In MRC-5 cells, 8-hydroxyquinoline (8HQ) (Compd 1) exhibits cytotoxicity with an IC50 of 6.27 μM[1]. When combined with CuCl2, 10.0 μM, for one hour, 8-hydroxyquinoline (8-OHQ) (Compd 1) creates a complex with copper that facilitates copper transport into human breast cancer DCIS cells [2]. When 8-hydroxyquinoline is combined with CuCl2, 0–20.0 μM, it binds to copper and produces a complex that has tyrosine kinase inhibitor-like activity (1–5 μM, 2–12 hours)[2]. causes time- and dose-dependent cell death in DCIS cells [2]. In Raw 264.7 cells, hydroxyquinoline (0-100 μM, 30 minutes) suppresses regulatory factors by blocking NO generation and iNOS expression through the activation of NF-κB and decreasing C/EBPb DNA-binding activity [3].

In CD1 mice, a single intraperitoneal injection of 8-hydroxyquinoline (HOQ) at a dose of 25–100 mg/kg significantly increases the quantity of micronucleated polychromatic erythrocytes (MPCE) [4]. Hair growth and loss are caused by 8-Hydroxyquinoline (8-HQ) (0.3%, Skin Appearance, 4 times weekly), with growth patterns altering over time [5].

Cell Viability Assay[2]
Cell Types: DCIS Cell
Tested Concentrations: 1, 2.5, 5, 10, 20 μM
Incubation Duration: 1 or 8 hrs (hours)
Experimental Results: Binds to copper and forms a complex, causing cells to agglomerate and separate, at a certain concentration and Induces cell death in a time-dependent manner. 8-OHQ- and CQ-Cu, but not their analogs and mixtures of Cu, can induce cancer cell death in a concentration- and time-dependent manner.

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Western Blot Analysis[2]
Cell Types: DCIS Cell
Tested Concentrations: 1, 2.5, 5 μM
Incubation Duration: 0, 2, 4, 8, 12 hrs (hours)
Experimental Results: CuCl2 mixture inhibited CT-like activity in a concentration and time dependent manner. Mixtures of CuCl2 diminished proteasome activity and increased accumulation of ubiquitinated proteins and Bax in a time-dependent manner.

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RT-PCR[3]
Cell Types: Lipopolysaccharide-stimulated original 264.7 cells
Tested Concentrations: 25, 50, 75, 100 μM
Incubation Duration: 30 minutes
Experimental Results: Inhibited of LPS-induced NO and iNOS expression.br/> Inhibits transcription of iNOS. Had not affect phosphorylation of MAPKs. Inhibited NF-jB-binding activity and C/EBPb-binding activity.

Animal/Disease Models: CD1 mice[4]
Doses: 25,50,100 mg/kg
Route of Administration: intraperitoneal (ip) injection
Experimental Results: All doses tested resulted in micronucleated polychromatic erythrocytes (MPCE) numbers over a 24-hour sampling period Significant dose-related increase.

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Animal/Disease Models: C57BL mice [5]
Doses: 0.3% Administration 4 times a week: Dermal administration
Experimental Results: Causes depigmented hair to grow in a time-varying manner. Frequent enough use results in nearly complete depigmentation in young adult C57BL female mice, whereas a single application results in isolated bands of depigmented hair.

Absorption, Distribution and Excretion
Hydroxyquinoline is primarily excreted in the urine, with a small amount excreted in the bile. Following intravenous injection in male Donglong strain rats, 8-hydroxyquinoline is metabolized into glucuronide and sulfate conjugates. More 8-hydroxyquinoline glucuronide is excreted in the urine than 8-hydroxyquinoline sulfate conjugates. Only the glucuronide conjugates are excreted in the bile. Following intravenous injection in male Donglong strain rats, 8-hydroxyquinoline is metabolized into glucuronide and sulfate conjugates. Glucuronide is excreted in both bile and urine, while sulfate is excreted only in the urine. Only a small amount of the unmetabolized form is excreted. Metabolites/Metabolites In urine, 60% of the dose is excreted as glucuronide conjugates, and 23% as sulfate conjugates. In bile, 9% of the total dose is present as glucuronide conjugates. In male Donglong strain rats, intravenous injection of 8-hydroxyquinoline resulted in its metabolism into glucuronide and sulfate conjugates. Only a small amount of the unmetabolized form was excreted.

Toxicity Data
LC50 (Rat) > 1,210 mg/m³/6h

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Non-human toxicity values
Oral LD50 in rats: 1200 mg/kg
Intraperitoneal LD50 in mice: 48 mg/kg
Intraperitoneal LD50 in rats: 50 mg/kg
Subcutaneous LD50 in mice: 83,600 μg/kg
For more complete non-human toxicity data on 8-hydroxyquinoline (out of 6), please visit the HSDB record page.

