Ginkgolide B reduces neuronal cell apoptosis in the hemorrhagic rat brain: possible involvement of Toll-like receptor 4/nuclear factor-kappa B pathway.

Ginkgolide B (GB) is one of the ginkgolides that have been isolated from leaves and root bark of the Chinese tree Ginkgo biloba L. (Ginkgoaceae), and is a specific and potent antagonist of platelet activating factor. There is a large body of data showing that GB possesses a markedly neuroprotective property against ischemia-induced impairment in vivo and in vitro. Recently it has been found that GB can inhibit the inflammation in the rat brain tissues with ischemia/reperfusion injury and in the astrocytes treated with lipopolysaccharide, as well as protect neurons against beta-amyloid 25-35 and ischemia-induced apoptosis. However, there have been few reports on the influence of GB on intracerebral hemorrhage (ICH). This study was to investigate the effects of intraperitoneal GB on neuronal cell apoptosis, inflammatory cytokines and Toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) pathway after ICH. Wistar rats obtained an intraperitoneal injection of 5, 10 and 20mg/kg GB after ICH once a day till day 5. Rats were sacrificed by decapitation at hour 2, 6 and 12, as well as day 1, 2, 3 and 5 after ICH. Gene expressions of TLR-4 and NF-κB, concentrations of tumor necrosis factor-alpha (TNF-α), interleukin-1beta (IL-1β) and interleukin-6 (IL-6) as well as number of apoptotic neuronal cells in hemorrhagic rat brain tissues were determined. The administration of 10 and 20mg/kg GB could significantly suppress gene expressions of TLR-4 and NF-κB, lessen concentrations of TNF-α, IL-1β and IL-6 as well as reduce number of apoptotic neuronal cells in hemorrhagic rat brain tissues by Least-significant Difference test (P<0.05), but the administration of 5mg/kg GB not (P>0.05). However, a clear concentration-response relationship was not found. GB may inhibit TLR4/NF-κB-dependent inflammatory responses, and furthermore lessen neuronal cell apoptosis after ICH, which may support the use of G. biloba extracts for the treatment of ICH.

Hu YY ，Huang M ，Dong XQ ，Xu QP ，Yu WH ，Zhang ZY ... -  《-》

Ginkgolide B reduces neuronal cell apoptosis in the traumatic rat brain: possible involvement of toll-like receptor 4 and nuclear factor kappa B pathway.

Ginkgolide B (GB) has been demonstrated to have a variety of pharmacological actions. Accumulating evidence indicates that GB may exert a protective effect on brain injury. The study was designed to investigate the influence of GB on toll-like receptor 4 (TLR-4) and nuclear factor κB (NF-κB)-dependent inflammatory responses and neuronal cell apoptosis after traumatic brain injury (TBI). Wistar rats were subjected to 5, 10 and 20 mg/kg GB daily for 5 days, intraperitoneally, following TBI. Rats were sacrificed at hour 2, 6 and 12, as well as day 1, 2, 3 and 5 after TBI. The administration of 10 and 20 mg/kg GB could significantly (least-significant difference test: p < 0.05) suppress gene expressions of TLR-4 and NF-κB, lessen concentrations of tumour necrosis factor α, interleukin-1β and interleukin-6, as well as reduce the number of apoptotic neuronal cells in traumatic rat brain tissues, but the administration of 5 mg/kg GB did not (p > 0.05). However, a clear concentration-response relationship was not found. Thus, GB may inhibit TLR-4 and NF-κB-dependent inflammatory responses, and furthermore lessen neuronal cell apoptosis after TBI, which may support the use of GB for the treatment of TBI.

Yu WH ，Dong XQ ，Hu YY ，Huang M ，Zhang ZY ... -  《-》

Ginkgo diterpene lactones inhibit cerebral ischemia/reperfusion induced inflammatory response in astrocytes via TLR4/NF-κB pathway in rats.

Ginkgo biloba L. (Ginkgoaceae) is a traditional Chinese medicine known to treating stroke and other cardio-cerebrovascular diseases for thousands of years in China. Ginkgo diterpene lactones (GDL) attracted much attention because of their neuroprotective properties. To uncover the effects of GDL, which consist of ginkgolide A (GA), ginkgolide B (GB), and ginkgolide K (GK), on ischemic stroke, as well as the underlying molecular mechanisms. We used middle cerebral artery occlusion/reperfusion (MCAO/R) and oxygen-glucose deprivation/reoxygenation (OGD/R) models mimicking the process of ischemia/reperfusion in vivo and in vitro, respectively. Anticoagulant effects of GDL were investigated on platelet activating factor (PAF), arachidonic acid (AA) and adenosine diphosphate (ADP)-induced platelet aggregation both in vivo and in vitro. We also evaluated the effects of GDL on lipopolysaccharide (LPS)-induced inflammatory response in primary cultured rats' astrocytes. Infarct size, neurological deficit score, and brain edema were measured at 72 h after MCAO. Immunohistochemistry was utilized to analyze neurons necrosis and astrocytes activation. Expression of pro-inflammatory cytokines, including tumor necrotic factor-α (TNF-α) and interleukin-1β (IL-1β) were detected using enzyme-linked immunosorbent assay (ELISA) and real time PCR. The levels of toll-like receptor 4 (TLR4) and nuclear factor κB (NF-κB) were assessed by real time PCR or Western blot. Compared with MCAO/R rats, GDL significantly reduced infarct size and brain edema, improved neurological deficit score. Meanwhile, GDL suppressed platelet aggregation, astrocytes activation, pro-inflammatory cytokines releasing, TLR4 mRNA expression and transfer of NF-κB from cytoplasm to nucleus. Furthermore, GDL alleviated OGD/R injury and LPS-induced inflammatory response in primary astrocytes, characterized by promoting cell viability, decreasing lactate dehydrogenase (LDH) activity, and inhibiting IL-1β and TNF-α releasing. In summary, GDL attenuate cerebral ischemic injury, inhibit platelet aggregation and astrocytes activation. The anti-inflammatory activity might be associated with the downregulation of TLR4/NF-κB signal pathway. Our present findings provide an innovative insight into the novel treatment of GDL in ischemic stroke therapy.

