Effect of Embelin Against Lipopolysaccharide‐induced Sickness Behaviour in Mice

Sickness behaviour is a coordinated set of adaptive behavioural changes that develop in ill individuals during the course of an infection. It is relevant to understanding depression and some aspects of the suffering that in cancer. Embelin has been reported to possess antiinflammatory, neuroprotective and anxiolytic assets and has been shown to inhibit nuclear factor κB pathway and cytokine production. The present study was undertaken to investigate the effect of embelin isolated from Embelia ribes Burm in lipopolysaccharide (LPS)‐induced sickness behaviour in mice. Adult male Swiss albino mice were pre‐treated with embelin (10 and 20 mg/kg, p.o.) or dexamethasone (1 mg/kg, i.p.) for 3 days and then challenged with LPS (400 µg/kg, i.p.). At different time intervals of post‐LPS challenge, sickness behaviour was evaluated in the animals by battery of behavioural tests (plus maze, open field, light–dark box, forced swim, social behaviour assessment, sucrose preference and food and water intake). Levels of oxidative stress makers (reduced glutathione and lipid peroxidation) in mice brain were also analysed. LPS induced behavioural alterations, anhedonia and anorexia, in mice. Pre‐treatment with embelin attenuated behavioural changes induced by LPS. In addition, embelin prevented anhedonia, anorexia and ameliorated brain oxidative stress markers. The experimental outcomes of the present study demonstrated protective effect of embelin in LPS‐induced sickness behaviour in mice. Copyright © 2016 John Wiley & Sons, Ltd.     

Effects of Ginkgo Biloba Extract EGb‐761 on Neuropathic Pain in Mice: Involvement of Opioid System

Neuropathic pain is considered as one of the most difficult types of pain to manage with conventional analgesics. EGb‐761 is extracted from leaves of Ginkgo biloba and has analgesia and anti‐inflammatory properties. This study aimed to examine the effect of EGb‐761 on chronic constriction injury (CCI)‐induced neuropathic pain behaviors, including thermal hyperalgesia and mechanical allodynia, and to explore the possible mechanisms underlying this action. To this end, CCI mice were intraperitoneally injected with EGb‐761 (10, 20, 40, and 80 mg/kg), and thermal hyperalgesia, mechanical allodynia, cytokines, and mu‐opioid receptor expression were measured. Results showed that EGb‐761 attenuated thermal hyperalgesia and mechanical allodynia dose‐dependently and the best delivery time window was from day 7 to day 14 after CCI. Additionally, EGb‐761 treatment significantly decreased pro‐inflammatory cytokines and enhanced mu opioid receptor (MOR) expression in the sciatic nerve. Moreover, the opioid antagonist naloxone prevented the effect of EGb‐761 on thermal hyperalgesia and mechanical allodynia but did not influence the effect of EGb‐761 on inflammatory cytokines. In conclusion, this study suggests that the potential of EGb‐761 as a new analgesic for neuropathic pain treatment, and opioid system may be involved in the EGb‐761‐induced attenuation of thermal hyperalgesia and mechanical allodynia. Copyright © 2016 John Wiley & Sons, Ltd.     

L‐theanine ameliorate depressive‐like behavior in a chronic unpredictable mild stress rat model via modulating the monoamine levels in limbic–cortical–striatal–pallidal–thalamic‐circuit related brain regions

L‐theanine, originally found in green tea, elicits various physiological effects, such as promoting relaxation, improving concentration and learning ability, and providing antianxiety‐like and antidepressant‐like properties. This study aims to investigate the effects of L‐theanine (2 mg/kg) on monoamine levels in an animal model of depression. The effect of l ‐theanine on the symptoms of depression was examined through the open‐field test, sucrose preference test, and forced swim test. The monoamine neurotransmitters that involve serotonin (5‐HT), norepinephrine (NE), and dopamine (DA) were measured in the limbic–cortical–striatal–pallidal–thalamic (LCSPT)‐circuit related brain regions, including the prefrontal cortex (PFC), nucleus accumbens (NAC), striatum (ST), amygdala, and hippocampus (HIP). L‐theanine ameliorated the depressive‐like behaviors in the chronic unpredictable mild stress (CUMS) rat model. In the PFC, NAC, and HIP, L‐theanine administration significantly increased the levels of 5‐HT, NE, and DA. In the ST, the levels of 5‐HT and DA were increased after the administration of L‐theanine. However, in the HIP, only the level of DA significantly changed after the treatment of L‐theanine. Taken together, these results indicated that L‐theanine has possibly antidepressant‐like effects in the CUMS rat model, which could be mediated by the monoamine neurotransmitters in the LCSPT‐circuit related brain regions.     

