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
◉ Overview of Medication Use During Lactation
Many reviews indicate that tetracyclines are contraindicated during lactation because they can cause staining of infant tooth enamel or deposition in bone. However, a careful review of existing literature suggests that short-term use of minocycline during lactation is unlikely to be harmful because the drug concentration in breast milk is low, and the infant's absorption of the drug is inhibited by calcium in breast milk. Short-term use of minocycline by lactating women is acceptable. As a theoretical precaution, long-term or repeated use during lactation should be avoided. The infant should be closely monitored for rashes and potential effects on the gut microbiota, such as diarrhea or candidiasis (thrush, diaper rash). There have been reports of minocycline causing darkening of breast milk. Topical application of minocycline by the mother to treat acne does not pose a risk to a breastfed infant.
◉ Effects on Breastfed Infants
No relevant published information was found as of the revision date.
◉ Effects on Lactation and Breast Milk
A woman who took 100 mg of minocycline twice daily for nearly 4 years experienced galactorrhea after taking perphenazine, amitriptyline, and diphenhydramine, with the milk turning black.
Another woman who breastfed for 18 months after weaning, occasionally producing small amounts of breast milk, then took 150 mg of minocycline orally daily. After 3 to 4 weeks, the expressed milk turned black. The iron content in the milk was more than 100 times higher than normal. Mammograms were normal.
In both cases, macrophages containing black iron-containing pigment were found in the breast milk. This pigment is believed to be an iron chelate of minocycline or 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 analog with a dimethylamino group at position 7 and lacking a methyl and hydroxyl group at position 5. It possesses antibacterial, E. coli metabolite, and anti-aging effects. It belongs to the tetracycline class, tetracycline group, and tertiary α-hydroxy ketone class of compounds. It is the conjugate acid of minocycline (1-) and also the tautomer of minocycline zwitterions. Minocycline belongs to the tetracycline class of drugs. The physiological effect of minocycline is achieved by reducing prothrombin activity. It is a tetracycline analog with a 7-dimethylamino group, lacking five methyl and hydroxyl groups, and is effective against tetracycline-resistant staphylococcal infections. See also: Minocycline (note moved to). Background: Minocycline is a semi-synthetic tetracycline antibiotic that is an effective neuroprotective agent when administered intraperitoneally at high doses in animal models of cerebral ischemia. This study aimed to determine whether administering minocycline at a lower intravenous (IV) dose corresponding to human clinical exposure regimens could effectively reduce infarct size in a transient middle cerebral artery occlusion (TMCAO) model. Methods: Rats underwent 90 minutes of TMCAO. Minocycline or a placebo (saline) was administered intravenously at 4, 5, or 6 hours post-TMCAO. Infarct volume and neurological function were assessed 24 hours post-TMCAO using 2,3,5-triphenyltetrazolium chloride (TTC) brain staining and neurological function scoring. Pharmacokinetic and hemodynamic studies were performed on minocycline-treated rats. Results: Intravenous administration of 3 mg/kg and 10 mg/kg doses of minocycline at 4 hours post-TMCAO effectively reduced infarct size. The 3 mg/kg dose reduced infarct size by 42%, while the 10 mg/kg dose reduced it by 56%. Five hours after TMCAO, minocycline at a dose of 10 mg/kg significantly reduced the infarct area by 40%, while minocycline at a dose of 3 mg/kg significantly reduced the infarct area by 34%. Within a 6-hour time window, the trend of infarct area reduction was not significant. At 4 hours, the neurological function scores of both the 3 mg/kg and 10 mg/kg dose groups were significantly better than those of the control group; at 5 hours, the neurological function scores of the 10 mg/kg dose group were also significantly better than those of the control group. Minocycline had no significant effect on hemodynamics and physiological parameters. After intravenous injection of 3 mg/kg minocycline, its serum concentration was similar to that achieved after human administration of the standard 200 mg dose. Conclusion: Minocycline has a neuroprotective effect under clinically applicable dosing regimens and within a treatment time window of at least 4-5 hours. Given its application prospects in stroke treatment, it is worth considering conducting a phase I human trial. [1]

