"Numerous in vivo and in vitro studies point to the possibility of using catechins in chemoprevention of cancer. Although its role in breast cancer development in humans is still unclear (Wu and Butler, 2011), there is some positive evidence for catechin intake and the risk and recurrence reduction of breast and other types of cancers (Crew et al., 2012; Johnson et al., 2012; Yu et al., 2013; Yuan et al., 2011) and high consumption of green tea was closely associated with decreased numbers of axillary lymph node metastases among premenopausal stage I and II breast cancer patients (Fujiki et al., 1999). A recent study showed a positive effect of epigallocatechin gallate on breast cancer patients under radiotherapy (Zhang et al., 2012). "
[Show abstract][Hide abstract] ABSTRACT: Mimosa caesalpiniifolia popularly known as “sabiá” or “sansão-do-campo” is a Brazilian Northeast native perennial tree used for several purposes and in traditional medicine. The aim of the present work was to determine some of the constituents and evaluate the cytotoxic activity of the ethanolic extract of M. caesalpiniifolia leaves (EEM) to MCF-7 cells, a human breast adenocarcinoma cell-line. EEM presented 651.90 ± 6.30 mg/g total phenols and 170.11 ± 1.20 mg/g flavonoids, namely catechin. EEM and cyclophosphamide (cytotoxic agent) treatment for 24 and 48 h decreased the MCF-7 cells protein content, as compared to control cells. Morphological analysis, after hematoxylin–eosin staining of cells, showed changes such as cell rounding-up, shrinkage, nuclear condensation and significantly (p < 0.01) reduction of cell and colony diameters, that indicates the EEM cytotoxic effect to MCF-7 cells. EEM treatment also induced cell death, with a maximum effect at 320.0 μg/mL, and its mechanism of action seems to include the induction of apoptosis, as DNA fragmentation in a ladder-pattern was obtained from the genomic DNA analysis. Our data support a positive role of the EEM as a chemopreventive agent and a good candidate for an antineoplastic drug development.
South African Journal of Botany 07/2014; 93:64–69. DOI:10.1016/j.sajb.2014.03.011 · 0.98 Impact Factor
"Although there is a strong interest in using more than one-hundred natural compounds  for cancer prevention, none of these dietary agents has been shown to consistently prevent breast cancer. Some of the most promising compounds include catechins (e.g., epigallocatechin gallate (EGCG), green tea extract) , curcumin , luteolin , carotenoids , omega-3-fatty acids , resveratrol [112–114], soy isoflavones [115, 116], and vitamin D [117, 118]. For example, green tea intake has been associated with reduced incidence of breast cancer, and a recent phase IB dose-escalation trial using 400–800 mg EGCG among women with a history of stage I to III hormone receptor-negative breast cancer demonstrated that this natural compound is well tolerated  (Table 2). "
[Show abstract][Hide abstract] ABSTRACT: Preventing breast cancer is an effective strategy for reducing breast cancer deaths. The purpose of chemoprevention (also termed preventive therapy) is to reduce cancer incidence by use of natural, synthetic, or biological agents. The efficacy of tamoxifen, raloxifene, and exemestane as preventive therapy against estrogen-receptor (ER)-positive breast cancer is well established for women at increased risk for breast cancer. However, because breast cancer is a heterogeneous disease, distinct preventive approaches may be required for effective prevention of each subtype. Current research is, therefore, focused on identifying alternative mechanisms by which biologically active compounds can reduce the risk of all breast cancer subtypes including ER-negative breast cancer. Promising agents are currently being developed for prevention of HER2-positive and triple-negative breast cancer (TNBC) and include inhibitors of the ErbB family receptors, COX-2 inhibitors, metformin, retinoids, statins, poly(ADP-ribose) polymerase inhibitors, and natural compounds. This review focuses on recent progress in research to develop more effective preventive agents, in particular for prevention of ER-negative breast cancer.
Current Breast Cancer Reports 06/2014; 6(2):96-109. DOI:10.1007/s12609-014-0144-1
"Therefore, the doses tested in this trial were equivalent to the EGCG content of eight to 24 cups of brewed green tea daily. Five DLTs occurred during this phase I trial (Crew et al., 2012), including indigestion , transaminitis, insomnia, rectal bleeding (all grade 3) and weight gain (grade 2). Based upon these findings, Poly E 600 mg twice daily was defined as the MTD with a DLT rate of 27% (three of 11). "
[Show abstract][Hide abstract] ABSTRACT: Background
Observational and experimental data support a potential breast cancer chemopreventive effect of green tea.Methods
We conducted an ancillary study using archived blood/urine from a phase IB randomised, placebo-controlled dose escalation trial of an oral green tea extract, Polyphenon E (Poly E), in breast cancer patients. Using an adaptive trial design, women with stage I–III breast cancer who completed adjuvant treatment were randomised to Poly E 400 mg (n = 16), 600 mg (n = 11) and 800 mg (n = 3) twice daily or matching placebo (n = 10) for 6 months. Blood and urine collection occurred at baseline, and at 2, 4 and 6 months. Biological endpoints included growth factor [serum hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF)], lipid (serum cholesterol, triglycerides), oxidative damage and inflammatory biomarkers.ResultsFrom July 2007-August 2009, 40 women were enrolled and 34 (26 Poly E, eight placebo) were evaluable for biomarker endpoints. At 2 months, the Poly E group (all dose levels combined) compared to placebo had a significant decrease in mean serum HGF levels (−12.7% versus +6.3%, P = 0.04). This trend persisted at 4 and 6 months but was no longer statistically significant. For the Poly E group, serum VEGF decreased by 11.5% at 2 months (P = 0.02) and 13.9% at 4 months (P = 0.05) but did not differ compared to placebo. At 2 months, there was a trend toward a decrease in serum cholesterol with Poly E (P = 0.08). No significant differences were observed for other biomarkers.Conclusions
Our findings suggest potential mechanistic actions of tea polyphenols in growth factor signalling, angiogenesis and lipid metabolism.
Journal of Human Nutrition and Dietetics 03/2014; 28(3). DOI:10.1111/jhn.12229 · 1.99 Impact Factor
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