Ginkgo biloba (EGb 761) Extract: Effects on the Myenteric Plexus of the Large Intestine in Wistar Rats

The objective of this study was to evaluate the effect of the purified extract of the Ginkgo biloba (EGb 761) plant on the myenteric plexus in the proximal and distal colon of Wistar rats for a period of 120 days. The experimental rats were divided into two age groups: a young group, sacrificed at age 90 days, and an adult group, sacrified at age 210 days. We observed a significant reduction in the number of neurons in the myenteric plexus of the adult group compared to the young group in both of the segments studied (P < 0.01). The adult group treated with Ginkgo biloba showed a significant increase in neuronal profile area in both the segments studied (P < 0.001). It can be concluded from these results that treatment with the purified Ginkgo biloba (EGb 761) plant extract at a dose of 50 mg/kg body weight has neurotrophic effect on the myenteric plexus in the proximal and distal colon of rats after 120 days of treatment.     

Ginkgo biloba extracts inhibit post-ischemic LTP through attenuating EPSCs in rat hippocampus

Ginkgo biloba extract 761 (EGb761), a standardized extract from the Ginkgo biloba leaf, is purported to inhibit NMDA receptor-mediated neuronal excitotoxicity and protect neurons form ischemic injury. However, the specific signal pathway involved in the effects of EGb761 on synaptic plasticity is still in dispute. In this article, effects of EGb761 and its monomer component ginkgolide A (GA), ginkgolide B (GB), ginkgolide C (GC) and quercetin on rat hippocampal synaptic plasticity were studied. The evoked Excitatory postsynaptic currents (EPSCs) and miniature EPSCs were recorded on hippocampal slices from SD rats (14–21 days of age) by whole-cell patch-clamp recording and long-term potentiation (LTP) was induced by theta-burst stimulation. Acutely applied EGb761 inhibited the LTP, but bilaterally affect the evoked EPSCs. The evoked EPSCs were increased by incubation of lower concentration of EGb761, then the evoked EPSCs were decreased by incubation of higher concentration of EGb761. EGb761 monomer component GA, GB and GC could also inhibit the TBS-induced LTP and EPSC amplitude but not paired-pulse ratio (PPR). But quercetin, another monomer component of EGb761, led to increase in EPSC amplitude and decrease in PPR. Simultaneously, EGb761 and its monomer component ginkgolides inhibited the post-ischemic LTP (i-LTP) by inhibiting the EPSCs and the AMPA receptor subunit GluA1 expression on postsynaptic membrane. The results indicated that high concentration of EGb761 might inhibit LTP and i-LTP through inhibition effects of GA, GB and GC on AMPA receptors.

     

Evaluation of the effect of <Emphasis Type="Italic">Ginkgo biloba</Emphasis> extract (EGb 761) on the myenteric plexus of the small intestine of Wistar rats

Background The aging process causes a reduction in the myenteric neuronal population, related to oxidative stress, resulting in malfunctioning of the digestive tract. The purpose of this study was to evaluate the action of Ginkgo biloba extract (EGb 761), an important antioxidant drug, on the myenteric plexus of the jejunum and ileum of rats after treatment for 120 days. Methods Fragments of the jejunum and ileum were collected from three groups of rats: a 90-day-old group (group Y), a 210-day-old group (group A), and a 210-day-old group treated daily with the extract EGb 761 (50 mg/kg body weight) (group TA). The analysis was carried out by using the myosin-V immunohistochemical technique. Neuronal densities were estimated, and a study of the neuronal profile area of 500 neurons from each group was carried out. Results In the jejunum, there was a significant neuronal population reduction of 17% only in group A compared with group Y. In the ileum, there was a significant neuronal reduction of 36% in group A compared with group Y, and a significant reduction in group TA of 20%. The difference in the reduction between groups A and TA in the ileum was also significant. In the jejunum, only group A showed a significant increase in neuronal profile area, but in the ileum, there was a significant increase in both groups A and TA. Conclusions A daily dose of 50 mg/kg body weight of Ginkgo biloba extract has a significant neuroprotector effect on the myenteric plexus of the ileum during the aging process in rats.     

