Thesis(Master)--İzmir Institute of Technology,İzmir, 2004 / Includes bibliographical references (leaves. 78).

published_or_final_version / Medical Sciences / Master / Master of Medical Sciences

Thesis (M. Med. Sc.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 40-48).

Thesis (M.Med.Sc.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 40-48). Also available in print.

This diploma thesis is related to usage of food supplements in general. It observes which food supplements are mostly used, how often and in which period they are used and also which supplements forms population prefer. Next is this diploma paper focused on supplements for the support of cerebration, concretely up to supplements containing Ginkgo biloba. It studies their vascular activity, effect on memory and concentricity in various age groups. Also HPLC method for quick analysis of selected food supplements containing Ginkgo biloba was tested.

Objective: To conduct an open label clinical pilot trial using Ginkgo biloba in the treatment of vitiligo in Toronto to test the feasibility of recruitment, patient retention, variability of outcome measures, identify safety concerns, and magnitude of treatment effect ahead of a full randomized clinical trial. Methods: 12 participants 12 to 35 years old were recruited to a prospective nonrandomized open-label pilot trial and treated with 60 mg of standardized G. biloba BID for 12 weeks. The primary outcome was the validated Vitiligo European Task Force (VETF). Secondary outcomes included the Vitiligo Area Scoring Index (VASI), photographs, and adverse reactions. Results: Ingestion of Ginkgo biloba was associated with a trend towards improvement on VETF measures of vitiligo lesion area and staging, and significant improvement in VETF spread and total VASI vitiligo measures. Conclusions: By achieving full recruitment, showing benefit, and indicating no adverse reactions the pilot study shows that a future RCT is feasible.

Objective: To conduct an open label clinical pilot trial using Ginkgo biloba in the treatment of vitiligo in Toronto to test the feasibility of recruitment, patient retention, variability of outcome measures, identify safety concerns, and magnitude of treatment effect ahead of a full randomized clinical trial. Methods: 12 participants 12 to 35 years old were recruited to a prospective nonrandomized open-label pilot trial and treated with 60 mg of standardized G. biloba BID for 12 weeks. The primary outcome was the validated Vitiligo European Task Force (VETF). Secondary outcomes included the Vitiligo Area Scoring Index (VASI), photographs, and adverse reactions. Results: Ingestion of Ginkgo biloba was associated with a trend towards improvement on VETF measures of vitiligo lesion area and staging, and significant improvement in VETF spread and total VASI vitiligo measures. Conclusions: By achieving full recruitment, showing benefit, and indicating no adverse reactions the pilot study shows that a future RCT is feasible.

Proefschrift Universiteit Maastricht. / Met lit. opg. - Met samenvatting in het Nederlands.

This thesis presents a new calibration of the Ginkgo stomatal index as a proxy for atmospheric CO2 concentrations using leaves from modern Ginkgo biloba herbarium specimens. Scanning electron images were obtained to count stomates and cells on leaves collected between 1829 and 2015. Average stomatal index (SI) was then calculated for each year. SI is defined as #stomates/(#stomates + # epidermal cells)*100. The relationship between stomatal index and atmospheric CO2 can be expressed in an equation following the form recommended by Wynn (2003), as the most likely representation of the physical laws governing CO2 diffusion across stomates. The new fitted equation for determining CO2 from Ginkgo SI is: CO2=205.7+13,630,000 x SI^(-5.224). This new equation is applied to suitably preserved Cenozoic fossil leaves of Ginkgo and results in a downward revision of estimated CO2 levels, while preserving the general shape of greenhouse spikes in the middle Miocene and Eocene. These spikes correlate to climatic warm and wet spikes derived from paleosol evidence during those times. / 10000-01-01

Pregnane X receptor (PXR) is a ligand-activated transcription factor that plays a role in a broad array of biological processes, including drug metabolism and transport. Ginkgo biloba is an herb commonly used to improve cognitive function. In primary cultures of rat hepatocytes, Ginkgo biloba induces the mRNA expression of CYP3A23, a target gene for rat PXR. The present study tested the hypothesis that Ginkgo biloba activates PXR. Cultured HepG2 human hepatoma cells were transfected with the full-length human PXR (pCR3-hPXR), the full-length mouse PXR (pCR3-mPXR), or an empty vector (pCR3) in addition to a reporter plasmid (XREM-CYP3A4-LUC; firefly luciferase) and an internal control plasmid (phRL-TK; Renilla luciferase). At 24 h after transfection, cells were treated for 24 h with Ginkgo biloba extract and luciferase activity was measured. The extract at 200 µg/ml increased mouse and human PXR activity by 3.0-fold and 9.5-fold, respectively, indicating that Ginkgo biloba more effectively activates human PXR. Dose-response experiments showed that the extract produced a log-linear increase over the range of 200–800 µg/ml. To determine whether Ginkgo biloba extract induces human PXR target gene expression, cultured LS180 human colon adenocarcinoma cells were treated for 72 h with the extract. Total cellular RNA was isolated and reverse transcribed. CYP3A4, CYP3A5, and ABCB1 cDNAs were amplified by real-time PCR. Ginkgo biloba extract at 200, 400, and 800 µg/ml increased CYP3A4 mRNA expression by 1.7-, 2.4-, and 2.5-fold, respectively. The extract at the same concentrations increased the mRNA expression of CYP3A5 (1.3 to 3.6-fold) and ABCB1 (2.7 to 6.4-fold). To determine whether the increased expression involved PXR activation, cells were treated with a PXR antagonist, L-sulforaphane, and Ginkgo biloba extract. L-sulforaphane at 5, 10, and 20 µM decreased CYP3A4 mRNA expression by 54%, 78%, and 93%, respectively, in cells co-treated with the extract. A similar pattern of response was obtained with CYP3A5 and ABCB1. In cells co-treated with the extract, L-sulforaphane (5 and 10 µM) was not cytotoxic and did not decrease PXR mRNA expression. Our data from cell culture experiments indicate that Ginkgo biloba activates PXR and increases CYP3A4, CYP3A5, and ABCB1 mRNA expression.