Cancer chemopreventive properties were evaluated in cranberries and cranberry products (mash, depectinized mash, pomace, raw juice, clarified juice and juice concentrate). Three extracts isolated from frozen cranberries and cranberry solids (mash, depectinized mash and pomace) containing anthocyanins, water-soluble and apolar phenolic compounds were tested. Cranberry juices and extracts were screened for their ability to induce the phase II xenobiotic detoxification enzyme quinone reductase (QR). The results showed that there was no cytotoxicity against the cells used in the test. All samples stimulated quinone reductase activity except the highest concentrations of the anthocyanin-rich extract of pomace, which inhibited QR activity. Also, the results showed that the QR induction for all samples varied with concentration and that there was an optimal concentration for which the QR induction was maximal. Although the three cranberry extracts were good QR inducers, our results indicated that the phenols present in aqueous extract showed QR inductions which were more important than those obtained with phenols present in solvent extracts. Also, the ability of phenols to stimulate the QR activity has been reduced continuously and significantly (P<=0.05) during the technological process. Especially, it appears that conditions of the evaporation to obtain a juice concentrate exerted a significant effect (P<=0.05) on inducer potencies of bioactive molecules.

Cranberries are rich in bioactive constituents purported to enhance immune function, improve urinary tract health, reduce cardiovascular disease and more recently, inhibit cancer in preclinical models. However, identification of the cranberry constituents with the strongest cancer inhibitory potential and the mechanism associated with cancer inhibition by cranberries remains to be elucidated. This study investigated the ability of a proanthocyanidin rich cranberry fraction (PAC) to alter gene expression, induce apoptosis and impact the cell cycle machinery of human NCI-H460 lung cancer cells. Lung cancer is the leading cause of cancer-related deaths in the United States and five year survival rates remain poor at 16%. Thus, assessing potential inhibitors of lung cancer-linked signaling pathways is an active area of investigation.

The effect of cranberry extracts and juices during cranberry juice processing on the antiproliferative properties against colon cancer cells was investigated. Two colon cancer cell lines HT-29 and LS-513 were treated with different concentrations of cranberry phenolic extracts from fruits, puree, depectinised puree and pomace and different concentration of three juices (raw, filtered and concentrated juices). The phenolic extracts consisted of water-soluble phenolic compounds, apolar phenolic compounds and anthocyanins. These phenolic extracts and juices were tested against two cell lines at pH 2.5 (natural
juice pH) and at pH 7.0 (physiological pH). All cranberry extracts and juices could inhibit the growth of both cell lines with the IC50 values (the concentration of phenolic content required to inhibit 50% the growth of cancer cells) varied from 3.8 to 179.2 lg gallic acid equivalent/ml. It was found that three types of extracts from fruit at pH 7.0 were the most effective at inhibiting the growth of HT-29 cell line. Extracts containing anthocyanins from fruit and from pomace were the most and the least efficient, respectively, in inhibiting the growth of both cancer cell lines. Further, three juices at natural pH (pH 2.5) were more effective at inhibiting the growth of two cell lines as compared to juices at pH 7.0. Concentrated juice at both pH values was the most effective at growth inhibition of two cancer cell lines compared to two other juices.

Cranberry extracts may provide beneficial health effects in the treatment of various diseases, including cancer. However, the underlying molecular mechanisms of antineoplastic properties are not understood. We report the effect of a proanthocyanidin (PAC)-rich isolate from cranberry (PAC-1) as a therapeutic agent with dual activity to target both ovarian cancer viability and angiogenesis in vitro. PAC-1 treatment of chemotherapy-resistant SKOV-3 cells blocked cell cycle progression through the G2/M phase, increased the generation of reactive oxygen species (ROS), and induced apoptosis through activation of intrinsic and extrinsic pathway components. Cytotoxicity of PAC-1 was partially based on ROS generation and could be blocked by co-treatment with antioxidant glutathione. PAC-1 reduced the cell viability of both SKOV-3 ovarian cancer cells and HUVEC endothelial cells in a dose-dependent manner and blocked the activation of the pro-survival factor AKT. Furthermore, PAC-1 blocked vascular endothelial growth factor (VEGF)-stimulated receptor phosphorylation in endothelial cells, which correlated with the inhibition of endothelial tube formation in vitro. Our findings suggest that PAC-1 exerts potent anticancer and anti-angiogenic properties and that highly purified PAC from cranberry can be further developed to treat ovarian cancer in combinational or single-agent therapy.

