Ginkgo biloba and Its Constituent 6-hydroxykynurenic-acid as well as Its Proanthocyanidins Exert Neurorestorative Effects against Cerebral Ischemia

Planta Medica ◽  
2020 ◽  
Vol 86 (10) ◽  
pp. 696-707
Author(s):  
Jianbiao Yao ◽  
Hongxiang Qiao ◽  
Zhuming Jin ◽  
Ruwei Wang ◽  
Haibo Huang ◽  
...  

AbstractNeuroprotective effects against cerebral ischemia/reperfusion (I/R) injury by Ginkgo biloba leaves are commonly attributed to the antioxidant activity of its proanthocyanidins. Furthermore, preliminary experiments identified 6-hydroxykynurenic acid (6-HKA) as a major contributor to this effect of extract of G. biloba leaves (EGb) prepared according to the Chinese Pharmacopoeia (ChP). In order to elucidate the specific contribution of both proanthocyanidins and 6-HKA to the overall neurorestorative effects of this extract according to ChP, EGb ChP was separated into pure 6-HKA and a newly developed Ginkgo proanthocyanidin extract (GPE), enriched in proanthocyanidins but not containing 6-HKA. Male Sprague-Dawley rats were divided into the groups: sham: 8; model (placebo): 25; GPE 80 mg/kg: 13; GPE 40 mg/kg: 13; GPE 20 mg/kg: 16; grape seed extract (negative control) 40 mg/kg: 18; nimodipine (positive control) 2 mg/kg: 8. All non-sham animals were subjected to cerebral I/R injury by occluding the middle cerebral artery with a nylon suture that was removed after 2 h of ischemia to establish reperfusion. For comparison, a parallel series of experiments were performed with 6-HKA. In these in vivo experiments, neurological dysfunctions were reduced by both GPE and 6-HKA, and both average infarct size and concentrations of malondialdehyde (MDA) and super oxide dismutase (SOD) were significantly ameliorated as compared to the model group. This data, therefore, demonstrates that the neuroprotective effects of EGb cannot be explained by a purely chemical antioxidative effect alone as has been previously proposed, especially with regards to the proanthocyanidins. A pharmacological neurorestorative effect of EGb on neurons and brain tissue itself seems to be a much more straightforward explanation for the presented observations. This effect is most likely explained by the synergistic action of both its numerous phenolic constituents (GPE) and 6-hydroxykynurenic acid (6-HKA), which could be identified as one major contributor to the observed activity.

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Lizong Wang ◽  
Jinghan Jiang ◽  
Taofeng Zhou ◽  
Xiang Xue ◽  
Yongjun Cao

Brain-derived neurotrophic factor (BDNF) provides neuroprotective effects towards therapeutic cerebral ischemia-reperfusion (I/R) injury. This view has been proposed by more and more evidence. However, due to the lack of permeability of the blood-brain barrier (BBB) as well as the brief half-life in serum, clinical application is not widespread. To study the participation of exosomes containing BDNF in I/R, we isolated exosomes from BDNF-overexpressing HEK293. The protective outcomes of exosomes in hypoxia/reoxygenation (H/R) experiments were determined by the use of SY-5Y cells. Exosome-BDNF therapy restrained H/R-induced apoptosis by inhibition of the reducing levels of oxidative stress and calcium ions in the cells while maintaining stable levels of mitochondrial membrane potential in brain cells damaged by I/R. We then constructed a cerebral I/R injury model using SD rats to find the function of BDNF in exosome-mediated neuroprotection. The in vivo experiments conducted established that exosomes from BDNF-overexpressing HEK293 cells improved cerebral I/R injury by concealing neuronal apoptosis. Findings gained demonstrated that BDNF is a part of preventing cerebral I/R injury due to exosome mediation by regulating the cellular internal environment and inhibiting apoptosis.


Molecules ◽  
2019 ◽  
Vol 24 (6) ◽  
pp. 1102 ◽  
Author(s):  
Zhekang Cheng ◽  
Meng Zhang ◽  
Chengli Ling ◽  
Ying Zhu ◽  
Hongwei Ren ◽  
...  

