Protective effect of olive leaf extract on hippocampal injury induced by transient global cerebral ischemia and reperfusion in Mongolian gerbils

Phytomedicine. 2011 Oct 15;18(13):1137-43. doi: 10.1016/j.phymed.2011.05.010. Epub 2011 Jul 14.


The beneficial effects of antioxidant nutrients, as well as complex plant extracts, in cerebral ischemia/reperfusion brain injury are well known. Mediterranean diet, rich in olive products, is associated with lower incidence of cardiovascular disease, cancer, inflammation and stroke. In this study, the possible neuroprotective effect of standardized dry olive leaf extract (OLE) is investigated for the first time. Transient global cerebral ischemia in Mongolian gerbils was used to investigate the OLE effects on different parameters of oxidative stress and neuronal damage in hippocampus. The biochemical measurements took place at different time points (80min, 2, 4 and 24h) after reperfusion. The effects of applied OLE were compared with effects of quercetin, a known neuroprotective plant flavonoid. Pretreatment with OLE (100mg/kg, per os) significantly inhibited production of superoxide and nitric oxide, decreased lipid peroxidation, and increased superoxide dismutase activity in all time points examined. Furthermore, OLE offered histological improvement as seen by decreasing neuronal damage in CA1 region of hippocampus. The effects of applied OLE were significantly higher than effects of quercetin (100mg/kg, per os). Our results indicate that OLE exerts a potent neuroprotective activity against neuronal damage in hippocampus after transient global cerebral ischemia, which could be attributed to its antioxidative properties.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antioxidants / pharmacology
  • Gerbillinae
  • Hippocampus / blood supply*
  • Hippocampus / drug effects*
  • Ischemic Attack, Transient / drug therapy*
  • Ischemic Attack, Transient / metabolism
  • Ischemic Attack, Transient / prevention & control
  • Male
  • Neuroprotective Agents / pharmacology*
  • Olea / chemistry*
  • Oxidative Stress / drug effects
  • Phytotherapy
  • Plant Extracts / pharmacology*
  • Plant Leaves / chemistry
  • Quercetin / analogs & derivatives
  • Quercetin / pharmacology
  • Reperfusion Injury / drug therapy*
  • Reperfusion Injury / metabolism
  • Reperfusion Injury / prevention & control


  • Antioxidants
  • Neuroprotective Agents
  • Plant Extracts
  • quercitrin
  • Quercetin