Optimized purification of oligomeric proanthocyanidines (PAC) from cranberry generated PAC-1A which selectively affected the viability of various neuroblastoma (NB) cell lines representing a spectrum of high-risk NB features. PAC-1A caused a loss of mitochondrial transmembrane depolarization potential (∆Ψm) and increased generation of reactive oxygen species (ROS) which was directly correlated to the modulation of apoptotic marker proteins in SMS-KCNR cells. PAC-1A reduced the expression of pro-survival (Bcl-2, MCL-1, Bcl-xL) and increased levels of pro-apoptotic (Bax, Bad, Bid) Bcl family proteins, upregulated the activity of SAPK/JNK MAPK and downregulated expression or activity of PI3K/AKT/mTOR pathway components. PAC-1A increased the cellular uptake/retention of cyclophosphamide (CP). PAC-1A and CP synergistically increased cytotoxicity and expression of pro-apoptotic markers, reduced cellular glutathione (GSH) and superoxide dismutase (SOD) levels. Additional features of PAC-1A as an anticancer drug as shown in SMS-KCNR NB cells include delay of cell cycle progression and induction of cell death via TNF-family death receptor activity, thus, targeting both the extrinsic and intrinsic pathway of apoptosis. PAC-1A partially blocked the cell cycle in G2/M phase which correlated with a decrease of the G0/G1 subpopulation, upregulation of cyclin D1 and downregulation of CDK6 and p27 expression. In summary, PAC-1A has demonstrated chemotherapeutic potential to treat a broad spectrum of NBs including highly malignant tumors that show resistance to standard chemotherapeutics and apoptotic stimuli.

Abstract:Proanthocyanidin-rich extracts were prepared by fractionation of the fruit of theNorthAmerican cranberry (Vaccinium macrocarpon). In vitro growth inhibition assays in eight tumor cell lines showed that selected fractions inhibited the growth of H460 lung tumors, HT-29 colon and K562 leukemia cells at GI50 values ranging from 20 to 80 μgml−1. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) of one of these fractions found it to be composed of polyflavan-3-ols, which are primarily tetramers through heptamers of epicatechin containing one or two A-type linkages. Whole cranberry extract and the proanthocyanidin fractions were screened for effect on the expression of matrix metalloproteinases in DU 145 prostate carcinoma cells. The expression of MMP-2 and MMP-9 was inhibited in response to whole cranberry extract and to a lesser degree by the proanthocyanidin fractions

BACKGROUND: Cranberry (Vaccinium marcocarpon) fruit and quercetin, a major flavonoid found in cranberries, are likely contributors to chemoprevention, and their anti-inflammatory activities may play a potential role in colon cancer prevention. The aim of this study was to examine the effect of cranberry extract and quercetin on basal expression of cyclooxygenase-2 (COX-2) and IκBα as well as the effect on phorbol 12-myristate 13-acetate (PMA)-induced COX-2 expression in colon cancer cells.
RESULTS: HT-29 human colon adenocarcinoma cells were treated with various concentrations of cranberry extract or quercetin and/or PMA, and the protein expression of COX-2 and IκBα was determined. The results indicated that cranberry extract and quercetin decreased COX-2 expression and suppressed degradation of IκBα in unstimulated cells. In PMA-stimulated cells, cranberry extract was also able to decrease COX-2 expression and suppress degradation of IκBα.
CONCLUSION: The results suggest that a possible mechanism involved in the anti-cancer activity of cranberry and quercetin is partly mediated through its anti-inflammatory action. These findings indicate that cranberry and quercetin may reduce the risk of colon cancer possibly by suppressing inflammatory responses.

