4E). The HPLC Selleckchem HKI-272 profiles clearly show the metabolites distribution of each fraction and suggest that the bioactive compound(s) may be eluted from 15 to 20 minutes in fraction A (Fig. 4F). In order to identify the bioactive phytocompounds in the A fraction, a total of eight subfractions were further purified by semipreparative HPLC (data not shown). Two major compounds were then isolated

and identified to be the bioactive principles. They are RA and BC (Fig. 4G) by analyzing their mass, 1H-, 13C-, and 2D-NMR data as well as by comparing their 1H-, 13C-NMR data with those of commercial authentic samples (data not shown). We tested next whether authentic RA and BC reproduce the effects observed with the YGW extract by testing a wide range of concentrations for HSC morphologic reversal. Indeed, both RA and BC morphologically reverse activated HSCs to quiescent cells with increased UV-excited autofluorescence at concentrations of 135 and 270 μM (Fig. 5A). Using AZD6244 price the concentration of 270 μM, RA and BC are shown to down-regulate α1(I) procollagen 2 to 3-fold and to induce PPARγ 3 to 4-fold (Fig. 5B). Both RA and BC reduce MeCP2 protein level (Fig. 5C) and its enrichment in the Pparγ promoter (Fig. 5D). RA and BC also reduce EZH2 expression

and H3K27me2 at the Pparγ exon (Fig. 5E,F). Collectively, these results support that RA and BC are indeed active phytocompounds that render the YGW’s effect to inhibit MCE公司 or reverse HSC activation by way of epigenetic derepression of Pparγ. We have previously shown that activation of canonical Wnt signaling underlies HSC activation11 by way of epigenetic repression of Pparγ involving MeCP2 and H3K27me2.16 Thus, we thought epigenetic derepression of Pparγ achieved by RA and BC is due to their ability to inhibit canonical Wnt signaling. Indeed, both RA and BC suppress the expression of Wnt10b and Wnt3a (Fig. 5G), the canonical Wnts up-regulated in HSC activation11 and TOPFLASH activity (Fig. 5H). Expression

of Necdin, which transcriptionally up-regulates Wnt10b,16 is also reduced by RA and BC (Fig. 5G), suggesting that these phytocompounds target the Necdin-Wnt-MeCP2 pathway for reversal of HSC activation. BC is the active ingredient of Sho-Saiko-To, a Japanese herbal medicine that has been tested for its antifibrotic effects in experimental models25 and patients.26 In contrast, studies on the effects of RA on liver fibrosis are limited to a few recent reports.27, 28 In one of these studies, RA was shown to prevent the development of CCl4-induced liver fibrosis in rats.27 As RA is an antioxidant, this effect on CCl4-induced oxidative liver damage and consequent liver fibrosis are rather expected. To extend this observation in a different etiological model, we considered testing the efficacy of RA for inhibiting progression of preexisting cholestatic liver fibrosis induced by BDL in mice.