Effect of tranilast on proliferation, collagen gel contraction, and transforming growth factor beta secretion of retinal pigment epithelial cells and fibroblasts.

The efficiency of tranilast for the treatment of proliferative vitreoretinopathy (PVR) was investigated in vitro. A tetrazolium-based colorimetric assay showed that the 300-microM concentration of tranilast inhibited proliferation of bovine retinal pigment epithelial (RPE) cells and rabbit dermal fibroblasts with no toxicity. The contraction of collagen gels embedded with these cells was evaluated in the cultures. Compared with the gel incubated with minimal essential medium and 0.35% bovine serum albumin and/or fetal calf serum, tranilast inhibited gel contraction. Enzyme-linked immunosorbent assay revealed that a 300-microM concentration of tranilast inhibited transforming growth factor-beta(1) (TGF-beta(1)) secretion significantly (p < 0.01). These results suggest that tranilast may inhibit the proliferation of RPE cells and fibroblasts and contraction of intraocular fibrous membranes by suppressing TGF-beta(1) secretion from these cells with a potential to treat PVR. Copyright 2002 S. Karger AG, Basel