BERRIES LIOFILIZADOS - Prevención del cáncer

PARECE QUE LOS BERRIES AYUDAN A DETENER EL CRECIMIENTO DEL CANCER

Berries seen to help halt cancer growth
Lab and animal tests add weight to anti-cancer reputation of berry polyphenols

by Craig Weatherby

Could berry pie serve double duty, as a delightful dessert and an anti-cagent? It seems so. We’ve reported in the past on cell studies that suggest that berries exert substantial anti-cancer effects.

Now, teams at UCLA’s Center for Human Nutrition and Ohio State University report that antioxidant-rich extracts from common berries--including blueberries, strawberries and raspberries--could inhibit the growth and spread of cancer cells in a wide range of cancers.

In the most recent investigation, researchers led by Professor Navindra Seeram, Ph.D., Assistant Director of UCLA Center for Human Nutrition, identified the polyphenol antioxidants in six berries and tested the ability of berry extracts to inhibit the growth of human mouth, prostate, breast and colon cells.

While each berry had a unique phenolic “profile”, all shared some combination of anthocyanins, flavonols, flavanols, ellagitannins, galltannins, proanthocyanidins, and phenolic acids. (Flavanols are also found in tea and chocolate.)

The UCLA group found that the proliferation (growth and spread) of cancer cells was reduced in a dose-dependent manner: that is, the more berry extract, the less proliferation.

They also reported that extracts from black raspberries, blackberries and strawberries were the most effective against the cancer cell lines tested.

Could berry pie serve double duty, as a delightful dessert and an anti-cancer agent? It seems so. We’ve reported in the past on cell studies whose results indicate that berries exert strong anti-cancer effects.

Now, teams at UCLA’s Center for Human Nutrition and Ohio State University report that antioxidant-rich extracts from several common berries--including blueberries, strawberries and raspberries--could inhibit the growth and spread of cancer cells in a wide range of cancers.

In the most recent investigation, researchers led by Professor Navindra Seeram, Ph.D. identified the polyphenol antioxidants in six berries and tested the ability of berry extracts to inhibit the growth of human mouth, prostate, breast and colon cells.

While each berry had a unique phenolic “profile”, all shared some combination of anthocyanins, flavonols, flavanols, ellagitannins, galltannins, proanthocyanidins, and phenolic acids. (Flavanols are also found in tea and chocolate.)

The UCLA group found that the proliferation (growth and spread) of cancer cells was reduced in a dose-dependent manner: that is, the more berry extract, the less proliferation.
They also reported that extracts from black raspberries, blackberries and strawberries were the most effective against the cancer cell lines tested.

Black raspberries extracts were the most effective at inducing programmed cell death (apoptosis), increasing it by 300 per cent, compared to "control" cancer cells not exposed to berry extract, while strawberry extracts produced a rate of apoptosis about 275 percent higher than found in the controls.

As Dr. Seeram explained, “Induction of apoptosis or cell cycle arrest can be an excellent approach to inhibit the promotion and progression of carcinogenesis and to remove genetically damaged, pre-initiated, or neoplastic cells from the body”.

The researchers suggested that anthocyanins may be the major factors inducing programmed cell death, but noted that significant further study is needed to nail that down. In fact, another recent study suggests that in the case of raspberries, their anti-cancer activity is predominantly associated with their ellagitannins.

Ohio State studies find berries benefit animals
While the concentrations of polyphenols in the berry extracts used in UCLA's cell culture experiments far exceed the levels achievable by eating berries, the positive results of several recent animal experiments at Ohio State University show that dietary berries produce some of these same effects against esophageal and liver cancers.
Together, the UCLA and Ohio State University studies illuminate further the reasons why berries appear to help halt cancer in its tracks, before it can really get going.

Sources
• Seeram NP, Adams LS, Zhang Y, Lee R, Sand D, Scheuller HS, Heber D. Blackberry, Black Raspberry, Blueberry, Cranberry, Red Raspberry, and Strawberry Extracts Inhibit Growth and Stimulate Apoptosis of Human Cancer Cells In Vitro. J Agric Food Chem. 2006 Dec 13;54(25):9329-9339.
• Ross HA, McDougall GJ, Stewart D. Antiproliferative activity is predominantly associated with ellagitannins in raspberry extracts. Phytochemistry. 2006 Nov 24; [Epub ahead of print]
• Olsson ME, Gustavsson KE, Andersson S, Nilsson A, Duan RD. Inhibition of cancer cell proliferation in vitro by fruit and berry extracts and correlations with antioxidant levels. J Agric Food Chem. 2004 Dec 1;52(24):7264-71.
• Liu M, Li XQ, Weber C, Lee CY, Brown J, Liu RH. Antioxidant and antiproliferative activities of raspberries. J Agric Food Chem. 2002 May 8;50(10):2926-30.
• Stoner GD, Chen T, Kresty LA, Aziz RM, Reinemann T, Nines R. Protection against esophageal cancer in rodents with lyophilized berries: potential mechanisms. Nutr Cancer. 2006;54(1):33-46.
• Chen T, Hwang H, Rose ME, Nines RG, Stoner GD. Chemopreventive properties of black raspberries in N-nitrosomethylbenzylamine-induced rat esophageal tumorigenesis: down-regulation of cyclooxygenase-2, inducible nitric oxide synthase, and c-Jun. Cancer Res. 2006 Mar 1;66(5):2853-9.
• Carlton PS, Kresty LA, Siglin JC, Morse MA, Lu J, Morgan C, Stoner GD. Inhibition of N-nitrosomethylbenzylamine-induced tumorigenesis in the rat esophagus by dietary freeze-dried strawberries. Carcinogenesis. 2001 Mar;22(3):441-6.
• Kresty LA, Morse MA, Morgan C, Carlton PS, Lu J, Gupta A, Blackwood M, Stoner GD. Chemoprevention of esophageal tumorigenesis by dietary administration of lyophilized black raspberries. Cancer Res. 2001 Aug 15;61(16):6112-9.
• Reen RK, Nines R, Stoner GD. Modulation of N-nitrosomethylbenzylamine metabolism by black raspberries in the esophagus and liver of Fischer 344 rats. Nutr Cancer. 2006;54(1):47-57.