Li X ，Huang L ，Liu G ，Fan W ，Li B ，Liu R ，Wang Z ，Fan Q ，Xiao W ，Li Y ，Fang W ... -  《-》

The protective role of oxymatrine on neuronal cell apoptosis in the hemorrhagic rat brain.

Oxymatrine is extracted from the traditional Chinese herb Sophora flavescens Ait, possesses anti-inflammatory, anti-oxidative and anti-apoptotic properties, and has been used for the treatment of chronic viral hepatitis and many other diseases. This study aimed to investigate the effects of oxymatrine on inflammatory response mediated by Toll-like receptor4 (TLR4) and nuclear factor kappa-B (NF-κB), oxidative injury induced by 12/15 lipoxygenase (12/15-LOX), phosphorylated p38 mitogen activated protein kinase (phosphor-p38 MAPK) and cytosolic phospholipase A2 (cPLA2), and neuronal cell apoptosis in rat brain with intracerebral hemorrhage (ICH). Wistar rats were treated intraperitoneally with 60 or 120mg/kg of oxymatrine daily for 5 days following ICH. The rats were sacrificed at hour 2, 6, 12, 24, 48, 72, and 120 after ICH. The gene expressions of TLR-4 and NF-κB, the levels of TNF-alpha, interleukin-1beta, interleukin-6, 12/15-LOX, phospho-p38 MAPK and cPLA2, and the number of apoptotic neuronal cells in rat brain were determined. Oxymatrine at 120mg/kg significantly suppressed gene expressions of TLR-4 and NF-κB, decreased levels of TNF-alpha, interleukin-1beta and interleukin-6, inhibited synthesis of 12/15-LOX, phospho-p38 MAPK and cPLA2 protein, and mitigated apoptotic neuronal changes following ICH in rat. Oxymatrine at 120mg/kg following ICH inhibits inflammatory responses, oxidative injury, and neuronal cell apoptosis in rats.

Huang M ，Hu YY ，Dong XQ ，Xu QP ，Yu WH ，Zhang ZY ... -  《-》

Inhibition of NF-κB activation is associated with anti-inflammatory and anti-apoptotic effects of Ginkgolide B in a mouse model of cerebral ischemia/reperfusion injury.

Ginkgolide B (GB) has potent neuroprotective effects against ischemia-induced brain injury in vivo and in vitro. However, the underlying mechanisms of GB's neuroprotection remain poorly understood. Excessive inflammation and apoptosis contribute to the pathogenesis of ischemic brain damage, and NF-κB is considered to be a key player in these processes. In the present study, we examined the detailed mechanisms underlying the inhibitory effects of GB on inflammatory and apoptotic responses induced by focal cerebral ischemia/reperfusion (I/R). Transient middle cerebral artery occlusion (tMCAO) model was produced by using an intraluminal filament technique in mice. GB (10, 20 and 40 mg/kg) was administered intravenously (i.v.) 2h after MCAO. The results demonstrated that MCAO-induced cerebral injury was associated with an upregulation of p-IKK, p-IκB-α and degradation of IκB-α, indicating of NF-κB activation. Meanwhile activation of microglial and increases in levels of TNF-α, IL-1β and iNOS were observed. Furthermore upregulation of the expression of NF-κB target gene p53 and p53 downstream gene Bax, but downregulation of Bcl-2 and activation of caspase-3 were found. GB treatment showed marked reduction in infarction volume, brain edema and neurological deficits. GB also inhibited I/R induced NF-κB, microglia activation and production of pro-inflammatory cytokines. We also demonstrated that GB reduced Bax protein levels and increased Bcl-2 protein levels in the post-ischemic brains. These results suggest that GB's neuroprotection is attributable to its anti-inflammatory and anti-apoptotic effect through inhibition of NF-κB.

Gu JH ，Ge JB ，Li M ，Wu F ，Zhang W ，Qin ZH ... -  《-》