ML336

ML336 is a Venezuelan equine encephalitis virus (VEEV) inhibitor with moderate passive blood-brain barrier permeability. ML336 inhibits viral RNA synthesis, virus-induced cytopathic effects and viral replication, reduces viral titers, and blocks the synthesis of VEEV genomic, subgenomic and template RNAs. ML336 can be used in studies related to VEEV infection^[1][2]. In Vitro:ML336 (48 h) potently inhibits the cytopathic effect induced by VEEV TC-83 in Vero 76 cells, with an EC₅₀ of 0.03 μM^[1].
ML336 (48 h) potently inhibits the cytopathic effect induced by VEEV V3526 in Vero 76 cells, with an EC₅₀ of 0.02 μM^[1].
ML336 (48 h) potently inhibits the cytopathic effect induced by VEEV TrD in Vero 76 cells, with an EC₅₀ of 0.04 μM^[1].
ML336 (0.5-5 μM; 40 h) potently reduces the viral titer of VEEV TC-83 in Vero 76 cells, leading to a > 7.2 log decrease in viral titer at a concentration of 1 μM, with an EC₉₀ of 0.17 μM^[1].
ML336 (0.5-5 μM; 40 h) completely blocks detectable VEEV TrD viral replication in Vero 76 cells at concentrations as low as 0.5 μM^[1].
The potency of ML336 (48 h) is significantly reduced against VEEV strains with mutations in nsP2 or nsP4, indicating that it inhibits viral replication by targeting viral non-structural proteins 2 and/or 4^[1].
ML336 (48 h) potently protects Vero 76 cells against the cytopathic effect (CPE) induced by VEEV TC-83, with an EC₅₀ of 32 nM, and reduces viral titers by more than 7.2 log orders at a concentration of 5 μM^[2].
ML336 (0.00001-1000 nM; 2 h) potently and dose-dependently inhibits VEEV TC-83 RNA synthesis in BHK21 cells, with an IC₅₀ of 1.1 nM; it reduces the synthesis level to 7% of that in the control group at a concentration of 40 nM, and completely blocks the synthesis of the parental V3526 strain at 5 μM^[2].
ML336 (5 μM) inhibits the RNA synthesis of both positive-sense and negative-sense VEEV TC-83 in BHK21 cells, and prevents any increase in viral RNA copy numbers during 4 to 6 HPI at a concentration of 5 μM^[2].
ML336 (5 μM; 2 h) inhibits positive-strand VEEV TC-83 RNA synthesis mediated by mature replicase complexes in BHK21 cells; even when translation (and negative-strand RNA synthesis) is inhibited by cycloheximide, 5 μM of this compound still completely blocks RNA production^[2].
ML336 (2.5 μM; 2 h) inhibits the synthesis of genomic (49S) and subgenomic (26S) VEEV TC-83 RNA in BHK21 cells, and completely abolishes the production of both RNAs when added at a concentration of 2.5 μM at any time within 8 hours post-infection (HPI)^[2].
ML336 (0.32-1000 nM; 90 min) directly inhibits RNA synthesis of VEEV TC-83 in a cell-free system by interacting with the viral replicase complex, with an IC₅₀ of 49 nM, and completely blocks the synthesis at concentrations ≥ 200 nM^[2]. In Vivo:ML336 (5 mg/kg/day; i.p.; twice daily; 4 days) confers 71% survival in VEEV TC-83-infected C3H/HeN mice over a 21-day period^[1].