褪黑素对烫伤大鼠脑组织抗氧化能力与星形胶质细胞的影响

目的 观察褪黑素(melatonin,MT)对烫伤大鼠脑组织GSH、SOD与MDA含量与星形胶质细胞的影响,以探讨烫伤后MT的神经保护机制.方法 随机将30只SD大鼠,分为正常对照组、烫伤组和MT治疗组;MT治疗组在烫伤后10 min,3 h分别给予MT (10 mg/kg)腹腔注射治疗,对照组与烫伤组给予等量体积的生理盐水.MT治疗结束后1 h取脑行GSH、SOD与MDA含量检测,然后取额叶皮质行GFAP免疫组化染色,光镜下观察星形胶质细胞的形态变化并进行计量分析.结果 与正常对照组相比,烫伤组大鼠脑组织GSH含量下降,而SOD与MDA含量增加,GFAP阳性神经元增多(P<0.05).与烫伤组相比,MT治疗组大鼠脑组织GSH含量增加,SOD与MDA含量下降,GFAP阳性神经元减少 (P<0.05).结论 烫伤后早期应用MT治疗,可以改善机体的氧化应激水平和神经系统的继发性损伤.     

Crocin ameliorates methotrexate-induced liver injury via inhibition of oxidative stress and inflammation in rats

BackgroundMethotrexate (MTX) is used commonly in the treatment of various cancers and inflammatory diseases; nevertheless, the associated hepatotoxicity has limited its clinical application. Crocin (CRO) is described as a natural carotenoid with analgesic, antioxidant, and antiinflammatory properties. This study aimed to determine the effects of CRO on MTX-induced hepatotoxicity.MethodsFor pretreatment, CRO at doses of 25 and 50 mg/kg (po), as well as 20 mg/kg (ip) of MTX, was injected in rats.ResultsMTX led to hepatotoxicity, as confirmed by the significant increase in liver markers, histopathological changes, decreased GSH content, and reduced antioxidant enzyme activity (i.e., CAT, SOD, and GPx). It increased TNF-α, IL-1β, lipid peroxidation, and nitric oxide levels. Nevertheless, by increasing antioxidant defense in hepatic tissues and reducing oxidative stress and proinflammatory mediators, pretreatment with CRO could alleviate hepatotoxicity.ConclusionCRO can inhibit MTX-induced hepatotoxicity through improving antioxidant defense and reducing oxidative stress and inflammation.     

Cytotoxicity,oxidative stress and inflammation induced by ZnO nanoparticles in endothelial cells: interaction with palmitate or lipopolysaccharide

Recent studies showed that ZnO nanoparticles (NPs) might induce the toxicity to human endothelial cells. However, little is known about the interaction between ZnO NPs and circulatory components, which is likely to occur when NPs enter the blood. In this study, we evaluated ZnO NP‐induced cytotoxicity, oxidative stress and inflammation in human umbilical vein endothelial cells (HUVECs), with the emphasis on the interaction with palmitate (PA) or lipopolysaccharide (LPS), because PA and LPS are normal components in human blood that increase in metabolic diseases. Overall, ZnO NPs induced cytotoxicity and intracellular reactive oxygen species (ROS) at a concentration of 32 μg ml⁻¹, but did not significantly affect the release of inflammatory cytokines or adhesion of THP‐1 monocytes to HUVECs. In addition, exposure to ZnO NPs dose‐dependently promoted intracellular Zn ions in HUVECs. PA and LPS have different effects. Two hundred μm PA significantly induced cytotoxicity and THP‐1 monocyte adhesion, but did not affect ROS or release of inflammatory cytokines. In contrast, 1 μg ml⁻¹ LPS significantly induced ROS, release of inflammatory cytokines and THP‐1 monocyte adhesion, but not cytotoxicity. The presence of ZnO NPs did not significantly affect the toxicity induced by PA or LPS. In addition, the accumulation of Zn ions after ZnO NP exposure was not significantly affected by the presence of PA or LPS. We concluded that there was no interaction between ZnO NPs and PA or LPS on toxicity to HUVECs in vitro . Copyright © 2016 John Wiley & Sons, Ltd.     

