serotonin reuptake ( IC50 = 1.8 nM )
Serotonin reuptake transporter (SERT), as a selective serotonin reuptake inhibitor (SSRI). [3].

Citalopram (Lu 10-171), an exceptionally strong inhibitor of neuronal serotonin (5-HT) uptake, a novel bicyclic phthalane derivative exhibits no antagonistic activity toward 5-HT, histamine, gamma aminobutyric acid (GABA), acetylcholine, and morphine receptors, and has no effect on the uptake of noradrenaline (NA) or dopamine (DA). It is a very strong and selective inhibitor of the uptake of 5-HT by neurons. The medication has no effect on the uptake mechanisms for other transmitter amines[1]. The effects of the SSRI citalopram are more pronounced on proliferation and less pronounced on apoptotic activity. By enhancing proliferative potential and lowering apoptotic activity in a site-specific manner that may be suggestive of hyperplasia, it influences the regulation of the cell cycle. In osteoblast cell culture, citalopram modifies the expression of FGF, MSX, and TGFB[3].

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Proliferation Assessment via MTS Assay: Mouse calvarial pre-osteoblast cells (MC3T3-E1) were cultured for 3 or 7 days in media supplemented with serial dilutions of citalopram ranging from 10⁻⁴ mol/L to 10⁻¹⁰ mol/L. A two-way analysis of variance revealed a significant effect of dose on MTS activity. Post-hoc analysis indicated that treatment with media only resulted in significantly less MTS activity compared to all treated groups (10⁻⁴ mol/L through 10⁻⁹ mol/L), with the exception of the 10⁻¹⁰ mol/L dose. This suggests that citalopram exposure increases the metabolic markers of cell proliferation. [3]
- Apoptosis Assessment via Caspase 3/7 Activity: MC3T3-E1 cells were treated with serial dilutions of citalopram (10⁻⁴ mol/L to 10⁻¹⁰ mol/L) for 3 or 7 days. Qualitative assessment suggested a decrease in Caspase 3/7 activity for all treated groups compared to the untreated baseline control. No caspase activity was detected for the 10⁻⁴ mol/L concentration after 7 days in culture. However, a two-way analysis of variance showed no statistically significant differences in Caspase activity by day, dose, or their interaction terms. [3]
- Gene Expression Analysis via qRT-PCR: MC3T3-E1 cells were treated with media only or media supplemented with 10⁻⁴ mol/L citalopram for 3 or 7 days. Gene expression was analyzed for markers of proliferation (Ki67, Ccnd1, Jun) and apoptosis (Bax, Casp3, Bcl2). For proliferation markers, mean increases were observed for all three markers at both time points. After 7 days, all three markers (Ki67, Ccnd1, Jun) showed a purported biological change (confidence intervals did not cross 1). Jun expression was found to be significantly different between treatment and control at both 3 and 7 days. For apoptosis markers, there was a slight decrease in expression of the pro-survival gene Bcl2 in response to citalopram treatment, with no associated increase in expression of the pro-apoptotic genes Bax or Casp3. [3]

Citalopram even when administered in quantities well above the therapeutic range, has no cardiotoxic effects on the animals. Citabram is metabolized in humans to produce substances that are less abundant than citalopram itself but are nevertheless strong 5-HT-uptake inhibitors without affecting noradrenaline (NA) uptake. Citalopram (1–16 mg/kg) causes the spinal rat's hindlimb flexor reflex to fire. Citalopram may increase the amount of 5-HT transmitted by causing marked uptake inhibition without also inhibiting the post-synaptic 5-HT receptors1.