[1]. Lawung R, et.al. Repositioning of 8-hydroxyquinoline derivatives as a new promising candidate for combating multidrug resistant Neisseria gonorrhoeae. EXCLI J. 2018 Aug 23;17:840-846.
[2]. 8-hydroxyquinoline and clioquinol requires their capabilities to bind copper and transport copper into cells. J Biol Inorg Chem. 2010 Feb;15(2):259-69.
[3]. Zhai S, et.al. Tumor cellular proteasome inhibition and growth suppression by
[4]. Hamoud MA, et.al. Effects of quinoline and 8-hydroxyquinoline on mouse bone marrow erythrocytes as measured by the micronucleus assay. Teratog Carcinog Mutagen. 1989;9(2):111-8.
[5]. Searle CE. The selective depigmenting action of 8-hydroxyquinoline on hair growth in the mouse. Br J Dermatol. 1972 May;86(5):472-80.

8-Hydroxyquinoline is a white to off-white or pale yellow crystalline powder with a phenolic odor. (NTP, 1992)
Quinoline-8-ol is a monohydroxyquinoline with a hydroxyl group substituted at the 8-position. It has fungicidal properties and can be used to control gray mold on grapevines and tomatoes. It can also be used as an antibacterial agent, iron chelating agent, preservative, and antifungal pesticide. It is a derivative of quinoline hydrogen.
Hydroxyquinoline is a heterocyclic phenol, a derivative of quinoline, with preservative, disinfectant, and insecticidal properties. It is used as a stabilizer for hydrogen peroxide and is sometimes added to cosmetics.
8-Hydroxyquinoline has been reported to be detected in Cortinarius subtortus and Allium stipitatum, with relevant data available.
It is a preservative with mild antibacterial, bacteriostatic, insecticidal, and amoeboid effects. It can also be used as a reagent and metal chelating agent, as well as a radioactive indium carrier for diagnostic purposes. In addition, its halogenated derivatives can be used as topical anti-infective agents and oral anti-amoebic drugs. See also: Acetic acid; Hydroxyquinoline (ingredient). Drug Indications: Hydroxyquinoline is used as a bactericidal ingredient in a variety of over-the-counter medications. These products are marketed to inhibit abnormal biological growth in the vagina and restore the natural pH balance. Mechanism of Action: The mechanism by which hydroxyquinoline exerts its bactericidal effect is not yet clear. Therapeutic Uses: Antibacterial and antifungal compounds; primarily used to treat minor burns and hemorrhoids. Hydroxyquinoline sulfate… is used to treat athlete's foot, vaginitis, and can be used as a mouthwash, eyewash, nasal rinse, and hemorrhoid preparation… /Hydroxyquinoline sulfate/ /Over-the-counter medication/ Hydroxyquinoline is one of four antifungal drugs recommended for the treatment of diaper rash and prickly heat-related fungal infections in infants. /Hydroxyquinoline/ 8-Hydroxyquinoline sulfate inhibits the formation of artificial stones in vitro and stones in rats in vivo. In rats, application via swab or intraoral drip prevented tartar formation. In dogs, plaque formation was inhibited by 33% to 98% compared to placebo. Furthermore, existing plaque was cleared at rates of 25% to 58%, compared to only 2% to 22% in the placebo group. For more complete data on the therapeutic uses of 8-hydroxyquinoline (one of seven), please visit the HSDB record page.
Pharmacodynamics
Hydroxyquinoline is a bactericide that eliminates bacteria and fungi.

C9H7O

145.16

145.052

148-24-3

8-Hydroxyquinoline hemisulfate;134-31-6

1923

White crystals or white crystalline powder

1.3±0.1 g/cm3

267.0±0.0 °C at 760 mmHg

70-73 °C(lit.)

143.1±20.4 °C

0.0±0.5 mmHg at 25°C

1.691

1.87

1

2

0

11

138

0

O([H])C1=C([H])C([H])=C([H])C2C([H])=C([H])C([H])=NC=21

MCJGNVYPOGVAJF-UHFFFAOYSA-N

InChI=1S/C9H7NO/c11-8-5-1-3-7-4-2-6-10-9(7)8/h1-6,11H

quinolin-8-ol

NSC-2039; NSC 2039; Oxyquinoline

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)

DMSO : ~50 mg/mL (~344.45 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (17.22 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 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: ≥ 2.5 mg/mL (17.22 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in 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 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
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.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (17.22 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (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 900 μL of corn oil and mix evenly.

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