Inhibitory effects of nitric oxide and interleukin-10 on production of tumor necrosis factorα,interleukin-1β,and interleukin-6 in mouse alveolar macrophages

目的：观察一氧化氮和ＩＬ１０对肺泡巨噬细胞炎症反应的调节作用．方法：小鼠肺泡巨噬细胞（ＡＭ）受脂多糖（ＬＰＳ）１０ｍｇ·Ｌ－１刺激同时,加入一氧化氮合酶抑制剂Ｓ硫酸甲基异硫脲（ＳＭＴ）或一氧化氮供体Ｓ亚硝基乙酰青霉胺（ＳＮＡＰ）．ＥＬＩＳＡ法测定上清液中ＴＮＦα、ＩＬ１β、ＩＬ６和ＩＬ１０浓度．结果：ＡＭ受ＬＰＳ刺激后,ＴＮＦα、ＩＬ１β和ＩＬ６释放峰值分别在６、１２和２４小时．ＳＭＴ抑制一氧化氮释放,但促进ＩＬ１β和ＩＬ６释放,对ＴＮＦα无影响．ＳＮＡＰ对ＩＬ１β和ＩＬ６释放有明显的抑制作用,呈剂量依赖效应．重组ＩＬ１０抑制ＴＮＦα、ＩＬ１β和ＩＬ６释放,而ＩＬ１０单克隆抗体促进上述因子释放．结论：内源及外源性一氧化氮和ＩＬ１０均对ＬＰＳ诱导的炎症性细胞因子释放有抑制作用．     

Effect of MePEG molecular weight and particle size on in vitro release of tumor necrosis factor-α-loaded nanoparticles

Aim: To study the in vitro release of recombinant human tumor necrosis factoralpha (rHuTNF-α) encapsulated in poly (methoxypolyethyleneglycol cyanoacrylate-co-n-hexadecyl cyanoacrylate) (PEG-PHDCA) nanoparticles, and investigate the influence of methoxypolyethyleneglycol (MePEG) molecular weight and particle size. Methods: Three sizes (approximately 80, 170, and 240 nm) of PEGPHDCA nanoparticles loading rHuTNF-α were prepared at different MePEG molecular weights (Mr =2000, 5000, and 10 000) using the double emulsion method. The in vitro rHuTNF-α release was studied in PBS and rat plasma. Results: A higher burst-release and cumulative-release rate were observed for nanoparticles with higher MePEG molecular weight or smaller particle size. A decreased cumulative release of rHuTNF-α following the initial burst effect was found in PBS, while the particle sizes remained constant and MePEG liberated. In contrast, in rat plasma, slowly increased cumulative-release profiles were obtained after the burst effect. During a 5-h incubation in rat plasma, more than 50% of the PEGPHDCA nanoparticles degraded. Conclusion: The MePEG molecular weight and particle size had an obvious influence on rHuTNF-α release, rHuTNF-α released from PEG-PHDCA nanoparticles in a diffusion-based pattern in PBS, but in a diffusion and erosion-controlled manner in rat plasma.     

Effect of gliclazide modified release on adiponectin,interleukin‐6, and tumor necrosis factor‐α plasma levels in individuals with type 2 diabetes mellitus

ABSTRACT

Objective: The aim of the study was to evaluate the effect of gliclazide modified release (MR) treatment on adiponectin, interleukin 6 (IL-6), and tumor necrosis factor-α (TNF‐α) plasma concentrations in type 2 diabetic patients.

Research design and methods: 24 randomly selected type 2 diabetic patients, aged 61.2 ± 15.4 years, with poorly controlled glucose level (mean glycated hemoglobin [HbA_1c] 7.6 ± 1.1%) despite treatment with diet and/or oral hypoglycemic agents, were included in the study. All of the patients, after a 2‐week run-in period, were given gliclazide MR for 12 weeks. At baseline, and after gliclazide MR treatment, HbA_1c and plasma concentrations of IL‐6, TNF‐α, and adiponectin were measured.

Results: Gliclazide MR treatment produced significant reductions in fasting plasma glucose (from 7.6 ± 1.4 to 6.6 ± 1.2?mmol/L, p < 0.01), HbA_1c (from 7.6 ± 1.1 to 6.9 ± 0.8%, p < 0.01), and plasma IL‐6 concentrations (from 2.5 ± 1.8 to 1.8 ± 1.2?pg/mL, p < 0.05). A significant increase in plasma adiponectin level was noted (from 6.4 ± 3.3 to 7.6 ± 4.4?µg/mL, p < 0.05). Plasma TNF‐α concentrations and homeostasis model assessment of insulin resistance (HOMA‐IR) decreased after treatment, but these changes did not reach statistical significance.