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In Utero Exposure Model: Pregnant C57BL/6 dams were administered a clinical dose of approximately 500 micrograms per day of citalopram in their drinking water from embryonic day (E)13 to E20 (roughly the third trimester). The resulting offspring (n=24 exposed, n=26 unexposed) were allowed to grow to postnatal day 15. This in vivo model was used to study the effects of citalopram exposure on cell proliferation and apoptosis in cranial sutures. [3]
- Histomorphometric Analysis of Proliferation (PCNA): Coronal and sagittal sutures from 15-day-old pups exposed to citalopram in utero were analyzed for Proliferating Cell Nuclear Antigen (PCNA), a marker of proliferation. A significant difference was found for the suture-by-exposure interaction. In the sagittal suture, citalopram exposure resulted in a statistically significant increase in PCNA positivity (47.94% ± 35.47%) compared to unexposed controls (21.38% ± 16.15%). The coronal suture did not show this effect, with data suggesting slight, non-significant decreases in proliferation in the periosteal and midsutural areas. [3]
- Histomorphometric Analysis of Apoptosis (TUNEL): Coronal and sagittal sutures from the same 15-day-old pups were analyzed for apoptosis using the TUNEL method. A significant difference was found for the suture-by-exposure interaction. In the coronal suture, citalopram-exposed sutures had statistically less TUNEL activity (4.74% ± 2.87%) than control sutures (14.90% ± 7.76%). In the sagittal suture, exposed sutures showed statistically greater TUNEL activity (4.16% ± 3.26%) compared to control (2.19% ± 1.72%), although the overall activity was very low. Site-specific analysis within the coronal suture revealed significant decreases in TUNEL activity due to citalopram exposure at the periosteal and dural areas. [3]

Eagles medium (alpha minimum) supplemented with 10% fetal bovine serum, 1% penicillin/streptomycin, and amphotericin B is used to cultivate the cells. The standard alpha proliferation media is used to culture the cells for a duration of 3 or 7 days, providing control data. A dose response curve is obtained for SSRI treatments by supplementing media with citalopram eluted to serially diluted doses between 10⁻⁴ mol and 10⁻¹⁰ mol.

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MTS Proliferation Assay Protocol: MC3T3-E1 murine calvaria osteoprogenitor cells were seeded in 96-well plates at a density of approximately 4,000 cells per well. Cells were cultured for either 3 or 7 days in media supplemented with citalopram at concentrations ranging from 10⁻⁴ mol/L to 10⁻¹⁰ mol/L to generate a dose-response curve. After the treatment period, 20 μL per well of CellTiter96 Aqueous One solution was added, and cells were incubated for one hour. Absorbance was then recorded at 490 nm using a 96-well plate reader to assess cell proliferation. All conditions were tested in triplicate. [3]
- Caspase 3/7 Apoptosis Assay Protocol: MC3T3-E1 cells were seeded and treated with citalopram (10⁻⁴ mol/L to 10⁻¹⁰ mol/L) for 3 or 7 days in 96-well plates. Following treatment, 100 μL per well of a substrate/buffer solution (prepared at a 1:100 ratio) was added. The plate contents were mixed for 30 seconds at 300 rpm and then incubated at room temperature for one hour. Fluorescence was measured using a plate reader with an excitation wavelength of 485 nm and an emission wavelength of 530 nm to quantify Caspase 3/7 activity. All conditions were tested in triplicate. [3]
- Quantitative Real-Time PCR (qRT-PCR) Protocol: MC3T3-E1 cells were cultured for 3 or 7 days in either control media or media supplemented with 10⁻⁴ mol/L citalopram. A one-step kit was used for cDNA synthesis and gene expression analysis. A master mix was prepared containing nuclease-free water, RT-mix, enzyme mix, and commercially prepared TaqMan probe/primer sets for target genes (Mki67, Ccnd1, Jun, Bax, Casp3, Bcl2) and the housekeeping gene 18S ribosomal RNA. A total of 50 ng of RNA from the cells was added to the master mix for each reaction, which was run in duplicate. Data were normalized to 18S expression using the ΔCT method, and gene expression changes due to treatment were compared. [3]

Spontaneously Hypertensive rats (SHRs), Lewis (LEW) rats, and Wistar-Kyoto (WKY) rats
1-10 mg/kg
i.p.

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In Utero Exposure Protocol:** Individually housed pregnant C57BL/6 dams were administered citalopram in their drinking water from embryonic day (E)13 to E20. The dosage was approximately 500 micrograms per day, identified as a mid-range dose for preclinical studies in murine models. The drinking water was replaced as needed to provide ad libitum access. The resulting offspring were allowed to grow until postnatal day 15, at which point they were sacrificed via carbon dioxide asphyxiation followed by cervical dislocation and decapitation. Calvaria were then harvested for analysis. [3]

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In Utero Exposure Protocol: Individually housed pregnant C57BL/6 dams were administered citalopram in their drinking water from embryonic day (E)13 to E20. The dosage was approximately 500 micrograms per day, identified as a mid-range dose for preclinical studies in murine models. The drinking water was replaced as needed to provide ad libitum access. The resulting offspring were allowed to grow until postnatal day 15, at which point they were sacrificed via carbon dioxide asphyxiation followed by cervical dislocation and decapitation. Calvaria were then harvested for analysis. [3]

[1]. Prog Neuropsychopharmacol Biol Psychiatry . 1982;6(3):277-95.