Ginkgo biloba extract （EGb 761） attenuates lung injury induced by intestinal ischemia/reperfusion in rats： Roles of oxidative stress and nitric oxide

AIM： To investigate the effect of ginkgo biloba extract （EGb 761） on lung injury induced by intestinal ischemia/ reperfusion （ Ⅱ/R）. METHODS： The rat model of Ⅱ/R injury was produced by damping the superior mesenteric artery for 60 min followed by reperfusion for 180 min. The 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 given via a gastric tube for 7 consecutive days prior to surgery. Rats in Ⅱ/R and sham groups were treated with equal volumes of the vehicle of EGb 761. Lung injury was assessed by light microscopy, wet-todry lung weight ratio （W/D） and pulmonary permeability index （PPT）. The levels of malondialdehyde （MDA） and nitrite/nitrate （NO2/NO3）, as well as the activities of superoxide dismutase （SOD） and myeloperoxidase （MPO） were examined. Western blot was used to determine the expression of inducible nitric oxide synthase （iNOS）. RESULTS： EGb 761 markedly improved mean arterial pressure and attenuated lung injury, manifested by the improvement of histological changes and significant decreases of pulmonary W/D and PPT （P 〈 0.05 or 0.01）.Moreover, EGb 761 markedly increased SOD activity, reduced MDA levels and MPO activity, and suppressed NO generation accompanied by down-regulation of iNOS expression （P 〈 0.05 or 0.01）. CONCLUSION： The results indicate that EGb 761 has a protective effect on lung injury induced by Ⅱ /R, which may be related to its antioxidant property and suppressions of neutrophil accumulation and iNOS- induced NO generation. EGb 761 seems to be an effective therapeutic agent for critically ill patients with respiratory failure related to Ⅱ/R.     

Egb 761对NO供体SNP诱导的海马神经元凋亡的保护作用

目的　探讨银杏叶提取物 (EGb761 )对 NO供体硝普钠 (SNP)引起的大鼠海马神经元凋亡的影响。方法　采用 MTT比色分析测细胞存活率、 Hoechst 332 58荧光染色及 DNA琼脂糖凝胶电泳分析等方法检测凋亡。结果　不同剂量 EGb 761预处理海马神经元 6 h可剂量依赖地对抗 SNP引起的神经元凋亡 ,提高神经元的存活率 ;减少 SNP引起的核固缩、凝聚和碎裂现象 ;DNA凝胶电泳图谱未见典型的“梯子状”改变。结论　 EGb 761对 NO供体 SNP诱导的海马神经元凋亡具有明显的保护作用     

山奈酚延缓自发性肥胖2型糖尿病小鼠肾损伤研究

目的观察山奈酚(KPF)干预自发肥胖2型糖尿病小鼠(db/db鼠)早期糖尿病肾病,并探讨相关机制。方法 24只健康雄性10周龄db/db鼠随机分为四组:不同剂量KPF给药组(50、200mg/kg)、db/db对照组和二甲双胍(0.2g/kg)阳性对照组,并设db/m对照组。连续灌胃给药10周,检测小鼠血清肌酐(SCr)、白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α),24小时尿白蛋白排泄率(UAER);留取肾组织,作病理形态学检查、实时定量PCR检测肾组织TNF-α、IL-6的m RNA表达、Western blot检测磷酸化核因子κB p65(p-NF-κBp65)、磷酸化核因子κB抑制蛋白α(p-IκBα)、核因子κB抑制蛋白α激酶(IKKα)蛋白的表达水平。结果不同剂量KPF干预10周,都能使db/db小鼠24小时UAER、SCr、IL-6、TNF-α水平下降,肾组织IL-6、TNF-α基因表达水平明显降低(P0.01、0.05),p-NF-κBp65、IKKα和p-IκBα蛋白表达水平下降(P0.01)。结论 KPF可通过抑制核因子κB(NF-κB)介导的炎症反应,对自发2型糖尿病小鼠早期的肾脏损害起到保护作用。     