Conclusions: Gliclazide MR improves glycemic control and, in addition, has a positive influence on the plasma level of some inflammatory markers and adiponectin. Increased plasma adiponectin and decreased plasma IL‐6, and TNF‐α levels may explain, at least in part, the anti-atherogenic action of this drug reported elsewhere.     

Aminoguanidine and curcumin attenuated tumor necrosis factor (TNF)-α-induced oxidative stress, colitis and hepatotoxicity in mice

The up regulation of gut mucosal cytokines such as tumor necrosis factor (TNF)-α and oxidative stress have been related to inflammatory bowel diseases (IBD) such as ulcerative colitis (UC) and Crohn's disease (CD). This study investigated an immune-mediated model of colitis. TNF-α injected intraperitonally to mice induced a dose-dependent recruitment of neutrophils into abdominal mesentery. The leukocytes influx induced by TNF-α (10 μg kg(-1) body weight) increased by 3 fold liver and colon damage scores. TNF-α-colitis was characterized by hemorrhagic edemas and crypt abscesses massively infiltrated by inflammatory cells, namely neutrophils. Moreover, TNF-α-toxicity resulted in liver steatosis and foci of necrosis infiltrated by Kupffer cells and neutrophils in parenchyma and around the centrilobular veins. The involvement of oxidative stress was evaluated using aminoguanidine (AG) as selective inhibitor of inducible NO synthase (iNOS) and curcumin (Cur), the polyphenolic antioxidant of turmeric (Curcuma longa L.). TNF-α-toxicity led to significant increase in myeloperoxidase (MPO, an index of neutrophils infiltration), nitrites (stable nitric oxide metabolites) and malondialdehyde (MDA, a marker of lipid peroxides) levels and cell apoptosis in liver and colon. AG and Cur treatments significantly attenuated the hallmarks of oxidative stress, neutrophils influx and ROS-related cellular and histological damages, in TNF-α-treated mice. Taken together, our results provide insights into the role of phagocytes-derived oxidants in TNF-α-colitis in mice. Cur and AG, by inhibiting neutrophils priming and iNOsynthase could be effective against oxidative bowel damages induced in IBD by imbalanced gut immune response.     

Protective effect of hesperidin against γ-radiation induced oxidative stress in Sprague-Dawley rats

The high risk of human exposure to ionizing radiations during radiation therapy and also during space travel underscores the need to develop novel radioprotectors with improved efficacy. Increased oxidative stress and antioxidant deficit have been suggested to play a major role in radiation induced toxicity, and hence maintaining an antioxidant balance through dietary supplementation might provide beneficial effects during radiation exposure. The present study was designed to evaluate the effect of hesperidin, a flavanone glycoside found in citrus plants, on the antioxidant defense system and lipid peroxidation against γ-radiation induced damage in rats. Exposure of rats to γ-radiation (5 Gy) resulted in tissue damage characterized by significantly elevated levels of serum marker enzymes (AST, ALT, ALP, LDH, and CPK) and a decrease in their activities in the heart tissue. γ-Radiation induced oxidative stress was observed by elevated levels of lipid peroxidation and a decrease in the activities of endogenous antioxidants (SOD, CAT, GPx, and GSH) in the heart and kidney of rats. Post-treatment with hesperidin (50 and 100?mg/kg bw/day, orally) for 7 days following exposure to γ-radiation significantly attenuated these changes when compared to the radiation exposed groups. Histopathological examination of the heart tissue of rats exposed to γ-radiation and treated with hesperidin also showed minimal damage when compared to those exposed to γ-radiation alone. These findings indicate the protective effect of hesperidin on lipid peroxidation and the antioxidant tissue defense system during γ-radiation induced tissue damage in rats.     

