Z-VAD(OMe)-FMK is a pan-caspase inhibitor with irreversible properties; Z-VAD(OMe)-FMK is also an inhibitor of ubiquitin C terminal hydrolase L1 (UCHL1), which is irreversibly modified by targeting the UCHL1 active site.

METHODS: Human leukemia cells HL60 were treated with Z-VAD(OMe)-FMK (50 µM) and camptothecin (50 M) for 3 h. Cell morphology was observed by electron microscopy.
RESULTS: Cells treated with camptothecin exhibited typical apoptotic features including cell shrinkage, chromatin condensation and nuclear fragmentation.Z-VAD(OMe)-FMK combination treatment eliminated the camptothecin-induced apoptotic pattern. Z-VAD(OMe)-FMK alone did not affect cell morphology. [1]
METHODS: Cholangiocarcinoma cells KKU100, KKU213A and KKU213B were pretreated with Z-VAD(OMe)-FMK (20 µM) for 1 h, followed by CH-MSCs (0%, 50% and 75%) for 24 h. Apoptosis was detected using Flow Cytometry.
RESULTS: Z-VAD(OMe)-FMK pretreatment prevented the apoptosis induced by CH-MSCs. [2]
METHODS: Human ovarian teratoma cells PA-1 were treated with Z-VAD(OMe)-FMK (50 μM) and UVB (100 J/m2) for 16 h, and the expression levels of target proteins were detected by Western Blot.
RESULTS: Z-VAD(OMe)-FMK eliminated PARP cleavage induced by UVB. [3]

METHODS: To investigate whether in vivo administration of Z-VAD(OMe)-FMK prevents infection-induced preterm labor, a single intraperitoneal injection of Z-VAD(OMe)-FMK (10 mg/kg) was administered to CD1 mice in which preterm labor was induced by heat-killed group B streptococcus (HK-GBS).
RESULTS: Z-VAD(OMe)-FMK pretreatment delayed but did not prevent HK-GBS-induced preterm labor in a pregnant mouse model. [4]
METHODS: To prevent LPS-induced acute lung injury, Z-VAD(OMe)-FMK (0.25 mg 15 min before LPS stimulation, 0.1 mg three times per hour) was injected intravenously into ICR mice with LPS-induced apoptosis and acute lung injury.
RESULTS: Z-VAD(OMe)-FMK inhibited caspase-3 activity in lung tissues. Z-VAD(OMe)-FMK significantly prolonged the survival of mice. Apoptosis may play an important role in acute lung injury, and thus inhibition of caspase activity may provide a new therapeutic approach for the treatment of this disease. [5]

The human monocytic tumour cell line, THP.1 and the leukaemic T-cell line, Jurkat (clone E-6) were maintained in RPMI 1640 supplemented with 10% (v/v) heat-inactivated fetal calf serum, 100 units/ml penicillin and 100 μg/ml streptomycin in an atmosphere of 5% CO2 in air at 37 °C. The cells were maintained in logarithmic growth phase by routine passage every 2–3 days. To induce apoptosis in THP.1 cells, 2×10^6 cells/ml were incubated either alone or in the presence of cycloheximide (25 μM) and TLCK (100 μM) as previously described. In order to assess the possible effects of various ICE-like protease inhibitors, THP.1 cells were also pretreated for 1 h with Z-VAD.FMK (10 μM), Ac-DEVD-CHO (20 μM) and Ac-YVAD-CHO (20 μM) before being exposed to the apoptotic stimulus. To induce apoptosis in Jurkat cells, 2×10^6 cells/ml were stimulated with 200 ng/ml anti-human Fas as described previously [1].

Mice used in this study were 5- to 6-week-old (20 to 22 g) ICR males. Mice were injected with 30 mg/kg LPS from E. coli serotype O111:B4 through the tail vein. Z-VAD.fmk was dissolved at 2 mg/ml in 1% dimethyl sulfoxide in sterile saline, and administered to mice by the method of Rodriguez et al. A single intravenous injection of Z-VAD.fmk (0.25 mg) was made 15 minutes before LPS injection, followed by three intravenous injections of Z-VAD.fmk (0.1 mg each) per hour. Control mice were injected with the same volume of 1% DMSO in sterile saline [4].