Suppression of Pro-Inflammatory Cytokine Release by Selective Inhibition of Inducible Nitric Oxide Synthase in Mucosal Explants from Patients with Ulcerative Colitis

Background: In ulcerative colitis (UC), inflammatory damage is associated with increased production of pro-inflammatory cytokines and nitric oxide through the inducible nitric oxide synthase (iNOS) pathway. In an animal model of acute experimental colitis we have previously shown amelioration of inflammation with the highly selective iNOS inhibitor 1400?W. The aim of the present study was to investigate the effects of selective iNOS inhibition on the production of pro-inflammatory cytokines by the colon mucosa in UC. Methods: Inflamed and uninflamed mucosa from patients with severe UC were incubated with a highly selective iNOS inhibitor N-[3-(aminomethyl)benzyl]acetamidine (1400?W), with a relatively selective cNOS inhibitor N(G)-nitro-L-arginine-methyl-esther (L-NAME), or with an NO-donor, S-nitroso-acetylpenicillamine (SNAP). Cytokine concentrations in the incubation medium were quantitated with ELISA. Results: Compared to uninflamed mucosa there was an increase in iNOS protein and nitrotyrosine levels in inflamed mucosal samples. Immunolocalization of iNOS and nitrotyrosine showed their expression in inflammatory cells in the lamina propria. Expression of iNOS was also found in the epithelial brush border. Selective inhibition of iNOS suppressed the release of tumour necrosis factor alpha (TNF-α, by 66%) and interleukin-6 (IL-6, by 27%). The NO-donor, SNAP, augmented the secretion of TNF-α, IL-6 and IL-1-β (by 62%, 52% and 175%, respectively) and decreased the release of IL-1 receptor antagonist (IL-1Ra, by 34%) by the inflamed mucosa. Moreover, in uninflamed samples, 1400?W suppressed the production of TNF-α (by 69%) and incubation with SNAP decreased IL-6 concentrations by 48%. The cNOS over iNOS selective inhibitor L-NAME had no significant effects on the accumulation of cytokines. Conclusion: Selective inhibition of iNOS suppresses mucosal TNF-α and IL-6 release in active UC, whereas NO seems to exacerbate the inflammatory response. These results suggest that selective iNOS inhibition may have therapeutic promise in the treatment of UC.     

Effect of the antioxidant action of Ginkgo biloba extract (EGb 761) on aging and oxidative stress

Aging is responsible for oxidative damage to DNA, protein, lipid, and other macromolecules linked to tissue alterations. The resultant damage contributes significantly to degenerative diseases, to include those of the brain, sensorial tissues, and cardiovascular system. To protect cellular components from oxyradical attack, especially lipoperoxidation, a substantial interest in the use of antioxidants has evolved. A free radical scavenger, Ginkgo biloba extract (EGb 761) may be effective in fighting the oxidative stress related to aging. Many data support the efficacy of EGb 761 in biological model systems. In aging processes, EGb 761 may ameliorate the mitochondria respiratory chain function by quenching the superoxide anion, and the hydroxyl and peroxyl radicals. It protects the brain by facilitating the uptake of neurotransmitters and by reducing ischemia-reperfusion episodes and level of apoptosis. Moreover, in sensorial tissues, EGb 761 reduces apoptosis in the olfactive bulb and in the retinal pigmented epithelium of the eye, and protects against the lipoperoxidation alteration of the retina that results in a decrease of the electroretinogram response. In the cardiovascular system, by a direct effect on oxidative low density lipoproteins, EGb 761 may decrease atherosclerosis evolution, and is shown to accelerate cardiac mechanical recovery after ischemia-reperfusion. In conclusion, the antioxidant effects of EGb 761 noted in many experimental data, may explain the therapeutic efficacy observed in clinical trials of the elderly. These beneficial properties seem in part to come from the activity of EGb 761 constituents, such as flavonoids and terpens.     