Phytochemicals from North American cranberry (Vaccinium macrocarpon) fruit may be expected to influence the development of colon cancer. Tissue-culture models were used to assess effects of cranberry components on cell proliferation, apoptosis, and the formation of tumor cell colonies. Several phytochemicals and fractions isolated from whole cranberry fruit were previously reported to inhibit growth and proliferation of breast, colon, prostate, and other tumor cell lines. In HT-29 and HCT116 colon tumor cell lines, cranberry proanthocyanidins (PACs) and ursolic acid inhibited the formation of tumor colonies over a two week period in a dose-dependent manner. Apoptosis is likely to play a role in limiting tumor cell proliferation. In HT-29 and HCT116 colon tumor cell lines treated with either ursolic acid or a cranberry proanthocyanidin fraction, the percentage of cells undergoing apoptosis increased in a dose-dependent manner. Thus, cranberry phytochemicals have the potential to limit carcinogenesis.

Fruit extracts of four Vaccinium species (lowbush blueberry, bilberry, cranberry, and lingonberry) were screened for anticarcinogenic compounds by a combination of fractionation and in vitro testing of their ability to induce the Phase II xenobiotic detoxification enzyme quinone reductase (QR) and to inhibit the induction of ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine synthesis, by the tumor promoter phorbol 12-myristate 13-acetate (TPA). The crude extracts, anthocyanin and proanthocyanidin fractions were not highly active in QR induction whereas the ethyl acetate extracts were active QR inducers. The concentrations required to double QR activity (designated CDqr) for the ethyl acetate extracts of lowbush blueberry, cranberry, lingonberry, and bilberry were 4.2, 3.7, 1.3, and 1.0 microgram tannic acid equivalents (TAE), respectively, Further fractionation of the bilberry ethyl acetate extract revealed that the majority of inducer potency was contained in a hexane/chloroform subfraction (CDqr = 0.07 microgram TAE). In contrast to their effects on QR, crude extracts of lowbush blueberry, cranberry, and lingonberry were active inhibitors of ODC activity. The concentrations of these crude extracts needed to inhibit ODC activity by 50% (designated IC50) were 8.0, 7.0, and 9.0 micrograms TAE, respectively. The greatest activity in these extracts appeared to be contained in the polymeric proanthocyanidin fractions of the lowbush blueberry, cranberry, and lingonberry fruits (IC50 = 3.0, 6.0, and 5.0 micrograms TAE, respectively). The anthocyanidin and ethyl acetate extracts of the four Vaccinium species were either inactive or relatively weak inhibitors of ODC activity. Thus, components of the hexane/chloroform fraction of bilberry and of the proanthocyanidin fraction of lowbush blueberry, cranberry, and lingonberry exhibit potential anticarcinogenic activity as evaluated by in vitro screening tests.

Prostate cancer is one of the most common cancers in the Western world, and it is believed that an individual's diet affects his risk of developing cancer. There has been an interest in examining phytochemicals, the secondary metabolites of plants, in order to determine their potential anti-cancer activities in vitro and in vivo. In this study we document the effects of proanthocyanidins (PACs) from the American Cranberry (Vaccinium macrocarpon) on matrix metalloproteinase (MMP) activity in DU145 human prostate cancer cells. Cranberry PACs decreased cellular viability of DU145 cells at a concentration of 25 µg/ml by 30% after 6 h of treatment. Treatment of DU145 cells with PACs resulted in an inhibition of both MMPs 2 and 9 activity. PACs increased the expression of TIMP-2, a known inhibitor of MMP activity, and decreased the expression of EMMPRIN, an inducer of MMP expression. PACs decreased the expression of PI-3 kinase and AKT proteins, and increased the phosphorylation of both p38 and ERK1/2. Cranberry PACs also decreased the translocation of the NF-κB p65 protein to the nucleus. Cranberry PACs increased c-jun and decreased c-fos protein levels. These results suggest that cranberry PACs decreases MMP activity through the induction and/or inhibition of specific temporal MMP regulators, and by affecting either the phosphorylation status and/or expression of MAP kinase, PI-3 kinase, NF-κB and AP-1 pathway proteins. This study further demonstrates that cranberry PACs are a strong candidate for further research as novel anti-cancer agents.