eur J Pharmacol . 2006 Feb 15;531(1-3):1-8.]

Cell invasion test [2]
Cell Types: human liver cancer cell lines Huh7 and HepG2
Tested Concentrations: 0, 10, 20 μM
Incubation Duration: 24 hrs (hours)
Experimental Results: Inhibition of liver cancer cell migration and epithelial-mesenchymal transition (EMT).

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Cell viability assay [2]
Cell Types: human liver cancer cell lines Huh7 and HepG2
Tested Concentrations: 0, 10, 20 μM
Incubation Duration: 0, 24, 48, 72, 96, 120 hrs (hours)
Experimental Results: Triggered cell apoptosis and inhibited cell viability Huh7 and HepG2 cells in a dose- and time-dependent manner.

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Western Blot Analysis [2]
Cell Types: Human liver cancer cell lines Huh7 and HepG2
Tested Concentrations: 0, 10, 20 μM
Incubation Duration: 72 hrs (hours)
Experimental Results: Inhibition of cholesterol biosynthesis in liver cancer cells.

Animal/Disease Models: Male Balb-c mouse (25-30 g) [1]
Doses: 3, 10, 30 mg/kg
Route of Administration: intraperitoneal (ip) injection; assessment 30 minutes after treatment
Experimental Results: Pain-related behaviors in neuropathic mice weaken.

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Animal/Disease Models: Nude mice (BALB/C nu/nu, 4-6 weeks old, female) [2]
Doses: 40 mg/kg
Route of Administration: intraperitoneal (ip) injection; twice a week; 3-week
Experimental Results: diminished serum and tumor cholesterol levels, inhibited the growth of Huh7-derived tumor xenografts without obvious toxic effects.

Absorption, Distribution and Excretion
Slowly, but completely absorbed from the GI tract following oral administration.
Approximately 60% of a single orally administered dose is excreted in urine as conjugated metabolites within 21 days; 30% is eliminated in feces.
Maprotiline and its metabolites may be detected in the lungs, liver, brain, and kidneys; lower concentrations may be found in the adrenal glands, heart and muscle. Maprotiline is readily distributed into breast milk to similar concentrations as those in maternal blood.

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Metabolism / Metabolites
Hepatic. Maprotiline is metabolized by N-demethylation, deamination, aliphatic and aromatic hydroxylations and by formation of aromatic methoxy derivatives. It is slowly metabolized primarily to desmethylmaprotiline, a pharmacologically active metabolite. Desmethylmaprotiline may undergo further metabolism to maprotiline-N-oxide.
Maprotiline has known human metabolites that include 2-hydroxy-maprotiline, desmethylmaprotiline, and 3-hydroxy-maprotiline.
Hepatic. Maprotiline is metabolized by N-demethylation, deamination, aliphatic and aromatic hydroxylations and by formation of aromatic methoxy derivatives. It is slowly metabolized primarily to desmethylmaprotiline, a pharmacologically active metabolite. Desmethylmaprotiline may undergo further metabolism to maprotiline-N-oxide.
Route of Elimination: Approximately 60% of a single orally administered dose is excreted in urine as conjugated metabolites within 21 days; 30% is eliminated in feces.
Half Life: Average ~ 51 hours (range: 27-58 hours)

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Biological Half-Life
Average ~ 51 hours (range: 27-58 hours)

Toxicity Summary
Maprotiline exerts its antidepressant action by inhibition of presynaptic uptake of catecholamines, thereby increasing their concentration at the synaptic clefts of the brain. In single doses, the effect of maprotiline on the EEG revealed a rise in the alpha-wave density, a reduction of the alpha-wave frequency and an increase in the alpha-wave amplitude. However, as with other tricyclic antidepressants, maprotiline lowers the convulsive threshold. Maprotiline acts as an antagonist at central presynaptic α₂-adrenergic inhibitory autoreceptors and hetero-receptors, an action that is postulated to result in an increase in central noradrenergic and serotonergic activity. Maprotiline is also a moderate peripheral α₁ adrenergic antagonist, which may explain the occasional orthostatic hypotension reported in association with its use. Maprotiline also inhibits the amine transporter, delaying the reuptake of noradrenaline and norepinephrine. Lastly, maprotiline is a strong inhibitor of the histamine H₁ receptor, which explains its sedative actions.

