Rat Hepatic Epithelial Stem-like Cells Research Articles

Two new iridoid glycosides from Callicarpa nudiflora

Two new iridoid glycosides, callicoside E (1) and callicoside F (2), were isolated from the leaves of Callicarpa nudiflora. Their structures were established by one- and two-dimensional NMR spectroscopy and mass spectrometry. In an in vitro bioassay, compounds 1 and 2 showed an pronounced hepatoprotective activity against d-galactosamine-induced toxicity in WB-F344 rat hepatic epithelial stem-like cells.

Two new iridoid glycosides from the leaves of Callicarpa nudiflora

Two new iridoid glycosides, callicoside C (1) and callicoside D (2), together with three known compounds (3–5), were isolated from the leaves of Callicarpa nudiflora. Their structures were established by 1D and 2D NMR spectroscopy and mass spectrometry. In an in vitro bioassay, compound 1 showed pronounced hepatoprotective activity against d-galactosamine-induced toxicity in WB-F344 rat hepatic epithelial stem-like cells.

Hepatoprotective iridoid glucosides from Callicarpa nudiflora

Two new iridoid glucosides, callicoside A (1) and callicoside B (2), were isolated from the leaves of Callicarpa nudiflora. Their structures were elucidated by means of spectroscopic methods and chemical evidences. In an in vitro bioassay, compound 1 showed pronounced hepatoprotective activity against D-galactosamine-induced toxicity in WB-F344 rat hepatic epithelial stem-like cells.

Hepatoprotective acyl glycosides obtained from Erycibe hainanesis

An ongoing search for naturally occurring hepatoprotective constituents has identified three new acyl glycosides (1–3) and a new lignan glycoside (4) in the roots and stems of Erycibe hainanesis using various column chromatography methods. The structures of these compounds have been determined based on chemical and spectroscopic evidence, and the following bioassay indicates that all four glycosides have moderate hepatoprotective activities against d-galactosamine induced toxicity in WB-F344 rat hepatic epithelial stem-like cells.

Hepatoprotective triterpenoid saponins from Callicarpa nudiflora.

Four new triterpenoid saponins, 2α,3α,19α,24-tetrahydroxyolean-12-en-28-oic-acid 28-O-β-D-glucopyranosyl ester (1), 2α,3α,19α,23-tetrahydroxyolean-12-en-28-oic-acid 28-O-β-D-xylopyranosyl-(1→2)-β-D-glu-copyranosyl ester (2), 2α,3α,19α-trihydroxyolean-12-en-28-oic-acid 28-O-β-D-xylopyranosyl-(1→2)-β-D-glucopyranosyl ester (3), 2α,3α,23,29-tetrahydroxyurs-12,19-dien-28-oic-acid 28-O-β-D-glucopyranosyl ester (4), together with three known compounds (5-7), were isolated from the leaves of Callicarpa nudiflora HOOK. Their structures were established by means of spectroscopic methods and chemical evidence. Hepatoprotective activities of the isolated compounds against D-galactosamine-induced toxicity have been tested. Among them, compounds 1-3 showed pronounced hepatoprotective activities against D-galactosamine-induced toxicity in WB-F344 rat hepatic epithelial stem-like cells.

Acyl glycosides with rare β-d-apiofuranosyl-β-d-glucopyranosyl-β-d-apiofuranosyl from Erycibe hainanesis

Three new acyl glycosides with rare β-d-apiofuranosyl-(1→2)-[β-d-apiofuranosyl-(1→6)]-β-d-glucopyranosyl moieties, 2-O-[2,6-O-bis(5-O-syringoyl-β-d-apiofuranosyl)-β-d-glucopyranosyl]-isopropyl alcohol (1), 1-O-[2,6-O-bis(5-O-syringoyl-β-d-apiofuranosyl)-β-d-glucopyranosyl]-isoamyl alcohol (2), and 1-O-[2,6-O-bis(5-O-vanilloyl-β-d-apiofuranosyl)-β-d-glucopyranosyl]-3,4,5-trimethoxyphenol (3) were obtained from Erycibe hainanesis. Their structures were determined by UV, IR, HRESIMS, 1D and 2D NMR data, and by chemical methods. Compounds 1–3 were evaluated against d-galactosamine induced toxicity in WB-F344 rat hepatic epithelial stem-like cells, and compounds 1 and 3 showed moderate hepatoprotective activities.

Hepatoprotective Constituents from the Roots and Stems of Erycibe hainanesis

Eleven new diglycosides, erycibosides A-K (1-11), four new chlorogenic acid derivatives (14-17), and a new bis-coumarin (18), together with 21 known compounds, have been isolated from an EtOH extract of the roots and stems of Erycibe hainanesis. Their structures were elucidated by means of spectroscopic methods and chemical evidence. Inhibitory activities of some of the compounds on d-galactosamine-induced cytotoxicity in WB-F344 rat hepatic epithelial stem-like cells were screened, and compounds 2, 6, 10, 18, and 32 showed potent hepatoprotective activities at concentrations of 1 x 10(-5) to 1 x 10(-4) M.