Intravitreal thalidomide ameliorates inflammation in a model of experimental uveitis induced by BCG

Uveitis encompasses a heterogeneous and complex group of conditions characterized by intraocular inflammation, frequently affecting young individuals and representing an important cause of irreversible blindness worldwide. Animal models have been critical to understand etiology and pathogenesis of uveitis, being also employed to assess new therapeutic strategies, preceding human studies. However, there is still a need of developing and studying different models, due to the difficulties in recapitulating all forms of human uveitis effectively. Although corticosteroids are usually the first-line therapy for non-infectious uveitis, their long-term use is limited by potentially serious side effects in all possible delivery routes. Thus, thalidomide, a drug with anti-inflammatory and antiangiogenic properties, was investigated in a novel experimental model of uveitis, induced by Mycobacterium bovis Calmette-Guérin Bacillus (BCG), in rabbits. The experimental protocol consisted of two subcutaneous injections of BCG, followed by two intravitreal injections of the same antigen, inducing panuveitis. Animals were treated with a single intravitreal injection of thalidomide suspension or PBS. Clinical manifestations of uveitis improved after intravitreal thalidomide, involving both anterior and posterior segments. Protein content, N-acetyl-b-glucosaminidase (NAG) and myeloperoxidase (MPO) activities were elevated in ocular tissues after disease induction, further decreasing post-treatment with intravitreal thalidomide. This therapeutic response was also confirmed on ocular electrophysiology, as well as histopathology. This experimental model induced panuveitis in rabbits using a low-cost mycobacterial antigen, with intraocular inflammation subsequently improving after treatment. Intravitreal thalidomide may be a potential alternative to treat intraocular inflammation in corticosteroid-sparing therapies.     

脂多糖加速饮食所致非酒精性脂肪肝小鼠的炎症和氧化应激

目的本研究旨在探讨脂多糖在非酒精性肝炎(NASH)模型中的作用。方法采用胆碱蛋氨酸缺乏(Methionine choline deficient,MCD)饮食诱导的小鼠NASH模型。18只雄性C57BL/6小鼠分为3组,MCS+Saline组给予正常饮食+腹腔生理盐水,MCD+Saline组给予胆碱蛋氨酸缺乏饮食+腹腔注射生理盐水,MCD+LPS组给予胆碱蛋氨酸缺乏饮食+腹腔注射1 mg/kg脂多糖,共2周。在最后一次注射的6 h之后处死小鼠,取血清和肝组织。进行肝脏HE染色和Sirius Red染色,观察肝组织病理学变化。并测定血清中血清丙氨酸氨基转移酶(ALT)和肿瘤坏死因子-α(TNF-α)的含量。结果 MCD造成小鼠肝脏中大量脂肪滴的沉积和炎症细胞浸润,血清ALT升高,脂多糖注射进一步加重肝细胞凋亡,肝脏中TBARS进一步升高,血清TNF-α含量显著增加。结论在MCD所致非酒精性脂肪肝炎模型小鼠中,腹腔注射脂多糖引起血清中TNF-α升高,进一步加重细胞凋亡,因此,脂多糖在非酒精性脂肪肝炎的进程中具有重要作用,提示临床预防或治疗非酒精性脂肪肝炎需要关注患者肠道菌群失调症状。     

Selenium ameliorates arsenic induced oxidative stress through modulation of antioxidant enzymes and thiols in rice (Oryza sativa L.)

