Journal of Ethnopharmacology 111 (2007) 512–516 Effect of Ginkgo biloba extract on the rat heart mitochondrial function Sonata Trumbeckaite a,∗ , Jurga Bernatoniene b , Daiva Majiene a , Valdas Jakˇ stas c , Arunas Savickas b , Adolfas Toleikis a a Institute for Biomedical Research, Kaunas University of Medicine, Eiveniu Street 4, LT-50009 Kaunas-7, Lithuania b Department of Drug Technology and Social Pharmacy, Kaunas University of Medicine, A. Mickeviciaus Street 9, LT-44307 Kaunas, Lithuania c Department of Pharmaceutical Chemistry and Pharmacognosy, Kaunas University of Medicine, A. Mickeviciaus Street 9, LT-44307 Kaunas, Lithuania Received 24 April 2006; received in revised form 1 July 2006; accepted 15 December 2006 Available online 28 December 2006 Abstract Ginkgo biloba L. (Ginkgoaceae) originated from China, first introduced to Europe in the 18th century, it is now distributed all over the world. The leaves of Ginkgo biloba include a rich complex of active compounds responsible for various pharmacological properties. Ginkgo biloba extract improves blood circulation, protects against oxidative cell damage, blocks platelet aggregation that could be important for prevention of cardiovascular diseases. Therefore the fluid extract from Ginkgo biloba leaves was prepared and tested for it is effect on rat mitochondrial function. Our data showed that 0.5 l/ml of GE (containing 0.57 ng/ml of rutin, 0.23 ng/ml of quercitrin, 0.105 ng/ml of hyperosid and 0.02 ng/ml of quercetin) had no effect on the State 2 respiration rate of mitochondria with all used substrates: pyruvate + malate, succinate and palmitoyl-l-carnitine. Further increase in GE concentration (2 and 4 l/ml), increased the State 2 respiration rate with all respiratory substrates in a dose-dependent manner (by 35–116%). The State 3 respiration rate was not affected by GE. In order to identify which compounds of GE could be responsible for the observed effects, we measured the effect of pure flavonoids: rutin, quercetin, hyperosid and quercitrin on mitochondrial respiration. All flavonoids (except of hyperosid) at maximal used concentration, comparable/identical to that in GE, stimulated the State 2 respiration rate only by 8–20%, i.e. less effectively as compared to GE. Therefore, for the explanation of the GE-induced uncoupling of oxidative phosphorylation, other biologically active compounds of GE have to be taken into account in future studies. © 2007 Elsevier Ireland Ltd. All rights reserved. Keywords: Mitochondria; Oxidative phosphorylation; Ginkgo biloba extract 1. Introduction Ginkgo biloba L. (Ginkgoaceae) in traditional Chinese medicine has been used for a very long time. Originated from China, first introduced to Europe in the 18th century (Stromgaard and Nakanishi, 2004), it is now distributed all over the world. Over the past 20 years Ginkgo biloba-derived preparations have became widely known and belong to the one of best selling phytomedicine in Europe. Wide pharmacological application of Ginkgo biloba extracts (GE) is determined by the main active substances: flavonoids (flavone glycosides, primarily composed of quercetin) and terpenoids (ginkolides and bilobalides). To this day, due to their vasorelaxing, anticoagulant, antioxidative, and anti-inflammatory properties GE have most frequently been ∗ Corresponding author. Fax: +370 37 302959. E-mail address: sonatai@centras.lt (S. Trumbeckaite). prescribed as preparations that improve cerebral blood circula- tion, and especially for memory improvement (Christen, 2004; Luo, 2001). Evidence from different studies on the antioxidant properties of GE supports the protective effect of this extract against ischemia-reperfusion injury and oxidative stress condi- tions (Pietri et al., 1997). It is postulated that both flavonoid and terpenoid constituents are involved in the antioxidant effects of GE due to decreasing of tissue level of reactive oxygen species (ROS) and inhibiting membrane lipid peroxidation (DeFeudis and Drieu, 2000). It is well known that mitochondria may gen- erate free radicals on the level of the respiratory chain. As ROS produced by mitochondria are increased in a variety of patholog- ical conditions including hypoxia, ischemia-reperfusion injury, thus GE may be effective against cardiovascular disorders. Clin- ical trials and studies on experimental animals showed that EGb 761, a standardized dry extract of Ginkgo biloba leaves, con- sisting of 24% ginkgo flavone glycosides and 6% terpenoids, improve myocardial functional recovery, reduce the number of 0378-8741/$ – see front matter © 2007 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.jep.2006.12.028