Fractionation of polyphenol-enriched apple juice extracts to identify constituents with cancer chemopreventive potential

Abstract

Apples and apple juices are widely consumed and rich sources of phytochemicals. The aim of the present study was to determine which apple constituents contribute to potential chemopreventive activities, using a bioactivity-directed approach. A polyphenol-enriched apple juice extract was fractionated by various techniques. Extract and fractions were tested in a series of test systems indicative of cancer preventive potential. These test systems measured antioxidant effects, modulation of carcinogen metabolism, anti-inflammatory and antihormonal activities, and antiproliferative potential. Regression analyses indicated that 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging potential correlated with the sum of low molecular weight (LMW) antioxidants (including chlorogenic acid, flavan-3-ols, and flavonols) and procyanidins, whereas peroxyl radicals were more effectively scavenged by LMW compounds than by procyanidins. Quercetin aglycone was identified as a potent Cyp1A inhibitor, whereas phloretin and (-)-epicatechin were the most potent cyclooxygenase 1 (Cox-1) inhibitors. Aromatase and Cyp1A inhibitory potential and cytotoxicity toward HCT116 colon cancer cells increased with increasing content in procyanidins. Overall, apple juice constituents belonging to different structural classes have distinct profiles of biological activity in these in vitro test systems. Since carcinogenesis is a complex process, combination of compounds with complementary activities may lead to enhanced preventive effects.

Identification of 3‐hydroxy‐β‐damascone and related carotenoid‐derived aroma compounds as novel potent inducers of Nrf2‐mediated phase 2 response with concomitant anti‐inflammatory activity

“…These results indicated that 3-hydroxy-bdamascone (4) can activate Nrf2 leading to ARE-mediated gene expression. Consistent with this finding early eluting fractions from apple extracts, which contain 3-hydroxy-bdamascone (4) [4], also potently activated Nrf2 reporter activity (data not shown). (4) stimulates Nrf2 transcriptional activity.…”

“…[4]) consistently enhanced the activity of QR in Hepa1c1c7 cell culture. Analyses with HPLC did not reveal the presence of phenolic compounds as potential ARE inducers in these fractions.…”

“…Polyphenol-enriched apple juice extracts were fractionated by column chromatography, and extracts and fractions were subjected to bioassay testing to identify compounds with antioxidative, anti-inflammatory, and anti-hor-monal activities and potential to modulate carcinogen metabolism [4]. Modulation of enzymes involved in the detoxification of xenobiotics and carcinogens belongs to the best investigated mechanisms of cancer chemopreventive agents [5].…”

Juices in the diet of a child and an adult: Their significance for health

“…Флавоноид кверцетин представляется в этой связи в качестве наиболее мощного модулятора активности CYP1A из всех ком-понентов яблочного сока [61,62].…”

Apple Extracts Present Catabolic and Hipocolesterolemic Effect in Mice

“…The importance of world apple production reached 76,000,000 tons in 2012 [6]. Besides, apple production represents 22% of phenols consumed in diet [7]. Apple skin, as a by-product of agro industry, and fruits discarded in the orchard, are the raw material that might be used as a source of phenolic antioxidants, to be added to diverse foods.…”