Résumé
<p><b>OBJECTIVE</b>To investigate whether the antioxidation and the regulation on the Extracellular Regulated Protein Kinases (ERK) signaling pathway are involved in the protective effects of blueberry on central nervous system.</p><p><b>METHODS</b>30 Senescence-accelerated mice prone 8 (SAMP8) mice were divided into three groups and treated with normal diet, blueberry extracts (200 mg/kg•bw/day) and cyaniding-3-O-galactoside (Cy-3-GAL) (50 mg/kg•bw/day) from blueberry for 8 weeks. 10 SAMR1 mice were set as control group. The capacity of spatial memory was assessed by Passive avoidance task and Morris water maze. Histological analyses on hippocampus were completed. Malondialdehyde (MDA) levels, Superoxide Dismutase (SOD) activity and the expression of ERK were detected.</p><p><b>RESULTS</b>Both Cy-3-GAL and blueberry extracts were shown effective functions to relieve cellular injury, improve hippocampal neurons survival and inhibit the pyramidal cell layer damage. Cy-3-GAL and blueberry extracts also increased SOD activity and reduced MDA content in brain tissues and plasma, and increased hippocampal phosphorylated ERK (p-ERK) expression in SAMP8 mice. Further more, the passive avoidance task test showed that both the latency time and the number of errors were improved by Cy-3-GAL treatment, and the Morris Water Maze test showed significant decreases of latency were detected by Cy-3-GAL and blueberry extracts treatment on day 4.</p><p><b>CONCLUSION</b>Blueberry extracts may reverse the declines of cognitive and behavioral function in the ageing process through several pathways, including enhancing the capacity of antioxidation, altering stress signaling. Cy-3-GAL may be an important active ingredient for these biological effects.</p>
Sujets)
Animaux , Souris , Vieillissement , Anthocyanes , Pharmacologie , Apprentissage par évitement , Myrtillier , Chimie , Compléments alimentaires , Galactoside , Pharmacologie , Hippocampe , Métabolisme , Malonaldéhyde , Métabolisme , Apprentissage du labyrinthe , Mémoire , Mitogen-Activated Protein Kinase 3 , Métabolisme , Phosphorylation , Extraits de plantes , Pharmacologie , Superoxide dismutase , MétabolismeRésumé
<p><b>OBJECTIVE</b>To investigate the protective effect of blueberry extract (BE, 25% anthocyanins) against oxidative damage in primary cultures of rat hippocampal neurons induced by H2O2.</p><p><b>METHODS</b>Rat hippocampal neurons were randomly assigned to control group, H2O2 group and BE pretreatment groups, BE at six different doses (0.01, 0.1, 1.0, 10.0, 20.0 and 40 microg/ml) and then exposed to 50 micromol/L H2O2 for twenty-four hours. To selecte the most fittest concentration of BE by testing viability of neurons and activity of LDH. Then MDA concentration, SOD activity and neuronal apoptosis were(checked) measured.</p><p><b>RESULTS</b>(1) Compared with H2O2 group, the hippocampal cell viabilities in the 0.1, 1.0 and 10 microg/ml BE groups were significantly increased from 57.44% to 78.42%, 87.71% and 72.40% separately. The activity of LDH in BE groups at varied concentrations (0.1, 1.0 and 10 microg/ml) was significiantly lower than that in H2O2 group. It was found that 1 microg/ml BE had the furthest protective effect against oxidative damage in primary cultures of rat hippocampal neurons induced by H2O2. (2) The concentration of MDA and the rate of neuronal apoptosis of BE group (1 microg/ml) were much lower than H2O2 group, while SOD activity was much higher.</p><p><b>CONCLUSION</b>Proper dose of BE has remarkable protective effect against oxidative stress in primary cultures of rat hippocampal neurons induced by H2O2, the mechanism may be related to decreasing the neuronal apoptosis and enhancing the antioxidation of hippocampal neurons.</p>