Arsenic (As) contamination of rice is a major problem for South-East Asia. In the present study, the effect of selenium (Se) on rice (Oryza sativa L.) plants exposed to As was studied in hydroponic culture. Arsenic accumulation, plant growth, thiolic ligands and antioxidative enzyme activities were assayed after single (As and Se) and simultaneous supplementations (As + Se). The results indicated that the presence of Se (25 µM) decreased As accumulation by threefold in roots and twofold in shoots as compared to single As (25 µM) exposed plants. Arsenic induced oxidative stress in roots and shoots was significantly ameliorated by Se supplementation. The observed positive response was found associated with the increased activities of ascorbate peroxidase (APX; EC 1.11.1.11), catalase (CAT; EC 1.11.1.6) and glutathione peroxidase (GPx; EC 1.11.1.9) and induced levels of non-protein thiols (NPTs), glutathione (GSH) and phytochelatins (PCs) in As + Se exposed plants as compared to single As treatment. Selenium supplementation modulated the thiol metabolism enzymes viz., γ-glutamylcysteine synthetase (γ-ECS; EC 6.3.2.2), glutathione-S-transferase (GST; EC 2.5.1.18) and phytochelatin synthase (PCS; EC 2.3.2.15). Gene expression analysis of several metalloid responsive genes (LOX, SOD and MATE) showed upregulation during As stress, however, significant downregulation during As + Se exposure as compared to single As treatment. Gene expressions of enzymes of antioxidant and GSH and PC biosynthetic systems, such as APX, CAT, GPx, γ-ECS and PCS were found to be significantly positively correlated with their enzyme activities. The findings suggested that Se supplementation could be an effective strategy to reduce As accumulation and toxicity in rice plants.     

芍药苷通过调控硫氧还蛋白结合蛋白表达对脂多糖诱导的肾小球系膜细胞氧化应激及凋亡的影响

目的 探讨芍药苷对脂多糖(LPS)诱导的肾小球系膜细胞氧化应激及凋亡的影响及其作用机制.方法 研究起止时间为2018年1月至2019年7月,体外培养人肾小球系膜细胞(HMCL),用不同浓度的(5、10、20μmol/L)芍药苷处理LPS诱导的HMCL细胞.采用流式细胞仪检测细胞凋亡率;应用试剂盒检测细胞中丙二醛(MDA)量及超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性;实时荧光定量聚合酶链反应(qRT-PCR)与蛋白质迹法(Western blotting)分别检测硫氧还蛋白结合蛋白(Thioredoxin-interacting protein,TXNIP)表达;观察干扰TXNIP的表达对LPS诱导的HMCL细胞氧化应激与凋亡的影响.结果 与对照组(Con)比较,LPS组细胞凋亡率升高[(6.58±0.66)％比(28.41±2.83)％](P<0.05),MDA含量增加[(1.26±0.13)nmol/L比(5.06±0.49)nmol/L](P<0.05),SOD[(26.41±2.31)U/mL比(12.46±1.21)U/mL]、GSH-Px[(45.61±4.13)U/mL比(8.12±0.83)U/mL]活性下降(P<0.05),TXNIP信使RNA(mRNA)及蛋白表达升高[(1.02±0.09)vs(2.54±0.25);(0.42±0.04)比(0.87±0.05)](P<0.05);与LPS组比较,芍药苷不同剂量组细胞凋亡率降低[(28.41±2.83)％比(22.16±2.17)/(16.48±1.03)/(11.25±1.12)％](P<0.05),MDA含量下降[(5.06±0.49)nmol/L比(4.12±0.41)/(2.94±0.29)/(1.68±0.17)nmol/L](P<0.05),SOD[(12.46±1.21)U/mL比(15.46±1.52)/(18.24±1.63)/(22.54±2.03)U/mL]、GSH-Px[(8.12±0.83)U/mL比(17.62±1.74)/(26.14±2.63)/(39.44±3.25)U/mL]活性升高(P<0.05),TXNIP mRNA及蛋白表达降低[(2.54±0.25)比(2.13±0.21)/(1.84±0.17)/(1.46±0.15);(0.87±0.05)比(0.72±0.05)/(0.61±0.04)/(0.49±0.03)](P<0.05);干扰TXNIP的表达可减轻LPS诱导的HMCL细胞氧化应激损伤,降低细胞凋亡率;TXNIP过表达可逆转芍药苷对LPS诱导的HMCL细胞氧化应激及凋亡的作用.结论 芍药苷可通过抑制TXNIP的表达对LPS诱导的HMCL细胞氧化应激发挥保护作用,抑制细胞凋亡.     