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Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Because there is little published experience with maprotiline during breastfeeding, other agents may be preferred, especially while nursing a newborn or preterm infant.
◉ Effects in Breastfed Infants
Although it is structurally a tetracyclic compound, maprotiline has pharmacologic actions similar to the tricyclic antidepressants.
Follow-up for 1 to 3 years in a group of 20 breastfed infants whose mothers were taking a tricyclic antidepressant found no adverse effects on growth and development. Two small controlled studies indicate that other tricyclic antidepressants have no adverse effect on infant development.
In another study, 25 infants whose mothers took a tricyclic antidepressant during pregnancy and lactation were assessed formally between 15 to 71 months and found to have normal growth and development. One of the mothers was taking maprotiline.
◉ Effects on Lactation and Breastmilk
Maprotiline has caused increased serum prolactin levels and galactorrhea in nonpregnant, nonnursing patients. The clinical relevance of these findings in nursing mothers is not known. The prolactin level in a mother with established lactation may not affect her ability to breastfeed.
An observational study looked at outcomes of 2859 women who took an antidepressant during the 2 years prior to pregnancy. Compared to women who did not take an antidepressant during pregnancy, mothers who took an antidepressant during all 3 trimesters of pregnancy were 37% less likely to be breastfeeding upon hospital discharge. Mothers who took an antidepressant only during the third trimester were 75% less likely to be breastfeeding at discharge. Those who took an antidepressant only during the first and second trimesters did not have a reduced likelihood of breastfeeding at discharge. The antidepressants used by the mothers were not specified.
A retrospective cohort study of hospital electronic medical records from 2001 to 2008 compared women who had been dispensed an antidepressant during late gestation (n = 575) to those who had a psychiatric illness but did not receive an antidepressant (n = 1552) and mothers who did not have a psychiatric diagnosis (n = 30,535). Women who received an antidepressant were 37% less likely to be breastfeeding at discharge than women without a psychiatric diagnosis, but no less likely to be breastfeeding than untreated mothers with a psychiatric diagnosis. None of the mothers were taking maprotiline.
In a study of 80,882 Norwegian mother-infant pairs from 1999 to 2008, new postpartum antidepressant use was reported by 392 women and 201 reported that they continued antidepressants from pregnancy. Compared with the unexposed comparison group, late pregnancy antidepressant use was associated with a 7% reduced likelihood of breastfeeding initiation, but with no effect on breastfeeding duration or exclusivity. Compared with the unexposed comparison group, new or restarted antidepressant use was associated with a 63% reduced likelihood of predominant, and a 51% reduced likelihood of any breastfeeding at 6 months, as well as a 2.6-fold increased risk of abrupt breastfeeding discontinuation. Specific antidepressants were not mentioned.

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Protein Binding
88%

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Toxicity Data
LD50: 900 mg/kg (Oral, Rat) (A308)
LD50: 90 mg/kg (Oral, Human) (A308)

[1]. Gunduz O, et al. Analysis of the anti-allodynic effects of combination of a synthetic cannabinoid and a selective noradrenaline re-uptake inhibitor in nerve injury-induced neuropathic mice. Eur J Pain. 2016 Mar. 20(3):465-71.
[2]. Zheng C, et al. Maprotiline Suppresses Cholesterol Biosynthesis and Hepatocellular Carcinoma Progression Through Direct Targeting of CRABP1. Front Pharmacol. 2021 May 20. 12:689767.

