Bacterial protein synthesis; 30S subunit of the bacterial ribosome; tetracycline antibiotic; hypoxia-inducible factor (HIF)-1α

OVCAR-3, SKOV-3, and A2780 are ovarian cancer cell lines whose proliferation and clonal activity are inhibited by minocycline (0-100 μM, 24-72 hours) [3]. Minocycline (0-100 μM, 24-48 hours) inhibits DNA incorporation and cyclins, which stops the cell cycle [3]. Ovarian cancer cell lines undergo apoptosis when exposed to minocycline (0-100 μM) for 72 hours [3]. Minocycline inhibits both caspase-dependent and caspase-independent cell death after exhibiting direct neuronal protection, a mechanism of protection that may be connected to the maintenance of mitochondrial integrity and cytochrome c [2]. Hypoxia-inducible factor (HIF)-1α is inhibited by minocycline, which also increases p53 protein levels and deactivates the AKT/mTOR/p70S6K/4E-BP1 pathway [6].

In female nude mice, minocycline (0–30 mg/kg) taken orally once a day for four weeks inhibits the growth of OVCAR-3 tumors [3]. When given at large intraperitoneal doses, minocycline (IP) is a neuroprotective agent in animal models of cerebral ischemia [1]. Mice exposed to a single intraperitoneal injection of minocycline (0–40 mg/kg) can greatly reduce the development of behavioral sensitization and excessive movement brought on by METH [2]. The temporary middle cerebral artery occlusion model (TMCAO) can effectively reduce infarct size when administered intravenously with 3 or 10 mg/kg of minocycline once [1]. Serum levels (3 mg/kg) of minocycline (3–10 mg/kg IV, once) are comparable to those attained following the typical 200 mg dose in humans [1]. Rats' ischemia-induced ventricular arrhythmias are lessened by minocycline. The activation of the L-type Ca2+ channel, mitochondrial KATP channel, and PI3K/Akt signaling pathway may be connected to this effect [7].

Cell proliferation assay[3]
Cell Types: Human ovarian cancer cell lines (OVCAR-3, SKOV-3 and A2780) and primary cells (HEK-293, HMEC, HUVEC, ATCC)
Tested Concentrations: 0, 1, 10, 50 and 100 μM
Incubation Duration: 24, 48 or 72 h
Experimental Results: Inhibited the proliferation of OVCAR-3, SKOV-3 and A2780 cells in a concentration-dependent manner, with IC50 values of 62.0, 56.1 and 59.5 μM respectively. There was no effect on the viability of HEK-293 or HUVEC.

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Cell cycle analysis[3]
Cell Types: OVCAR-3, SKOV-3 and A2780 Cell
Tested Concentrations: 0, 10, 50 and 100 μM
Incubation Duration: 24 or 48 hrs (hours)
Experimental Results: G0-G1 phase cells were Block in a time-dependent manner. At 100 μM, the percentage of cells in S phase and G2-M phase diminished by more than 80%.

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Western Blot Analysis[3]
Cell Types: OVCAR-3, SKOV-3 and A2780 Cell
Tested Concentrations: 0, 10, 50 and 100 μM
Incubation Duration: 72 hrs (hours)
Experimental Results: Cyclins A, B and E were expressed at low levels. caspase- increasing by 3 levels increased more than 3.0-fold at 100 μM. Minocy

Animal/Disease Models: Female nude mice (6 weeks old, 9 mice per group, each mouse was injected with OVCAR-3 cells subcutaneously (sc) (sc) on the left side of the abdomen) [3]
Doses: 10 or 30 mg/kg
Route of Administration: Oral administration through drinking water The drug was administered one time/day starting on the 8th day of cell inoculation for 4 weeks.
Experimental Results: Inhibited the growth of OVCAR-3 tumors in these female nude mice and diminished microvessel density.