Preventative Effects of Ginkgo biloba Extract (EGb761) on High Glucose‐Cultured Opacity of Rat Lens

Diabetic cataract is one of the earliest secondary complications of diabetes, and it is characterized by opacification of the eye lens. In this study, we examined the protective effects of Ginkgo biloba extract (EGb761) on rat lenses cultured in high‐glucose conditions. The cultured rat lenses were divided into six groups: normal group, high‐glucose group, high glucose plus low, medium, and high concentrations of EGb761 groups, and a high glucose plus bendazac lysine group. The activities of antioxidases, aldose reductase, advanced glycosylation end products, transforming growth factor‐β2, Smad2/3, E‐cadherin, and α‐smooth muscle actin were assessed by different methods. Compared with the levels in the high glucose group, EGb761 decreased the intensity of oxidative stress, decreased aldose reductase activation and the level of advanced glycosylation end products, and suppress the transforming growth factor‐β2 or Smad pathway activation, further increase the expression of E‐cadherin and decrease α‐smooth muscle actin, and therefore, prevents the pathological changes of high glucose‐induced lens epithelial cells and ameliorated lens opacity. These results suggest that EGb761 has protective effects on several pharmacological targets in the progress of diabetic cataract and is a potential drug for the prevention of diabetic cataract. Copyright © 2013 John Wiley & Sons, Ltd.     

Protective Effect and Potential Mechanism of Ginkgo biloba Extract EGb 761 on STZ‐induced Neuropathic Pain in Rats

Diabetes induced neuropathic pain is recognized as one of the most difficult types of pain to treat with conventional analgaesics. EGb 761 is a standardized extract of Ginkgo biloba that has analgaesic and antiinflammatory properties and modulatory effects on key pain‐related molecules. We examined the effect of EGb 761 on streptozotocin (STZ)‐induced neuropathic pain behaviours and assessed its mechanism of action. Streptozotocin (20 mg/kg i.p for 5 days) was administered to induce experimental diabetes. Pain hypersensitivity to radiant heat was measured using the Dynamic Plantar Aesthesiometer to test the pain threshold. Diabetic rats exhibited mechanical allodynia and thermal hyperanalgaesia after the third week of STZ injection and concomitantly increased thiobarbituric acid reactive substance and nitric oxide concentration. The antioxidant enzymes level of superoxide dismutase and catalase was markedly reduced in STZ‐diabetic rats (p < 0.05). Systemic administration of EGb 761 (25, 50 and 100 mg/kg), starting after the third week following STZ injection, dose‐dependently reversed STZ‐induced thermal hyperanalgaesia and mechanical allodynia. Moreover, it reduced oxidonitrosative stress and concomitantly restored the level of antioxidant enzymes (p < 0.05) as compared with untreated diabetic rats. These results suggest that EGb 761 attenuated STZ‐induced neuropathic pain behaviours by inhibiting oxidative and nitrosative stress and may constitute a new approach for treatment of painful diabetic neuropathy. Copyright © 2012 John Wiley & Sons, Ltd.     

The Ginkgo biloba extract, EGb 761, fails to reduce brain infarct size in rats after transient, middle cerebral artery occlusion in conditions of unprevented, ischemia-induced fever

