En-Ji Cui

Flavonoid glycosides from cowpea seeds (Vigna sinensis K.) inhibit LDL oxidation

Six flavonoid glycosides were isolated from the n-butanol fraction of cowpea seeds (Vigna sinensis K.) through silica gel (SiO2) and octadecyl silica gel (ODS) column chromatographies. Based on their chemical structures determined via interpretation of spectroscopic data including NMR, MS, and IR, the compounds were identified as kaempferol 3-O-β-d-sophoroside (1), quercetin 3-O-β-d-sophoroside (2), isoquercitrin (3), hyperin (4), catechin 7-O-β-d-glucopyranoside (5), and quercetin 3-O-β-Dglucopyranosyl( 1→6)-O-β-d-galactopyranoside (6). This is the first report of the isolation of these flavonoids from this plant. Among these flavonoids, compound 2, 5, and 6 significantly inhibited LDL oxidation exhibiting 96.0±0.1 (IC50: 3.9 μM), 96.8±1.7 (IC50: 2.9 μM), and 97.4±0.1% (IC50: 3.5 μM) inhibition, respectively, at a concentration of 40 μM.

Sterols from the leafy culms of Desmostachya bipinnata

0009-3130/11/4705-0852 2011 Springer Science+Business Media, Inc. Graduate School of Biotechnology, Institute of Life Sciences & Resources, Kyung Hee University, Yongin 446-701, Korea, fax: 82 31 204 8116, e-mail: nibaek@khu.ac.kr. Published in Khimiya Prirodnykh Soedinenii, No. 5, pp. 744–745, September–October, 2011. Original article submitted May 19, 2010. Chemistry of Natural Compounds, Vol. 47, No. 5, November, 2011 [Russian original No. 5, September–October, 2011]

3-O-Acetyloleanolic acid exhibits anti-angiogenic effects and induces apoptosis in human umbilical vein endothelial cells.

Abstract3-O-Acetyloleanolic acid, a pentacyclic triterpenoid isolated from cowpea seeds, inhibited proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVECs) in a dose-dependent manner. HUVECs. The induced apoptosis was characterized by detection of cell surface annexin V and sub-G1 populations. The number of cells immunostained with annexin V-fluorescein isothiocyanate increased after treatment with 3-O-acetyloleanolic acid. The sub-G1 cell populations were also increased in treated HUVECs. 3-O-Acetyloleanolic acid induced activation of caspase 3, a critical mediator of apoptosis signaling. It also significantly inhibited angiogenesis in an in vivo Matrigel plug assay. 3-O-Acetyloleanolic acid thus exhibits anti-angiogenic effects and induces apoptosis in HUVECs and the results suggest that it has a potential use for suppression of the tumor growth stimulated by angiogenesis.

Anti-inflammatory effects of cowpea (Vigna sinensis K.) seed extracts and its bioactive compounds

Anti-inflammatory effects of methanol extract and solvent fractions of cowpea (Vigna sinensis K.; VS) seeds and the isolated compounds were evaluated. Ethyl acetate and n-butanol fractions of VS seeds were found to strongly inhibit nitric oxide (NO) production, and inducible nitric oxide synthase (iNOS) mRNA and protein expressions in lipopolysaccharides (LPS)-stimulated RAW264.7 macrophage cells. Compounds inhibiting NO production in RAW264.7 cells were isolated and identified via successive partitioning and spectroscopic characterization. The active compounds included oleanolic acid, linolenic acid (LnA), linoleic acid (LA), 7-ketositosterol, stigmasterol-glucose (glc), and soyasaponin 1. Among the isolated compounds, LnA and LA were found to inhibit NO production significantly. Contents of LnA and LA in VS seeds were 2.034 and 1.162 mg/g on dry weight basis, respectively. Reverse transcriptase-polymerase chain reaction (RTPCR) and Western blot analysis show inhibitory effects of these compounds. LnA and LA repressed mRNA and protein levels of iNOS in LPS-stimulated cells. LA suppressed the production of pro-inflammatory cytokines such as interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α in LPS-induced macrophage cells. Thus, VS was found to exhibit strong antiinflammatory activity, which may be partly attributed to the polyunsaturated fatty acids such as LnA and LA.