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

OVCAR-3, SKOV-3, and A2780 pearl cotton lines are inhibited in terms of proliferation and clonogenic activity by minocycline hydrochloride (0-100 μM, 24-72 hours) [3]. Hydrochloride of minocycline (0-100 μM, 24-48 hours). In an oscilloscope, minocycline hydrochloride (0-100 μM, 72 h)) causes a cell cycle [3]. In addition to inhibiting both caspase-dependent and caspase-independent cell death, direct neural protection may also be linked to mitochondrial abnormalities and cytochrome c protection [2]. Examination of the proliferation of hypoxia-inducible factor (HIF) cells induced by minocycline hydrochloride [3]

In female nude mice, ovccrine hydrochloride (0–30 mg/kg) administered intravenously once daily for four weeks inhibits the growth of OVCAR-3 tumors [3]. In animal models of brain damage, minocycline hydrochloride (IP), a powerful medication, exhibits neuroprotective effects when administered intraperitoneally in high dosages [1]. METH-induced hyperlocomotion and behavioral sensitization in mice are markedly inhibited by minocycline hydrochloride (0–40 mg/kg, IP, once) [2]. In a model of temporary middle cerebral artery occlusion (TMCAO), minocycline hydrochloride (3 and 10 mg/kg IV once) effectively reduces infarct size [1]. The effects of minocycline hydrochloride (3–10 mg/kg IV once) on blood may be mitigated by potential-induced ventricular arrhythmias. This effect in humans at the standard 200 mg dose may be associated with mitochondrial KATP channels, PI3K/Akt signaling, and L-type levels (3 mg/kg) [1].

Cell Proliferation Assay[3]
Cell Types: human ovarian cancer cell line (OVCAR-1α inhibition, and regulation of up-p53 protein and AKT levels/mTOR/p70S6K/ Inactivation of 4E-BP1 dye [6]. 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 hrs (hours)
Experimental Results: Inhibition of the proliferation of OVCAR-3, SKOV-3 and A2780 cells was concentration-dependent, 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.

---

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. Minocycline-activated caspase-3 in turn leads to the cleavage of PARP-1. Caspase-3 increases the degradation product of PARP-1, p89.

---

Cell cycle analysis[3]
Cell Types: OVCAR-3, SKOV-3 and A2

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: Orally in drinking water Administration, starting on day 8 of cell inoculation, one time/day for 4 weeks.
Experimental Results: Inhibited OVCAR-3 tumor growth and diminished microvessel density in these female nude mice.

---

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: Significantly attenuated METH-induced hyperlocomotion and the development of behavioral sensitization in mice at 40 mg/kg. Did not exert any effect on the induction of METH-induced hyperthermia in mice. Significantly attenuated the reduction of DA and DOPAC in the striatum. Significantly attenuated the reduction of DAT-immunoreactivity in the mouse striatum. Significantly attenuated the increase in MAC1-immunoreactivity in the striatum after the administration of METH.

---

Animal/Disease Models: Male Sprague-Dawley rats (270-330 g, TMCAO model)[1]
Doses: 3 mg/kg and 10 mg/kg
Route of Administration: IV, once, 4, 5, or 6 hours post TMCAO
Experimental Results: Reduced infarct size by 42% while 10 mg/kg reduced infarct size by 56% at doses of 3 mg/kg; significantly reduced infarct size at 5 hours by 40% at doses of 10 mg/kg 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.

---

Animal/Disease Models: Male Sprague-Dawley rats (270-330 g)[1]
Doses: 3, 10, or 20 mg/kg
Route of Administration: IV, once
Experimental Results: Peak concentrations of serum levels of minocycline averaged 3.6, 13.0 and 28.8 mg/L with 3, 10 and 20 mg/kg doses respectively. The serum levels of minocycline at a 3 mg/kg dose (3.6 mg/L) were similar to that reported in humans after a standard 200 mg dose. Did not significantly affect hemodynamic and physiological variables.

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 hydrochloride (oral) may cause developmental toxicity, depending on state or federal labeling requirements. It is a tetracycline analog with a 7-dimethylamino group lacking the five methyl groups and hydroxyl groups, and is effective against tetracycline-resistant staphylococcal infections. See also: Minocycline hydrochloride (note moved here). Treatment options for multidrug-resistant (MDR) Acinetobacter baumannii infections are extremely limited. Intravenous minocycline is effective against many MDR Acinetobacter baumannii strains, and the Clinical and Laboratory Standards Institute (CLSI) has established breakpoints to guide the interpretation of minocycline susceptibility testing results for Acinetobacter baumannii. Furthermore, intravenous minocycline has been approved by the U.S. Food and Drug Administration (FDA) for the treatment of Acinetobacter baumannii infections. A growing body of literature reports the successful use of intravenous minocycline in the treatment of severe MDR-resistant Acinetobacter baumannii infections, particularly hospital-acquired pneumonia. These results, coupled with the generally good tolerability of intravenous minocycline, support its use as a viable treatment option for MDR-resistant Acinetobacter baumannii infections. [5]

