Dolomiaea souliei ethyl acetate extract protected against α-naphthylisothiocyanate-induced acute intrahepatic cholestasis through regulation of farnesoid x receptor-mediated bile acid metabolism.

BACKGROUND: Cholestasis is characterized by accumulation of bile components in liver and systemic circulation. Restoration of bile acid homeostasis via activating farnesoid x receptor (FXR) is a promising strategy for the treatment of cholestasis. FXR-SHP (small heterodimer partner) axis plays an important role in maintaining bile acid homeostasis. PURPOSE: To investigate the anti-cholestasis effect of Dolomiaea souliei (Franch.) C.Shih (D. souliei) and clarify its underlying mechanism against α-naphthylisothiocyanate (ANIT) induced acute intrahepatic cholestasis. METHODS: ANIT-induced Sprague-Dawley rats were employed to investigate the anti-cholestasis effect of D. souliei ethyl acetate extract (DSE). Ursodeoxycholic acid (UDCA) was used as positive control. Bile flow and blood biochemical parameters were measured. Liver histopathological examination was conducted via hematoxylin-eosin staining. Western blot analysis was carried out to evaluate the protein levels related to bile acids metabolism and inflammation. The interactions between FXR and costunolide or dehydrocostus lactone, were conducted by molecular docking experiments. The effect of costunolide and dehydrocostus lactone on aspartate aminotransferase (AST), alanine aminotransferase (ALT) levels and FXR expression were also evaluated using guggulsterone-induced L02 cells. RESULTS: DSE could promote bile excretions and protect against ANIT-induced liver damage in cholestasis rats. Protein levels of FXR, SHP, Na+/taurocholate cotransporter (NTCP), bile salt export pump (BSEP), multidrug resistance-associated protein 2 (MRP2) were increased and the expressions of cholesterol 7α-hydroxylase (CYP7A1) and sterol 27-hydroxylase (CYP27A1) were decreased by DSE. Meanwhile, the anti-inflammatory factors, tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6) were also significantly increased, and the pro-inflammatory factor, interleukin-10 (IL-10), was significantly decreased in rats of DSE groups. Molecular docking revealed that costunolide and dehydrocostus lactone could be well docked into the FXR protein molecule, and hydrophobic interactions played the main function. Costunolide could reverse the increased AST and ALT levels and increase the FXR expression in guggulsterone-induced L02 cells. CONCLUSION: DSE had an anti-cholestasis effect by activating FXR-SHP axis, inhibiting synthesis of bile acid, and increasing bile secretion, together with inflammatory response and improving liver injury. Costunolide may be the main active component. This study provided a potential therapeutic mechanism for D. souliei as an anti-cholestasis medicine in the treatment of cholestasis liver diseases.

A new neolignan glycoside from Dolomiaea souliei.

One new neolignan glycoside, dolomiside A (1), together with 11 known phenylpropanoid glycosides were isolated from Dolomiaea souliei (Franch.) Shih. The structures of these isolates were determined by UV, CD, HR-ESI-TOFMS, 1D and 2D NMR analysis.

Costunolide isolated from Vladimiria souliei inhibits the proliferation and induces the apoptosis of HepG2 cells.

Costunolide (cos) is one of the major sesquiterpenes isolated from the ethyl acetate soluble fraction of the roots of Vladimiria souliei. In order to explore the effects and molecular mechanism of cos, the anti­proliferative and apoptotic effects of cos against the human hepatoblastoma HepG2 cell line was examined in vitro in the current study. Cell viability was measured using an MTT assay, and IC50 values (indicating the concentration required to achieve half­maximal inhibition) were calculated to detect the inhibitory effect of cos on HepG2 cell growth. Cell morphology was subsequently observed under an inverted microscope, and cell cycle distribution and apoptosis were detected using flow cytometric analysis. In addition, changes in the protein expression levels of B­cell lymphoma 2 (Bcl­2), Bcl­2­associated X protein (Bax), and caspases­3, ­8 and ­9 were detected by western blotting. The results of cell analyses indicated that cos treatment inhibited the proliferation and promoted the apoptosis of HepG2 cells in vitro. Cos markedly induced HepG2 cell apoptosis by arresting the cell cycle at the G2/M phase in a dose­dependent manner. In terms of the underlying mechanism, cos was revealed to inhibit the anti­apoptotic capacity of the cells, possibly via upregulating the expression levels of Bax protein and caspases­3, ­8 and ­9, and downregulating the expression of Bcl­2 protein. Taken together, the results of the present study indicate that cos may be a promising candidate for liver cancer therapy, and have provided an insight into the mechanism of action involved in its anti­cancer properties.