Inhibitory Effects of Tranilast on the Proliferation and Functions of Human Pterygium-derived Fibroblasts

PURPOSE.We studied the possibility that tranilast, an antiallergic and antiproliferative drug, may be beneficial for the treatment of pterygium. METHODS.Pterygium-derived cells were identified by immunohistochemical methods. Growth rate of pterygium-derived cells was determined by using a hemocytometer. Chemotaxis was determined in a microchemotaxis chamber. Pterygium-derived cells were cultured on floating collagen gel, and the contracted diameter was measured. Collagen synthesis by pterygium-derived cells was determined by the collagenase digestive method. Tranilast was added to the culture medium at final concentrations of 0, 12.5, 25, 50, and 100 μg/ml. RESULTS.Pterygium-derived cells were stained with anti-prolylhydroxylase and anti-α-smooth muscle actin, and identified as fibroblasts. Tranilast inhibited the proliferation and chemotaxis of pterygium-derived fibroblasts, and the collagen-gel contraction induced by these cells, but it exerted no inhibitory action on collagen synthesis by pterygium-derived fibroblasts. CONCLUSION.Tranilast may be useful for suppressing the recurrence and, possibly, the development of pterygium.