Dual Effects of Ginkgo biloba Leaf Extract on Human Red Blood Cells

Abstract

Extracts from the leaves of Ginkgo biloba have been used in Chinese medicine for thousands of years. Today, various standardized preparations from G. biloba leaf extract have been developed. G. biloba leaf extract, which contains flavonoids and terpenoids as the major biologically active components, has become one of the most popular and commonly used herbal remedies due to its wide spectrum of beneficial effects on health. In this study, we investigated the effects of G. biloba leaf extract on the properties of human red blood cells in the presence and absence of amyloid peptide (A β 25-35), peroxide and hypotonic stress. The results suggest that G. biloba leaf extract has a dual action, both protective and disruptive, on red blood cells, depending on whether an exogenous stress is present. G. biloba leaf extract has a protective role on red blood cells against A β -and hypotonic pressure-induced haemolysis, peroxide-induced lipoperoxidation, as well as glutathione consumption and methaemoglobin formation. On the other hand, G. biloba leaf extract also exhibited damage to red blood cells by increasing cell fragility, changing cellular morphology and inducing glutathione consumption and methaemoglobin formation, especially when applied at high doses. These anti-and pro-oxidative activities of polyphenolic substances are thought to be involved in the dual function of G. biloba leaf extract. The results of this study suggest that high doses of herbal remedies and dietary supplements can be toxic to cells.

Ginkgo biloba extract (EGb 761) attenuates oxidative stress induction in erythrocytes of sickle cell disease patients

“…Kose and Dogan (1995) observed that the antioxidant potential of EGb 761 on hydrogen peroxide-induced lipoperoxidation in healthy human erythrocyte membranes increased in a dose-and time-dependent manner, in vitro. He et al (2008), observed the same pattern with the t-BHP-induced formation of malonyldialdehyde in healthy human erythrocytes.…”

“…The analyses were done in basal states, after oxidant incubation (AAPH/t-BHP) and after EGb 761 + oxidant incubation (EGb 761 pre-incubation of 30 min, according to He et al, 2008).…”

“…In recent years, standardized Ginkgo biloba leaf extracts with well-defined components have been developed, including EGb 761, which contains 24% ginkgo-flavone glycosides and 6% terpenoids. Several studies have demonstrated the antioxidant action of EGb 761 in erythrocyte models of oxidative stress (He et al, 2008;Kose et al, 1997;Sarikcioglu, Oner, Tercan, 2004;Foroughinia, Karimi, 2007). However, to our knowledge, this is the first study examining the effect of EGb 761 in the prevention of oxidative damage in SCD.…”

Herbal Drugs in Mirror of Alzheimer’s Disease

“…2 Furthermore, the results from the study of He and colleagues suggested that high doses of herbal remedies can even be toxic to cells. 4 Thus Ginkgo biloba extracts may induce unwanted side-effects and may also lack specificity as to the binding of Cu + and Zn 2+ ions in the cytoplasm. [3][4][5] These extracts can neither reduce metal-based oxidative stress nor contribute to the homeostatic control of those metal ions in human cells.…”

“…4 Thus Ginkgo biloba extracts may induce unwanted side-effects and may also lack specificity as to the binding of Cu + and Zn 2+ ions in the cytoplasm. [3][4][5] These extracts can neither reduce metal-based oxidative stress nor contribute to the homeostatic control of those metal ions in human cells. Yet, for the recovery and modulation of metal ion homeostasis in the treatment of Alzheimer's disease, we have proposed another class of pharmacologically active plant ingredients as antioxidant: plant copper chaperones for superoxide dismutase (pCCS).…”