Tranilast inhibits cell proliferation and collagen synthesis by rabbit corneal and Tenon's capsule fibroblasts

Purpose. To determine whether tranilast, N-(3,4-dimethoxycinnamoyl) anthranilic acid, influences cell proliferation and collagen synthesis by rabbit Tenon's capsule fibroblasts (TFs) and corneal stromal fibroblasts (CFs). Methods. Rabbit TFs and CFs (7000 cells/well) were cultured in F-12 nutrient mixture supplemented with 1% FBS, plus 0, 3, 30, or 300 mu M tranilast, and the number of cells was counted 72 hrs later. To determine the effect of tranilast on collagen synthesis, cells at confluence were cultured in a medium containing 0, 3, 30, or 300 mu M tranilast and labeled with H-3-proline, and the amount of radioactivity incorporated into collagenase-sensitive proteins was measured. Results. At 300 mu M, tranilast decreased the number of TFs by about 27% and the number of CFs by about 45%, but had no effect on cell viability. The same concentration of tranilast reduced TFs collagen synthesis and CFs collagen synthesis. Conclusions. Tranilast may inhibit scar formation after trabeculectomy for glaucoma and after excimer laser photorefractive keratectomy.