Antifibrotic Effects of Sakuraso-Saponin in Primary Cultured Pterygium Fibroblasts in Comparison With Mitomycin C

To investigate the antifibrotic effects of sakuraso-saponin on a primary culture of human pterygium fibroblasts (HPFs) and normal human Tenon fibroblasts (HTFs) as compared to the effects of mitomycin C (MMC). Samples of HPFs and HTFs were acquired during primary pterygium surgery. Cell toxicity, cell migration, and expression of α-smooth muscle actin (α-SMA) and transforming growth factor-β (TGF-β) were evaluated in HPFs and HTFs after treatment with sakuraso-saponin and MMC. To determine the possible mechanisms underlying the antifibrotic effects of sakuraso-saponin, the expression of phosphorylated Smad2/3 was evaluated after treatment with sakuraso-saponin and MMC. MMC (≥200 μg/mL) significantly reduced cell viability in both HPFs and HTFs, whereas sakuraso-saponin (1.0 μg/mL) decreased cell viability in HPFs only. Both sakuraso-saponin (1.0 μg/mL) and MMC (200 μg/mL) treatment significantly reduced the expression of α-SMA and TGF-β in HPFs (P < 0.05). It is interesting that the expression of α-SMA and TGF-β after treatment with sakuraso-saponin was significantly lower than that after treatment with MMC (P < 0.05). The expression of phosphorylated Smad2/3 protein was decreased by sakuraso-saponin and MMC in HPFs. Both sakuraso-saponin and MMC inhibited TGF-β1-induced cell migration as compared to the control in HPFs. Sakuraso-saponin could be more effective than MMC for the reduction of fibrosis in HPFs. Our results might present the basis for its use as a promising candidate drug for adjuvant therapy to prevent recurrent pterygium after surgery.