Effect of quercetin on lipopolysaccharide induced-sickness behavior and oxidative stress in rats

Objectives:

Gram-negative infections and control infusion of recombinant cytokines in human have been shown to induce sickness behavior characterized by fever, prolong sleep, decreased food and water intake, reduced mobility, depression, and anxiety. Therefore, the present study was undertaken to investigate the effect of bioflavonoid quercetin in lipopolysaccharide (LPS)-induced sickness behavior.

Materials and Methods:

Wistar albino rats were divided into six groups (n=6). Three groups received vehicle and two doses of quercetin (2 and 25 mg/kg, i.p.) respectively for 2 weeks before being challenged with LPS (1 mg/kg, i.p). One group received vehicle for 2 weeks and was challenged with saline on day 15. The per se effect of quercetin (2 and 25 mg/kg, i.p.) was also seen after 2 weeks of dosing. LPS-induced sickness behavior in rats was quantified by measuring time in social exploration, anxiety, food and water consumption, and weight loss. Levels of cytokines (TNF-α, IL-1β, and IL-6) and oxidative stress in rat brain were also analyzed.

Results:

Quercetin (2 and 25 mg/kg) administration significantly (P<0.05) attenuated LPS-induced sickness behavior by modulating cytokines production as well inhibiting LPS-induced oxidative stress.

Conclusions:

Adequate intake of dietary flavonoids (like quercetin) may help promote recovery from sickness behavior.     

Barrier protective effects of rutin in LPS-induced inflammation in vitro and in vivo

Rutin, an active flavonoid compound, is well known to possess potent antiplatelet, antiviral and antihypertensive properties. In this study, we first investigated the possible barrier protective effects of rutin against pro-inflammatory responses in human umbilical vein endothelial cells (HUVECs) induced by lipopolysaccharide (LPS) and the associated signaling pathways. The barrier protective activities of rutin were determined by measuring permeability, monocytes adhesion and migration, and activation of pro-inflammatory proteins in LPS-activated HUVECs. We found that rutin inhibited LPS-induced barrier disruption, expression of cell adhesion molecules (CAMs) and adhesion/transendothelial migration of monocytes to human endothelial cells. Rutin also suppressed acetic acid induced-hyperpermeability and carboxymethylcellulose-induced leukocytes migration in vivo. Further studies revealed that rutin suppressed the production of tumor necrosis factor-α (TNF-α) and activation of nuclear factor-κB (NF-κB) by LPS. Collectively, these results suggest that rutin protects vascular barrier integrity by inhibiting hyperpermeability, expression of CAMs, adhesion and migration of leukocytes, thereby endorsing its usefulness as a therapy for vascular inflammatory diseases.     

Regulation of c-fos and c-jun gene expression by lipopolysaccharide and cytokines in primary cultured astrocytes: effect of PKA and PKC pathways

The effects of lipopolysaccharide (LPS) and several cytokines on the c-fos and c-jun mRNA expression were examined in primary cultured astrocytes. Either LPS (500 ng/mL) or interferon-gamma (IFN-gamma; 5 ng/mL) alone increased the level of c-fos mRNA (1 h). However, tumor necrosis factor-alpha (TNF-alpha; 10 ng/mL) or interleukin-1beta (IL-1beta; 5 ng/mL) alone showed no significant induction of the level of c-fos mRNA. TNF-alpha showed a potentiating effect in the regulation of LPS-induced c-fos mRNA expression, whereas LPS showed an inhibitory action against IFN-gamma-induced c-fos mRNA expression. LPS, but not TNF-alpha, IL-1beta and IFN-gamma, increased the level of c-jun mRNA (1 h). TNF-alpha and IFN-gamma showed an inhibitory action against LPS-induced c-jun mRNA expression. Both phorbol 12-myristate 13-acetate (PMA; 2.5 mM) and forskolin (FSK; 5 mM) increased the c-fos and c-jun mRNA expressions. In addition, the level of c-fos mRNA was expressed in an antagonistic manner when LPS was combined with PMA. When LPS was co-treated with either PMA or FSK, it showed an additive interaction for the induction of c-jun mRNA expression. Our results suggest that LPS and cytokines may be actively involved in the regulation of c-fos and c-jun mRNA expressions in primary cultured astrocytes. Moreover, both the PKA and PKC pathways may regulate the LPS-induced c-fos and c-jun mRNA expressions in different ways.     

