Antioxidative and Antidiabetic Effects of Natural Polyphenols and Isoflavones

Molecules. 2016 May 30;21(6):708. doi: 10.3390/molecules21060708.


Many polyphenols that contain more than two phenolic hydroxyl groups are natural antioxidants and can provide health benefits to humans. These polyphenols include, for example, oleuropein, hydroxytyrosol, catechin, chlorogenic acids, hesperidin, nobiletin, and isoflavones. These have been studied widely because of their strong radical-scavenging and antioxidative effects. These effects may contribute to the prevention of diseases, such as diabetes. Insulin secretion, insulin resistance, and homeostasis are important factors in the onset of diabetes, a disease that is associated with dysfunction of pancreatic β-cells. Oxidative stress is thought to contribute to this dysfunction and the effects of antioxidants on the pathogenesis of diabetes have, therefore, been investigated. Here, we summarize the antioxidative effects of polyphenols from the perspective of their radical-scavenging activities as well as their effects on signal transduction pathways. We also describe the preventative effects of polyphenols on diabetes by referring to recent studies including those reported by us. Appropriate analytical approaches for evaluating antioxidants in studies on the prevention of diabetes are comprehensively reviewed.

Keywords: catechin; chlorogenic acids; diabetes; glucose tolerance; hesperidin; hydroxytyrosol; insulin secretion; isoflavone; oleuropein; oxidative stress.

Publication types

  • Review

MeSH terms

  • Animals
  • Antioxidants / pharmacology*
  • Biological Products / pharmacology*
  • Carotenoids / chemistry
  • Carotenoids / metabolism
  • Diabetes Mellitus, Type 2 / drug therapy
  • Diabetes Mellitus, Type 2 / metabolism
  • Free Radical Scavengers / chemistry
  • Free Radical Scavengers / pharmacology
  • Free Radicals / adverse effects
  • Humans
  • Hypoglycemic Agents / pharmacology*
  • Isoflavones / pharmacology*
  • Lipid Metabolism / drug effects
  • Oxidative Stress / drug effects
  • Plant Extracts / chemistry
  • Plant Extracts / pharmacology
  • Polyphenols / pharmacology*
  • Signal Transduction / drug effects
  • Superoxide Dismutase / metabolism


  • Antioxidants
  • Biological Products
  • Free Radical Scavengers
  • Free Radicals
  • Hypoglycemic Agents
  • Isoflavones
  • Plant Extracts
  • Polyphenols
  • Carotenoids
  • Superoxide Dismutase