ABSTRACT
To study the chemical constituents of Veratrum dahuricum (Turcz.) Loes. f., a new aurone glycoside named as (Z)-7, 4'-dimethoxy-6-hydroxyl-aurone-4-O-β-glucopyranoside was isolated from the 95% ethanol extracts of the rhizomes and roots of Veratrum dahuricum (Turcz.) Loes. f. by repeated column chromatography on silica gel and recrystallization. Its structure was established by extensive spectroscopic analyses, and its cytotoxicities against HepG-2, MCF7 and A549 cell lines were measured in vitro.
ABSTRACT
This paper is to report the study of resveratrol-induced apoptosis and its mechanisms in MCF-7 cells. MTT assay was performed to assess the cytotoxicity of resveratrol on MCF-7 cells. Hoechst 33258 staining was used to observe cellular morphologic changes in apoptosis. Apoptosis was measured by flow cytometric analysis and the protein expression was examined by Western blotting analysis. The results indicated that resveratrol could inhibit MCF-7 cell growth in a time- and concentration-dependent manner. Remarkable morphologic changes in the cells after 60 micromol L(-1) resveratrol treatment, including cell nuclear shrinkage, DNA condensation and apoptotic bodies, were observed by Hoechst 33258 staining. Resveratrol could induce apoptosis and activate p38 and p53 in a time dependent manner in MCF-7 cells. In addition, the cell growth inhibitory ratio and the apoptotic ratio of resveratrol-treated group decreased markedly by the p38 MAPK inhibitor SB203580 or p53 inhibitor pifithrin-alpha. Further experiments confirmed that resveratrol-induced p53 activation was reduced by SB203580 whereas the activation of p38 was not affected by pifithrin-alpha. In conclusion, resveratrol induced apoptosis in MCF-7 cells could be through activating p38-p53 signal pathway.
ABSTRACT
The chemical constituents of Leonurus heterophyllus were separated and purified by repeated column chromatography on silica gel, HPD 100, Sephadex LH-20, and PHPLC. Each compound was characterized by spectroscopic and physical data. Eight compounds have been purified and identified to be quercetin 3-O-robinobioside (1), rutin (2), isoquerci trin (3), hyperoside (4), quercetin (5), apigenin (6), genkwanin (7), and benzoic acid (8). Among them, compounds 2, 5-7 were isolated from L. heterophyllus for the first time; Compounds 1, 3, 4, 8 were obtained for the first time from the genus Leonurus. The in vitro activities against leukemia K562 Cells of pure components were evaluated by testing their IC50. Compounds 1-6, 8 exhibited in-vitro inhibitory activities against leukemia K562 cells in different extent.