Interleukin 8 modulates interleukin-1β, interleukin-6 and tumor necrosis factor-α release from normal human mononuclear cells

Recombinant human interleukin 8 (IL-8) enhanced the release of inflammatory cytokines including interleukin 1β (IL-1β), interleukin 6 (IL-6) and tumor necrosis factor-α (TNF-α) from normal human mononuclear cells in a dose-related manner (from 1 ng/ml to 10 ng/ml with a maximal effect at 5 ng/ml( when the cells incubated with IL-8 for 24 h. This cytokine-releasing activity of IL-8 is temperature-dependent and required protein synthesis since low temperature (4°C) and cycloheximide (100 μg/ml) minimized the cytokine release from MNC. However, when IL-8 concentration was greater than 20 ng/ml, the cytokine release was supressed. For further investigating the subcellular mechanism of the adverse effect of high dose IL-8 (20 ng/ml) in cytokine synthesis, human mononuclear cells (1 × 10⁶/ml) were stimulated with PHA (1 μg/ml) in the presence of 20 ng/ml IL-8 for 3 days. We found not only [³H]thymidine incorporation of MNC was tremendously inhibited but DNA fragmentation appeared. Subsequently, the cell cycle of PHA-stimulated MNC retarded in the phase of G₀/G₁. These results suggest that in low concentration (5–10 ng/ml) IL-8 not only activated neutrophil phagocytosis but facilitated the release of inflammatory cytokines from mononuclear cells. Higher dose of IL-8 (more than 20 ng/ml) conversely suppressed these cytokine release from damaged cells by its cytotoxic effect. This newly found cytokine-releasing activity of IL-8 may play a role in the modulation of inflammation.     

Effects of bilobalide on interleukin-1, tumor necrosis factor-α and nitric oxide production by rat microglia stimulated with lipopolysaccharides in vitro

The effects of bilobalide,a sesquiterpene isolated from Ginkgo biloba, on interelukin-1 (IL-l), tumor necrosis factor-α(TNF-α) and nitric oxide (NO) production in resting and lipopolysaccharide (LPS )-stimulated cultured neonatal rat microglia were studied. Apafant, a platelet activating factor (PAF) antagonist of triazolobenzodiazepine type was ttsed as control.The biological activities of IL-1 and TNF_α were tested     

Effects of dl-praeruptorin A on nucleus factor-κB and tumor necrosis factor-α expression in ischemia-reperfusion hearts

AIM: To study the effects of dl-praeruptorin A (Pd-Ia) on nucleus factor-κB (NF-κB) activativity and tumor necrosis factor-α(TNF-α)expression in ischemia-reperfusion (I/R) myocardium. METHODS: Langendorff's isolated rat heart was subjected to a 10-min ischemia followed by a 30-min reperfusion. NF-κB activity in nucleus was analyzed by Sandwich Enzyme-Linked Immunosorbent Assay (ELISA). TNF-α level in cytoplasm was measured by     

Effects of methione-enkaphalin on interleukin- 1, tumor necrosis factor-α and nitric oxide production from rat microglia stimulated with lipopolysaccharides

Methione-enkaphine (Met-Enk), an opioid pentapeptide with awide distribution in the central nervous system and peripheral tissue, was studied its effects on proinflamamtory cytokines, such as, interleukin-I (IL-1) and tumor necrosis factor-α(TNF-α) and nitric oxide (NO) which are involved in various physiopathological conditions in the CNS on rat microglia cultures. The biological activities of IL-1, TNF-α was tested by mouse thymocyte proliferation and L929 cytotoxity assay.NO levels were represented as nitrite concentration which is determined     

Molecular biomarkers of cantharidin-induced cardiotoxicity in Sprague-Dawley rats: Troponin T,vascular endothelial growth factor and hypoxia inducible factor-1α

Early diagnosis of cantharidin-induced myocardial injury is the key to reduce the fatality rate in clinical practice. The purpose of the present study was to explore biomarkers that can be used for the prediction and diagnosis of cantharidin-induced myocardial injury. Of 65 male Sprague-Dawley rats weighing 200-230 g, 25 rats were divided into five groups according to the administration dose of cantharidin (0, 1.34, 2.67, 4 and 5.34 mg/kg; n = 5 per group) and the other 40 rats were treated with 2.67 mg/kg cantharidin and divided into nine groups according to the administration time (0, 1, 2, 4, 6, 8, 12, 24, 48 and 72 hours; n = 4 per group). Pathological changes of hypoxia, necrosis and inflammation were confirmed in heart samples that were exposed to cantharidin by hematoxylin-eosin staining and overall scores of pathological changes among heart samples in cantharidin exposure groups showed an increasing trend compared with in the control group. Coexpression of vascular endothelial growth factor (VEGF), hypoxia inducible factor-1α (HIF-1α) and caspase9 was shown in the myocardium by immunofluorescence staining. Western blotting results showed that expression of VEGF, HIF-1α and caspase9 in cantharidin-treated rat hearts showed an increasing trend compared with in the control group. Results of enzyme-linked immunosorbent assay suggested that plasma levels of troponin T (TN-T), VEGF and HIF-1α were elevated at different intervals after cantharidin administration, and VEGF and HIF-1α had a significant linear relationship with TN-T that was verified by multiple linear regression analysis. Preliminary results serve to illustrate that TN-T, VEGF and HIF-1α might be valuable molecular markers in cantharidin-induced myocardial injury and that diagnostic accuracy needs to be studied further.     

