Brequinar

Kinase experiment [1]:

Preparation method

Immunoprecipitated p59^fyn or p56^lck from CTLL-4 cells or LSTRA cells (5×10⁶) was preincubated with various concentrations of Brequinar(0-200μM) in the PTK buffer on ice for 10 min. Exogenous substrate, histone 2B (2μg), was added and, after 10 min, the reaction was initiated by addition of 10 μCi [γ-³²P]ATP. After incubation at 20°C for 10 min, the reaction mixture was subjected to electrophoresis in a 12.5% SDS-polyacrylamide gel. Phosphorylation of the kinase and the exogenous substrate was analyzed by autoradiography.

Reaction Conditions

0-200μM;

Applications

Brequinar inhibited autophosphorylation of p56lck with an IC₅₀ of 70 μM; Brequinar inhibited autophosphorylation of p59fyn with an IC₅₀ of 105 μM; Brequinar also inhibited the phosphorylation by p59fyn of histone 2B with an IC₅₀ of 20 μM.

Cell experiment [2]:

Cell lines

Vero cells

Preparation method

Spectrum of Brequinar antiviral activity. Vero cells were infected with the indicated viruses at an MOI of 0.1; the infected cells were immediately treated with Brequinar(0-25μM). For DENV-2, WNV, YFV, PWV, and WEEV, culture media were collected at 42 h p.i. and viral titers were measured using plaque assays.

Reaction Conditions

0-25μM; 42h

Applications

Brequinar effectively inhibited all viruses tested and antiviral activity was not due to compound-mediated toxicity.

Animal experiment [3]:

Animal models

Specific-pathogen-free suckling mice

Preparation method

Specific-pathogen-free suckling mice, 3 to 4 days old, weighing 3 to 4g. Suckling mice were inoculated by intraperitoneal injection with 50 μg of Brequinar. Mice were treated with PBS containing 10% DMSO and 5% Tween-80 in the same volume as controls. Two hours following Brequinar injection, the suckling mice were challenged with 100 LD₅₀ FMDV in a volume of 100 μL by intraperitoneal injection. The animals were monitored for 5 days.

Dosage form

50μg; i.p.

Applications

Brequinar significantly prolonged the survival time of infected suckling mice. Brequinar treatment significantly alleviated lesions in the heart tissue of FMDV-infected mice.

References:

[1] Xu X , Williams J W , Shen J ,et al.In vitro and in vivo mechanisms of action of the antiproliferative and immunosuppressive agent, brequinar sodium.[J].Journal of Immunology, 1998, 160(2):846-53.

[2] Qing M , Zou G , Wang Q Y ,et al. Characterization of dengue virus resistance to brequinar in cell culture.[J].Antimicrobial Agents and Chemotherapy, 2010, 54(9):3686-3695.

[3]Li S F , Gong M J , Sun Y F ,et al.Antiviral activity of brequinar against foot-and-mouth disease virus infection in vitro and in vivo[J].Biomedicine & pharmacotherapy , 2019, 116:108982.