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Animal/Disease Models: Male Balb/cAnNCrICrIj mice (8 weeks old, 23-30 g, methamphetamine (METH, 3 mg/kg) subcutaneously (sc) (sc) (sc) in a volume of 10 ml/kg) [2]
Doses: 0, 10 , 20 or 40 mg/kg
Route of Administration: intraperitoneal (ip) injection, once, 30 minutes before METH administration
Experimental Results: At the 40 mg/kg dose, the development of METH-induced hyperlocomotion and behavioral hypersensitivity was Dramatically attenuated in mice. It had no effect on the induction of METH-induced hyperthermia in mice. Dramatically attenuated reductions in DA and DOPAC in the striatum. S

Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Many reviews state that tetracyclines are contraindicated during breastfeeding because of possible staining of infants' dental enamel or bone deposition of tetracyclines. However, a close examination of available literature indicates that there is not likely to be harm in short-term use of minocycline during lactation because milk levels are low and absorption by the infant is inhibited by the calcium in breastmilk. Short-term use of minocycline is acceptable in nursing mothers. As a theoretical precaution, avoid prolonged or repeat courses during nursing. Monitor the infant for rash and for possible effects on the gastrointestinal flora, such as diarrhea or candidiasis (thrush, diaper rash). Black discoloration of breastmilk has been reported with minocycline. Topical minocycline for acne by the mother poses no risk to the breastfed infant.
◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk
A woman taking minocycline 100 mg twice daily for almost 4 years developed galactorrhea after taking perphenazine, amitriptyline and diphenhydramine, and the breast secretion was black in color.
Another woman who had nursed her infant and produced occasional small amounts of breastmilk during the 18 months after weaning was given oral minocycline 150 mg daily. After 3 to 4 weeks, expressed milk had become black. Iron levels in milk were over 100 times greater than that found in normal milk. A mammogram was normal.
In both of these cases, macrophages containing a black, iron-containing pigment were found in milk. It is thought that the pigment is an iron chelate of minocycline or one of its metabolites.

[1]. Low dose intravenous minocycline is neuroprotective after middle cerebral artery occlusion-reperfusion in rats. BMC Neurol. 2004 Apr 26;4:7.

[2]. Protective effects of minocycline on behavioral changes and neurotoxicity in mice after administration of methamphetamine. Prog Neuropsychopharmacol Biol Psychiatry. 2006 Dec 30;30(8):1381-93.

[3]. Minocycline inhibits growth of epithelial ovarian cancer. Gynecol Oncol. 2012 May;125(2):433-40.

[4]. Antidepressant-like actions of minocycline combined with several glutamate antagonists. Prog Neuropsychopharmacol Biol Psychiatry. 2008 Feb 15;32(2):380-6.

[5]. A review of intravenous minocycline for treatment of multidrug-resistant Acinetobacter infections. Clin Infect Dis. 2014 Dec 1;59 Suppl 6:S374-80.

[6]. Minocycline attenuates hypoxia-inducible factor-1α expression correlated with modulation of p53 and AKT/mTOR/p70S6K/4E-BP1 pathway in ovarian cancer: in vitro and in vivo studies. Am J Cancer Res. 2015 Jan 15;5(2):575-88.

[7]. Hu X, Wu B, Wang X, Xu C, He B, Cui B, Lu Z, Jiang H. Minocycline attenuates ischemia-induced ventricular arrhythmias in rats. Eur J Pharmacol. 2011 Mar 11;654(3):274-9.

Minocycline is a tetracycline analogue having a dimethylamino group at position 7 and lacking the methyl and hydroxy groups at position 5. It has a role as an antibacterial drug, an Escherichia coli metabolite and a geroprotector. It is a member of tetracyclines, a tetracenomycin and a tertiary alpha-hydroxy ketone. It is a conjugate acid of a minocycline(1-). It is a tautomer of a minocycline zwitterion.
Minocycline is a Tetracycline-class Drug. The physiologic effect of minocycline is by means of Decreased Prothrombin Activity.
A TETRACYCLINE analog, having a 7-dimethylamino and lacking the 5 methyl and hydroxyl groups, which is effective against tetracycline-resistant STAPHYLOCOCCUS infections.
See also: Minocycline (annotation moved to).

