Anti-proliferative and pro-apoptotic activity of whole extract and isolated indicaxanthin from Opuntia ficus-indica associated with re-activation of the onco-suppressor p16(INK4a) gene in human colorectal carcinoma (Caco-2) cells.
Biochem Biophys Res Commun
; 450(1): 652-8, 2014 Jul 18.
Article
en En
| MEDLINE
| ID: mdl-24937448
ABSTRACT
Phytochemicals may exert chemo-preventive effects on cells of the gastro-intestinal tract by modulating epigenome-regulated gene expression. The effect of the aqueous extract from the edible fruit of Opuntia ficus-indica (OFI extract), and of its betalain pigment indicaxanthin (Ind), on proliferation of human colon cancer Caco-2 cells has been investigated. Whole extract and Ind caused a dose-dependent apoptosis of proliferating cells at nutritionally relevant amounts, with IC50 400±25 mg fresh pulp equivalents/mL, and 115±15 µM (n=9), respectively, without toxicity for post-confluent differentiated cells. Ind accounted for â¼80% of the effect of the whole extract. Ind did not cause oxidative stress in proliferating Caco-2 cells. Epigenomic activity of Ind was evident as de-methylation of the tumor suppressor p16(INK4a) gene promoter, reactivation of the silenced mRNA expression and accumulation of p16(INK4a), a major controller of cell cycle. As a consequence, decrease of hyper-phosphorylated, in favor of the hypo-phosphorylated retinoblastoma was observed, with unaltered level of the cycline-dependent kinase CDK4. Cell cycle showed arrest in the G2/M-phase. Dietary cactus pear fruit and Ind may have chemo-preventive potential in intestinal cells.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Piridinas
/
Extractos Vegetales
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Apoptosis
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Inhibidor p16 de la Quinasa Dependiente de Ciclina
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Opuntia
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Proliferación Celular
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Betaxantinas
Tipo de estudio:
Risk_factors_studies
Límite:
Humans
Idioma:
En
Revista:
Biochem Biophys Res Commun
Año:
2014
Tipo del documento:
Article
País de afiliación:
Italia