秦皮甲素减轻脂多糖刺激小鼠急性肾损伤和炎症反应的作用及其机制（英文）

急性肾损伤是临床常见的严重疾病。秦皮甲素是一种香豆素类化合物,前期研究发现秦皮甲素对糖尿病大鼠肾脏损伤具有保护作用,本研究旨在探讨秦皮甲素对脂多糖(LPS)致小鼠急性肾损伤的作用及其可能机制。H&E染色观察肾脏形态;测定血尿素氮(BUN)水平和血清肌酐含量评价肾功能;ELISA法检测炎症因子水平;RT-PCR和Western blotting分析炎症蛋白表达水平。结果表明,ES可减轻LPS所致的病理损伤和肾功能损伤,降低血清BUN水平和肌酐含量;此外, ES显著降低肾组织中IL-1β、IL-6和TNF-α、趋化因子MCP-1和细胞黏附分子ICAM-1等的释放。进一步研究发现,秦皮甲素在m RNA水平和蛋白水平下调LPS导致的小鼠肾组织中炎症通路蛋白P2X7、HMGB1、TLR4和MyD88的表达。以上结果表明,秦皮甲素对LPS刺激所致急性肾损伤具有保护作用,抑制炎症反应与下调P2X7和HMGB1/TLR4炎症通路相关。     

Protective effects of polydatin in free and nanocapsulated form on changes caused by lipopolysaccharide in hippocampal organotypic cultures

BackgroundPolydatin (PD) is a compound, originally isolated from the root and rhizome of the Chinese herb Polygonum cuspidatum. To date, various biological properties of this compound, such as analgesic, anti-pyretic or diuretic effects, have been shown. Recently, anti-oxidant and anti-inflammatory properties have been widely postulated, yet PD instability and low bioavailability limit its beneficial actions. Therefore, it has been suggested that an encapsulation process may be a promising strategy for overcoming these limitations and increasing the therapeutic efficacy of PD.MethodsWe examined the effects of PD in two forms, including free and in PD-loaded polymeric nanocapsules, on lipopolysaccharide (LPS)-induced changes in hippocampal organotypic cultures.ResultsOur results indicated that free and encapsulated PD diminished cell death processes and attenuated the secretion of pro-inflammatory cytokines induced by LPS administration. Additionally, PD in both forms strongly inhibited the production of nitric oxide and down-regulated the level of iNOS enzyme in LPS-stimulated hippocampal cultures.ConclusionTaken together, our study showed that PD exerts anti-inflammatory and anti-oxidant properties in LPS-treated hippocampal organotypic cultures. Furthermore, we show that the encapsulation procedure preserved the features of the free form of this compound, and therefore, the polymeric nanocapsules containing PD may be used as a novel and promising delivery system in therapeutic strategies.     

IDH2 gene deficiency accelerates unilateral ureteral obstruction-induced kidney inflammation through oxidative stress and activation of macrophages

Mitochondrial NADP⁺-dependent isocitrate dehydrogenase 2 (IDH2) produces NADPH, which is known to inhibit mitochondrial oxidative stress. Ureteral obstruction induces kidney inflammation and fibrosis via oxidative stress. Here, we investigated the role and underlying mechanism of IDH2 in unilateral ureteral obstruction (UUO)-induced kidney inflammation using IDH2 gene deleted mice (IDH2^–/–). Eight- to 10-week-old female IDH2^–/– mice and wild type (IDH2^+/+) littermates were subjected to UUO and kidneys were harvested 5 days after UUO. IDH2 was not detected in the kidneys of IDH2^–/– mice, while UUO decreased IDH2 in IDH2^+/+ mice. UUO increased the expressions of markers of oxidative stress in both IDH2^+/+ and IDH2^–/– mice, and these changes were greater in IDH2^–/– mice compared to IDH2^+/+ mice. Bone marrow-derived macrophages of IDH2^–/– mice showed a more migrating phenotype with greater ruffle formation and Rac1 distribution than that of IDH2^+/+ mice. Correspondently, UUO-induced infiltration of monocytes/macrophages was greater in IDH2^–/– mice compared to IDH2^+/+ mice. Taken together, these data demonstrate that IDH2 plays a protective role against UUO-induced inflammation through inhibition of oxidative stress and macrophage infiltration.     

