P3‐149: THE ANTIOXIDATIVE EFFECT OF ASTAXANTHIN ON GLIAL ACTIVATION INDUCED BY OLIGOMERIC OR FIBRILLAR Aβ _1‐42 IN VITRO

We have shown that the LPS or amyloid-beta1-42(Aβ1-42) strongly induced glial activation and that some synthesized compounds limited oxidative stress and neuroinflammation mediated by LPS or Aβ1-42 in SD rats, monkey or postmortem human glia. Based on the more benefits of some natural products than some synthesized compounds to human, the anti-oxidative stress effects of Astaxanthin or Anthocyanin(C3G), as natural products, on glia, and the working mechanisms had been explored. They may be potentially new drugs to help postpone or limit the processes of Alzheimer's disease in the near future. Aging Aβ1-42 (AnaSpec, Cat#24224) at 4°C for 24 hours to form oligomeric Aβ1-42, and at 37°C for 4 days to form fibrillar Aβ1-42 at 100uM. Mixed primary glia were derived from the cortex of Sprague Dawley neonatal rats and tertiary passage of the cells were stimulated by either the two conformations of Aβ1-42 while BV2 induced by LPS as positive contrl in paralleled experiments. Time course and concentration course of experiments of Astaxanthin or Anthocyanin(C3G) were done (N=5) with the different types of glia in 24-well, 48-well or 96-well plates. Nitrix oxide, iNOS and ROS were measured via Griess assay or Western Blotting or NBT assay. NO, iNOS and ROS were upregulated in primary mixed glia or microglia induced by oligomeric Aβ1-42 or fibrillar Aβ1-42 at 10 uM, and also were upregulated in BV2 cells stimulated by LPS at 100ng-1ug/ml for 30min - 36hrs. The cells were treated with Astaxanthin at 17 - 88.9 ug/ml for 30min, 60min, 12hr, 24hr or 36hr and NO, iNOS and ROS were inhibited in a concentration-dependent manner. Also, ROS were down-regulated started from 70min while NO and iNOS were down-regulated at 12, 24 and 36hrs in a time-dependent manner. Further, down-regulation of NO and iNOS by Astaxanthin via MAPK pathways in glia mediated by LPS or the two conformations of Aβ1-42. Astaxanthin is effective to inhibit oxidative activation in primary glia induced by oligomeric or fibrillar Aβ1-42 in vitro.