There is much biochemical evidence, but very few studies in animal models of stroke in vivo, to suggest that Ginkgo biloba (EGb 761) may offer neuroprotection against regional, ischemic brain damage; additional investigations are needed to ensure future clinical trials. This study reports the effects of EGb 761 given acutely or chronically before ischemia. Rats were subjected to middle cerebral artery occlusion (MCAO) for 2 h and the brain infarct size was assessed 24 h later. Dipyrone (100 mg/kg, i.p.) was injected 30 min before ischemia, and 2.5 and 5.5 h after ischemia, to reduce ischemia-induced fever. EGb 761 (Tebonin) was given acutely (200 mg/kg, p.o., 60 min before ischemia) or chronically (100 mg/kg, p.o., once daily, for 14 days before ischemia). Acute or chronic treatment with EGb 761, either alone or in combination with dipyrone, did not reduce the infarct size compared with saline alone (p > 0.05). Dipyrone failed to prevent ischemia-induced fever during the intra-ischemic period (p > 0.05 vs saline; p < 0.001 vs sham). In the reperfusion phase, dipyrone reduced fever to normothermic levels in the group treated acutely with EGb 761 (p < 0.01 vs saline, p > 0.05 vs sham) but not after chronic EGb 761 (p < 0.01 vs sham), indicating possible pharmacokinetic interaction. In conclusion, within the context of unprevented, ischemia-induced fever, the present results demonstrate that EGb 761 has no significant effect on brain infarct size.     

Ginkgo biloba leaf extract (EGb761) combined with neuroprotective agents reduces the infarct volumes of gerbil ischemic brain

Ginkgo biloba exerts many pharmacological actions. It possesses antioxidant properties, the ability of neurotransmitter/receptor modulation and antiplatelet activation factor. This research is designed to investigate the neuroprotective effects of long-term treatment with EGb761 (a standard form of the extract of Ginkgo biloba leaf) in combination with MgSO(4), FK506, or MK-801 on the infarct volume of male gerbils' brain induced by unilateral middle cerebral artery occlusion (MCAO). Thirty-five gerbils fed a standard diet were intragastrically given water or EGb761 (100 mg/kg/day) for one week. Five randomized groups were established: control (n = 7), EGb761 (n = 8), EGb761 + MgSO(4) (n = 7), EGb761 + FK506 (n = 7), and EGb761 + MK-801 (n = 6). The three drug-combination groups were injected with MgSO(4) (90 mg/kg), FK506 (0.5 mg/kg), or MK-801 (1 mg/kg), respectively 30 min before MCAO. Gerbils were anesthetized and craniectomized to expose the right middle cerebral artery (MCA). The right MCA was constricted with an 8-0 suture to produce a permanent ligation for 24 hours. Postmortem infarct volumes were determined by quantitative image analysis of 2,3,5-triphenyltetrazolium chloride (TTC)-stained brain sections. Results showed that the total infarct volumes of the four treated groups either EGb761 alone or in combination with drugs were lower than the control group by 36.1% (EGb761 alone), 40.3% (EGb761 + MgSO(4)), 35.3% (EGb761 + FK506), and 56.4% (EGb761 + MK-801), respectively (p < 0.01). The main affected areas of the brain in the four treated groups were significantly focused between 4 and 6 mm from the frontal pole, when compared to the control group (p < 0.01). All animals in the five groups had infarctions in both cortex and subcortex. These results indicate that long-term pre-treatment of EGb761 administered either alone or in combination with drugs significantly effective neuroprotection on infarct volume in gerbil ischemic brains.     

Identification of proteins differentially expressed in cerebral cortexes of Ginkgo biloba extract (EGb761)-treated rats in a middle cerebral artery occlusion model--a proteomics approach

EGb 761 is a standardized extract of Ginkgo biloba that appears to have a neuroprotective effect against neurodegenerative diseases. Adult male rats were treated with EGb 761 (100 mg/kg) or vehicle prior to middle cerebral artery occlusion (MCAO), and brains were collected 24 h after MCAO. Proteins that were differentially expressed after EGb 761 treatment during cerebral ischemia were detected using two-dimensional gel electrophoresis. Protein spots with more than a 2.5-fold change in intensity between vehicle- and EGb 761-treated groups were identified by mass spectrometry. The levels of peroxiredoxin-2 and protein phosphatase 2A subunit B were significantly decreased in the vehicle-treated group in comparison to the EGb 761-treated group. In contrast, levels of the collapsing response mediator protein 2 (CRMP2) were significantly increased in vehicle-treated animals, while EGb 761 prevented the injury-induced increase of CRMP2. These results suggest that EGb 761 protects neuronal cells against ischemic brain injury through the specific up- and down-modulation of various proteins.     