[2]. Neuropsychopharmacology . 2000 Jan;22(1):64-76.

[3]. PLoS One . 2015 Oct 2;10(10):e0139719.

Citalopram hydrobromide is a highly bioavailable oral hydrobromide of citalopram, a racemic bicyclic phthalide derivative with antidepressant activity. As a selective serotonin reuptake inhibitor (SSRI), citalopram selectively inhibits the reuptake of serotonin by neurons in the central nervous system (CNS), thereby enhancing CNS serotonergic activity. It has minimal effect on the reuptake of norepinephrine (NE) and dopamine (DA) by CNS neurons. Citalopram is a furanyl nitrile compound, belonging to the class of selective serotonin reuptake inhibitors, and is used as an antidepressant. It is also effective in reducing ethanol intake in patients with alcohol dependence and is preferentially used to treat patients with depression accompanied by tardive dyskinesia, rather than tricyclic antidepressants that exacerbate dyskinesia. See also: Citalopram (containing the active moiety).

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Background and Context: Citalopram is a selective serotonin reuptake inhibitor (SSRI) used to treat depression. Its use during pregnancy has been suggested to increase the incidence of craniofacial abnormalities, including craniosynostosis (premature fusion of cranial sutures). This study investigates the mechanism by which citalopram exposure may affect cranial suture development. [3]
- Proposed Mechanism of Action on Craniofacial Development: The study proposes that citalopram exposure disrupts the balance between cell proliferation and apoptosis within the cranial sutures. The findings suggest that exposure leads to hyperplasia (increased proliferation without a concomitant increase in apoptosis) in a site-specific manner within the sutures. This imbalance may lead to later differentiation of cells, bony infiltration, and ultimately, suture fusion (synostosis). [3]
- Gene Expression Insights: The upregulation of proliferation-related genes (Ki67, Ccnd1, Jun) and the lack of significant change in pro-apoptotic genes (Bax, Casp3) in MC3T3-E1 cells exposed to citalopram support the hyperplasia hypothesis. The increase in Jun expression is also noted to have anti-apoptotic properties, further contributing to the imbalance. [3]

C20H22BRFN2O

405.3039

404.089

C, 59.27; H, 5.47; Br, 19.71; F, 4.69; N, 6.91; O, 3.95

59729-32-7

Citalopram; 59729-33-8; 207559-01-1 (oxalate); 59729-32-7 (HBr)

77995

White to off-white solid powder

182-188ºC

182-188ºC

212.8ºC

4.771

1

4

5

25

466

0

Br[H].FC1C([H])=C([H])C(=C([H])C=1[H])C1(C2C([H])=C([H])C(C#N)=C([H])C=2C([H])([H])O1)C([H])([H])C([H])([H])C([H])([H])N(C([H])([H])[H])C([H])([H])[H]

WIHMBLDNRMIGDW-UHFFFAOYSA-N

InChI=1S/C20H21FN2O.BrH/c1-23(2)11-3-10-20(17-5-7-18(21)8-6-17)19-9-4-15(13-22)12-16(19)14-24-20;/h4-9,12H,3,10-11,14H2,1-2H3;1H

1-[3-(dimethylamino)propyl]-1-(4-fluorophenyl)-3H-2-benzofuran-5-carbonitrile;hydrobromide

Lu10-171-BLu-10-171-BCelexa Cipramil Citalopram HBr HSDB 7042 EINECS 261-890-6 Lu 10-171-B CPD000326936

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment, avoid exposure to moisture.

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

DMSO: ~81 mg/mL (~199.9 mM)
Water: ~81 mg/mL
Ethanol: ~81 mg/mL

Solubility in Formulation 1: ≥ 2.5 mg/mL (6.17 mM) (saturation unknown) in 10% DMSO + 40% PEG300 +5% Tween-80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 + to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: 110 mg/mL (271.40 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication.

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