Ace-inhibition with quinapril modulates the nitric oxide pathway in normotensive rats

Angiotensin-converting enzyme (ACE) inhibitors exert some cardiovascular benefits by improving endothelial function. We evaluated the effects of chronic treatment with quinapril (Q) on the l -arginine/nitric oxide (NO) pathway in normotensive rats under baseline and inflammatory conditions. The role of bradykinin was also investigated. The animals received for 1 week either the ACE-inhibitor Q (1 and 10 mg/kg/day), the B(2)receptor antagonist HOE 140, Q+HOE 140, or no drug. At the end of chronic treatment, rats underwent either a 6-h placebo or an E. coli endotoxin challenge. The following measurements were made: (i) endothelial and inducible NO synthase (eNOS and iNOS) protein expression; (ii) eNOS/iNOS activity; (iii) serum levels of nitrite/nitrate and tumour necrosis factor (TNF)- alpha; (iv) NO in the expired air (eNO). Q increased baseline aortic eNOS protein expression (up to 99%, P<0.001) and activity (l -citrulline synthesis up to 94%, P<0.01; serum nitrite/nitrate up to 55%, P<0.05). HOE 140 partially reversed Q-induced upregulation of eNOS (P<0.05). Moreover, Q counteracted LPS effects, i.e. increased the impaired eNOS pathway and limited iNOS induction (up to 94 and 24%, respectively), and reduced the increased nitrite/nitrate and TNF- alpha serum levels as well as eNO (up to 25, 38 and 28%, respectively, P<0.01 for all comparisons). HOE 140 did not influence Q effects on iNOS during endotoxaemia. In conclusion, in (patho)physiological conditions in rats, Q up-regulated eNOS with a bradykinin-mediated mechanism, while downregulated iNOS with a possible TNF- alpha -mediated mechanism.     

Protective effect of Ferula gummosa hydroalcoholic extract against nitric oxide deficiency-induced oxidative stress and inflammation in rats renal tissues

Abstract

Nitric oxide (NO) synthase inhibition increases hypertension and causes renal injury. Ferula gummosa is used in Iranian traditional medicine for treatment of several diseases and has been reported to exert a potent anti-inflammatory and antioxidant action. The aim of this investigation was to evaluate the renoprotective effects of hydroalcoholic extract of Ferula gummosa (HEG) on Nω-nitro-l-arginine methyl ester (l-NAME)-induced oxidative stress and inflammation and explore the mechanisms that link NO deficiency with altered renal heat shock protein (HSP70). Rats were injected intraperitoneally with l-NAME (10?mg/kg) to induce renal injury. Simultaneously, HEG (90?mg/kg) was administered by gastric gavage to l-NAME-treated rats for 6 days/week during an 8-week period. Renal thiobarbituric acid reactive substances (TBARS), superoxide dismutase (SOD), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-α), HSP70, plasma NO and total antioxidant capacity (TAC) were evaluated. The administration of l-NAME significantly increased renal TBARS, TNF-α, IL-6, HSP70 levels and decreased renal SOD activity, that these changes were accompanied by the reduced plasma NO and TAC levels. HEG administration decreased TBARS, HSP70, TNF-α and IL-6 levels and increased SOD activity in the kidney tissues of l-NAME treated rats (p?<?0.05). Also, plasma TAC level and NO bioavailability have been elevated after administration of HEG (p?<?0.05). These findings support that NO deficiency induces renal stress oxidative and inflammation, which markedly increased renal HSP70 and HEG could protect kidney against these damaging effects via its anti-oxidative, anti-inflammatory action and modulate renal HSP70.     