银杏叶提取物对AFB1诱发大鼠肝癌过程中CYP3A4活性的影响

目的动态观察银杏叶提取物(Ginkgo biloba extract,EGb761)在黄曲霉毒素B1(AFB1)诱发大鼠肝癌过程中对肝组织代谢酶CYP3A4活性的影响。方法将70只4周龄Wistar雄性大鼠随机分为3组:AFB1组(25只),AFB1+EGb761组(25只)及对照组(20只)。在诱发肝癌过程中,分别于第13,23,33,43,53,63周对大鼠进行肝活检;实验至第73周处死全部动物取肝组织;利用大鼠肝组织微粒体混合酶体外代谢体系,采用荧光分光光度定量法动态检测肝标本中CYP3A4酶代谢活性。结果 AFB1+EGb761组肝癌发生率明显低于AFB1组(P<0.01),而对照组为无肿瘤发生。各组肝组织CYP3A4活性在第23周和第53周呈现双波峰变化;AFB1+EGb761组在第53周和第63周时CYP3A4酶活性低于AFB1组,差异有统计学意义(P<0.05)。结论 EGb761可显著降低AFB1诱发大鼠肝癌的发生率。其机制之一可能为抑制大鼠肝组织CYP3A4活性从而减少前致癌物的代谢,降低AFB1致癌性及其化学性肝损伤达到保护肝脏的作用。     

Methylalpinumisoflavone Inhibits Lipopolysaccharide‐Induced Inflammation in Microglial Cells by the NF‐kappaB and MAPK Signaling Pathway

Neuroinflammation is chronic inflammation within the brain that is attributed to prolonged activation of microglial cells and results in neurodegenerative events, such as neuronal dysfunction and neuronal loss. Therefore, suppression of neuroinflammation would theoretically slow progression of neurodegenerative disease. In this study, we investigated the anti‐inflammatory effects of 4′‐O‐methylalpinumisoflavone (methylalpinumisoflavone), isolated from Cudrania tricuspidata, against LPS‐induced microglial activation in BV2 cells. Exposure of BV2 cells to LPS (0.5 µg/mL) significantly increased production of pro‐inflammatory mediators, including NO, PGE₂, and pro‐inflammatory cytokines. Conversely, pre‐treatment with methylalpinumisoflavone (10 and 20 µg/mL) prior to treatment with LPS resulted in a significant decrease of LPS‐induced production of pro‐inflammatory mediators in a dose‐dependent manner. In addition, reduction of pro‐inflammatory mediators by treatment with methylalpinumisoflavone prior to treatment with LPS was accompanied by a decrease in translocation of NF‐κB p50 and p65 from the cytoplasm to the nucleus and by a decrease in activation of mitogen‐activated protein kinases (MAPKs), such as ERK1/2 and JNK. Taken together, these results suggest that methylalpinumisoflavone suppressed LPS‐induced microglial activation and production of pro‐inflammatory mediators by decreasing NF‐κB signaling and by phosphorylation of MAPKs. These results suggest the potential of methylalpinumisoflavone as an anti‐inflammatory drug candidate. Copyright © 2012 John Wiley & Sons, Ltd.     

The effect of ginkgo biloba extract (EGb 761) pretreatment on intestinal epithelial apoptosis induced by intestinal ischemia/reperfusion in rats: role of ceramide

Apoptosis was demonstrated to be a major mode of intestinal epithelial cell death caused by intestinal ischemia/reperfusion (II/R). Ceramide has been proposed as a messenger for apoptosis. The present study was aimed to investigate the effect of Ginkgo biloba extract 761 (EGb 761) pretreatment on II/R-induced intestinal mucosal epithelial apoptosis in rats and the mechanism related to ceramide. The rat model of II/R injury was produced by clamping superior mesenteric artery for 60 min followed by reperfusion for 180 min. Twenty four rats were randomly allocated into Sham, II/R and EGb + II/R groups. In EGb + II/R group, EGb 761 (100 mg/kg per day) was administered intragastrically for 7 days before the surgery. Animals in II/R and sham groups were treated with equal volume of normal saline solution. Intestinal mucosal epithelial apoptosis was detected via electron microscopy and TUNEL method. Lipid peroxidation in intestinal mucosa was determined by detecting the malondialdehyde level and the activities of superoxide dismutase and peroxidase glutathione. The ceramide generation and sphingomyelinase (SMase) mRNA expression in intestinal mucosa were determined by high performance, thin layer chromatography, and RT-PCR, respectively. II/R caused intestinal mucosal epithelial apoptosis and over-production of the ceramide accompanied by up-regulation of SMase mRNA expression and increases of lipid peroxidation. EGb 761 pretreatment significantly decreased apoptosis index, and concurrently reduced the ceramide generation accompanied by down-regulation of SMase expression and inhibition of lipid peroxidation. The findings indicate that EGb 761 pretreatment attenuates II/R-induced intestinal epithelial apoptosis, which might be attributable to its antioxidant action of mediating ceramide pathway.     

