Analytical Methods for Characterizing Bioactive Terpene Lactones in Ginkgo Biloba Extracts and Performing Pharmacokinetic Studies in Animal and Human

Abstract

Ginkgo biloba is an ancient Chinese tree, appeared more than 250 million years ago, and the only surviving member of Ginkgoacea family [Schmid, 1997]. Ginkgo biloba was used as herbal remedy for many centuries in China, and now its extracts are one of the most widely used herbal products in the world, especially in the United States and in Europe [Blumenthal, 2000; Mahadevan & Park, 2008]. Ginkgo biloba extract is considered an alternative medicine for the treatment and/or the prevention of different pathologies and in some cases it could be suggested to be used as complementary of the mainstream medicine [Ernst, 2000]. In fact, over the past decades, there was a steady growth trend in the use of these alternative treatments. In particular, concentrated and partially purified products, containing Ginkgo biloba active constituents, have been marketed widely in the world for the treatment of cognitive deficits and other age-associated impairments [Kanowski et al., 1996; Le Bars et al., 1997]. Furthermore, it has been used as therapeutic compound for many other chronic and acute forms of diseases such as cardiovascular and bronchial pathologies [Diamond et al., 2000]. In view of the large market as well as the keen interest in the use and rediscovery of these herbal products throughout the world, the quality control of Ginkgo biloba extracts becomes necessary, in order to guarantee their clinical efficacy and safety. Therefore, it is important to monitor simultaneously the bioactive constituents present in Ginkgo biloba extracts, optimizing the analysis time and reducing costs. In fact, in the recent years, numerous groups reported in literature different analytical methods, using various chromatographic conditions and spectophotometric technologies, to create quick, accurate and applicable analytical approaches for the identification and the chemical structure characterization of Ginkgo biloba constituents. Ginkgo biloba extracts contain a large number of representative constituents such as terpenoids, polyphenols, allyl phenol, organic acids, carbohydrates, fatty acids and lipids, inorganic salts and amino acids. However, the pharmacological activity of Ginkgo biloba