Effects of Ginkgo biloba extract on cell proliferation and cytotoxicity in human hepatocellular carcinoma cells

AIM: To study the effect of Ginkgo biloba extract (EGb 761) containing 22-27% flavonoids (ginkgo-flavone glycosides) and 5-7% terpenoids (ginkgolides and bilobalides) on cell proliferation and cytotoxicity in human hepatocellular carcinoma (HCC) cells. METHODS: Human HCC cell lines (HepG2 and Hep3B) were incubated with various concentrations (0-1 000 mg/L) of EGb 761 solution. After 24 h incubation, cell proliferation and cytotoxicity were determined by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay and lactate dehydrogenase (LDH) release, respectively. After 48 h incubation, the expression of proliferating cell nuclear antigen (PCNA) and p53 protein was measured by Western blotting. RESULTS: The results showed that EGb 761 (50-1 000 mg/L) significantly suppressed cell proliferation and increased LDH release (P<0.05) in HepG2 and Hep3B cells compared with the control group. The cell proliferation of HepG2 and Hep3B cells treated with EGb 761 (1 000 mg/L) was 45% and 39% of the control group (P<0.05), respectively. LDH release of HepG2 cells without and with EGb 761 (1 000 mg/L) treatment was 6.7% and 37.7%, respectively, and that of Hep3B cells without and with EGb 761 (1 000 mg/L) treatment was 7.2% and 40.3%, respectively. The expression of PCNA and p53 protein in HepG2 cells treated with EGb 761 (1 000 mg/L) was 85% and 174% of the control group, respectively. CONCLUSION: Ginkgo biloba extract significantly can suppress proliferation and increase cytotoxicity in HepG2 and Hep3B cells. Additionally, Ginkgo biloba extract can decrease PCNA and increase p53 expression in HepG2 cells.     

银杏叶提取物EGb761对局灶性脑缺血再灌注大鼠XIAP和Smac表达的影响

目的 探讨银杏叶提取物EGb761对局灶性脑缺血大鼠脑组织X-连锁凋亡蛋白抑制剂(X-linked inhibitor of apoptosis protein,XIAP)和Smac蛋白表达的影响.方法 40只雄性Wistar大鼠随机分为假手术组、脑缺血再灌注组、EGb761小剂量组和EGb761大剂量组,每组10只.制作大鼠大脑中动脉闭塞1.5 h再灌注24 h模型.EGb761小剂量组和EGb761大剂量绀于模型制作前1 h分别腹腔注射ECY0761 50 mg/kg和100 mg/kg.大鼠脑组织XIAP和Smac表达用免疫组化方法 检测.结果 EGb761小剂量绀和EGb761大剂量组脑组织XIAP表达分别为18.33±4.01和26.7±3.27,显著高于脑缺血再灌注绀的12.13±3.44(P均<0.01),且EGb761大剂量组高于EGb761小剂量组(P<0.01);EGb761小剂量组和EGb761大剂量组脑组织Smac表达分别为21.33±3.15和11.33±2.10,显著低于脑缺血再灌注组的28.93±4.96(P均<0.05),EGb761大剂最组显著低于EGb761小剂量组(P<0.01).结论 脑缺血再灌注可诱导XIAP和Smae表达,EGn761干预在上调XIAP表达的同时能抑制Smac蛋白表达,提高XIAP/Smac比值,可能是EGb761干预的保护机制之一.     

Tumor necrosis factor–α–induced hypertension in pregnant rats results in decreased renal neuronal nitric oxide synthase expression

