Impaired tricarboxylic acid cycle flux and mitochondrial aerobic respiration during isoproterenol induced myocardial ischemia is rescued by bilobalide

There is an urgent need to elucidate the pathogenesis of myocardial ischemia(MI)and potential drug treatments.Here,the anti-MI mechanism and material basis of Ginkgo biloba L.extract(GBE)were studied from the perspective of energy metabolism flux regulation.Metabolic flux analysis(MFA)was performed to investigate energy metabolism flux disorder and the regulatory nodes of GBE components in isoproterenol(ISO)-induced ischemia-like cardiomyocytes.It showed that[U-13 C]glucose derived m+2 isotopologues from the upstream tricarboxylic acid(TCA)cycle metabolites were markedly accumulated in ISO-injured cardiomyocytes,but the opposite was seen for the downstream metabolites,while their total cellular concentrations were increased.This indicates a blockage of carbon flow from glycolysis and enhanced anaplerosis from other carbon sources.A Seahorse test was used to screen for GBE components with regulatory effects on mitochondrial aerobic respiratory dysfunction.It showed that bilobalide protected against impaired mitochondrial aerobic respiration.MFA also showed that bilobalide significantly modulated the TCA cycle flux,reduced abnormal metabolite accumulation,and balanced the demand of different carbon sources.Western blotting and PCR analysis showed that bilobalide decreased the enhanced expression of key metabolic enzymes in injured cells.Bilobalide’s efficacy was verified by in vivo experiments in rats.This is the first report to show that bilobalide,the active ingredient of GBE,protects against MI by rescuing impaired TCA cycle flux.This provides a new mechanism and potential drug treatment for MI.It also shows the potential of MFA/Seahorse combination as a powerful strategy for pharmacological research on herbal medicine.

Effect of bilobalide B on cholinergic hippocampal neurons exposed to cholesterol and apolipoprotein E4

BACKGROUND： Extracts of ginkgo biloba leaves have been reported to improve nerve function and activity in Alzheimer＇s disease, which is associated with reduced secretion of cholinergic neurotransmitter in hippocampal neurons. OBJECTIVE： To validate the protective effect of bilobalide B against in vitro injury of cholinergic neurons of the hippocampus induced by combined cholesterol and apoE4 DESIGN, TIME AND SETTING： This randomized, controlled animal experiment was performed in the Pathology Laboratory, Tianjin University of Traditional Chinese Medicine from July 2003 to July 2006. MATERIALS： Neonatal Wistar rats, 1-day-old, both male and female, and mean body mass of 5 g were selected for this study. Cholesterol and apolipoprotein E4 （apoE4） were purchased from Sigma Company （USA）, bilobalide B was purchased from Tianjin Zhongyi Pharmaceutical Factory, batch number 20050312. METHODS： Hippocampal neurons were divided into three groups： a normal control group （routinely added media）, a model group （exposed to media containing 40 mg/L cholesterol and 30 mg/L apoE4 for 24 hours） and a bilobalide B group （exposed to media containing 160 mg/L bilobalide B for 16 hours, and then with addition of 40 mg/L cholesterol and 30 mg/L apoE4 for an additional 24 hours）. MAIN OUTCOME MEASURES： Levels of acetylcholine （ACh） and activity of acetylcholinesterase （ACHE） and choline acetyltransferase （CHAT） in hippocampal neurons were determined by microdosage hydroxylamine colorimetry, hydroxylamine colorimetry and radiological chemistry, respectively. RESULTS： The ACh level was significantly lower in the model group than that in the normal control group （P 〈 0.01）, while it was markedly higher in the bilobalide B group than in the model group （P 〈 0.05）. Activity of AChE was significantly decreased in the model group compared with the normal control group （P 〈 0.05）. However, there was no significant difference between the model group and the bilobalide B group （P 〉 0.05）. Activity of ChAT was significantly lower in the model group than in the normal control group （P 〈 0.01）, while the activity was significantly higher in the bilobalide B group than in the model group （P 〈 0.05）. CONCLUSION： Bilobalide B can enhance the ACh level of hippocampal neurons damaged by combined cholesterol and apoE4, by promoting the synthesis, but not the degradation, of ACh.

