Ginkgo biloba extract and its diterpene ginkgolide constituents ameliorate the metabolic disturbances caused by recombinant tissue plasminogen activator in rat prefrontal cortex

Abstract

Introduction

Although recombinant tissue plasminogen activator (rtPA) is a widely used therapy in patients with acute ischemic stroke, rtPA-induced toxicity or its adverse effects have been reported in our previous studies. However, Ginkgo biloba extract (GBE) may provide neuroprotective effects against rtPA-induced toxicity. Thus, in the present study, we investigated whether a single administration of rtPA caused neurotoxicity in the prefrontal cortex (PFC) of rats and determined whether GBE or its diterpene ginkgolide (DG) constituents were neuroprotective against any rtPA-induced toxicity.

Materials and methods

We randomly divided adult Sprague-Dawley rats into four groups that were intravenously administered saline, rtPA, rtPA+DG, or rtPA+GBE. The rats were sacrificed 24 hours later and the whole brain removed. A gas chromatography–mass spectrometry metabolomic approach was used to detect molecular changes in the PFC among the groups. Multivariate statistical and pathway analyses were used to determine the relevant metabolites as well as their functions and pathways.

Results

We found 32 metabolites differentially altered in the four groups that were primarily involved in neurotransmitter, amino acid, energy, lipid, and nucleotide metabolism. Our results indicated that a single rtPA administration caused metabolic disturbances in the PFC. Both GBE and DG effectively ameliorated these rtPA-induced disturbances, although DG better controlled the rtPA-induced glutamate and aspartate excitotoxicity and the activation of NMDA receptor.

Conclusion

Our results provide important novel mechanistic insights into the adverse effects of rtPA and offer directions for future exploration on the thrombolytic effects of rtPA combined with the administration of DG or GBE for the treatment of acute ischemic stroke in humans.

Keywords:

• recombinant tissue plasminogen activator (rtPA)
• diterpene ginkgolides (DG)
• Ginkgo biloba extract (GBE)
• metabolomics
• prefrontal cortex
• excitotoxicity

Supplementary materials

Figure S1 Principal component analysis (PCA) score plot of all samples. R²X =0.987, Q² =0.859. The main parameters of PCA are the two principal components, including R²X and Q². Generally, the main parameter for judging the quality of the model is R²X, which indicates how well the model explains the data. A value of 0.4 indicates that the model is reliable.

Abbreviations: rtPA, recombinant tissue plasminogen activator; DG, diterpene ginkgolide; GBE, Ginkgo biloba extract; QC, quality control; CON, control.

Table S1 Key differential metabolites in the comparison of rtPA+DG and CON groups in rat PFC

Table S2 Key differential metabolites in the comparison of rtPA+GBE and CON groups in rat PFC

Acknowledgments

This work was supported by the National Basic Research Program of China (973 Program, grant no. 2009CB918300), National Key R&D Program of China (grant no. 2017YFA0505700), the National Natural Science Foundation of China (grant nos. 81371310, 81701360), the Natural Science Foundation of Inner Mongolia Autonomous Region of China (grant no. 2016MS0884), the Foundation Project of the Inner Mongolia Autonomous Region People’s Hospital (grant no. 201551), and the China Postdoctoral Science Foundation Funded Project (project no. 2015M570772).

Author contributions

All authors contributed toward data analysis, drafting and revising the paper and agree to be accountable for all aspects of the work.

Disclosure

The authors report no conflicts of interest in this work.