银杏叶提取物(EGb761)通过调控AMPK/KLF4途径抑制血管平滑肌细胞表型转化

目的探讨银杏叶提取物(EGb761)对血小板源生长因子(PDGF)诱导的血管平滑肌细胞(VSMCs)表型转化的影响及其机制。方法体外培养原代VSMCs,使用20 ng·mL^-1的PDGF诱导VSMCs表型转化,采用MTT法和划痕实验检测不同浓度(1、10、100μg·mL^-1)EGb761对VSMCs增殖和迁移的作用;采用免疫荧光和Western blot分别检测VSMCs肌丝排列情况和表型转化相关蛋白α平滑肌肌动蛋白(α-SMA)、calopnin、骨桥蛋白(OPN)以及AMPK/KLF4通路蛋白表达的改变。结果与对照组相比,PDGF诱导VSMCs增殖和迁移明显增强,而EGb761呈浓度依赖性抑制PDGF诱导的VSMCs增殖和迁移;与对照组相比,PDGF组细胞肌丝F-actin排列紊乱、荧光减弱;α-SMA、calponin表达减弱,而OPN表达增强;PDGF+EGb761组细胞肌丝F-actin排列较整齐、荧光较强;α-SMA、calponin表达增强,OPN表达减弱,且呈浓度依赖性。此外,与对照组相比,PDGF能明显诱导AMPK磷酸化水平增加和KLF4表达上调,EGb761呈浓度依赖性抑制AMPK/KLF4通路的激活。使用AMPK通路抑制剂compound C抑制AMPK/KLF4通路后,EGb761对PDGF介导的VSMCs表型转化的抑制作用得到加强;反之,使用AMPK通路激活剂AICAR激活AMPK/KLF4通路后,EGb761对介导的VSMCs表型转化的抑制作用得到逆转。结论EGb761通过抑制APMK/KLF4通路拮抗PDGF诱导的VSMCs表型转化。     

Gingko biloba extract (EGb 761) attenuates the focal cerebral ischemic injury-induced decrease in astrocytic phosphoprotein PEA-15 levels

EGb 761 is an extract of Gingko biloba that is neuroprotective against focal cerebral ischemic injury. PEA-15 (phosphoprotein enriched in astrocytes 15) modulates cell proliferation and apoptosis. In this study, we investigated whether EGb 761 regulates the expression of PEA-15 and two phosphorylated forms of PEA-15 (Ser 104 and Ser 116) in middle cerebral artery occlusion (MCAO)-induced injury. Adult male rats were treated with vehicle or EGb 761 (100 mg/kg) prior to MCAO and cerebral cortices were collected 24 h after MCAO. A reduction in expression of PEA-15 and its phosphorylated forms induced by MCAO injury was detected using a proteomic approach. EGb 761 pretreatment prevented the ischemic injury-induced decrease in PEA-15 expression. Western blot analysis demonstrated that EGb 761 attenuates the injury-induced reduction in PEA-15, phospho-PEA-15 (Ser 104), phospho-PEA-15 (Ser 116). Phosphorylation of PEA-15 influences its anti-apoptotic function; a decrease in PEA-15 phosphorylation induces apoptotic cell death. The maintenance of PEA-15 phosphorylation by EGb 761 pretreatment during cerebral ischemic injury indicates that EGb 761 is a neuroprotective against cerebral ischemic injury.     