BackgroundPreeclampsia is associated with increases in plasma levels of tumor necrosis factor–α (TNF-α), a cytokine known to contribute to endothelial dysfunction. We recently reported that a twofold elevation in plasma TNF-α produces significant reductions in renal function and hypertension in pregnant rats. The purpose of this study was to determine the role of the nitric oxide (NO) system in TNF-α–induced hypertension in pregnant rats.MethodsTumor necrosis factor–α (50 ng/day) was chronically infused starting at day 14 of gestation. Mean arterial pressure, 24-h urinary nitrite/nitrate excretion, and renal nitric oxide synthase (NOS) protein expression by Western blot analysis was measured at day 19 of gestation.ResultsA twofold increase in plasma TNF-α levels in pregnant rats resulted in a significant increase in arterial pressure (97 ± 3.6 v 116 ± 2.1 mm Hg, pregnant versus TNF-α pregnant, respectively, P < .05), but no significant change in urinary nitrite/nitrate excretion (22.0 ± 1.9 v 20.8 ± 2.5 μmol/24 h, pregnant versus TNF-α pregnant, respectively), a measure of whole body NO production. As abnormalities in renal production of NO would not be reflected in the measure of whole body NO production, changes in renal NOS protein levels were determined. The protein expression of both neuronal (nNOS) and inducible (iNOS) nitric oxide synthase were significantly decreased in the medulla of TNF-α pregnant rats (nNOS: 10.6 ± 0.7 v 8.2 ± 0.8 densitometric units, P < .05; and iNOS: 19.2 ± 0.9 v 15.4 ± 0.8 densitometric units, P < .05, pregnant versus TNF-α pregnant, respectively).Conclusion:The hypertension associated with a chronic twofold increase in TNF-α in pregnant rats is associated with significant decreases in renal nNOS and iNOS protein production.     

Effects of Ginkgo biloba extract and preconditioning on the diabetic rat myocardium

Summary Effects of preconditioning and Ginkgo biloba extract (EGb 761) were studied in isolated non-diabetic and diabetic ischaemic and re-perfused rat hearts. Hearts were randomly divided into five groups in both the age-matched non-diabetic and the 8-week streptozotocin-induced diabetic groups: Group I, hearts were subjected to 30 min of global ischaemia followed by 30 min of re-perfusion; Group II, one cycle of preconditioning consisting of 5 min ischaemia and 10 min re-perfusion before the induction of 30 min of ischaemia and 30 min of re-perfusion; Group III, two cycles of preconditioning; Group IV, three cycles; and Group V, four cycles before the onset of 30 min ischaemia followed by 30 min of re-perfusion. Four cycles of ischaemic preconditioning resulted in a reduction of arrhythmias in non-diabetic rats. Thus, in non-diabetics, the incidence of ventricular fibrillation and tachycardia fell from 92 % and 100 % (no preconditioning) to 33 % (p < 0.05) and 42 % (p < 0.05), respectively. Four cycles of preconditioning failed to reduce the incidence of re-perfusion arrhythmias in diabetic subjects. Preconditioning reduced the formation of oxygen free radicals measured by electron spin resonance spectroscopy, but the recovery of cardiac function was low in all non-diabetic and diabetic preconditioned groups. EGb 761 at 25 and 50 mg/kg improved cardiac function in non-preconditioned and preconditioned non-diabetic and diabetic hearts. During re-perfusion in the four-cycle preconditioned non-diabetic and diabetic groups, the amount of free radicals was reduced approximately by 50 and 70 % using 25 and 50 mg/kg of EGb 761, respectively. EGb 761 improved cardiac function after ischaemia in both non-preconditioned and preconditioned non-diabetic and diabetic rats. Our data suggest that diabetes could abolish the precondition-induced protection. [Diabetologia (1996) 39: 1255–1262] Received: 28 March 1996 and in revised form: 3 June 1996     

