Antifibrotic effect of the herbal medicine Saiko-keishi-to (TJ-10) on chronic pancreatitis in the WBN/Kob rat.

Chronic pancreatitis is characterized by fibrosis. We reported an anti-inflammatory effect of the herbal medicine Saiko-keishi-to (TJ-10) on chronic pancreatitis. This study aimed to elucidate the antifibrotic effect of TJ-10. Four-week-old male WBN/Kob rats were fed a special pellet diet (MB-3) with or without TJ-10 (80 mg/100 g body weight) for 20 weeks. Pancreata were histopathologically examined at every 4 weeks, and the expression of fibrosis-related factors such as transforming growth factor beta1 (TGF-beta1), fibronectin (FN), alpha-smooth muscle actin (alpha-SMA), and type III collagen was analyzed. In untreated WBN/Kob rats, chronic pancreatitis developed at 12 weeks and progressed with marked fibrosis at 16 weeks, and the expression of TGF-beta1 and FN peaked at 12 weeks. However, in the TJ-10-treated rats, the rate of pancreatic fibrosis and the expression of TGF-beta1, FN, alpha-SMA, and type III collagen at 12 and 16 weeks decreased significantly compared to those in the untreated rats. These results suggest that TJ-10 inhibits the pancreatic fibrosis by the suppression of TGF-beta1 expression.