Purple sweet potato color alleviates D-galactose-induced brain aging in old mice by promoting survival of neurons via PI3K pathway and inhibiting cytochrome C-mediated apoptosis

Brain Pathol. 2010 May;20(3):598-612. doi: 10.1111/j.1750-3639.2009.00339.x. Epub 2009 Sep 21.

Abstract

Purple sweet potato color (PSPC), a class of naturally occurring anthocyanins, protects brain function against oxidative stress induced by D-galactose (D-gal) (Sigma-Aldrich, St. Louis, MO, USA). Our data showed that PSPC enhanced open-field activity, decreased step-through latency, and improved spatial learning and memory ability in D-gal-treated old mice by decreasing advanced glycation end-products' (AGEs) formation and the AGE receptor (RAGE) expression, and by elevating Cu,Zn-superoxide dismutase (Cu,Zn-SOD) (Sigma-Aldrich) and catalase (CAT) expression and activity. Cleavage of caspase-3 and increased terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick-end-labeling (TUNEL)-positive cells in D-gal-treated old mice were inhibited by PSPC, which might be attributed to its antioxidant property. PSPC also suppressed the activation of c-Jun NH(2)-terminal kinase (JNK) and the release of cytochrome c from mitochondria that counteracted the onset of neuronal apoptosis in D-gal-treated old mice. Furthermore, it was demonstrated that phosphoinositide 3-kinase (PI3K) activation was required for PSPC to promote the neuronal survival accompanied with phosphorylation and activation of Akt and p44/42 mitogen-activated protein kinase (MAPK) by using PI3K inhibitor LY294002 (Cell Signaling Technology, Inc., Beverly, MA, USA), implicating a neuronal survival mechanism. The present results suggest that neuronal survival promoted by PSPC may be a potentially effective method to enhance resistance of neurons to age-related disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aging / drug effects*
  • Aging / physiology
  • Animals
  • Brain / drug effects*
  • Brain / enzymology
  • Brain / physiology
  • Cell Survival / drug effects
  • Cell Survival / physiology
  • Cytochromes c / physiology*
  • Galactose / antagonists & inhibitors*
  • Galactose / toxicity
  • Inhibitor of Apoptosis Proteins / physiology*
  • Ipomoea batatas / chemistry
  • Ipomoea batatas / physiology*
  • Male
  • Mice
  • Neurons / cytology
  • Neurons / enzymology
  • Neurons / physiology
  • Phosphatidylinositol 3-Kinase / physiology*
  • Plant Extracts / pharmacology
  • Plant Extracts / therapeutic use
  • Signal Transduction / drug effects*
  • Signal Transduction / physiology

Substances

  • Inhibitor of Apoptosis Proteins
  • Plant Extracts
  • Cytochromes c
  • Phosphatidylinositol 3-Kinase
  • Galactose