BACKGROUND: The formation and accumulation of
advanced glycation end-products (AGEs) are implicated in several chronic human illnesses including type-2 diabetes,
renal failure, and
neurodegenerative diseases. The cranberry (Vaccinium macrocarpon) fruit has been previously reported to show anti-AGEs effects, attributed primarily to its phenolic constituents. However, there is lack of similar data on the non-phenolic constituents found in the cranberry fruit, in particular, its
carbohydrate constituents. Herein, a chemically characterized
oligosaccharide-enriched fraction purified from the cranberry fruit was evaluated for its potential anti-AGEs and
free radical scavenging effects. OBJECTIVE: The aim of this study was to evaluate the in vitro anti-AGEs and
free radical scavenging effects of a chemically characterized
oligosaccharide-enriched fraction purified from the North American cranberry (Vaccinium macrocarpon) fruit. METHOD: The cranberry
oligosaccharide-enriched fraction was purified from cranberry hull
powder and characterized based on spectroscopic and spectrometric (NMR, MALDI-TOF-MS, and HPAEC-PAD) data. The
oligosaccharide-enriched fraction was evaluated for its anti-AGEs and
free radical scavenging effects by the
bovine serum albumin-
fructose, and DPPH assays, respectively. RESULTS: Fractionation of cranberry hull material yielded an
oligosaccharide-enriched fraction named Cranf1b-CL. The 1H NMR and MALDI-TOF-MS revealed that Cranf1b-CL consists of
oligosaccharides ranging primarily from 6-mers to 9-mers. The
monosaccharide composition of Cranf1b-CL was
arabinose (25%),
galactose (5%),
glucose (47%) and
xylose (23%). In the
bovine serum albumin-
fructose assay, Cranf1b-CL inhibited AGEs formation in a concentration-dependent manner with comparable activity to the synthetic
antiglycating agent,
aminoguanidine, used as the positive control (57 vs. 75%; both at 500μg/mL). In the DPPH
free radical scavenging assay, Cranf1b-CL showed superior activity to the synthetic commercial
antioxidant,
butylated hydroxytoluene, used as the positive control (IC50 = 680 vs. 2200μg/mL, respectively). CONCLUSION: The in vitro anti-AGEs and
free radical scavenging effects of cranberry
oligosaccharides support previous data suggesting that these constituents may also contribute to biological effects of the whole fruit beyond its phenolic constituents alone. Also, this is the first study to evaluate a chemically characterized
oligosaccharide fraction purified from the North American cranberry fruit for anti-AGEs and
free radical scavenging properties.