Ginseng has been used worldwide as traditional medicine for thousands of years, and ginsenosides have been proved to be the main active components for their various pharmacological activities. Based on their structures, ginsenosides can be divided into ginseng diol-type A and ginseng triol-type B with different pharmacological effects. In this study, six ginsenosides, namely ginsenoside Rb1, Rh2, Rg3, Rg5 as diol-type ginseng saponins, and Rg1 and Re as triol-type ginseng saponins, which were reported to be effective for ischemia-reperfusion (I/R) treatment, were chosen to compare their protective effects on cerebral I/R injury, and their mechanisms were studied by in vitro and in vivo experiments. It was found that all ginsenosides could reduce reactive oxygen species (ROS), inhibit apoptosis and increase mitochondrial membrane potential in cobalt chloride-induced (CoCl2-induced) PC12 cells injury model, and they could reduce cerebral infarction volume, brain neurological dysfunction of I/R rats in vivo. The results of immunohistochemistry and western blot showed that the expression of Toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), silencing information regulator (SIRT1) and nuclear transcription factor P65 (NF-κB) in hippocampal CA1 region of some ginsenoside groups were also reduced. In general, the effect on cerebral ischemia of Rb1 and Rg3 was significantly improved compared with the control group, and was the strongest among all the ginsenosides. The effect on SIRT1 activation of ginsenoside Rb1 and the inhibition effect of TLR4/MyD88 protein expression of ginsenoside Rb1 and Rg3 were significantly stronger than that of other groups. The results indicated that ginsenoside Rg1, Rb1, Rh2, Rg3, Rg5 and Re were effective in protecting the brain against ischemic injury, and ginsenoside Rb1 and Rg3 have the strongest therapeutic activities in all the tested ginsenosides. Their neuroprotective mechanism is associated with TLR4/MyD88 and SIRT1 activation signaling pathways, and they can reduce cerebral ischemic injury by inhibiting NF-κB transcriptional activity and the expression of proinflammatory cytokines, including interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6).


2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Jing Zeng ◽  
Long Zhu ◽  
Jing Liu ◽  
Tao Zhu ◽  
Zhaohui Xie ◽  
...  

Previous studies have shown that metformin not only is a hypoglycemic agent but also has neuroprotective effects. However, the mechanism of action of metformin in ischemic stroke is unclear. Oxidative stress is an important factor in the pathogenesis of cerebral ischemia-reperfusion injury. It has been reported that metformin is associated with stroke risk in the clinical population. This study is aimed at investigating the effect and mechanism of metformin in an experimental model of oxidative stress induced by ischemia/reperfusion (I/R) in vivo and oxygen glucose deprivation/reperfusion (OGD/R) in vitro. Metformin (100, 200, and 300 mg/kg) was administered intraperitoneally immediately after induction of cerebral ischemia. The indicators of oxidative stress selected were antioxidant enzyme activities of catalase, malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), and glutathione peroxidation enzyme (GSHPx). First, we demonstrated that metformin can significantly alleviate acute and chronic cerebral I/R injury and it has a strong regulatory effect on stroke-induced oxidative stress. It can reduce the elevated activities of MDA and NO and increase the levels of GSHPx and SOD in the cerebrum of mice and N2a cells exposed to I/R. Furthermore, real-time PCR and western blot were used to detect the expression of long noncoding RNA H19 (lncRNA-H19), microRNA-148a-3p (miR-148a-3p), and Rho-associated protein kinase 2 (Rock2). The direct interaction of lncRNA-H19, miR-148a-3p, and Rock2 was tested using a dual luciferase reporter assay. lncRNA-H19 altered OGD/R-induced oxidative stress by modulating miR-148a-3p to increase Rock2 expression. The expression of lncRNA-H19 and Rock2 could be downregulated with metformin in vivo and in vitro. In conclusion, our study confirmed that metformin exerts neuroprotective effects by regulating ischemic stroke-induced oxidative stress injury via the lncRNA-H19/miR-148a-3p/Rock2 axis. These results provide new evidence that metformin may represent a potential treatment for stroke-related brain injury.