Bilobalide inhibits the expression of aquaporin 1, 4 and glial fibrillary acidic protein in rat brain tissue after permanent focal cerebral ischemia

The present results demonstrated that in an adult rat model of permanent middle cerebral artery occlusion （pMCAO）, pretreatment with bilobalide reduced brain water content and infarct area, down-regulated aquaporin 1, 4 mRNA expression in brain edema tissue, then inhibited their synthesis in the striatum, in particular at the early stage of ischemia （at 8 hours after pMCAO）, inhibited glial fibrillary acidic protein expression, and lightened reactive gliosis. These data sug-gest that bilobalide attenuates brain edema formation due to reduced expression of aquaporins.

THE APPLICATION OF A NOVEL ADSORBENT IN RAPID SAMPLE CLEAN-UP OF GINKGOLIDES AND BILOBALIDE IN EXTRACTS OF GINKGO BILOBA LEAVES

A rapid method has been developed for rapid sample clean-up in the determination of the pharmocologically active terpenoid including ginkgolide A, B. C and bilobalide in ginkgo biloba leaves extracts (GBE). The extracts are dissolved in 7% of ethanol aqueous solution and then purified by a highly selective polymeric absorbent solid-phase chromatographic column. After being concentrated, the separated terpenoids with no phenolic disturbance are determined by highperformance liquid chromatography on a Nova-Pak C18 column with methanol-water (30:70) as effluent and refractive index defection. The recovery of the method is about 95% and the new method saves more time than the conventional two-column purification method.

Bilobalide的全合成

Bilobalide是从银杏叶中提取的一种倍半萜的内酯化合物,是一种神经系统、精神类的药物,对治疗因年老而出现的呆傻有较好的效果。它是一种五元环类物质,含有3个五元内酯和1个大位阻的叔丁基。合成这种超级拥挤的立体结构且含有大位阻的不稳定物质,对研究者来说是一项巨大的挑战。为了更好地推近Bilobalide全合成的研究,本文对已报道的天然产物Bilobalide全合成的相关工作进行了总结,详细阐述了整个合成过程。

The mixture of procyanidins extracted from the lotus seed pod and bilobalide ameliorates scopolamine-induced memory impairment in mice

Objective To study the co-effect of procyanidins extracted from the lotus seed pod （LSPC） and bilobalide （BIL） on ameliorating scopolamine-induced learning and memory impairment in young mice. Methods Fifty male Kunming mice with similar learning and memory capabilities were selected by Morris water maze test and were randomized into 5 groups （n=10 in each group）： control group, scopolamine group, L-（LSPC＋BIL） group （50 mg/kg LSPC＋10 mg/kg BIL）, M-（LSPC＋BIL） group （100 mg/kg LSPC＋20 mg/kg BIL）, H-（LSPC＋BIL） group （150 mg/kg LSPC＋30 mg/kg BIL）. Scopolamine model with impaired learning and memory was established by scopolamine treatment （1 mg/kg）, and after 10 min mice were tested. In L-, M-, and H- （LSPC＋BIL） groups, mice were treated with LSPC and BIL ig. for 30 days, while mice in the other 2 groups were treated with normal saline ig. instead. After the 30-day＇s treatment, the co-effect of LSPC and BIL on learning and memory was tested by Morris water maze and the step-down avoidance tests. Results The memory impairment caused by scopolamine in young mice could be ameliorated by co-treatment of LSPC and BIL, as indicated by significantly shorter escape latency and swimming distance in the Morris water maze test, when compared with those in the scopolamine group. In the step-down avoidance test, mice in all the 3 dose groups showed significantly smaller number of errors and longer latency than mice in the scopolamine group did. Conclusion Co-treatment of LSPE and BIL can ameliorate scopolamine-induced learning and memory impairment in young mice.