银杏叶提取物对星形胶质细胞诱导型一氧化氮合酶基因表达的调控

 目的研究银杏叶提取物(EGh761)对星形胶质细胞合成一氧化氮(NO)的作用以及对共培养的小脑颗粒神经元的作用。方法以脂多糖(LPS)和IFN-γ诱导体外培养的大鼠星形胶质细胞表达诱导型一氧化氮合酶(iNOS),产生NO作为病理条件下胶质细胞过度活化的实验模型,应用逆转录基因扩增技术和蛋白质印迹技术检测EGb761对星形胶质细胞中iNOS基因表达的影响,并探讨这一调控作用的分子机制。结果EGb761能明显降低星形胶质细胞中iNOS mRNA和蛋白质的表达、减少NO 的生成、防止活化的胶质细胞损伤共培养神经元,抑制IκB-α的降解和阻止p65/RelA进入细胞核,提示EGb761对iNOS基因表达的抑制作用依赖于NF-κB信号通路。结论EGb761可能对与胶质细胞过度活化有关的神经系统疾病具有治疗、预防的作用。     

Suppression of experimental abdominal aortic aneurysms in the mice by treatment with Ginkgo biloba extract (EGb 761)

Ethnopharmacological relevance

Ginkgo biloba extract (EGb 761) is widely used to treat cerebral disorders. Clinical trials have demonstrated therapeutic benefits of EGb 761 in various vascular diseases. Because the potential pathophysiological mechanisms appear similar to those involved in aneurysmal degeneration, we postulated that EGb 761 might affect the development and progression of experimental abdominal aortic aneurysm (AAA). This study was aimed to investigate whether EGb 761 influences the development of experimental AAAs, and to explore the underlying mechanisms.

Material and methods

C57/BL6 mice underwent abluminal application of CaCl₂ to the abdominal aorta followed by gavages with either 200 mg/kg EGb 761 per day or vehicle. Six weeks after AAA induction, aortic tissue was excised for further examinations.

Results

EGb 761 treatment reduced the aneurysm size compared with vehicle-treated controls. EGb 761 had no effect on hemodynamics or macrophage infiltration in the aortic wall. However, nuclear factor κB protein levels were decreased in the aortas of EGb 761 treated animals. The increased ROS production, SOD and CAT activities, and mRNA expression of p47phox nicotinamide adenine dinucleotide phosphate oxidase were attenuated by EGb 761 treatment. Moreover, administration of EGb 761 preserved the destruction of the wavy morphology of the elastin during AAA formation. Zymographic activity of matrix metalloproteinase (MMP)-9 and MMP-2 was lowered in EGb 761 treated mice.

Conclusions

These results suggest that treatment with EGb 761 in mice prevented the development of CaCl₂-induced AAA. The possible mechanisms include decreased oxidative damage and inflammation, preservation of aortic wall architecture, and altered MMPs activities.     

银杏叶提取物对大鼠视网膜神经节细胞的保护作用

目的研究急性高眼压缺血再灌注模型中银杏叶提取物对视网膜神经节细胞的保护作用。方法实验用SD大鼠30只分为3组,分别为阴性对照组、阳性对照组、用药组,每组各10只。大鼠右眼为损伤眼,分别行前房穿刺灌注形成110mmHg的眼压维持60min,左眼未做损伤,作为正常对照。阴性对照组于损伤后2h及此后每日腹腔分别灌胃生理盐水5mL/kg。按这种给药方法,阳性对照组给予1%灯盏细辛5mL/kg,用药组给予1%银杏叶提取物5mL/kg,实验持续时间28d。动物安死术前5d用3%荧光金双上丘注射,逆行标记视网膜神经节细胞。做视网膜定向铺片,距离视乳头中心上下左右各2mm拍摄照片。利用彩色颗粒分析软件做节细胞计数,计算各组节细胞的存活率并做统计分析。结果阴性对照组、阳性对照组、用药组节细胞存活率分别为61.46%、72.73%、76.20%。用药组与阴性对照组的节细胞存活率存在显著性差异(P<0.05),用药组与阳性对照组无显著性差异(P>0.05),阳性对照组与阴性对照组之间存在显著性差异(P<0.05)。结论在急性高眼压缺血再灌注模型中,银杏叶提取物能有效地保护视网膜节细胞,与阳性对照药灯盏细辛比较,保护节细胞的效果两者接近。     

Parthenolide Inhibits the LPS‐induced Secretion of IL‐6 and TNF‐α and NF‐κB Nuclear Translocation in BV‐2 Microglia

