Enhanced effects of novel oridonin analog CYD0682 for hepatic fibrosis.

BACKGROUND: Activated hepatic stellate cells (HSCs) are responsible for excess extracellular matrix (ECM) protein deposition in liver fibrosis. Previously, our group reported that the natural compound oridonin induces apoptosis, inhibits cell proliferation, and downregulates ECM proteins in activated HSC. In this study, the antifibrogenic effects of oridonin derivative CYD0682 on the activated human LX-2 and rat HSC-T6 stellate cell lines were investigated. METHODS: Cell proliferation was measured by alamarBlue assay. Apoptosis was detected by Cell Death ELISA and staining of Yo-Pro-1 and propidium iodide. Cell cycle was determined by flow cytometry. Immunoblot and immunofluorescence staining were performed for cellular protein expression. RESULTS: CYD0682 treatment significantly inhibited LX-2 cell proliferation in a dose- and time-dependent manner with an IC50 value of 0.49 µM for 48 h, ∼10-fold greater potency than oridonin. Similar results were observed in HSC-T6 cells. In contrast, 2.5 µM of CYD0682 treatment had no significant effects on proliferation of the human hepatocyte cell line C3A. CYD0682 treatment induced LX-2 cell apoptosis and S-phase cell cycle arrest and was associated with activation of p53, p21, and cleaved caspase-3. The myofibroblast marker protein α-smooth muscle actin and major ECM proteins type I collagen and fibronectin were markedly suppressed in a time- and dose-dependent fashion by CYD0682. Furthermore, pretreatment with CYD0682 blocked transforming growth factor-ß-induced type I collagen and fibronectin production. CONCLUSIONS: In comparison with oridonin, its novel derivative CYD0682 may act as a more potent antihepatic fibrosis agent.

Enhanced anti-fibrogenic effects of novel oridonin derivative CYD0692 in hepatic stellate cells.

Oridonin, isolated from Rabdosia rubescens, has been proven to possess various anti-neoplastic and anti-inflammatory properties. Previously, we reported the anti-fibrogenic effects of oridonin for liver in vitro. In the present study, we investigated the effects of a newly designed analog CYD0692 in vitro. Cell viability was measured by Alamar Blue assay. Cell apoptosis was assessed by Cell Death ELISA and Yo-Pro-1 staining. Western blots were performed for cellular proteins. Flow cytometry was used to measure cell cycle regulation. CYD0692 significantly inhibited LX-2 cells proliferation in a dose- and time-dependent manner with an IC50 value of ~0.7 µM for 48 h, ~tenfold greater potency than oridonin. Similar results were observed in HSC-T6 cells. In contrast, on the human hepatocyte cell line C3A, only 12 % of the cell growth was inhibited with 5 µM of CYD0692 treatment for 48 h, while 30 % inhibited at 10 µM. After CYD0692 treatment on LX-2 cells, apoptosis and S-phase cell cycle arrest were induced; cleaved-PARP, p21, and p53 were activated while cyclin-B1 levels declined. In addition, α-smooth muscle actin, type I Collagen, and fibronectin (FN) were markedly down regulated. Transforming growth factor ß1 (TGF ß1) has been identified as a dominant stimulator for ECM production in HSC. Our results indicated that pretreatment with CYD0692 blocked TGF ß1-induced FN expression, thereby decreasing the downstream factors of TGF ß1 signaling, such as Phospho-Smad2/3 and phospho-ERK. In comparison with oridonin, its novel derivative CYD0692 has demonstrated to be a more potent and potentially safer anti-fibrogenic agent for the treatment of hepatic fibrosis.