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Oncology/Anti-Cancer: In-Vitro

Displaying 21 - 28 of 28

In vivo inhibition of growth of human tumor lines by flavonoid fractions from cranberry extract.

Posted: 
November 10, 2010
Authors: 
Ferguson PJ, Kurowska EM, Freeman DJ, Chambers AF and Koropatnick J
Journal: 
Nutr Cancer 56(1):86-94
Abstract: 

Edible fruits and berries may serve as sources for novel anticancer agents, given that extracts of these foods have demonstrated cytotoxic activity against tumor cell lines. Semipurified, flavonoid-rich extracts of cranberry (Vaccinia macrocarpa) were shown previously to arrest proliferation of tumor cells and induce apoptosis. However, the ability of cranberry flavonoids to inhibit tumor growth in vivo has not been reported other than in a preliminary report. As model systems for testing this activity, human tumor cell lines representative of three malignancies were chosen: glioblastoma multiforme (U87), colon carcinoma (HT-29), and androgen-independent prostate carcinoma (DU145). A flavonoid-rich fraction 6 (Fr6) and a more purified proanthocyanidin (PAC)-rich fraction were isolated from cranberry presscake and whole cranberry, respectively, by column chromatography. Fr6 and PAC each significantly slowed the growth of explant tumors of U87 in vivo, and PAC inhibited growth of HT-29 and DU145 explants (P

Cranberry proanthocyanidins induce apoptosis and inhibit acid-induced proliferation of human esophageal adenocarcinoma cells.

Posted: 
November 9, 2010
Authors: 
Kresty LA, Howell AB, Baird M
Journal: 
J Agric Food Chem 56(3):676-80
Abstract: 

The occurrence of esophageal adenocarcinoma and its only recognized precursor lesion, Barrett's esophagus, has rapidly increased during the past three decades. The precise reason for the rise remains to be elucidated, but increasing rates have been linked to multiple nutritional factors. Plant-based diets have generally been associated with a reduction of risk for esophageal adenocarcinoma and those of animal origin with risk escalation. Moreover, a number of recent in vitro and limited in vivo investigations have reported that cranberry extracts affect multiple cancer-associated processes in breast, colon, prostate, and other cancer cell lines of epithelial origin. Thus, this study sought to investigate the chemopreventive potential of a cranberry proanthocyanidin rich extract (PAC) in SEG-1 human esophageal adenocarcinoma (EAC) cells. PAC pretreatment significantly inhibited the viability and proliferation of EAC cells in a time- and dose-dependent manner. Moreover, PAC (50 microg/mL) significantly inhibited acid-induced cell proliferation of SEG-1 cells. PAC treatment induced cell cycle arrest at the G1 checkpoint and significantly reduced the percentage of SEG-1 cells in S-phase following 24 and 48 h of exposure. PAC treatment also resulted in significant induction of apoptosis. Thus, PAC modulates cell cycle regulation, aberrant proliferation, and apoptosis, all key biological processes altered during progression to esophageal adenocarcinoma. These findings support that further mechanistic studies are warranted to more fully elucidate the inhibitory potential of PAC against esophageal cancer.

Blackberry, black raspberry, blueberry, cranberry, red raspberry, and strawberry extracts inhibit growth and stimulate apoptosis of human cancer cells in vitro

Posted: 
November 8, 2010
Authors: 
Seeram NP, Adams LS, Zhang Y, Lee R, Sand D, Scheuller HS, Heber D
Journal: 
J Agric Food Chem 54(25):9329-39
Abstract: 

Berry fruits are widely consumed in our diet and have attracted much attention due to their potential human health benefits. Berries contain a diverse range of phytochemicals with biological properties such as antioxidant, anticancer, anti-neurodegerative, and anti-inflammatory activities. In the current study, extracts of six popularly consumed berries--blackberry, black raspberry, blueberry, cranberry, red raspberry and strawberry--were evaluated for their phenolic constituents using high performance liquid chromatography with ultraviolet (HPLC-UV) and electrospray ionization mass spectrometry (LC-ESI-MS) detection. The major classes of berry phenolics were anthocyanins, flavonols, flavanols, ellagitannins, gallotannins, proanthocyanidins, and phenolic acids. The berry extracts were evaluated for their ability to inhibit the growth of human oral (KB, CAL-27), breast (MCF-7), colon (HT-29, HCT116), and prostate (LNCaP) tumor cell lines at concentrations ranging from 25 to 200 micro g/mL. With increasing concentration of berry extract, increasing inhibition of cell proliferation in all of the cell lines were observed, with different degrees of potency between cell lines. The berry extracts were also evaluated for their ability to stimulate apoptosis of the COX-2 expressing colon cancer cell line, HT-29. Black raspberry and strawberry extracts showed the most significant pro-apoptotic effects against this cell line. The data provided by the current study and from other laboratories warrants further investigation into the chemopreventive and chemotherapeutic effects of berries using in vivo models.