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The effects of minocycline on methamphetamine (METH)-induced changes in dopaminergic neuronal behavior and neurotoxicity were studied. Studies have found that pre-administration of minocycline (40 mg/kg) reduced hyperactivity in mice following a single injection of methamphetamine (METH, 3 mg/kg). Pre-administration of minocycline (40 mg/kg) significantly reduced behavioral sensitization following repeated injections of METH (3 mg/kg/day, once daily for 5 days). Pre-administration of minocycline (10, 20, or 40 mg/kg) resulted in a dose-dependent decrease in striatal levels of dopamine (DA) and its major metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) following repeated injections of METH (3 mg/kg, 3 hours apart). Furthermore, pre-administration of minocycline (40 mg/kg) significantly reduced the decrease in striatal dopamine transporter (DAT) immunoreactivity following repeated METH injections. In vivo microdialysis studies have shown that pre-administration of minocycline (40 mg/kg) significantly reduced the increase in extracellular dopamine (DA) levels in the striatum after methamphetamine (METH, 3 mg/kg) administration. Furthermore, minocycline did not alter the concentration of METH in plasma or brain tissue after three injections of METH (3 mg/kg), indicating that minocycline does not alter the pharmacokinetics of METH in mice. Interestingly, METH-induced striatal neurotoxicity was significantly reduced by subsequent administration of minocycline (40 mg/kg). These findings suggest that minocycline may be able to improve behavioral changes and neurotoxicity of dopaminergic nerve endings after METH administration. Therefore, minocycline could be considered an effective drug for treating various symptoms associated with methamphetamine abuse in humans. [2]

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Objective: This study aimed to determine whether minocycline inhibits the growth of ovarian cancer in vitro and in vivo and its molecular mechanism. Materials and Methods: The effects of minocycline on ovarian cancer cell proliferation, cell cycle progression and apoptosis were evaluated using human ovarian cancer cell lines OVCAR-3, SKOV-3 and A2780. Then, the ability of minocycline to inhibit the growth of OVCAR-3 xenograft tumors in female nude mice was examined. Results: Minocycline inhibited cell proliferation and colony formation, downregulated the expression of cyclin A, B and E, caused cell cycle arrest at G0 phase and inhibited DNA synthesis. In addition, these cells showed DNA fragmentation, caspase-3 activation and PARP-1 cleavage after exposure to minocycline. In a nude mouse subcutaneous tumor model, minocycline inhibited tumor proliferation index, angiogenesis and tumor growth. Conclusion: These findings provide a preliminary basis for further evaluation of the application of minocycline in the treatment of ovarian cancer. [3]

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This study used the forced swimming test time sampling method to examine the potential antidepressant activity of minocycline alone or in combination with two conventional antidepressants or several glutamate receptor antagonists. The 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) all reduced immobility time by increasing climbing activities. Fluoxetine (20.0 mg/kg, P<0.05; 25.0 mg/kg, P<0.05) reduced immobility time by increasing swimming activities. Metapeptide (5.0 mg/kg, P<0.05; 10.0 mg/kg, P<0.05) and dezoceppine (1.0 mg/kg, P<0.05; 1.5 mg/kg, P<0.05) reduced immobility time by increasing swimming and climbing activities. Combined experiments showed that subthreshold doses of minocycline (50.0 mg/kg) could produce synergistic antidepressant-like effects with subthreshold doses of the following drugs: 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 dezoceppine (0.5 mg/kg; P<0.05). In summary, minocycline exhibited an antidepressant-like effect in the forced swimming test (FST), and subthreshold doses of minocycline, combined with subthreshold doses of desipramine and several glutamate receptor antagonists, also produced an antidepressant-like effect. [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.)