Maprotiline is a member of anthracenes.
Maprotiline is a tetracyclic antidepressant with similar pharmacological properties to tricyclic antidepressants (TCAs). Similar to TCAs, maprotiline inhibits neuronal norepinephrine reuptake, possesses some anticholinergic activity, and does not affect monoamine oxidase activity. It differs from TCAs in that it does not appear to block serotonin reuptake. Maprotiline may be used to treat depressive affective disorders, including dysthymic disorder (depressive neurosis) and major depressive disorder. Maprotiline is effective at reducing symptoms of anxiety associated with depression.
Maprotiline is a tetracyclic antidepressant with similar pharmacological properties to tricyclic antidepressants (TCAs). Similar to TCAs, maprotiline inhibits neuronal norepinephrine reuptake, possesses some anticholinergic activity, and does not affect monoamine oxidase activity. It differs from TCAs in that it does not appear to block serotonin reuptake. Maprotiline may be used to treat depressive affective disorders, including dysthymic disorder (depressive neurosis) and major depressive disorder. Maprotiline is effective at reducing symptoms of anxiety associated with depression.
A bridged-ring tetracyclic antidepressant that is both mechanistically and functionally similar to the tricyclic antidepressants, including side effects associated with its use.

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Drug Indication
For treatment of depression, including the depressed phase of bipolar depression, psychotic depression, and involutional melancholia, and may also be helpful in treating certain patients suffering severe depressive neurosis.

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Mechanism of Action
Maprotiline exerts its antidepressant action by inhibition of presynaptic uptake of catecholamines, thereby increasing their concentration at the synaptic clefts of the brain. In single doses, the effect of maprotiline on the EEG revealed a rise in the alpha-wave density, a reduction of the alpha-wave frequency and an increase in the alpha-wave amplitude. However, as with other tricyclic antidepressants, maprotiline lowers the convulsive threshold. Maprotiline acts as an antagonist at central presynaptic α₂-adrenergic inhibitory autoreceptors and hetero-receptors, an action that is postulated to result in an increase in central noradrenergic and serotonergic activity. Maprotiline is also a moderate peripheral α₁ adrenergic antagonist, which may explain the occasional orthostatic hypotension reported in association with its use. Maprotiline also inhibits the amine transporter, delaying the reuptake of noradrenaline and norepinephrine. Lastly, maprotiline is a strong inhibitor of the histamine H₁ receptor, which explains its sedative actions.

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Pharmacodynamics
Maprotiline is a tetracyclic antidepressant. Although its main therapeutic use is in the treatment of depression, it has also been shown to exert a sedative effect on the anxiety component that often accompanies depression. In one sleep study, it was shown that maprotiline increases the duration of the REM sleep phase in depressed patients, compared to imipramine which reduced the REM sleep phase. Maprotiline is a strong inhibitor of noradrenaline reuptake in the brain and peripheral tissues, however it is worthy to note that it is a weak inhibitor of serotonergic uptake. In addition, it displays strong antihistaminic action (which may explain its sedative effects) as well as weak anticholinergic action. Maprotiline also has lower alpha adrenergic blocking activity than amitriptyline.

C20H23N

277.40332

277.183

C, 86.59; H, 8.36; N, 5.05

10262-69-8

Maprotiline hydrochloride;10347-81-6

4011

Typically exists as solid at room temperature

1.08 g/cm3

399.6ºC at 760 mmHg

187.7ºC

1.35E-06mmHg at 25°C

1.599

4.602

1

1

4

21

339

0

CNCCCC12CCC(C3=CC=CC=C31)C4=CC=CC=C42

QSLMDECMDJKHMQ-UHFFFAOYSA-N

InChI=1S/C20H23N/c1-21-14-6-12-20-13-11-15(16-7-2-4-9-18(16)20)17-8-3-5-10-19(17)20/h2-5,7-10,15,21H,6,11-14H2,1H3

N-methyl-3-(1-tetracyclo[6.6.2.02,7.09,14]hexadeca-2,4,6,9,11,13-hexaenyl)propan-1-amine

maprotiline; 10262-69-8; Maprotylina [Polish]; Maprotylina; Maprotilinum [INN-Latin]; Maprotilina [INN-Spanish]; 9,10-Ethanoanthracene-9(10H)-propanamine, N-methyl-; 276-Ba;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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 (Please use freshly prepared in vivo formulations for optimal results.)