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Background: Minocycline, a semi-synthetic tetracycline antibiotic, is an effective neuroprotective agent in animal models of cerebral ischemia when given in high doses intraperitoneally. The aim of this study was to determine if minocycline was effective at reducing infarct size in a Temporary Middle Cerebral Artery Occlusion model (TMCAO) when given at lower intravenous (IV) doses that correspond to human clinical exposure regimens. Methods: Rats underwent 90 minutes of TMCAO. Minocycline or saline placebo was administered IV starting at 4, 5, or 6 hours post TMCAO. Infarct volume and neurofunctional tests were carried out at 24 hr after TMCAO using 2,3,5-triphenyltetrazolium chloride (TTC) brain staining and Neurological Score evaluation. Pharmacokinetic studies and hemodynamic monitoring were performed on minocycline-treated rats. Results: Minocycline at doses of 3 mg/kg and 10 mg/kg IV was effective at reducing infarct size when administered at 4 hours post TMCAO. At doses of 3 mg/kg, minocycline reduced infarct size by 42% while 10 mg/kg reduced infarct size by 56%. Minocycline at a dose of 10 mg/kg significantly reduced infarct size at 5 hours by 40% and the 3 mg/kg dose significantly reduced infarct size by 34%. With a 6 hour time window there was a non-significant trend in infarct reduction. There was a significant difference in neurological scores favoring minocycline in both the 3 mg/kg and 10 mg/kg doses at 4 hours and at the 10 mg/kg dose at 5 hours. Minocycline did not significantly affect hemodynamic and physiological variables. A 3 mg/kg IV dose of minocycline resulted in serum levels similar to that achieved in humans after a standard 200 mg dose. Conclusions: The neuroprotective action of minocycline at clinically suitable dosing regimens and at a therapeutic time window of at least 4-5 hours merits consideration of phase I trials in humans in view of developing this drug for treatment of stroke. [1]

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The effects of minocycline on behavioral changes and neurotoxicity in the dopaminergic neurons induced by the administration of methamphetamine (METH) were studied. Pretreatment with minocycline (40 mg/kg) was found to attenuate hyperlocomotion in mice after a single administration of METH (3 mg/kg). The development of behavioral sensitization after repeated administration of METH (3 mg/kg/day, once daily for 5 days) was significantly attenuated by pretreatment with minocycline (40 mg/kg). A reduction in the level of dopamine (DA) and its major metabolite, 3,4-dihydroxyphenyl acetic acid (DOPAC), in the striatum after the repeated administration of METH (3 mg/kg x 3, 3-h interval) was attenuated in a dose-dependent manner by pretreatment with and the subsequent administration of minocycline (10, 20, or 40 mg/kg). Furthermore, minocycline (40 mg/kg) significantly attenuated a reduction in DA transporter (DAT)-immunoreactivity in the striatum after repeated administration of METH. In vivo microdialysis study demonstrated that pretreatment with minocycline (40 mg/kg) significantly attenuated increased extracellular DA levels in the striatum after the administration of METH (3 mg/kg). In addition, minocycline was not found to alter the concentrations of METH in the plasma or the brain after three injections of METH (3 mg/kg), suggesting that minocycline does not alter the pharmacokinetics of METH in mice. Interestingly, METH-induced neurotoxicity in the striatum was significantly attenuated by the post-treatment and subsequent administration of minocycline (40 mg/kg). These findings suggest that minocycline may be able to ameliorate behavioral changes as well as neurotoxicity in dopaminergic terminals after the administration of METH. Therefore, minocycline could be considered as a useful drug for the treatment of several symptoms associated with METH abuse in humans.[2]