Total cranberry extract versus its phytochemical constituents: antiproliferative and synergistic effects against human tumor cell lines

Posted: 
November 6, 2010
Authors: 
Seeram NP, Adams LS, Hardy ML, Heber D
Journal: 
J Agric Food Chem 52(9):2512-7
Abstract: 

Cranberries (Vaccinium macrocarpon Ait.) are an excellent dietary source of phytochemicals that include flavonol glycosides, anthocyanins, proanthocyanidins (condensed tannins), and organic and phenolic acids. Using C-18 and Sephadex Lipophilic LH-20 column chromatography, HPLC, and tandem LC-ES/MS, the total cranberry extract (TCE) has been analyzed, quantified, and separated into fractions enriched in sugars, organic acids, total polyphenols, proanthocyanidins, and anthocyanins (39.4, 30.0, 10.6, 5.5, and 1.2% composition, respectively). Using a luminescent ATP cell viability assay, the antiproliferative effects of TCE (200 microg/mL) versus all fractions were evaluated against human oral (KB, CAL27), colon (HT-29, HCT116, SW480, SW620), and prostate (RWPE-1, RWPE-2, 22Rv1) cancer cell lines. The total polyphenol fraction was the most active fraction against all cell lines with 96.1 and 95% inhibition of KB and CAL27 oral cancer cells, respectively. For the colon cancer cells, the antiproliferative activity of this fraction was greater against HCT116 (92.1%) than against HT-29 (61.1%), SW480 (60%), and SW620 (63%). TCE and all fractions showed >/=50% antiproliferative activity against prostate cancer cells with total polyphenols being the most active fraction (RWPE-1, 95%; RWPE-2, 95%; 22Rv1, 99.6%). Cranberry sugars (78.8 microg/mL) did not inhibit the proliferation of any cancer cell lines. The enhanced antiproliferative activity of total polyphenols compared to TCE and its individual phytochemicals suggests synergistic or additive antiproliferative interactions of the anthocyanins, proanthocyanidins, and flavonol glycosides within the cranberry extract.

Antioxidant activities and antitumor screening of extracts from cranberry fruit (Vaccinium macrocarpon)

Posted: 
November 5, 2010
Authors: 
Yan X, Murphy BT, Hammond GB, Vinson JA, Neto CC
Journal: 
J Agric Food Chem 50(21):5844-9
Abstract: 

Polyphenolic compounds in cranberries have been investigated to determine their role in protection against cardiovascular disease and some cancers. Extracts of whole fruit were assayed for radical-scavenging activity and tumor growth inhibition using seven tumor cell lines. Selective inhibition of K562 and HT-29 cells was observed from a methanolic extract in the range of 16-125 microg/mL. Radical-scavenging activity was greatest in an extract composed primarily of flavonol glycosides. Seven flavonol glycosides were isolated and purified from whole fruit for further evaluation; the anthocyanin cyanidin 3-galactoside was also purified for comparison with the flavonoids. Three flavonol monoglycosides were newly identified by (13)C NMR as myricetin 3-alpha-arabinofuranoside, quercetin 3-xyloside, and 3-methoxyquercetin 3-beta-galactoside (isorhamnetin); the other four isolated were the previously identified myricetin 3-beta-galactoside, quercetin 3-beta-galactoside, quercetin 3-alpha-arabinofuranoside, and quercetin 3-alpha-rhamnopyranoside. These compounds were evaluated for 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity and ability to inhibit low-density lipoprotein oxidation in vitro. Most of the flavonol glycosides showed antioxidant activity comparable or superior to that of vitamin E; cyanidin 3-galactoside showed activity superior to that of the flavonoids as well as vitamin E or Trolox in both antioxidant assays.

Cranberry phytochemical extracts induce cell cycle arrest and apoptosis in human MCF-7 breast cancer cells.

Posted: 
November 4, 2010
Authors: 
Sun J, Hai Liu R.
Journal: 
Cancer Lett 241(1):124-34
Abstract: 

