Effect of Anthocyanin Fractions from Selected Cultivars of Georgia-Grown Blueberries on Apoptosis and Phase II Enzymes

Abstract

In recent years, considerable attention has been paid to anthocyanins due to their abilities to inhibit oxidative stress and cell proliferation. The regulations of apoptosis and the phase II enzymes glutathione-S-transferase (GST) and quinone reductase (QR) are other potential mechanisms through which flavonoids such as anthocyanins may prevent cancer. Our study confirmed that anthocyanin fractions from high bush blueberry cultivars increased apoptosis using two different methods: DNA fragmentation and caspase-3 activity. The effect of anthocyanins on the activity of the detoxifying enzymes GST and QR was also determined. Major anthocyanins identified were delphinidin, cyanidin, peonidin, petunidin, and malvidin. In Tifblue and Powderblue cultivars, DNA fragmentation increased at anthocyanin concentrations from 50 to 150 microg/mL, but cells treated with the anthocyanin fraction of Brightblue and Brightwell showed a prominent ladder at 50-100 microg/mL when compared to cells treated with 150 microg/mL. There was a significant difference in the caspase-3 activity (P < 0.05) between the control cells and the cells treated with anthocyanins from all of the cultivars. The response correlated positively with dose. The QR activity was lower in all cells treated with an anthocyanin fraction from Tifblue, Powderblue, Brightblue, and Brightwell cultivars than in control cells (P < 0.05). The activity decreased gradually when treated with increased concentrations of anthocyanin fractions (50-150 microg/mL) in the Tifblue and Powderblue cultivars. The GST activity was lower (P < 0.05) in cells treated with anthocyanin fractions from all of the cultivars and at all concentrations. These results indicated that apoptosis was confirmed in HT-29 cells when treated with anthocyanins from blueberry cultivars at 50-150 microg/mL concentrations, but these same concentrations decrease QR and GST activities rather than induce them.

Effect of Microencapsulation by Spray Drying and Freeze Drying Technique on the Antioxidant Properties of Blueberry (Vaccinium myrtillus) Juice Polyphenolic Compounds

“…They have been considered one of the fruits with the highest antioxidant potentials, and a few studies have evaluated their anticancer activities. Many benefi cial properties of blueberries are attributed to their bioactive polyphenolic compounds: proanthocyanidins and anthocyanins [Yi et al, 2005;Seeram et al, 2006;Srivastava et al, 2007;Matchett et al, 2005]. Anthocyanins are also known as non--toxic food pigments, when compared to the synthetic colorants.…”

Genotype, Environment and Management Practices on Red/ Dark-Colored Fruits Phenolic Composition and Its Impact on Sensory Attributes and Potential Health Benefits

“…Blueberries are lowering plants of the genus Vaccinium with dark-purple berries, whose anthocyanins are considered to be nature's most potent antioxidants [47]. The genus Vaccinium belongs to the Ericaceae family [48] and includes many popular berries consumed around the world including blueberries, huckleberries, cranberries, lingonberries, and bilberries [49].…”

Redox protective potential of fruits and vegetables: A review

“…Black berries contain phenolic compounds, such as ellagic acid, tannins, ellagitannins, quercetin, gallic acid, anthocyanins, and cyanidins [47]. Blue berries' redox protective ability is due to presence of anthocyanin pigments [48,49].…”