Critical role of P-selectin-dependent rolling in tumor necrosis factor-α-induced leukocyte adhesion and extravascular recruitment in vivo

Leukocyte-endothelium interactions are dependent on a coordinated expression and function of specific adhesion molecules. The objective of the present study was to examine the role of selectin function and leukocyte rolling in tumor necrosis factor-alpha (TNF-alpha)-induced leukocyte adhesion and extravasation in venules in vivo. For this purpose, we used intravital microscopy in the mouse cremaster muscle stimulated for 2-3 h with TNF-alpha intrascrotally. Pretreatment with fucoidan, which inhibits P- and L-selectin, and a P-selectin monoclonal antibody (RB40.34) abolished TNF-alpha-stimulated leukocyte rolling. This great reduction in rolling caused a marked attenuation of firm adhesion and extravascular accumulation of leukocytes. When fucoidan and RB40.34 were administrated after stimulation with TNF-alpha, it was found that leukocyte rolling was greatly reduced whereas the number of firmly adherent leukocytes was completely unchanged, suggesting that the inhibitory effect of blocking P-selectin function on firm leukocyte adhesion and recruitment was due to the reduction in leukocyte rolling along the endothelium. Moreover, pretreatment with a monoclonal antibody against intercellular adhesion molecule-1 (ICAM-1) and a platelet-activating factor (PAF)-receptor antagonist had no effect of TNF-alpha-induced leukocyte rolling and adhesion, indicating that molecules other than ICAM-1 and PAF mediate firm adhesion and recruitment of leukocytes in TNF-alpha-activated tissues. Taken together, our data demonstrate that P-selectin function plays an important role in TNF-alpha-induced inflammatory cell recruitment by mediating leukocyte rolling as a precondition for cytokine-provoked firm adhesion and transmigration in vivo. These findings, thus, suggest that inhibition of P-selectin may be a central target for pharmacological intervention in inflammatory diseases.     

Effect of endogenous nitric oxide on tumour necrosis factor-α-induced leukosequestration and IL-8 release in guinea-pigs airways in vivo

1. Tumour necrosis factor-α (TNF-α) is implicated in the pathogenesis of many pulmonary and airway diseases. TNF-α stimulation may release interleukin-8 (IL-8) in airways mediated via an increase in intracellular oxidant stress. In the present study, we have assessed leukosequestration and IL-8 release in the airways in response to intratracheal administration of human recombinant TNF-α, and examined the modulatory role of endogenous NO by pretreatment with a NO synthase inhibitor N^ω-nitro-L-arginine methyl ester (L-NAME).
2. TNF-α (10²–10⁴ u) was administered intratracheally in male guinea-pigs which were anaesthetized with urethane and were ventilated artificially. TNF-α induced a time- and dose-related increase in neutrophil numbers and a concomitant increase in human IL-8 equivalent level retrieved from bronchoalveolar lavage (BAL) with the peak effect at 10³ u at 6 h of TNF-α injection (late phase). Intratracheal administration of recombinant human (rh)IL-8 (0.025, 0.25, 2.5 ng) producing a similar range of human IL-8 equivalent levels in BAL as measured in our results induced neutrophil recovery in BAL fluid to a similar extent. Administration of anti-IL-8 antibody prevented the late phase of neutrophil recruitment induced by TNF-α or rhIL-8.
3. Pretreatment with L-NAME significantly enhanced the TNF-α (10³ u)-induced neutrophil recruitment and human IL-8 equivalents production at 6 h, but not at 1 h of TNF-α administration (early phase). L-Arginine reversed the responses to L-NAME. Pretreatment with 0.2% DMSO (i.v.) significantly inhibited TNF-α-induced neutrophil recruitment and human IL-8 equivalents release both in the early and late phase of the responses. Pretreatment with DMSO also inhibited the enhancement effect of L-NAME on the late phase of TNF-α-induced responses. DMSO failed to modify exogenous rhIL-8-induced neutrophil recruitment. Neither L-NAME nor DMSO alone induced any significant change in neutrophil numbers or human IL-8 equivalent level in BAL fluid.
4. Neutrophil depletion by cyclophosphamide pretreatment failed to modify TNF-α-induced human IL-8 equivalent release.
5. The expression of β2-integrin, CD11b/CD18 on neutrophils was increased only in the late but not early phase of TNF-α stimulation. L-NAME failed to modify these responses.
6. In conclusion, we demonstrated that NO may be an important endogenous inhibitor of TNF-α-induced leukocyte chemotaxis via inhibition of IL-8 production. Thus, the production of NO in airway inflammatory diseases may play a negative feedback role in self-limiting the magnitude of inflammatory responses.

