To investigate the effects of valproic acid on the survival of cultured human Tenon's capsule fibroblasts (HTFBs).

Primary cultured HTFBs were exposed to 0, 0.25, 0.5, and 1.0 mM valproic acid with or without 0, 1.0, 2.5 µg/mL mitomycin C, and incubated for 5 days. Cell survival was assessed using an MTT (3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide) assay and the degree of apoptosis was assessed by flow cytometry using annexin-V/propidium iodide double staining.

Valproic acid decreased the survival of HTFBs in a dose-dependent manner, and survival was further decreased by adding mitomycin C to valproic acid. Both valproic acid and mitomycin C induced apoptosis of HTFBs. Valproic acid induced less apoptosis than mitomycin C.

Valproic acid decreased the cellular survival of HTFBs and induced apoptosis. The antiproliferative effects of valproic acid were further enhanced by the addition of mitomycin C.