Breast cancer is the most commonly diagnosed cancer in women in the US and is one of the leading causes of death due to cancer. Epidemiological studies have consistently suggested the inverse association between cancer risk and intake of fruits and vegetables. These health benefits have been linked to the additive and synergistic combination of phytochemicals in fruits and vegetables. Cranberries have been shown to possess anti-carcinogenic activities such as inhibition of growth of several cancer cell lines, and inhibition of ornithine decarboxylase (ODC) activity in vitro. However, the molecular mechanisms of the anti-cancer properties of cranberry phytochemical extracts have not been completely understood. Our data showed that cranberry phytochemical extracts significantly inhibited human breast cancer MCF-7 cell proliferation at doses of 5 to 30mg/mL (P<0.05). Apoptotic induction in MCF-7 cells was observed in a dose-dependent manner after exposure to cranberry phytochemical extracts for 4h. Cranberry phytochemical extracts at a dose of 50mg/mL resulted in a 25% higher ratio of apoptotic cells to total cells as compared to the control groups (P<0.05). Cranberry phytochemical extracts at doses from 10 to 50mg/mL significantly arrested MCF-7 cells at G0/G1 phase (P<0.05). A constant increasing pattern of the G1/S index was observed in the cranberry extract treatment group while the G1/S ratio of the control group decreased concomitantly between 10 and 24h treatment. After 24-h exposure to cranberry extracts, the G1/S index of MCF-7 cells was approximately 6 times higher than that of the control group (P<0.05). These results suggest that cranberry phytochemical extracts possess the ability to suppress the proliferation of human breast cancer MCF-7 cells and this suppression is at least partly attributed to both the initiation of apoptosis and the G1 phase arrest.

Cranberry proanthocyanidins are cytotoxic to human cancer cells and sensitize platinum-resistant ovarian cancer cells to paraplatin

Posted: 
November 2, 2010
Authors: 
Singh AP, Singh RK, Kim KK, Satyan KS, Nussbaum R, Torres M, Brard L and Vorsa N
Journal: 
Phytother Res 23(8):1066-74
Abstract: 

Polyphenolic extracts of the principal flavonoid classes present in cranberry were screened in vitro for cytotoxicity against solid tumor cells lines, identifying two fractions composed principally of proanthocyanidins (PACs) with potential anticancer activity. Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry (MALDI-TOF-MS) analysis of the proanthocyanidins (PACs) fractions indicated the presence of A-type PACs with 1-4 linkages containing between 2-8 epicatechin units with a maximum of 1 epigallocatechin unit. PACs exhibited in vitro cytotoxicity against platinum-resistant human ovarian, neuroblastoma and prostate cancer cell lines (IC50 = 79-479 microg/mL) but were non-cytotoxic to lung fibroblast cells (IC50 > 1000 microg/ml). SKOV-3 ovarian cancer cells treated with PACs exhibited classic apoptotic changes. PACs acted synergistically with paraplatin in SKOV-3 cells. Pretreatment of SKOV-3 cells with PACs (106 microg/ml) resulted in a significant reduction of the paraplatin IC50 value. Similarly, in a BrdU incorporation assay, co-treatment of SKOV-3 cells with PACs and paraplatin revealed reduced cell proliferation at lower concentrations than with either individually. In SKOV-3 cell cultures co-treated with PAC-1 and paraplatin, an HPLC analysis indicated differential quantitative presence of various PAC oligomers such as DP-8, -9, -11 and -14 indicating either selective binding or uptake. Cranberry proanthocyanidins exhibit cell-line specific cytotoxicity, induce apoptotic markers and augment cytotoxicity of paraplatin in platinum-resistant SKOV-3 ovarian cancer cells.

A Flavonoid Fraction from Cranberry Extract Inhibits Proliferation of Human Tumor Cell Lines

Posted: 
October 13, 2010
Authors: 
Ferguson PJ,Kurowska E, Freeman DJ, Chambers AF,
Journal: 
J Nutr 134:1529-1535
Abstract: 

In light of the continuing need for effective anticancer agents, and the association of fruit and vegetable consumption with reduced cancer risk, edible plants are increasingly being considered as sources of
anticancer drugs. Cranberry presscake (the material remaining after squeezing juice from the berries), when fed to mice bearing human breast tumor MDA-MB-435 cells, was shown previously to decrease the growth and
metastasis of tumors. Therefore, further studies were undertaken to isolate the components of cranberry that
contributed to this anticancer activity, and determine the mechanisms by which they inhibited proliferation. Using
standard chromatographic techniques, a warm-water extract of cranberry presscake was fractionated, and an
acidified methanol eluate (Fraction 6, or Fr6) containing flavonoids demonstrated antiproliferative activity. The
extract inhibited proliferation of 8 human tumor cell lines of multiple origins. The androgen-dependent prostate cell
line LNCaP was the most sensitive of those tested (10 mg/L Fr6 inhibited its growth by 50%), and the estrogen independent breast line MDA-MB-435 and the androgen-independent prostate line DU145 were the least sensitive
(250 mg/L Fr6 inhibited their growth by 50%). Other human tumor lines originating from breast (MCF-7), skin
(SK-MEL-5), colon (HT-29), lung (DMS114), and brain (U87) had intermediate sensitivity to Fr6. Using flow
cytometric analyses of DNA distribution (cell cycle) and annexin V-positivity (apoptosis), Fr6 was shown in
MDA-MB-435 cells to block cell cycle progression (P 0.05) and induce cells to undergo apoptosis (P 0.05) in
a dose-dependent manner. Fr6 is potentially a source of a novel anticancer agent.

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