The effect of Ginkgo biloba extract on mitochondrial oxidative phosphorylation in the normal and ischemic rat heart.

Abstract

Free radical-induced myocardial damage and impairment of vascular endothelium-dependent relaxation are amongst the most important mechanisms responsible for ischemic heart injury. Ginkgo biloba leaf extract (GE) has been reported to improve blood circulation in the brain and have a beneficial impact on the cardiovascular system but its cardioprotective effects have not been elucidated yet. Therefore, this study investigated the influence of GE in 70% ethanol (1:5) administered orally to rats on the functions of isolated heart mitochondria under normal and ischemic conditions. Wistar rats were given GE or ethanol (solvent control) at a dosage of 0.32 mL/kg in drinking water for 10 and 18 days, while the control animals received untreated drinking water. Mitochondrial respiration rates were determined oxygraphically. Pyruvate and malate, succinate or palmitoyl-L-carnitine and malate were used as substrates. The GE treatment partially uncoupled mitochondrial oxidation from phosphorylation, reduced the generation of free radicals in the mitochondria, diminished the ischemia-induced V₃ decrease and the degree of respiration stimulation by exogenous cytochrome c. Thus, these results indicate that GE exerts cardioprotective effects reducing ischemia-caused impairment of the functions of heart mitochondria.

• Authors: Jurga Bernatoniene, Daiva Majiene, Rimantas Peciura, Ale Laukeviciene, Ruta Bernatoniene, Tauras Mekas, Arturas Kasauskas, Dalia Kopustinskiene
• Journal: Phytotherapy research : PTR (Phytother Res) Vol. 25 Issue 7 Pg. 1054-60 (Jul 2011) ISSN: 1099-1573 [Electronic] England
• PMID: 21259351 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2011 John Wiley & Sons, Ltd.

Chemical References

• Plant Extracts
• Reactive Oxygen Species

Topics

• Animals
• Ginkgo biloba (chemistry)
• Ischemia (drug therapy)
• Male
• Mitochondria, Heart (drug effects, metabolism)
• Oxidation-Reduction
• Oxidative Phosphorylation
• Plant Extracts (pharmacology)
• Rats
• Rats, Wistar
• Reactive Oxygen Species (metabolism)