Simvastatin effects on portal‐systemic collaterals of portal hypertensive rats

Background and Aim: Portal‐systemic collateral vascular resistance and vasoconstrictor responsiveness are crucial in portal hypertension and variceal bleeding control. Statins enhance vasodilators production, but their influence on collaterals is unknown. This study aimed to survey the effect of simvastatin on collaterals. Methods: Partially portal vein‐ligated rats received oral simvastatin (20 mg/kg/day) or distilled water from ?2 to +7 day of ligation. After hemodynamic measurements on the eighth postoperative day, baseline perfusion pressure (i.e. an index of collateral vascular resistance) and arginine vasopressin (AVP, 0.1 nM–0.1 µM) responsiveness were evaluated with an in situ perfusion model for collateral vascular beds. RT‐PCR of endothelial NO synthase (eNOS), inducible NOS (iNOS), cyclooxygenase‐1 (COX‐1), COX‐2, thromboxane A₂ synthase (TXA₂‐S) and prostacyclin synthase genes was performed in parallel groups for splenorenal shunt (SRS), the most prominent intra‐abdominal collateral vessel. To determine the acute effects of simvastatin, collateral AVP response was assessed with vehicle or simvastatin. SRS RT‐PCR of eNOS, iNOS, COX‐1, COX‐2 and TXA₂‐S, and measurements of perfusate nitrite/nitrate, 6‐keto‐PGF1_α and TXB₂ levels were performed in parallel groups without AVP. Results: Acute simvastatin administration enhanced SRS eNOS expression and elevated perfusate nitrite/nitrate and 6‐keto‐PGF1_α concentrations. Chronic simvastatin treatment reduced baseline collateral vascular resistance and portal pressure and enhanced SRS eNOS, COX‐2 and TXA₂‐S mRNA expression. Neither acute nor chronic simvastatin administration influenced collateral AVP responsiveness. Conclusion: Simvastatin reduces portal‐systemic collateral vascular resistance and portal pressure in portal hypertensive rats. This may be related to the enhanced portal‐systemic collateral vascular NO and prostacyclin activities.     

Application of a new immunohistology scoring system (IH score): Analysis of TNF-α in synovium related to disease activity score in infliximab-treated patients with rheumatoid arthritis

Abstract

Objectives. This study aimed to analyze the relationship between the expression of tumor necrosis factor alpha (TNF-α) or interleukin-6 (IL-6) in synovium and the disease activity score (DAS) 28 (C-reactive protein, CRP) in treatment of infliximab for rheumatoid arthritis (RA).

Methods. Synovial tissues were obtained from 16 infliximab-treated patients and assessed for TNF-α and IL-6 with a new immunohistology (IH) scoring system. The validation of IH score was performed and applied for the analysis of correlation between synovial TNF-α or IL-6 and DAS28 (CRP) in addition to Rooney score.

Results. The IH score had high internal validity; the IH score of TNF-α strongly correlated with serum CRP and matrix metalloprotease-3 (MMP-3), as well as DAS28 (CRP) and the Rooney score. IL-6 did not correlate with DAS28 (CRP).

Conclusions. This study indicates that the IH score is useful as a new procedure to assess the cytokine expression easily and TNF-α in synovium correlates with disease activity in patients with RA treated with infliximab.     

Ginkgo biloba Extract (EGb 761) Pretreatment Limits Free Radical Oxidative Stress in Patients Undergoing Coronary Bypass Surgery

A growing body of evidence supports the trigger role of free radicals in the delayed functional and metabolic myocardial recovery following cardiopulmonary bypass (CPB) in humans, thus opening the field to specific therapies. This clinical study was designed to evaluate, in 15 patients undergoing aortic valve replacement, whether the extent of CPB- and reperfusion-induced lipid peroxidation, ascorbate depletion, tissue necrosis, and cardiac dysfunction is reduced by orally administered EGb 761, a Ginkgo biloba extract withpotent in vitro antiradical properties. Patients received either EGb 761 (Tanakan, 320 mg/day, n = 8) or a matching placebo (n = 7) for 5 days before surgical intervention. Plasma samples were obtained from the peripheral circulation and the coronary sinus at crucial stages of the operation (i.e., before incision, during ischemia, and within the first 30 minutes post-unclamping), and up to 8 days postoperatively. Upon aortic unclamping, EGb 761 inhibited the transcardiac release of thiobarbituric acid species (p ` 0.05), as assessed by high-performance liquid chromatography, and attenuated the early (5–10 minute) decrease in dimethylsulfoxide/ascorbyl free radical levels, an electron spin resonance index of the plasma ascorbate pool (p ` 0.05). EGb 761 also significantly reduced the more delayed leakage of myoglobin (p = 0.007) and had an almost significant effect on ventricular myosin leakage (p = 0.053, 6 days postoperatively). The clinical outcome of recovery of treated patients was improved, but not significantly, compared with untreated patients. Our results demonstrate the usefulness of adjuvant EGb 761 therapy in limiting oxidative stress in cardiovascular surgery and suggest the possible role of highly bioavailable terpene constituents of the drug.     

