Ginkgolides and bilobalide protect BV2 microglia cells against OGD/reoxygenation injury by inhibiting TLR2/4 signaling pathways

Abstract

Ginkgolide and bilobalide are major trilactone constituent of Ginkgo biloba leaves and have been shown to exert powerful neuroprotective properties. The aims of this study were to observe the inhibitory effects of ginkgolide and bilobalide on the activation of microglial cells induced by oxygen-glucose deprivation and reoxygenation (OGD/R) and the specific mechanisms by which these effects are mediated. For detecting whether ginkgolide and bilobalide increased cell viability in a dose-dependent manner, BV2 cells were subjected to oxygen-glucose deprivation for 4 h followed by 3 h reoxygenation with various concentrations of drugs (6.25, 12.5, 25, 50, and 100 μg/ml). The extent of apoptosis effect of OGD/R with or without ginkgolide and bilobalide treatment were also measured by Annexin V-FITC/PI staining. Similarly, the levels of pro-inflammatory cytokines TNF-α, IL-1β, IL-6, IL-8, and IL-10 were detected using a specific Bio-Plex Pro™ Reagent Kit. The effects of ginkgolide and bilobalide on protein levels of TLR2/4, MyD88, p-TAK1, p-IKKβ, p-IkBα, NF-κB p65, Bcl-2, Bax, Bak, RIP3, cleaved-Caspase-3, cleaved PARP-1 and cellular localization of NF-κB p65 were evaluated by Western blot and double-labeled immunofluorescence staining, respectively. OGD/R significantly decreased the cell viability and increased the release of IL-1β, IL-6, IL-8, IL-10, TNF-α in BV2 microglia cells; these effects were suppressed by ginkgolide and bilobalide. Meanwhile, ginkgolide and bilobalide also attenuated the OGD/R-induced increases in TLR2, TLR4, MyD88, Bak, RIP3 levels and reversed cleaved caspase-3/caspase-3, Bax/Bcl-2 and cleaved PARP-1/PARP-1 ratio. Furthermore, ginkgolide and bilobalide also downregulated p-TAK1, p-IkBα, and p-IKKβ and inhibited the OGD/R-induced transfer of NF-κB p65 from cytoplasm to nucleus in BV2 microglia cells. The results showed that ginkgolide and bilobalide can inhibit OGD/R-induced production of inflammatory factors in BV2 microglia cells by regulating the TLRs/MyD88/NF-κB signaling pathways and attenuating inflammatory response. The possible mechanism of anti-inflammatory and neuroprotective effects of ginkgolides results from the synergistic reaction among each monomer constituents.

Cannabidiol attenuates OGD/R-induced damage by enhancing mitochondrial bioenergetics and modulating glucose metabolism via pentose-phosphate pathway in hippocampal neurons

“…These results are consistent with the attenuation of oxidative damage by CBD in a diabetic retinopathy model [24], in PC12 cells stimulated with β-amyloid [9], and in oligodendrocyte progenitor cells treated with H 2 O 2 [8], and with the antioxidant property of CBD in rats with renal ischemia/reperfusion injury [25]. Furthermore, consistent with previous studies [26], [27], [28], we found that OGD/R insult markedly reduced cell viability and induced apoptosis and PARP-dependent cell death, which were significantly attenuated by the administration of CBD.…”

Activated Microglia Induce Bone Marrow Mesenchymal Stem Cells to Produce Glial Cell-Derived Neurotrophic Factor and Protect Neurons Against Oxygen-Glucose Deprivation Injury

“…Numerous studies have shown that MG produce TNFα, IL6 and IL1β in response to OGD exposure (Chock and Giffard, 2005; Zhou et al, 2016); this was also confirmed in our study. The levels of TNFα, IL6 and IL1β produced by BV2 and MG were increased by OGD ( P < 0.001, Figures 2A,B).…”

Bilobalide protects astrocytes from oxygen and glucose deprivation‐induced oxidative injury by upregulating manganese superoxide dismutase

“…In addition, BB also acts on astrocytes to alleviate the swollen of brain (Goldie & Dolan, ). Our result that BB reduced OGD‐R‐induced apoptosis is also consistent with reports showing that BB attenuated the OGD‐induced apoptosis by reversing cleaved caspase‐3, Bax/Bcl‐2, and cleaved PARP‐1 in microglia cells (Zhou et al, ). BB also reduced apoptosis in α‐Synuclein treated SH‐SY5Y cell (Hua et al, ).…”

“…Bilobalide (BB) is a sesquiterpene trilactone constituent that accounts for~2.9% of the standardized Ginkgo biloba extract EGb 761, which has been widely used to treat a variety of neurological disorders including cerebral ischemia and neurodegeneration (Attia et al, 2012;Deng, Wei, & Zhang, 2006;Oskouei et al, 2013;Sadowska-Krepa et al, 2017;Vellas et al, 2012;Yancheva et al, 2009). Substantial experiments indicate that BB is a neuroprotective agent with multiple mechanisms of action (Goldie & Dolan, 2013;Jiang et al, 2014;Lang et al, 2011;Mdzinarishvili, Kiewert, Kumar, Hillert, & Klein, 2007;Suzuki, Sato, Takezawa, Usuki, & Okada, 2011;Zhou et al, 2016). However, its effects on astrocytes remain largely unknown.…”