---

Hypoxia-inducible factor (HIF)-1α is a key cell survival protein under hypoxic conditions and is associated with tumor progression and angiogenesis. We recently found that the inhibitory effect of minocycline on ovarian tumor growth is associated with attenuation of vascular endothelial growth factor (VEGF). This paper reports a related laboratory study aimed at verifying whether these effects are a result of HIF-1α inhibition. In this study, we investigated the effects of minocycline on HIF-1 and its upstream pathway components in vitro using human ovarian cancer cell lines (A2780, OVCAR-3, and SKOV-3) to elucidate the mechanism of action of minocycline. At the same time, we treated mice carrying OVCAR-3 xenografts with minocycline to evaluate the efficacy of minocycline in the HIF-1 pathway in vivo. The results showed that minocycline negatively regulates HIF-1α protein levels in a concentration-dependent manner and induces its degradation through a prolyl hydroxylation-independent mechanism. In addition, the inhibition of HIF-1α is associated with the upregulation of endogenous p53, which is a tumor suppressor and has been shown to be involved in the degradation of HIF-1α. Further studies have shown that the effect of minocycline is not limited to proteasome degradation, but can also downregulate the translation of HIF-1α by inhibiting the AKT/mTOR/p70S6K/4E-BP1 signaling pathway. In mice with established ovarian tumors, minocycline treatment led to the inhibition of HIF-1α expression, while p53 protein levels were upregulated and the AKT/mTOR/p70S6K/4E-BP1 pathway was inactivated. These data reveal that minocycline, as a drug targeting the oncogenic factor HIF-1α, has potential therapeutic value in the treatment of ovarian cancer, and its mechanism of action involves multiple pathways. [6] Minocycline has been shown to protect the myocardium from ischemia-reperfusion injury. This study investigated the effect of minocycline on ischemia-induced ventricular arrhythmias in rats. Male rats under anesthesia received minocycline (45 mg/kg, intraperitoneal injection) once an hour before ischemia, concurrently with or without 2-(4-morpholino)-8-phenyl-1(4H)-benzopyran-4-one hydrochloride (LY294002, 0.3 mg/kg, intravenous injection, a PI3K inhibitor) and 5-hydroxydecanoic acid [5-HD, 10 mg/kg, intravenous injection, a specific inhibitor of mitochondrial ATP-sensitive potassium channels (K(ATP))], administered once 10 minutes before ischemia, followed by 30 minutes of ischemia. Ventricular arrhythmias were assessed. L-type Ca²⁺ currents were measured using patch-clamp technique. During the 30-minute ischemia period, minocycline significantly reduced the incidence of ventricular fibrillation (VF) (P<0.05). Compared with the myocardial ischemia group, minocycline significantly reduced the duration of ventricular tachycardia with ventricular fibrillation (VT+VF), the number of VT+VF episodes, and the severity of arrhythmias (all P<0.05). Administration of LY294002 or 5-HD eliminated the protective effect of minocycline on the incidence of ventricular fibrillation, duration of VT+VF, number of VT+VF episodes, and severity of arrhythmias (all P<0.05). In addition, minocycline inhibited L-type Ca²⁺ currents in normal myocardial cell membranes in a dose-dependent manner. This study suggests that minocycline may alleviate ischemia-induced ventricular arrhythmias in rats through the PI3K/Akt signaling pathway, mitochondrial K (ATP) channels, and L-type Ca²⁺ channels. [7]

C23H28CLN3O7

493.9373

493.161

C, 55.93; H, 5.71; Cl, 7.18; N, 8.51; O, 22.67

13614-98-7

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

54685925

Light yellow to yellow solid powder

659.4ºC at 760mmHg

205-210° (dec)

352.6ºC

6.33E-28mmHg at 25°C

1.688

6

9

3

34

971

4

CN(C)[C@H]1[C@@H]2C[C@@H]3CC4=C(C=CC(=C4C(=C3C(=O)[C@@]2(C(=C(C1=O)C(=O)N)O)O)O)O)N(C)C.Cl

KDLQIOPKJDNQIM-YKWOUSISSA-N

InChI=1S/C23H27N3O7.ClH/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;/h5-6,9,11,17,27-28,32-33H,7-8,24H2,1-4H3;1H/b22-16+;/t9-,11-,17+,23-;/m1./s1

(4S,4aR,5aS,12aR,E)-2-(amino(hydroxy)methylene)-4,7-bis(dimethylamino)-10,11,12a-trihydroxy-4a,5a,6,12a-tetrahydrotetracene-1,3,12(2H,4H,5H)-trione hydrochloride

NSC 141993; Minocycline HCl; NSC 141993; Mynocine hydrochloride; NSC141993; NSC-141993; Periocline; Klinomycin; Minocin; Solodyn; Mynocine; Tri-mino; Vectrin; Ximino; Minomax; Minomycin chloride; Mynocine hydrochloride

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 : ~19.23 mg/mL (~38.93 mM)
H2O : ~9.09 mg/mL (~18.40 mM)

Solubility in Formulation 1: 7.69 mg/mL (15.57 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with sonication.

---

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