Cancer claims the lives of more than six million people each year in the world. About 1,268,000 new cancer cases, and 553,400 deaths were reported in the United States in 2001. Current treatment approaches have yielded significant progress in the fight against cancer, but the incidence of developing certain types of cancer continues to rise. This is especially true in the African-American communities. African Americans are about 33% more likely to die of cancer than are whites and more than twice likely to die of cancer as are Asian-Islander, American-Indians, and Hispanics. This increase coupled with the harsh side effects of some of the cancer chemotherapies have led to the search for more natural biological products, especially those derived from plant products, currently known as herbal medicine. There is a need for a continued search for novel natural products that may be used as cancer chemopreventive and/or chemotherapeutic agents. The objective of this study was to evaluate the effect(s) of a novel water-soluble leaf extract of Vernonia amygdalina (VA) on human breast cancer cell DNA synthesis. MCF-7 cell line, considered a suitable model, was used in this study. Treatment of cells with physiologically relevant concentrations of water-soluble VA extract potently inhibited DNA synthesis in a concentration-dependent fashion both in the absence and presence of serum. Fractions of VA extract separated using preparative reverse-phase chromatography also inhibited DNA synthesis (P < 0.005). These results suggest that VA vegetable, if incorporated in the diet, may prevent or delay the on-set of breast cancer.
Water-soluble extracts of edible Vernonia amygdalina leaves were recently reported as potent inhibitors of cultured MCF-7 cells. The mechanism by which V. amygdalina inhibits MCF-7 cell growth has not been previously studied. The objective of this study was to evaluate the effects of V. amygdalina on the activities, DNA synthesis, and subsequent cell growth of extracellular signal-regulated protein kinases 1 and 2 (ERKs 1/2;). Treatment of cells with various concentrations (3-100 mg/ml) of water-soluble V. amygdalina extract potently inhibited ERK activities, DNA synthesis (P < 0.005), and cell growth (P < 0.01) in a concentration-dependent fashion, both in the absence and presence of serum. The growth rate of cells pretreated with 10 mg/ml V. amygdalina for 48 hrs before transfer to V. amygdalina-free medium was not significantly different (P > 0.05) from untreated cells. These results suggest that V. amygdalina, at least at concentrations up to 10 mg/ml, exhibits cytostatic action to retard the growth of human breast cancer cells. In addition, the ERK signaling pathways may be one or more of the intracellular targets for V. amygdalina antineoplastic actions.
Breast cancer is the leading cause of death among women between 40 and 55 years of age and is the second overall cause of death among women. Fortunately, the mortality rate from breast cancer has decreased in recent years due to an increased emphasis on early detection and more effective treatments. Despite early detection, conventional and chemotherapeutic methods of treatment, about 7% of women still died every year. Hence, the aim of the present study was to assess the therapeutic efficacy of vernonia amygdalina (VA) leaf extracts as anti-cancer agent against human breast cancer in vitro using the MTT [3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] and alkaline single cell gel electrophoresis (Comet) assays, respectively. In this experiment, human breast adenocarcinoma (MCF-7) cells were treated with different doses of VA leaf extracts for 48 hours. Data obtained from the MTT assay showed that VA significantly ((P < 0.05) reduced the viability of MCF-7 cells in a dose-dependent manner upon 48 hours of exposure. Data generated from the comet assay also indicated a slight dose-dependent increase in DNA damage in MCF-7 cells associated with VA treatment. We observed a slight increase in comet tail-length, tail arm and tail moment, as well as in percentages of DNA cleavage at all doses tested, showing an evidence that VA-induced minimal genotoxic damage in MCF-7 cells. Taken together, our findings suggest that VA treatment moderately (P < 0.05) reduces cellular viability and induces minimal DNA damage in MCF-7 cells. These findings provide evidence that VA extracts represent a DNA-damaging anti-cancer agent against breast cancer and its mechanisms of action functions, at least in part, through minimal DNA damage and moderate toxicity in tumors cells.
The role of ethanol or its metabolites on breast neoplasm has not been characterized. We hypothesized that ethanol may alter the growth rate of human breast tumor epithelial cells by modulating putative growth-promoting signaling pathways such as p44/42 mitogen-activated protein kinases (MAPKs). The MCF-7 cell line, considered a suitable model, was used in these studies to investigate the effects of ethanol on [3H]thymidine incorporation, cell number, and p44/42 MAPK activities in the presence or absence of a MAPK or extracellular signal-regulated kinase ERK-1, and (MEK1) inhibitor (PD098059). Treatment of MCF-7 cells with a physiologically relevant concentration of ethanol (0.3% or 65 mM) increased p44/42 activities by an average of 400% (P < 0.02), and subsequent cell growth by 200% (P < 0.05) in a MEK1 inhibitor (PD098059)-sensitive fashion, thus suggesting that the Ras/MEK/MAPK signaling pathways are crucial for ethanol-induced MCF-7 cell growth.
Context Vernonia amygdalina Del. (VA; Asteraceae or Compositae) is a small tree growing throughout tropical Africa. It is widely used for food and medicinal purposes by local people. It was reported that it had several qualities, including anticancer activity. Objective A sesquiterpene lactone, vernodalinol, was isolated from VA leaves. The first reported source of vernodalinol was in 2009 from a different plant, only 1H NMR spectrum and no detailed structural analysis was carried out. No whole spectroscopic data were provided. Materials and methods VA dried leaves were extracted with 85% ethanol followed by further separation into four fractions by liquid–liquid extraction technique using various solvents: hexane, chloroform, and n-butanol. Vernodalinol was separated from the n-butanol fraction by column chromatography. The biological activity of vernodalinol was evaluated in estrogen receptor-positive (ER+) human breast carcinoma cells (MCF-7) in vitro. Results Results indicated that vernodalinol (25 and 50 μg/mL) inhibited breast cancerous cell growth (DNA synthesis) by 34% (P < 0.025) and 40% (P < 0.025), respectively. It is reasonable to expect an LC50 of 70–75 μg/mL for vernodalinol in MCF-7 cells. Discussion and conclusion Vernodalinol structure was confirmed using a battery of spectroscopic methods, 1D and 2D NMR, high-resolution mass spectrometry (HR-MS), UV, IR, and X-ray. These results suggest that vernodalinol, although it has some biological activity, is likely to work in concert with other ingredients responsible for the anticancer activity exhibited of VA.
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