A lipopolysaccharide and concanavalin A induce variations of serotonin levels in mouse tissues

The administration of an Escherichia coli lipopolysaccharide (LPS), or an endotoxin into mice produced a variation in tissue serotonin (5HT) levels within 4.5 h. 5HT levels in the kidney and lung were decreased by the higher doses of LPS, but those in the liver and spleen were increased even by lower doses of the agent. The increase in liver 5HT was most marked. Such variations in 5HT levels were also produced by the administration of concanavalin A. In vitro experiments using extracts from livers of LPS-treated and non-treated mice indicated that there was no difference in the 5HT formation from 5-hydroxytryptophan between the two groups, but that 5HT formation from tryptophan was higher in the LPS-treated mice. The LPS-induced 5HT increase in liver was suppressed by p-chlorophenylalanine (an inhibitor of tryptophan hydroxylase), actinomycin D, cycloheximide and dexamethasone, but not by Ro 4-4602 (an inhibitor of aromatic amino acid decarboxylase), pargyline (an inhibitor of monoamine oxidase) and indomethacin. A possible mechanism of the 5HT increase in the liver is discussed on the basis of these results.     

Catalpol ameliorates cognition deficits and attenuates oxidative damage in the brain of senescent mice induced by D-galactose

The neuroprotective effects of catalpol, an iridoid glycoside isolated from the fresh Rehmannia roots, on the senescent mice induced by D-galactose were assessed. The mice subcutaneously injected with catalpol (5 or 10 mg/kg, 2 weeks, from fifth week) showed significantly improved learning and memory ability in Morris water maze test compared with d-galactose treated mice (150 mg/kg, 6 weeks). We further investigated the mechanism involved in the neuroprotective effects of catalpol on the mice brain tissue. The results showed that catalpol increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), decreased the malondialdehyde (MDA) level, elevated the activities of Na+ -K+ ATPase and Ca2+ -Mg2+ ATPase on the cerebral cortex and hippocampus of d-galactose treated mouse. All the data suggested that catalpol had the potential to be a useful cognitive impairment treatment, and its beneficial effects may be partly mediated via enhancing endogenous antioxidant enzymatic activities and inhibiting free radical generation.     

Melatonin alleviates memory deficits and neuronal degeneration induced by intracerebroventricular administration of streptozotocin in rats

In the present study the effect of melatonin on intracerebroventricularly administered streptozotocin (STZ)-induced neurodegeneration was investigated in rats. STZ (3 mg/kg), administered twice with an interval of 48 h between the two doses, showed impairment in spatial memory tested by water maze test after 14 days of 1st dose. Administration of melatonin (2.5, 5.0 and 10 mg/kg, i.p.) was started 1 h prior to 1st dose of STZ and continued up to 14 days. Glutathione and malondialdehyde were used as biochemical markers of oxidative stress in different brain regions. Histopathological changes were examined by using hematoxylin and eosin stain. STZ administration caused significant decrease in glutathione and increase in malondialdehyde as compared to control and artificial Cerebrospinal Fluid treated rats indicating oxidative stress. Brain sections of STZ-treated rats showed increased vacuoles in the periventricular cortical area, damaged periventricular cells and damaged cells in the hippocampal CA4 region as compared to control and artificial Cerebrospinal Fluid treated groups. Melatonin treatment significantly attenuated the effect of STZ-induced oxidative stress and histopathological changes. The results indicate that melatonin is effective in providing protection against memory deficit, oxidative stress and neuronal damage induced by STZ.     

