Blueberry extracts antagonize Aß25-35 neurotoxicity and exert a neuroprotective effect through MEK-ERK-BDNF/UCH-L1 signaling pathway in rat and mouse hippocampus.

BACKGROUND: The neuroprotective potential of blueberry (BB) extracts against Alzheimer's disease (AD) has been previously hinted at, while its exact mechanism has remained largely enigmatic. OBJECTIVE: Our study endeavored to unravel the impacts and mechanisms by which BB extracts ameliorated the learning and memory prowess of AD-afflicted mice, with a specific focus on the MEK-ERK pathway. METHODS: We employed 3-month-old APP/PS1 transgenic mice and stratified them into three distinct groups: AD+BB, AD, and control (CT). The Morris Water Maze Test (MWMT) was then administered to gauge their learning and memory faculties. In vitro experiments were executed on Aß25-35-afflicted rat hippocampal neurons, which were subsequently treated with varying concentrations of BB extracts. We then assessed the expression levels of genes and proteins integral to the MEK-ERKBDNF/UCH-L1 pathway. RESULTS: The data showed that the AD mice demonstrated compromised learning and memory faculties in MWMT. However, the AD+BB cohort showcased marked improvements in performance. Furthermore, in the AD subset, significant elevations in the expressions of MEK2 and ERK1/2 were observed, both at the mRNA and protein levels. Conversely, UCH-L1 mRNA expressions exhibited a decline, while BDNF expressions surged significantly. However, post BB extract treatment, the expressions of MEK2 and ERK1/2 were subdued, with UCH-L1 and BDNF mRNA expressions reverting to control levels. CONCLUSIONS: Our findings propounded that BB extracts could offer therapeutic promise for AD by bolstering learning and memory capacities. The unwarranted activation of the MEK-ERK pathway, coupled with the aberrant expressions of BDNF and UCH-L1, might underpin AD's pathogenesis.

Changes of hippocampus proteomic profiles after blueberry extracts supplementation in APP/PS1 transgenic mice.

Objective: To examine protein changes in the hippocampus of APP/PS1 transgenic mice after blueberry extracts (BB) intervention.Methods: Eight APP/PS1 transgenic mice were randomly assigned to Alzheimer's disease (AD)+BB group (n=4) and AD+control group (n=4). After a 16-week treatment, 2-DE and MALDI-TOF-MS were used to compare the proteomic profiles of the hippocampus in the two groups and Western blot was used to confirm the important differentially expressed proteins.Results: Twelve proteins were differentially expressed between the two groups. Nine of them were identified. Cytochrome b-c1 complex subunit 6, beta-actin, dynamin 1, and heat shock cognate 71 were up-regulated in AD+BB group, while a-enolase, stress-induced-phosphoprotein 1, malate dehydrogenase (MDH), MDH 1, and T-complex protein 1 subunit beta were down-regulated, respectively. Importantly, some of the identified proteins (e.g. dynamin 1) are known to be involved in cognitive impairment. Western blot analysis of hippocampus dynamin 1 expression confirmed the proteomic findings.Conclusions: The consumption of BB modulates the expression of proteins that are linked to the improvements of cognitive dysfunction in hippocampus of APP/PS1 transgenic mice.

Combinatorial effect of blueberry extracts and oxaliplatin in human colon cancer cells.

The use of natural compounds to potentiate the effect of drugs and lower their adverse effects is an active area of research. The objective is to determine the effect of combined blueberry extracts (BE) and oxaliplatin (OX) in colon cancer cells. The results demonstrated that treatments of BE/OX showed inhibitory effects on HCT-116 cell and nontoxic effect on CCD-18Co normal colon cells. Flow cytometry analysis indicated that treatment with the BE, OX or in combination could induce G0/G1 cell cycle arrest, apoptosis, increase of reactive oxygen species, and induce loss of mitochondrial membrane potential in HCT-116 cells. Furthermore, after treatments, the expression of inflammatory cytokines was decreased, cyclin D1 and CDK4 were decreased; caspases-3 and 9 were activated; the Akt/Bad/Bcl-2 pathway was modulated. Moreover, the combination treatment had a considerably higher growth inhibitory effect on human colon cancer HCT-116 cells than that of BE or oxaliplatin alone. Our results showed that BE increased the anticolon cancer effect of OX making it an attractive strategy as adjuvant therapy to potentially reduce the adverse side effects associated with chemotherapeutic drugs.

Improved Preventive Effects of Combined Bioactive Compounds Present in Different Blueberry Varieties as Compared to Single Phytochemicals.

Blueberries contain many different phytochemicals which might be responsible for their disease preventive properties. In a previously conducted human dietary intervention study, we showed that a 4-week intervention with blueberry⁻apple juice protected the participants against oxidative stress and modulated expression of genes involved in different genetic pathways contributing to the antioxidant response. The present study investigates the effect of different blueberry varieties (Elliot, Draper, Bluecrop, and Aurora, and the blueberry⁻apple juice from our previous human dietary intervention study), and four different single compounds (vitamin C, peonidin, cyanidin, and quercetin) on antioxidant capacity and gene expression changes in colonic cells in vitro, and compares the outcome with the earlier in vivo findings. The results demonstrate that all blueberry varieties as well as the blueberry⁻apple juice were more effective in reducing oxidative stress as compared to the single compounds (e.g., DNA strand break reduction: EC50: Elliot 8.3 mg/mL, Aurora and Draper 11.9 mg/mL, blueberry⁻apple juice 12.3 mg/mL, and Bluecrop 12.7 mg/mL; single compounds). In addition, the gene expression profiles (consisting of 18 selected genes from the in vivo study) induced by the blueberry varieties were more similar to the profile of the human intervention study (range 44⁻78%). The blueberry variety Elliot showed the strongest and most similar effects, almost 80% of gene expression modulations were similar compared to the in vivo results. From the single compounds (range 17⁻44%), quercetin induced the most comparable gene expression changes, i.e., 44%. This approach could be useful in agriculture for identifying crop varieties containing combinations of phytochemicals which show optimal preventive capacities.

Anthocyanin determination in blueberry extracts from various cultivars and their antiproliferative and apoptotic properties in B16-F10 metastatic murine melanoma cells.

Blueberry consumption is associated with health benefits contributing to a reduced risk for cardiovascular disease, diabetes and cancer. The aim of this study was to determine the anthocyanin profile of blueberry extracts and to evaluate their effects on B16-F10 metastatic melanoma murine cells. Seven blueberry cultivars cultivated in Romania were used. The blueberry extracts were purified over an Amberlite XAD-7 resin and a Sephadex LH-20 column, in order to obtain the anthocyanin rich fractions (ARF). The antioxidant activity of the ARF of all cultivars was evaluated by ABTS, CUPRAC and ORAC assays. High performance liquid chromatography followed by electrospray ionization mass spectrometry (HPLC-ESI-MS) was used to identify and quantify individual anthocyanins. The anthocyanin content of tested cultivars ranged from 101.88 to 195.01 mg malvidin-3-glucoside/100g fresh weight. The anthocyanin rich-fraction obtained from cultivar Torro (ARF-T) was shown to have the highest anthocyanin content and antioxidant activity, and inhibited B16-F10 melanoma murine cells proliferation at concentrations higher than 500 µg/ml. In addition, ARF-T stimulated apoptosis and increased total LDH activity in metastatic B16-F10 melanoma murine cells. These results indicate that the anthocyanins from blueberry cultivar could be used as a chemopreventive or adjuvant treatment for metastasis control.