Ameliorative effect of Alnus japonica ethanol extract on colitis through the inhibition of inflammatory responses and attenuation of intestinal barrier disruption in vivo and in vitro.

Inflammatory bowel disease (IBD) is chronic inflammation of the gastrointestinal tract caused by high levels of pro-inflammatory cytokines and epithelial barrier dysfunction. Alnus japonica Steud. (Betulaceae) has been used in traditional Asian medicine. However, the potential of A. japonica for the treatment of intestinal inflammation has not been investigated. This study investigated the effects of ethanol extract from A. japonica bark (AJE) on colonic mucosa injury in mice with dextran sodium sulfate (DSS)-induced colitis. Treatment with AJE ameliorated pathological damage and the histopathologic features of DSS-induced colitis. The administration of AJE also inhibits DSS-induced pro-inflammatory cytokines expression, including interleukin (IL)-1ß, IL-6, tumor necrosis factor (TNF)-α, and cyclooxygenase (COX)-2. Notably, AJE administration attenuated the reduction of tight junction proteins, zonula occludens (ZO)-1 and occludin, in DSS-induced colitis. In addition, AJE increased heme oxygenase (HO)-1 expression and prevented DSS-induced apoptosis in colonic epithelial cells. Furthermore, in vitro studies demonstrated that AJE inhibits TNF-α-induced IL-8, IL-1ß, and COX-2 expression in human intestinal epithelial HT-29 cells and tert-butyl hydroperoxide-induced reduction of ZO-1 and occludin expression in human intestinal epithelial Caco-2 cells. AJE-induced HO-1 protein expression was also found in both HT-29 and Caco-2 cells. Taken together, our findings demonstrated that AJE inhibits intestinal inflammation and protects against intestinal barrier disruption in mice with DSS-induced colitis in vivo and human intestinal epithelial cells in vitro. These results suggest that AJE might have beneficial effects for the treatment of IBD.

Anti-fibrotic effect of PF2401-SF, a standardized fraction of Salvia miltiorrhiza, in thioacetamide-induced experimental rats liver fibrosis.

We previously reported the in vitro and in vivo hepatoprotective and anti-fibrotic effects of PF2401-SF, a standardized fraction of Salvia miltiorrhiza, against acute and subacute liver injury. The aim of this study was to investigate the effect of PF2401-SF on liver fibrosis induced by thioacetamide (TAA), a chronic liver injury model (12 weeks) that closely resembles fibrosis and cirrhosis in humans. Hepatoprotective activity was indicated by low serum levels of the markers aspartate amino transferase and alanine amino transferase .In addition, compared to the TAA-group livers, the PF2401-SF-treated liver tissues showed no fibrous tissue deposition in the portal areas, hepatocyte morphology more closely resembling normal tissue morphology, and significantly reduced collagen deposition. Furthermore, downregulation of collagen 1(α) and tissue inhibitor of metalloproteinase (TIMP)1 protein and mRNA expression also supports PF2401-SF's anti-fibrotic effect. We also observed reduced expression of α-smooth muscle actin (α-SMA), an important marker of hepatic stellate cells (HSCs) activation. From these results, we conclude that PF2401-SF's anti-fibrotic mechanism in the TAA model involves reduced HSC activation, and may be mediated by downregulation of central markers of fibrosis, including collagen 1(α), TIMP1, and α-SMA.