Effect of Purple Sweet Potato Anthocyanins on β-Amyloid-Mediated PC-12 Cells Death by Inhibition of Oxidative Stress
ABSTRACT Amyloid-beta peptide (Abeta) is known to induce the redox imbalance, mitochondrial dysfunction and caspase activation, resulting in neuronal cell death. Treatment with antioxidants provided a new therapeutic strategy for Alzheimer's disease (AD) patients. Here we investigate the effects of purple sweet potato anthocyanins (PSPA), the known strong free radical scavengers, on Abeta toxicity in PC12 cells. The results showed that pretreatment of PC12 cells with PSPA reduced Abeta-induced toxicity, intracellular reactive oxygen species (ROS) generation and lipid peroxidation dose-dependently. In parallel, cell apoptosis triggered by Abeta characterized with the DNA fragmentation and caspase-3 activity were also inhibited by PSPA. The concentration of intracellular Ca(2+) and membrane potential loss associated with cell apoptosis were attenuated by PSPA. These results suggested that PSPA could protect the PC-12 cell from Abeta-induced injury through the inhibition of oxidative damage, intracellular calcium influx, mitochondria dysfunction and ultimately inhibition of cell apoptosis. The present study indicates that PSPA may be a promising approach for the treatment of AD and other oxidative-stress-related neurodegenerative diseases.
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ABSTRACT: Strawberry tree (Arbutus unedo) belongs to the Ericaceae family and is endemic to the Mediterranean area. Its fruits are edible and its fruits and leaves are used in folk medicine for diverse purposes. Previous studies have shown that the fruits are rich in flavonoids, responsible for their antioxidant properties and compounds isolated from the entire plant were promising in cancer chemopreventive therapy. Strawberry tree fruits and leaves extracts enriched in polyphenols, but devoid of organic acids, carotenoids and sugars, were prepared by solid phase extraction (SPE) and tested for their antioxidant activities and their ability to inhibit metalloproteinases: attributes that could be related with initiation and proliferation of cancer cells. After fractionation by SPE, the apparent polyphenol yield was reduced for both leaf and fruit samples by the elimination of vitamins and organic acids, but the antioxidant and metalloproteinases inhibitory activities were potentiated. The antioxidant activity and the MMP-9 inhibitory activity of the polyphenol-enriched fractions of A. unedo tissues were similar or higher than those of blackberry and green tea, which have been recognized in the literature as highly effective. The phenolic profile of the fruit was dominated by gallic acid and quercetin derivatives with smaller amounts of proanthocyanidins and anthocyanins. The phenolic profile of the leaves was also dominated by gallic acid derivatives, flavonol derivatives and some tannins but lacked anthocyanins. The fractions obtained from both strawberry tree tissues seem to be quite promising as antioxidants and antiproliferative agents. Further cell-based assays are underway to study these possible outcomes.Journal of Berry Research 01/2010; 1(1-1):3-12. DOI:10.3233/BR-2010-001
Conference Paper: Analytical analysis of effect of sampling plan on Cpk[Show abstract] [Hide abstract]
ABSTRACT: The use and abuse of process capability indices (PCIs) have become topics of considerable controversy in the last few years. A simulation shows that the difference in Cpk's estimated by three approaches, which are widely used in manufacturing industry, is at least 0.5. In this paper, the authors study analytically the differences in Cpk's calculated by these three different approaches. A few analytical relationships among the Cpk's are derived in this paper and are illustrated with a case studyEngineering Management Conference, 1995. 'Global Engineering Management: Emerging Trends in the Asia Pacific'., Proceedings of 1995 IEEE Annual International; 07/1995
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ABSTRACT: Purple sweet potato (PSP) pigments have been widely accepted as antioxidants but their radioprotective effect still remains unclear. In this study we investigated the effect of PSP pigments on ⁶⁰Co γ-ray-induced mitochondria-mediated apoptosis in murine thymocytes. The murine thymocytes were pretreated by PSP pigments before exposure to 4 Gy ⁶⁰Co γ-rays. Flow cytometry analysis was used to measure apoptotic cells and mitochondrial membrane potential. Reactive oxygen species (ROS) were detected using 2',7',-dichlorofluorescein diacetate (DCFH-DA) probe and the activity of antioxidant enzymes was tested by biochemical assay after irradiation. Cytochrome c, caspase-3 and poly ADP-ribose polymerase (PARP) were measured by Western blotting. After treatment with PSP pigments and exposure to 4 Gy radiation the apoptosis of thymocytes was reduced and the mitochondrial transmembrane potential was maintained compared to control cells. In the presence of PSP pigments, ROS were reduced and the activities of glutathione peroxidase (GSH-px) and superoxide dismutase (SOD) were protected and in some cases increased. All the pro-apoptotic proteins (cytochrome oxidase, caspase 3 and PARP) decreased in PSP pigments pretreated thymocytes compared to irradiated cells in the absence of PSP pigments. Pre-treatment with PSP pigments significantly inhibited ⁶⁰Co γ-ray-induced mitochondria-mediated apoptosis. This radioprotective effect might be related to ROS scavenging, the enhancement of the activity of antioxidant enzymes, the maintenance of mitochondrial transmembrane potential, and the sequential inhibition of cytochrome c release and downstream caspase and PARP cleavage.International Journal of Radiation Biology 12/2010; 86(12):1061-9. DOI:10.3109/09553002.2010.501840 · 1.69 Impact Factor