2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Jaleh Varshosaz ◽  
Somayeh Taymouri ◽  
Abbas Pardakhty ◽  
Majid Asadi-Shekaari ◽  
Abodolreza Babaee

The objective of the present study was to prepare a stableivinjectable formulation of ascorbic acid and α-tocopherol in preventing the cerebral ischemia. Different niosomal formulations were prepared by Span and Tween mixed with cholesterol. The physicochemical characteristics of niosomal formulations were evaluatedin vitro. Forin vivoevaluation, the rats were made ischemic by middle cerebral artery occlusion model for 30 min and the selected formulation was used for determining its neuroprotective effect against cerebral ischemia. Neuronal damage was evaluated by optical microscopy and transmission electron microscopy. The encapsulation efficiency of ascorbic acid was increased to more than 84% by remote loading method. The cholesterol content of the niosomes, the hydrophilicity potential of the encapsulated compounds, and the preparation method of niosomes were the main factors affecting the mean volume diameter of the prepared vesicles. High physical stability of the niosomes prepared from Span 40 and Span 60 was demonstrated due to negligible size change of vesicles during 6 months storage at 4–8°C.In vivostudies showed that ST60/Chol 35 : 35 : 30 niosomes had more neuroprotective effects against cerebral ischemic injuries in male rats than free ascorbic acid.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yong Gu ◽  
Xi Chen ◽  
Shuping Fu ◽  
Wenlan Liu ◽  
Qi Wang ◽  
...  

Isoflavones are major neuroprotective components of a medicinal herb Astragali Radix, against cerebral ischemia-reperfusion injury but the mechanisms of neuroprotection remain unclear. Calycosin and formononetin are two major AR isoflavones while daidzein is the metabolite of formononetin after absorption. Herein, we aim to investigate the synergistic neuroprotective effects of those isoflavones of Astragali Radix against cerebral ischemia-reperfusion injury. Calycosin, formononetin and daidzein were organized with different combinations whose effects observed in both in vitro and in vivo experimental models. In the in vitro study, primary cultured neurons were subjected to oxygen-glucose deprivation plus reoxygenation (OGD/RO) or l-glutamate treatment. In the in vivo study, rats were subjected to middle cerebral artery occlusion to induce cerebral ischemia and reperfusion. All three isoflavones pre-treatment alone decreased brain infarct volume and improved neurological deficits in rats, and dose-dependently attenuated neural death induced by l-glutamate treatment and OGD/RO in cultured neurons. Interestingly, the combined formulas of those isoflavones revealed synergistically activated estrogen receptor (estrogen receptors)-PI3K-Akt signaling pathway. Using ER antagonist and phosphatidylinositol 3-kinase (PI3K) inhibitor blocked the neuroprotective effects of those isoflavones. In conclusion, isoflavones could synergistically alleviate cerebral ischemia-reperfusion injury via activating ER-PI3K-Akt pathway.


2021 ◽  
Vol 8 (1) ◽  
pp. 29-38
Author(s):  
Serap Gokce Eskin ◽  
Yucel Basimoglu Koca ◽  
Serdal Ogut

Objective: Wound healing is a dynamic process that includes biochemical and physiological phenomena. Studies confirm that plants are used in wound healing to a great extent.  Antique oil (HBX 2371) has been produced as a traditional herbal mixed. This herbal mixture contains sesame oil, thyme oil, olive leaf, fig seed, grape seed, turmeric, and cinnamon. We evaluated traditional plant mixed oil ( Antique oil) for its wound-healing activity using an excision wound model in rats. Methods: The study used a preclinical, in vivo experimental, and analytical design. In the study, a total of 21 Sprague-Dawley rats, including 7 as experimental group, 7 as negative-control group, and 7 as positive-control group, were used. After the ischemic wound was created in experimental animals, the research data relating to the histochemical changes and biochemical parameters of the wound healing parameters were collected Results: A to research in experimental group fibroblast count, collagen density, fat cells, epithelization scores higher than the other groups and inflammatory cell density lower than the others. According to the results of the study, the highest TAC value (3.94 ± 0.21) was determined in the experimental group and results showed that antique oil administration decreased the TOC value. Conclusion: In conclusion, it was observed that antique oil prevented the wound changes induced by the incision, increased the repair of the epidermal and dermal structure in a short time, increased the antioxidant level, and decreased the oxidation level. Clinical studies are recommended.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yijia Fangma ◽  
Huifen Zhou ◽  
Chongyu Shao ◽  
Li Yu ◽  
Jiehong Yang ◽  
...  