Benzophenone C-glucosides from Polygala glomerata Lour

Four new benzophenone C-glucosides, glomeratides A (1), B (2), C (3), and D (4), along with a known compound arrilanin G (5), have been isolated from the whole plant of Polygala glomerata Lour. Their structures were determined by extensive analyses of their spectral data. Compounds 1–5 showed hepatoprotective activities against d-galactosamine-induced toxicity in WB-F344 rat hepatic epithelial stem-like cells.

New Hepatoprotective Coumarinolignoids from Mallotus apelta

Three new coumarinolignoids, malloapelins A-C (1-3, resp.), together with three known coumarinolignoids, cleomiscosin A (4), cleomiscosin B (5), and 5'-demethylaquillochin (6), were isolated from the roots of Mallotus apelta MUELL.-ARG. Compounds 1-6 are three pairs of regioisomeric coumarinolignoids. Their structures were elucidated on the basis of spectral evidence. Compounds 3 showed promising hepatoprotective activity against D-galactosamine-induced toxicity in WB-F344 rat hepatic epithelial stem-like cells.

Anthraquinone-Benzisochromanquinone Dimers from the Roots of Berchemia floribunda

Four novel anthraquinone-benzisochromanquinone dimers, named floribundiquinones A, B, C, and D (1-4), along with six known anthraquinones, 10-(chrysophanol-7'-yl)-10-hydroxychrysophanol-9-anthrane (5), physcion (6), chrysophanol (7), 1,5,8-trihydroxy-3-methyl-anthraquinone (8), aloe-emodin (9), and xanthorin (10), were isolated from the roots of Berchemia floribunda. Their structures including the absolute axial stereochemistry were elucidated on the basis of spectroscopic methods. Floribundiquinones represent a novel carbon skeleton with an anthraquinone-benzisochromanquinone unit. Hepatoprotective activities were evaluated against D-galactosamine-induced toxicity in WB-F344 rat hepatic epithelial stem-like cells.

Two new flavanonol glycosides from Gordonia chrysandra

Two new flavanonol glycosides named chrysandrosides A and B were isolated from the roots of Gordonia chrysandra Cowan. Their structures were determined by 1D and 2D NMR, FAB-MS techniques and chemical methods. Chrysandrosides A and B showed pronounced hepatoprotective activities against d-galactosamine ( d-GalN)-induced toxicity in rat hepatic epithelial stem-like cells (WB-F344).

Hepatoprotective Sesquiterpene Glycosides from Sarcandra glabra

Six new sesquiterpene glycosides, compounds 1-6, with eudesmanolide, elemanolide, lindenane, and germacranolide sesquiterpene aglycons, along with one known compound, chloranoside A (7), have been isolated from the whole plant of Sarcandra glabra. The structures of 1-6 were elucidated by chemical and spectroscopic methods including (1)H-(1)H COSY, HMQC, HMBC, and NOESY NMR experiments. In addition, compounds 1-7 showed pronounced hepatoprotective activities against D-galactosamine-induced toxicity in WB-F344 rat hepatic epithelial stem-like cells.

Telomere shortening, telomerase expression, and chromosome instability in rat hepatic epithelial stem-like cells.

Telomeres, which are specialized structures consisting of T2AG3 repeats and proteins at the ends of chromosomes, may be essential for genomic stability. To test whether telomere length maintenance preserves genomic stability in rats (Rattus rattus and Fischer 344), we assayed telomerase activity and telomere length in the rat hepatic epithelial stem-like cell line WB-F344 during aging in vitro and in tumor-derived lines. Telomerase activity in the parental WB-F344 line was repressed at low and intermediate passage levels in vitro and reexpressed at high passages. Southern blot hybridization and quantitative fluorescence in situ hybridization analyses demonstrated that telomeres were significantly eroded at intermediate passage levels, when telomerase was repressed, and at high passage levels, when telomerase was expressed. Fluorescence in situ hybridization analysis also revealed interstitial telomeric sequences in rat chromosomes. Tumor-derived WB-F344 cell lines that express telomerase had variably shortened telomeres. Cytogenetic analyses performed on WB-F344 cells at low, intermediate, and high passages demonstrated that chromosome instability was most severe in the intermediate passage cells. These data suggest that telomere shortening during aging of rat hepatic epithelial stem-like WB-F344 cells in vitro and during selection of tumorigenic lines in vivo may destabilize chromosomes. Expression of telomerase in high passage cells appeared to partially stabilize chromosomes.