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Objective: These studies were designed to determine whether minocycline inhibits ovarian cancer growth in vitro and in vivo and the molecular mechanisms involved. Materials and methods: The effect of minocycline on ovarian cancer cell proliferation, cell cycle progression and apoptosis was assessed using human ovarian cancer cell lines OVCAR-3, SKOV-3 and A2780. Then, the capacity of minocycline to inhibit growth of OVCAR-3 xenografts in female nude mice was examined. Results: Minocycline inhibited cell proliferation and colony formation, down-regulated cyclins A, B and E leading to arrest of cells in the G(0) phase of the cycle and suppression of DNA synthesis. Furthermore, exposure of these cells to minocycline led to DNA laddering, activation of caspase-3 and cleavage of PARP-1. In nude mice bearing sub-cutaneous tumors, minocycline suppressed tumor proliferation index, angiogenesis and tumor growth. Conclusion: These findings provide the initial basis for further evaluation of minocycline in the treatment of ovarian cancer.[3]

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This study tested the potential antidepressant activity of minocycline alone or combined with two traditional antidepressant drugs or several glutamate receptor antagonists, using the time sampling method in the forced swimming test. Results showed that: desipramine (10.0 mg/kg, P<0.05; 15.0 mg/kg, P<0.05), minocycline (60.0 mg/kg, P<0.05; 80.0 mg/kg, P<0.05) and EMQMCM (1.5 mg/kg, P<0.05; 2.0 mg/kg, P<0.05), reduced immobility by increasing climbing. Fluoxetine (20.0 mg/kg, P<0.05; 25.0 mg/kg, P<0.05) reduced immobility by increasing swimming. MTEP (5.0 mg/kg, P<0.05; 10.0 mg/kg, P<0.05) and dizolcipine (1.0 mg/kg, P<0.05; 1.5 mg/kg, P<0.05) reduced immobility by increasing swimming and climbing. Combination experiments showed that a subthreshold dose of minocycline (50.0 mg/kg) synergized the antidepressant-like actions of subthreshold doses of: desipramine (5.0 mg/kg; P<0.05), EMQMCM (0.6 mg/kg; P<0.05), MTEP (2.5 mg/kg; P<0.05) and dizolcipine (0.5 mg/kg; P<0.05). In conclusion, minocycline produced antidepressant-like actions in the FST and subthreshold dose of minocycline combined with subthreshold dose of desipramine and several glutamate receptor antagonists and produced antidepressant-like actions.[4]

C23H27N3O7

457.48

457.184

C, 60.39; H, 5.95; N, 9.19; O, 24.48

10118-90-8

Minocycline hydrochloride;13614-98-7;Minocycline-d6;1036070-10-6; 10118-90-8; 128420-71-3 (HCl hydrate)

54675783

Typically exists as green solid at room temperature

1.6±0.1 g/cm3

803.3±65.0 °C at 760 mmHg

439.6±34.3 °C

0.0±3.0 mmHg at 25°C

1.718

-0.65

5

9

3

33

971

4

CN(C1=CC=C(O)C2=C1C[C@H]3C[C@H]4[C@H](N(C)C)C(O)=C(C(N)=O)C([C@@]4(O)C(O)=C3C2=O)=O)C

FFTVPQUHLQBXQZ-KVUCHLLUSA-N

InChI=1S/C23H27N3O7/c1-25(2)12-5-6-13(27)15-10(12)7-9-8-11-17(26(3)4)19(29)16(22(24)32)21(31)23(11,33)20(30)14(9)18(15)28/h5-6,9,11,17,27-28,31,33H,7-8H2,1-4H3,(H2,24,32)/t9-,11-,17-,23-/m0/s1

(4S,4aS,5aR,12aR)-4,7-bis(dimethylamino)-1,10,11,12a-tetrahydroxy-3,12-dioxo-4a,5,5a,6-tetrahydro-4H-tetracene-2-carboxamide

HSDB3130; HSDB-3130; HSDB 3130

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.)