Interactions of deoxynivalenol and lipopolysaccharides on cytokine excretion and mRNA expression in porcine hepatocytes and Kupffer cell enriched hepatocyte cultures

The effects of deoxynivalenol (DON) on the mRNA expression of cytokines and inflammation-related genes, as well as the cytokine secretion of porcine hepatocytes and Kupffer cell enriched hepatocyte cultures (co-cultures), were investigated in the absence or presence of LPS.DON and LPS acted in a synergistic manner with regard to a significantly increased mRNA expression of TNF-α in hepatocytes exposed to 500 nM or 2000 nM DON, or non-significant increase in co-cultures after 3 h of exposure. TNF-α supernatant concentrations were increased due to LPS but did not reflect the synergistic effects with DON as observed at mRNA level. IL-6 mRNA in hepatocyte cultures at 6 h paralleled the TNF-α supernatant pattern at this time point. In co-cultures and hepatocytes, a DON dose dependent induction of IL-6 mRNA was detected in cells not exposed to LPS. Supernatant concentrations of LPS-induced IL-6 were significantly decreased by 2000 nM DON in both types of cell cultures. Also the mRNA expression of the anti-inflammatory IL-10 was increased by DON to various degrees depending on DON-dose, stimulation with LPS and time point of measurement. After 6 h, expression of iNOS was only induced by 2000 nM DON, but not in LPS treated cells.Even if mRNA induction was not paralleled by related supernatant concentrations of TNF-α, IL-6 and IL-10 under the conditions of the present investigations, it was clearly demonstrated that DON has the potential to provoke and modulate immunological reactions of porcine liver cells.     

Mycotoxin-induced depletion of intracellular glutathione and altered cytokine production in the human alveolar epithelial cell line A549

Mould exposure has been associated with asthma and other inflammatory airway conditions. However, cellular effects of inhaled mould components are not well understood. We hypothesised that host defence mechanisms, such as production of cytokines (TGFbeta1, IL-6 and IL-8) and the intracellular antioxidant glutathione (GSH), could be adversely affected by different concentrations of mycotoxins. We studied the effects of citrinin and gliotoxin on lipopolysaccharide (LPS)-stimulated alveolar epithelial cells (A549). Cytokines in cell culture supernatants were analysed by ELISA and levels of GSH were measured by colorimetric (absorbance) determination. We found that GSH decreased in a dose- and time-dependent manner when cells were exposed to citrinin in particular. TGFbeta1 was moderately reduced at low mycotoxin concentrations but elevated at higher sub-toxic concentrations. A tendency for an inverse relationship between TGFbeta1 and GSH levels was observed. IL-6 and IL-8 were not significantly reduced at non-toxic mycotoxin concentrations. Thus, reduced epithelial GSH and TGFbeta1 levels combined with elevated IL-6 and IL-8 levels may result in increased pro-inflammatory activity during mycotoxin exposure. We suggest that this mechanism can contribute to inflammation in mould exposure.     

Ursolic acid ameliorates cognition deficits and attenuates oxidative damage in the brain of senescent mice induced by D-galactose

Ursolic acid (UA), a pentracyclic triterpene, is reported to have an antioxidant activity. Here we assessed the protective effect of UA against the d-galactose (D-gal)-induced neurotoxicity. We found that UA markedly reversed the D-gal induced learning and memory impairment by behavioral tests. The following antioxidant defense enzymes were measured: superoxide dismutases (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione reductase (GR). The content of the lipid peroxidation product malondialdehyde (MDA) was also analyzed. Our results indicated that the neuroprotective effect of UA against D-gal induced neurotoxicity might be caused, at least in part, by the increase in the activity of antioxidant enzymes with a reduction in lipid peroxidation. And UA also inhibited the activation of caspase-3 induced by D-gal. Furthermore, we found that UA significantly increased the level of growth-associated protein GAP43 in the brain of D-gal-treated mice. These results suggest that the pharmacological action of UA may offer a novel therapeutic strategy for the treatment of age-related conditions.