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Anticarcinogenic Activities (anticarcinogenic + activity)

Distribution by Scientific Domains

Medical Sciences	50%
Life Sciences	50%

Selected Abstracts

Modifying effect of propolis on dimethylhydrazine-induced DNA damage but not colonic aberrant crypt foci in rats

ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 1 2005
Rodrigo O. Alves de Lima
Abstract Propolis is a honeybee product with several biological and therapeutic properties, including antimutagenic and anticarcinogenic activities. The effects of an aqueous extract of propolis (AEP) were evaluated on the formation of 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) and DNA damage in the colon of male Wistar rats by the ACF and Comet assays, respectively. AEP was administered orally at 0.01%, 0.03%, 0.1%, and 0.3% in the drinking water, which resulted in doses of approximately 12, 34, 108, and 336 mg/kg body weight/day. Animals were also given a single subcutaneous injection of 40 mg/kg DMH and sacrificed 4 hr later for evaluating DNA damage, or 4 doses of 40 mg/kg DMH, administered 2 doses/week for 2 weeks, and sacrificed 12 weeks after the last injection for evaluating ACF development in the distal colon. Administration of AEP either simultaneously with or after the DMH treatment resulted in no statistically significant reduction of ACF. In contrast, 0.01%, 0.03%, and 0.3% AEP, given simultaneously with DMH, reduced DNA damage induction in the mid and distal colon. However, 0.3% AEP alone increased DNA damage in the colon. In conclusion, AEP had no effect on the formation of DMH-induced ACF in rat colon, but it modulated DMH-induced DNA damage in colon cells. Further investigations are recommended in order to establish the conditions under which propolis produces either protective or deleterious effects. Environ. Mol. Mutagen., 2005. © 2004 Wiley-Liss, Inc. [source]

Differential apoptosis by gallotannin in human colon cancer cells with distinct p53 status

MOLECULAR CARCINOGENESIS, Issue 3 2007
Sahar Al-Ayyoubi
Abstract Gallotannin (GT), a plant polyphenol, has shown anticarcinogenic activities in several animal models including colon cancer. In our previous study, we showed that GT inhibits 1,2-dimethylhydrazine-induced colonic aberrant crypt foci and tumors in Balb/c mice, thus supporting a role for GT as a chemopreventive agent in colon cancer. However, at the molecular level, GT's mechanism of chemoprevention is still unclear. In this study, we aim at identifying GT's potential molecular mechanisms of action in in vitro studies. We show that GT differentially inhibits the growth of two isogenic HCT-116 (p53+/+, p53,/,) human colon cancer cells versus normal human intestinal epithelial cells (FHs 74Int). DNA flow cytometric analysis showed that GT induced S-phase arrest in both HCT-116 cell lines. Cell-cycle arrest in p53 (+/+) cells was associated with an increase in p53 protein levels and p21 transcript and protein levels. The inhibition of cell-cycle progression of HCT-116 p53 (+/+) cells by GT correlated with a reduction in the protein levels of cyclin D1, pRb, and the Bax/Bcl-2 ratio. Although GT did not induce apoptosis in p53 (+/+) cells, a significant induction of apoptosis was observed in p53 (,/,) cells as shown by TUNEL staining and flow cytometry analysis. Apoptosis induction in p53 (,/,) cells was associated with a significant increase in Bax/Bcl-2 protein levels. Our results demonstrate that GT inhibits the growth of HCT-116 colon cancer cells in a p53-independent manner but exhibits differential sensitivity to apoptosis induction in HCT-116 cells with distinct p53 status. © 2006 Wiley-Liss, Inc. [source]

Erythrodiol, a natural triterpenoid from olives, has antiproliferative and apoptotic activity in HT-29 human adenocarcinoma cells

MOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 5 2008
M. Emília Juan
Abstract Erythrodiol is the precursor of pentacyclic triterpenic acids present in Olea Europaea. Although olive oil and some of its constituents are reported to have anticarcinogenic activities, erythrodiol has not been assessed in its cell biological functions in detail. We therefore determined its effects on cell growth and apoptosis in human colorectal carcinoma HT-29 cells. Proliferation, cytotoxicity, and apoptosis were measured by fluorescence-based techniques. Erythrodiol inhibited cell growth with an EC50 value of 48.8 ± 3.7 ,M without any cytotoxic effects in a concentration range up to 100 ,M. However, exposure of cells for 24 h to 50, 100, and 150 ,M erythrodiol increased caspase-3-like activity by 3.2-, 4.8-, and 5.2-fold over that in control cells. We here demonstrate for the first time that, in colon adenocarcinoma cells, erythrodiol exerts antiproliferative and proapoptotic activity. [source]

Beta-glucans in higher fungi and their health effects

NUTRITION REVIEWS, Issue 11 2009
Otakar Rop
Together with chitin, the ,-glucans are components of mycetes' cell walls. A high level of biological efficiency has been found in ,-glucans, especially ,-1,3-D-glucans and ,-1,6-D-glucans isolated from some basidiomycetes. (Biological efficiency refers to the relative ability of ,-glucans to promote a desired response, for example to induce leukocyte activation and to produce inflammatory mediators.) These polysaccharides increase the number of Th1 lymphocytes, which help protect organisms against allergic reactions. A number of ,-glucans, for example pleuran from Oyster (Pleurotus spp.) mushrooms or lentinan from Shiitake (Lentinus edodes) mushrooms, have shown marked anticarcinogenic activity. In addition to having an immunity-stimulating effect, ,-glucans may participate in physiological processes related to the metabolism of fats in the human body. Their application results in a decrease in the total cholesterol content in blood and may also contribute to reductions in body weight. [source]