Interspecific variation in anthocyanins, phenolics, and antioxidant capacity among genotypes of highbush and lowbush blueberries (Vaccinium section cyanococcus spp.).
J Agric Food Chem 2001 Oct;49(10):4761-7 (ISSN: 0021-8561) Kalt W; Ryan DA; Duy JC; Prior RL; Ehlenfeldt MK; Vander Kloet SP Agriculture and Agri-Food Canada, Kentville, Nova Scotia B4N 1J5, Canada.
Recent interest in the possible protective effects of dietary antioxidant compounds against human degenerative disease has prompted investigation of foods such as blueberries (Vaccinium sp.), which have a high antioxidant capacity. Fruit obtained from genotypes of highbush blueberries (Vaccinium corymbosum L.) and lowbush blueberries (Vaccinium angustifolium Aiton) were analyzed for their antioxidant capacity, their content of anthocyanins, and total phenolic compounds, to evaluate the intraspecific and interspecific variation in these parameters.
The method of extraction influenced the composition of fruit extracts; the highest anthocyanin and total phenolic contents and antioxidant capacity were found in extracts obtained using a solvent of acidified aqueous methanol. Regardless of the method, lowbush blueberries were consistently higher in anthocyanins, total phenolics, and antioxidant capacity, compared with highbush blueberries. There was no relationship between fruit size and anthocyanin content in either species.
Feeding rats diets enriched in lowbush blueberries for six weeks decreases ischemia-induced brain damage.
Nutr Neurosci 2002 Dec;5(6):427-31 (ISSN: 1028-415X) Sweeney MI; Kalt W; MacKinnon SL; Ashby J; Gottschall-Pass KT, Department of Biology, University of Prince Edward Island, 550 University Ave, Charlottetown, PEI, Canada C1A 4P3. [email protected]
Oxidative stress is an important element in the etiology of ischemic stroke. Lowbush blueberries (Vaccinium angustifolium Aiton) have a high antioxidant capacity and thus we determined whether consumption of lowbush blueberries would protect neurons from stroke-induced damage. Rats were fed AIN-93G diets containing 0 or 14.3% blueberries (g fresh weight/100 g feed) for 6 weeks. Stroke was then simulated by ligation of the left common carotid artery (ischemia), followed by hypoxia.
One week later, plasma and urine were collected, and neuronal damage in the hippocampus was determined histologically. In control rats, hypoxia-ischemia resulted in 40 +/- 2% loss of neurons in the hippocampus of the left cerebral hemisphere, as compared to the right hemisphere. Rats on blueberry-supplemented diets lost only 17 +/- 2% of neurons in the ischemic hippocampus.
Neuroprotection was observed in the CA1 and CA2 regions, but not CA3 region, of the hippocampus. The blueberry diet had no detectable effects on the plasma or urine oxygen radical absorbance capacity (ORAC) or plasma lipids. We conclude that consumption of lowbush blueberries by rats confers protection to the brain against damage from ischemia, suggesting that inclusion of blueberries in the diet may improve ischemic stroke outcomes.