Feverfew (Tanacetum parthenium [L.] Sch. Bip. [Asteraceae]) is a popular herbal treatment used to prevent and treat headache and migraine. Parthenolide (PTN), the sesquiterpene lactonic derivative that is the plant's major component, might be one of the ingredients that act on mediators of inflammation. In the present study, in cultured lipopolysaccharide (LPS)‐stimulated BV‐2 microglia pretreatment with PTN caused a dose‐dependent reduction of interleukin‐6 (IL‐6) secretion (29% by 200 nm, p < 0.001; 45% by 1 µm, p < 0.001; 98% by 5 µm, p < 0.001); at 5 µm, the highest concentration tested, it also reduced the secretion of TNF‐α (54%, p < 0.001). Western blotting analysis on separate cytoplasmic and nuclear extracts showed that PTN strongly reduced the translocation of nuclear factor (NF)‐κB to the cell nucleus. The reduction of microglial activation by inhibition of proinflammatory agents may help attenuate the onset and intensity of acute migraine attacks. These in vitro results provide an additional explanation for the efficacy of orally administered T. parthenium as an antimigraine agent. Copyright © 2012 John Wiley & Sons, Ltd.     

Summative interaction between astaxanthin,Ginkgo biloba extract (EGb761) and vitamin C in Suppression of respiratory inflammation: a comparison with ibuprofen

In this study, combinations of Ginkgo biloba leaf extract (EGb761) plus the carotenoid antioxidant astaxanthin (ASX) and vitamin C were evaluated for a summative dose effect in the inhibition of asthma‐associated inflammation in asthmatic guinea‐pigs. Ovalbumin‐sensitized Hartley guinea‐pigs challenged with ovalbumin aerosol to induce asthma, were administered EGb761, ASX, vitamin C or ibuprofen. Following killing, bronchoalveolar lavage (BAL) fluid was evaluated for inflammatory cell infiltrates and lung tissue cyclic nucleotide content. Each parameter measured was significantly altered to a greater degree by drug combinations, than by each component acting independently. An optimal combination was identified that included astaxanthin (10 mg/kg), vitamin C (200 mg/kg) and EGb761 (10 mg/kg), resulting in counts of eosinophils and neutrophils each 1.6‐fold lower; macrophages 1.8‐fold lower, cAMP 1.4‐fold higher; and cGMP 2.04‐fold higher than levels in untreated, asthmatic animals (p < 0.05). In conclusion, EGb761, ASX and vitamin C are shown here to interact summatively to suppress inflammation with efficacy equal to or better than ibuprofen, a widely used non‐steroidal antiinflammatory drug (NSAID). Such combinations of non‐toxic phytochemicals constitute powerful tools for the prevention of onset of acute and chronic inflammatory disease if consumed regularly by healthy individuals; and may also augment the effectiveness of therapy for those with established illness. Copyright © 2010 John Wiley & Sons, Ltd.     

The effect of Ginkgo biloba extract (EGb 761) on hepatic sinusoidal endothelial cells and hepatic microcirculation in CCl4 rats

It has been shown that Ginkgo biloba Extract (EGb 761) increases peripheral and cerebral blood flow and microcirculation and improves myocardial ischemia reperfusion injury. This study was designed to investigate the effect of EGb 761 on hepatic endothelial cells and hepatic microcirculation. Sixty male Wister rats were divided into normal, carbon tetrachloride (CCl4) and EGb groups, and were given normal saline, CCl4 and CCl4 plus EGb 761, respectively, for 10 weeks. Samples were taken from the medial lobe of the rat livers ten weeks later. Hepatic sinusoidal endothelial cells and other parameters of hepatic microcirculation were observed under transmission electron microscopy (TEM). The amount of malondialdehyde (MDA), endothelin (ET-1), platelet-activating factor (PAF) and nitric oxide (NO) in liver tissue was determined by spectrophotometry and radioimmunoassay, respectively. Compared with the CCl4 group, aggregation of blood cell or micro thrombosis in hepatic sinusoids, deposition of collagen in hepatic sinusoids and space of Disse, injury of endothelial cells and capillization of hepatic sinusoid was significantly reduced in the EGb group. The amount of MDA, ET-1 and PAF was markedly reduced in the EGb group than in the CCl4 group, while no significant difference in the amount of NO was observed between the two groups. The results demonstrate that EGb 761 has protective effect on hepatic endothelial cells and hepatic microcirculation in rats with chronic liver injury induced by CCl4. The mechanisms may involve its inhibition on ET-1, PAF and lipid peroxidation.