Bessen bij darmkanker.*

Uit eerdere studies is reeds gebleken dat flavonoïden in voeding de kans op chronische ziektes en kanker kan verlagen. Deze studie betreft blauwe bosbessen in relatie met darmkanker. Verschillende bioactieve flavonoïden in deze bessen veroorzaken een remming van de groei van deze kankercellen. De meeste belangrijke flavonoïden is wel anthocyanide die de celgroei wel met 50% verminderde.

Phenolic Compounds from Blueberries Can Inhibit Colon Cancer Cell Proliferation and Induce Apoptosis

Weiguang Yi, Joan Fischer, Gerard Krewer, and Casimir C. Akoh*

Department of Food Science and Technology, The University of Georgia, Athens, Georgia 30602-7610; Department of Foods and Nutrition, The University of Georgia, Athens, Georgia 30602-3622; and Department of Horticulture, The University of Georgia, Tifton, Georgia 31793

Abstract:

Research has shown that diets rich in phenolic compounds may be associated with lower risks of several chronic diseases including cancer. This study systematically evaluated the bioactivities of phenolic compounds in rabbiteye blueberries and assessed their potential antiproliferation and apoptosis induction effects using two colon cancer cell lines, HT-29 and Caco-2. Polyphenols in three blueberry cultivars, Briteblue, Tifblue, and Powderblue, were extracted and freeze-dried. The extracts were further separated into phenolic acids, tannins, flavonols, and anthocyanins using an HLB cartridge and LH20 column. Some individual phenolic acids and flavonoids were identified by HPLC with >90% purity in anthocyanin fractions. The dried extracts and fractions were added to the cell culture medium to test for antiproliferation activities and induction of apoptosis. Flavonol and tannin fractions resulted in 50% inhibition of cell proliferation at concentrations of 70-100 and 50-100 ug/mL in HT-29 and Caco-2 cells, respectively. The phenolic acid fraction showed relatively lower bioactivities with 50% inhibition at ~1000 ug/mL. The greatest antiproliferation effect among all four fractions was from the anthocyanin fractions. Both HT-29 and Caco-2 cell growth was significantly inhibited by >50% by the anthocyanin fractions at concentrations of 15-50 ug/mL. Anthocyanin fractions also resulted in 2-7 times increases in DNA fragmentation, indicating the induction of apoptosis. The effective dosage levels are close to the reported range of anthocyanin concentrations in rat plasma. These findings suggest that blueberry intake may reduce colon cancer risk. (Aug. 2005)