Ketotifen

Ketotifen (HC 20-511) is an orally active second-generation noncompetitive histamine 1 (H1) receptor blocker and mast cell stabilizer. Ketotifen can block 6-phosphogluconate dehydrogenase (PGD) in vitro. Ketotifen also has antiviral activity against SARS-CoV-2 and Influenza virus. Ketotifen can be used to the research of autoimmune encephalomyelitis (EAE) and asthma attack prevention[1][2][3][4].

Signaling Pathways >> Anti-infection >> Influenza Virus

Signaling Pathways >> Immunology/Inflammation >> Histamine Receptor

Research Areas >> Endocrinology

Research Areas >> Infection

Signaling Pathways >> Anti-infection >> SARS-CoV

Research Areas >> Inflammation/Immunology

Signaling Pathways >> GPCR/G Protein >> Histamine Receptor

Histamine 1, SARS-CoV-2, Influenza virus[1][3][4]

Ketotifen (0-100 μM; 2 or 4 days) inhibits SARS-CoV-2 with an EC50 of 48.9 μM; and increases the percentage inhibition of SARS-CoV-2 to 79%, 83% and 93% when co-administers with 25, 50 and 100 μM Indomethacin, respectively[3]. Ketotifen (0-50 μM; 24 h) has inhibitory activity against PR8, pH1N1 and H3N2 with EC50s of 5.9 μM, 33.7 μM and 48.5 μM, respectively; and exhibits relatively low cytotoxicity in MDCK cells (EC50=291 μM)[4].

Ketotifen (80 mg/kg; i.g.; daily for 3 days) reduces end organ damage and mortality in mice infected with influenza virus[4]. Ketotifen (0.4 mg/kg; i.p.; daily for 10 days) reduces encephalomyelitis (EAE) prevalence and severity[5]. Animal Model: Female C57BL/6 mice (4-6 weeks; intranasal infection with 1×103 TCID50 of PR8 in 30 μL of DMEM)[4] Dosage: 80 mg/kg Administration: i.g.; daily for 3 days Result: Reduced end organ damage and mortality in infected mice. Animal Model: Female C57BL/6 mice (5-6 weeks old; subcutaneously immunized with 150 μg of MOG35-55 peptide containing 4 mg/mL of Mycobacterium tuberculosis)[5] Dosage: 0.4 mg/kg Administration: i.p.; daily for 10 days (from the 7th day of infection) Result: Reduced EAE prevalence and severity; reduced oxidative stress status and inflammasome activation at the CNS; reduced the amount of T cells, especially Th1, in the CNS; downregulated local mRNA expression for mast cell enzymes and preserves blood-CNS barrier permeability; triggered lymphocyte accumulation in draining lymph nodes.

[1]. Klooker TK, et al. The mast cell stabiliser ketotifen decreases visceral hypersensitivity and improves intestinal symptoms in patients with irritable bowel syndrome. Gut. 2010 Sep;59(9):1213-21.

[2]. Zhang H, et al. Advances in the discovery of exosome inhibitors in cancer. J Enzyme Inhib Med Chem. 2020;35(1):1322-1330.

[3]. Kiani P, et al. In Vitro Assessment of the Antiviral Activity of Ketotifen, Indomethacin and Naproxen, Alone and in Combination, against SARS-CoV-2. Viruses. 2021 Mar 26;13(4):558.

[4]. Enkirch T, et al. Identification and in vivo Efficacy Assessment of Approved Orally Bioavailable Human Host Protein-Targeting Drugs With Broad Anti-influenza A Activity. Front Immunol. 2019 Jun 5;10:1097.

[5]. Pinke KH, et al. Calming Down Mast Cells with Ketotifen: A Potential Strategy for Multiple Sclerosis Therapy? Neurotherapeutics. 2020 Jan;17(1):218-234.

MOLECULAR FORMULA :

C19-H19-N-O-S

MOLECULAR WEIGHT :

309.45

HEALTH HAZARD DATA

ACUTE TOXICITY DATA

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Oral

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

179 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

JMCMAR Journal of Medicinal Chemistry. (American Chemical Soc., Distribution Office Dept. 223, POB POB 57136, West End Stn., Washington, DC 20037) V.6- 1963- Volume(issue)/page/year: 30,13,1987

TYPE OF TEST :

LD50 - Lethal dose, 50 percent kill

ROUTE OF EXPOSURE :

Intraperitoneal

SPECIES OBSERVED :

Rodent - mouse

DOSE/DURATION :

108 mg/kg

TOXIC EFFECTS :

Details of toxic effects not reported other than lethal dose value

REFERENCE :

JMCMAR Journal of Medicinal Chemistry. (American Chemical Soc., Distribution Office Dept. 223, POB POB 57136, West End Stn., Washington, DC 20037) V.6- 1963- Volume(issue)/page/year: 30,13,1987