Anticlastogenic effect of Ginkgo biloba extract in Graves' disease patients receiving radioiodine therapy

BACKGROUND: Chromosomal damage, as assessed by clastogenic factors (CFs) and micronuclei (MN) appearance, after radioiodine therapy of Graves' disease has been reported. OBJECTIVE AND METHODS: Our objective was to evaluate the effect of Ginkgo biloba extract (EGb 761) supplementation on the time course (up to 120 d) of CFs and MN appearance in lymphocytes from patients with Graves' disease after iodine-131 ((131)I) therapy. Patients were randomly assigned to EGb 761 or placebo, in a blinded manner. RESULTS: In the placebo group, MN increased early (P < 0.001) after (131)I, peaking at the 21st day (P = 0.0003) and declining thereafter. In EGb 761-treated patients, MN increased early (P < 0.05), while returning toward baseline value thereafter. Therefore, mean MN increment was significantly higher in the placebo group as compared with EGb 761-treated patients (P < 0.01). Moreover, an early (P < 0.0001) and sustained (up to 35 d; P < 0.001) MN increase induced by CFs was observed in the placebo group. Conversely, in EGb 761-treated patients, MN increase induced by CFs never reached the statistical significance; therefore, the mean of the MN increments was significantly lower than in placebo (P < 0.05). A significant positive correlation between MN maximum increment and the bone marrow dose was observed in the placebo group only (P = 0.03). No significant difference was observed in clinical outcome between the two groups. CONCLUSIONS: EGb 761 supplementation neutralized genotoxic damage induced by radioiodine treatment, without affecting the clinical outcome. Although (131)I therapy is generally safe, our data suggest that Gingko biloba extracts may prevent genetic effects of radioiodine therapy for hyperthyroid Graves' disease.     

Interleukin-6 and Tumor Necrosis Factor-α Clearance and Metabolism In Vivo and by the Isolated, Perfused Liver in the Rat: Effect of Acute Alcohol Administration

Plasma clearance and organ distribution of intravenously injected human recombinant [¹²⁵I]interleukin (IL)-6 and [¹²⁵I]tumor necrosis factor (TNF)-α were studied in male rats, 2 hr after intravenous alcohol (ethanol) administration (single dose, 2.2 g · kg^-1 body weight). Also, the rate of uptake and degradation of the two cytokines by the isolated, perfused rat liver was studied in the absence or in the presence of ethanol (35 mM) in the perfusate. Acute ethanol administration significantly increased plasma clearance rate for both cytokines (36% and 72%, for IL-6 and TNF-α, respectively), decreased the t_1/2α (30% and 11%, for IL-6 and TNF-α, respectively), abolished the slow (β)-phase component for TNF-α, and increased t_1/2β for IL-6 (31%). Although alcohol did not affect organ distribution of TNF-α, it increased the IL-6 content in the liver, kidney, and blood. IL-6 uptake rate by the isolated, perfused rat liver was 2-fold higher than TNF-α uptake, whereas the rate of degradation was larger for TNF-α than for IL-6, despite the fact that both cyokines were presented to the liver at the same concentration (6 nM). Ethanol addition to the perfusate (35 mM, final concentration) significantly increased TNF-α uptake (24%), without affecting IL-6 uptake or the degradation rate of either cytokine. Also, the kinetics of degradation by the isolated, perfused rat liver was linear for TNF-α, but exponential for IL-6. Data presented in this study demonstrate that: (1) acute alcohol consumption can alter the kinetic behavior of IL-6 and TNF-α in the bloodstream, mainly by accelerating their clearance which, in turn, may counteract the outcome of cytokine secretion and delivery to the blood; and (2) short exposure of liver to ethanol levels commonly seen in humans after binge drinking may alter its capacity to take up cytokines.