Multiple Mechanistic Models Reveal the Neuroprotective Effects of Diterpene Ginkgolides against Astrocyte-Mediated Demyelination via the PAF-PAFR Pathway

Abstract

Currently, therapies for ischemic stroke are limited. Ginkgolides, unique Folium Ginkgo components, have potential benefits for ischemic stroke patients, but there is little evidence that ginkgolides improve neurological function in these patients. Clinical studies have confirmed the neurological improvement efficacy of diterpene ginkgolides meglumine injection (DGMI), an extract of Ginkgo biloba containing ginkgolides A (GA), B (GB), and K (GK), in ischemic stroke patients. In the present study, we performed transcriptome analyses using RNA-seq and explored the potential mechanism of ginkgolides in seven in vitro cell models that mimic pathological stroke processes. Transcriptome analyses revealed that the ginkgolides had potential antiplatelet properties and neuroprotective activities in the nervous system. Specifically, human umbilical vein endothelial cells (HUVEC-T1 cells) showed the strongest response to DGMI and U251 human glioma cells ranked next. The results of pathway enrichment analysis via gene set enrichment analysis (GSEA) showed that the neuroprotective activities of DGMI and its monomers in the U251 cell model were related to their regulation of the sphingolipid and neurotrophin signaling pathways. We next verified these in vitro findings in an in vivo cuprizone (CPZ, bis(cyclohexanone)oxaldihydrazone)-induced model. GB and GK protected against demyelination in the corpus callosum (CC) and promoted oligodendrocyte regeneration in CPZ-fed mice. Moreover, GB and GK antagonized platelet-activating factor (PAF) receptor (PAFR) expression in astrocytes, inhibited PAF-induced inflammatory responses, and promoted brain-derived neurotrophic factor (BDNF) and ciliary neurotrophic factor (CNTF) secretion, supporting remyelination. These findings are critical for developing therapies that promote remyelination and prevent stroke progression.

Antiplatelet effect of ginkgo diterpene lactone meglumine injection in acute ischemic stroke: A randomized, double‐blind, placebo‐controlled clinical trial

“…For management of AIS patients within 4.5 hr from the symptom onset, intravenous rt-PA was approved, and researchers reported that the combination of GDLI and rt-PA was superior to rt-PA alone for clinical efficacy, supporting add-on effects of GDLI in thrombolytic therapy on AIS (Zhao et al, 2022) signaling pathways (Liu et al, 2019;Zhang et al, 2018). Recently, researchers found that the neuroprotective activities of GDLI were related to its regulation of the sphingolipid and neurotrophin signaling pathways via gene set enrichment analysis (GSEA) (Wang et al, 2022).…”

“…Meanwhile, GDLI could significantly decrease rat neurological deficit scores, reduce brain infarct volume, and protect against cerebral ischemia–reperfusion damage by activating both Akt/Nrf2 and Akt/CREB signaling pathways (Liu et al, 2019; Zhang et al, 2018). Recently, researchers found that the neuroprotective activities of GDLI were related to its regulation of the sphingolipid and neurotrophin signaling pathways via gene set enrichment analysis (GSEA) (Wang et al, 2022). As the main active components of GDLI, GB was reported to possess multiple neuroprotective mechanisms including antiinflammation, antiexcitotoxicity, antiapoptosis, and the blood–brain barrier (BBB) protection; and the neuroprotective strategies of GK involved antioxidation, mitochondrial protection, elevation of autophagy via upregulation of the AMPK/mTOR/ULK1 signaling pathway, and promotion of neurogenesis by activating JAK2/STAT3(Xu et al, 2021).…”

“…Previous clinical studies suggested the effectiveness of GDLI for the treatment of the sub‐acute stroke patients due to its neuroprotective and antiinflammatory properties (Fan et al, 2020; Zhao, Guo, Li, & Shi, 2022), but there were very few studies investigating its antiplatelet effect and mechanism of action in clinical practice. The two main active components of GDLI, GB (60%) and GK (2%), were reported to be potent and specific inhibitors of platelet activating factor (PAF) which can activate platelet function and generate thrombus (Wang et al, 2022; Zhang et al, 2022). However, the original experiments were conducted in animals, and the sensitivity of PAF in human cells was found to be much weaker than in animals (Montrucchio, Alloatti, & Camussi, 2000).…”

“…Furthermore, an in vitro study showed that Ginkgo biloba extract could inhibit PFA‐mediated human platelet aggregation, but the plasma concentration required to achieve such effect would be 100 times higher than that measured after oral intake of standardized ginkgo biloba extract (EGb761) at recommended doses (usually between 120 and 240 mg) (Koch, 2005). Therefore, researchers believed that PAF was a weak platelet activator, and more and more researchers contended that PAF was a promising inflammatory factor (Travers, Rohan, & Sahu, 2021; Wang et al, 2022). Besides PAF, platelet aggregation in vivo is mainly induced by agonists, such as AA, ADP, collagen (COL), and epinephrine (EPI) (Lordan et al, 2021; Yeung et al, 2018).…”

Efficacy and Safety of Ginkgo Diterpene Lactone Meglumine in Acute Ischemic Stroke

“…Ginkgo diterpene lactone meglumine (GDLM) is made of extracts from ginkgo biloba L, composed of the active ingredients of ginkgolides A, B, and K, and some other contents. It has been widely used in the treatment of ischemic stroke in China . The active ingredient in GDLM has been shown to have a variety of neuroprotective and reparative effects that can help maintain the blood-brain barrier; reduce brain edema; improve energy metabolism; help with antioxidation, anti-inflammation, and antiapoptosis; and promote angiogenesis .…”