Hydroxysafflor yellow A (HSYA) and anhydrosafflor yellow B (AHSYB) are the main water-soluble compounds in Carthamus tinctorius L. However, studies on the effect of AHSYB on cerebral ischemia/reperfusion (I/R) injury and the therapeutic effect of HSYA by regulating silent information regulator 1 (SIRT1) pathway remain obscure. In this study, we investigated whether the neuroprotective effects of HSYA and AHSYB on oxygen-glucose deprivation/reoxygenation in primary-cultured hippocampal neuronal cells and the middle cerebral artery occlusion and reperfusion model in rats are associated with the regulation of the SIRT1 pathway. In vitro, HSYA and AHSYB increased cell viability, depressed oxidation properties, and reduced neuronal cell apoptosis. In vivo results showed that HSYA and AHSYB effectively reduced infarct volume, improved neurological function, suppressed apoptosis, and decreased the oxidative stress reaction. Besides, RT-PCR and Western blot analysis showed that HSYA and AHSYB increased the mRNA and protein expressions of the main factors in the SIRT1 pathway, including SIRT1, forkhead box O (FOXO) 1, and peroxisome proliferator–activated receptor coactivator 1α (PGC1α), decreased the expression of Bax, and increased the expression of Bcl-2. The results from immunohistochemistry also showed that the expressions of SIRT1, FOXO1, and PGC1α were increased after treatment with HSYA and AHSYB. Furthermore, the neuroprotective effects of HSYA and AHSYB were abolished by EX527 (SIRT1–specific inhibitor). These results indicated that HSYA and AHSYB should be developed into potential drugs for treating cerebral I/R injury via the SIRT1 pathway. Although HSYA and AHSYB have different chemical structures, both of them exert similar neuroprotective properties against I/R injury in vitro and in vivo, which means that AHSYB is also a non-negligible component in safflower.


2021 ◽  
Author(s):  
Beilei Chen ◽  
Pingping Cao ◽  
Xin Guo ◽  
Xiaobo Li ◽  
Li Jiang ◽  
...  

Abstract Neuroinflammation is a key factor that contributes to the secondary injury after cerebral ischemia/reperfusion (CI/R) injury. Chemokine receptor type 5(CCR5) has shown its pro-inflammatory effects during central nervous system (CNS) diseases. However, the role of CCR5 in CI/R injury is still unclear. In this study, we administered maraviroc (MVC,APEXBIO,UK-427857), a CCR5 antagonist, to the middle cerebral artery occlusion(MCAO) mice. In vivo studies showed that MVC was successively intraperitoneally (i.p.) with different doses (5, 20, or 50 mg/kg body weight) for 3 days after mice MCAO. MVC showed its neuroprotective effects in alleviating neurological deficits and infarct volumes after MCAO. The level of apoptosis and inflammation were remarkably decreased by MVC treatment after CI/R injury. Subsequently, primary microglia were stimulated with different doses of MVC (0.2, 2, 20 or 200nM) for 12h after oxygen-glucose deprivation/reoxygenation model (OGD/R) in vitro. MVC significantly increased the viability of primary microglia after (OGD/R). The expression of pro-inflammatory cytokines (IL-1β and IL-6) in microglia were down-regulated by MVC treatment. Mechanistically, MVC also inhibited the secretion of IL-1β and IL-6 by microglia after OGD stimulation. Furthermore, the key components of NF-κB pathway were measured in vivo and in vitro after MCAO and OGD. MVC significantly inhibited the activity of NF-κB pathway in the above pathological environments. Finally, our data indicated that MVC treatment decreased the activation of JNK signaling pathway after CI/R injury in vivo and in vitro. The JNK activator anisomycin (AN,Beyotime,SC0132-5mg) reversed the neuroprotective effects of MVC, indicating that the JNK pathway is involved in the anti-inflammatory and anti-apoptotic mechanisms of MVC in CI/R injury. Our data demonstrated that CCR5 inhibition exhibits neuroprotective effects after CI/R injury. MVC, which is widely used for HIV treatment by its anti-virus effect, is a potential drug for the treatment of ischemic stroke in the future clinical trials.


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