Ginkgolide B (GB), a main constituent of Ginkgo biloba extracts, reduces hepatic lipid accumulation and ameliorates nonalcoholic fatty liver disease (NAFLD) in obese mice, but the potential mechanism is unclear. Here we investigated the attenuated effects of GB on the disorder of lipid metabolism, oxidative stress and iron deposition in NAFLD and its potential mechanism associated with ferroptosis. Our preliminary research focused on high fat diet (HFD)-induced ApoE-/-mice gavaged with GB (20 and 30 mg kg-1•d-1, approximately equal to the human dose of 2 and 3 mg kg-1•d-1, respectively) and palmitic acid and oleic acid (PA/OA)-induced HepG2 cells treated with GB (4, 8, 16 μg/mL), respectively. Hepatic injury was assessed via biochemical, histopathological and immunohistochemical evaluations. In order to examine the mechanism of GB on ferroptosis-regulated pathway, we analyzed the expression levels of ferroptosis-related proteins, including nuclear factor erythroid 2 (Nrf2), glutathione peroxidase 4 (GPX4), heme oxygenase-1 (HO-1), transferrin receptor-1 (TFR1) and ferritin heavy chain-1 (FTH1) in vivo and vitro experiments by Western blotting. In order to further verify the correlation pathway of ferroptosis, after Nrf2 short hairpin RNA interference, we analyzed the effects of GB on Nrf2 pathway. Both HFD-fed mice and PA/OA-induced HepG2 cells displayed ferroptosis-based panel of biomarkers such as iron overload with the up-regulation of TFR1 and the down-regulation of FTH1, lipid peroxidation and inhibition of Nrf2 activity, which further induced GPX4 and HO-1 levels. Remarkably, after Nrf2 interference, GB treatment significantly increased Nrf2 expression, indicating that GB exerted anti-ferroptosis effects by activation of Nrf2 pathway. Our results are preliminarily illustrated that GB treatment has a specific effect on lipid accumulation and oxidative stress caused ferroptosis in NAFLD, possibly through Nrf2 signaling pathway.

1. Ginkgolide B (GB), the most active of the ginkgolides, has been developed as a new drug for the treatment of vascular insufficiency; however, the pharmacokinetics of GB remain unclear. Here, we investigated the pharmacokinetics and urine excretion properties of GB in healthy Chinese subjects administered single- and multiple-dose injectable GB based on a new LC-MS/MS method.2. GB pharmacokinetics were found to be dose-dependent from 20 to 60 mg. GB reached a steady state by day 6 with once-daily dosing at 40 mg. Systemic exposure to GB, as characterised by AUC0-∞, indicated accumulation following repeated once-daily dosing for seven consecutive days. The mean urinary cumulative excretion rate of GB in response to 20, 40, and 60 mg GB was 41.9 ± 18.5%, 32.9 ± 12.2%, and 43.9 ± 8.5%, respectively.3. Dose-proportional pharmacokinetics of GB were observed after intravenous administration in healthy subjects. A gradual reduction in the volume of distribution and slight change in mean resistance time led us to conjecture the limited accumulation of GB based on distribution equilibrium in vivo.4. This comprehensive study of the clinical pharmacokinetics of GB will provide useful information for its application and further development.

The study of pharmacokinetics of Ginkgo biloba extracts in Traditional Chinese Medicine was relatively recent. In this study, a simple, quick and sensitive LC-MS/MS analytical method was developed for the determination of ginkgolides A, B, C and bilobalide in rat plasma. The analytes were completely separated from the endogenous compounds on an Agilent Zorbax Eclipse plus C18 column (50 mm × 3.0 mm, 1.8 µm) using an isocratic elution. The single-run analysis time was as short as 5.0 min. Sample preparation for protein removal was accomplished used a simple methanol precipitation method, after SPE showing a simultaneous extraction and cleanup of extracts allowing for a direct analysis. Extraction recoveries in rat plasma for ginkgolides A, B, C and bilobalide ranged from 75.6% to 89.0%. The calibration curves were determined over the ranges 0.5-20,000 ng/mL for ginkgolides A, B, C and bilobalide respectively. The lower limits of quantification (LLOQ) of the analytes were 0.5 ng/mL. Inter-day and intra-day precision and accuracy were below 15% and between 85 and 115%, respectively. Finally, the developed method was successfully applied to a pharmacokinetic study following oral administration of the Ginkgo biloba extracts to the male ICR rats.

The goal of this study was to develop a novel oil-body nanoemulsion (ONE) for Ginkgolide B (GB) and to conduct pharmacokinetics and pharmacodynamics evaluations. GB-ONE was prepared by O/O emulsion method. The differences in pharmacokinetics parameters and tissue distribution of rats after oral administrated with GB-ONE were investigated by liquid chromatography-tandem mass spectrometry. Changes in the ethological and pathological characterizations of the Alzheimer\'s disease rats after treated with GB-ONE were evaluated by Morris water maze (MWM) and pathological section, respectively. Furthermore, choline acetyltransferase (ChAT) and acetylcholinesterase (AchE) activity in hippocampus was analyzed by spectrophotometric method. The results indicated that the AUC of GB in rats\' plasma was significantly improved after incorporated into ONE, and GB-ONE was significantly targeted into brain. In MWM experiment, memory improvement of rats with cognition impaired was confirmed after administrated with GB-ONE. Furthermore, GB-ONE significantly inhibited AchE activity and enhanced the activity of ChAT in the hippocampus. The overall results implicated that the novel ONE was effective for improving the drawbacks of GB and showed great potential for clinical application.