     

Protective effect of L-carnitine and coenzyme Q10 on CCl₄-induced liver injury in rats

This study provides an information about the mechanisms of liver injury induced by CCl(4), and determines the influence of administration of L-carnitine or/and CoQ10 as prophylactic agents against CCl(4) deteriorative effect. The study was carried out on 80 adult male albino rats divided into eight groups, 10 animals each, as follows: four normal groups (control, treated with L-carnitine, treated with CoQ10, and treated with a combination of Lcarnitine and CoQ10) and four liver injury groups treated with CCl(4) (control, treated with L-carnitine, treated with CoQ10, and treated with a combination of L-carnitine and CoQ10). Liver injury was induced by s.c. injection of a single dose of CCl(4) (1 ml/kg). L-carnitine (50 mg/kg/day) was given i.p. for four successive days 24 hours before CCl(4) injection, and CoQ10 (200 mg/kg) was given as a single i.p. dose 24 hours before CCl(4) injection. Animals were sacrificed 24 hours after CCl(4) injection, blood samples were withdrawn and liver tissue samples were homogenized. The levels of the following parameters were determined: hepatic reduced glutathione, serum ALT and AST, hepatic lipid peroxides, hepatic vitamin C, hepatic and serum total protein, serum albumin, serum sialic acid, serum nitrite, and serum and hepatic total LDH activities and LDH isoenzymes. The obtained data revealed that CCl(4) injection produced a significant decrease in reduced glutathione content, vitamin C, total protein and albumin levels. However, there was a significant increase in serum ALT and AST activities, lipid peroxides, sialic acid, nitric oxide, serum and hepatic total LDH activities. On the other hand, groups treated with L-carnitine or/and CoQ10 prior to CCl(4) injection showed an improvement in most parameters when compared with cirrhotic control group. It has been concluded that L-carnitine and coenzyme Q10 have a pronounced prophylactic effect against liver damage induced by halogenated alkanes such as carbon tetrachloride.     

The influence of mianserin on TNF-α, IL-6 and IL-10 serum levels in rats under chronic mild stress

BackgroundAntidepressants are known to affect the immunological system through mechanisms which are not completely understood. The aim of the present study was to evaluate the effect of the atypical antidepressant mianserin on the levels of tumor necrosis factor alpha (TNFα), interleukin-6 (IL-6) and interleukin-10 (IL-10) in the blood of rats in an experimental model of depression.MethodsMale Wistar rats were subjected to chronic mild stress (CMS) according to Willner's method for 6 weeks. Following the development of anhedonia, the stressed and control rats (non-stressed animals) were treated with mianserin (10 mg/kg ip, twice daily) for three weeks. On the last day of the experiment, a lipopolysaccharide (LPS, 100 μg/kg ip) was injected to mianserin- or vehicle-treated rats. TNFα, IL-6 and IL-10 levels in the blood of the rats were assayed using ELISA methods.ResultsThe results indicated a significantly increased TNFα level in stressed animals when compared with the non-stressed (control) group. The levels of IL-6 and IL-10 were also elevated, especially after LPS administration. Treatment with mianserin resulted in a significant lowering of TNFα and IL-6 levels both in LPS-treated and LPS-untreated animals. There was also a decrease in IL-10 concentration in LPS-treated stressed animals.ConclusionsThe results confirm an increase in proinflammatory cytokines in the blood of rats with experimentally induced depression and show the protective role of the activity of mianserin on the cytokine levels, expressed in a lowering of TNFα and IL-6 levels in stressed animals, and of IL-10 levels after LPS administration.     

Effects of carnosine on prooxidant–antioxidant status in heart tissue,plasma and erythrocytes of rats with isoproterenol-induced myocardial infarction

Rats were injected with isoproterenol (ISO; 110 mg/kg, ip, 2 doses, 24 h interval) to induce acute myocardial infarction (AMI) and were sacrificed 6 and 24 h after the last ISO injection. The heart tissue, plasma and erythrocytes of these rats were evaluated for cardiac markers and oxidative stress parameters. Levels of cardiac troponin T (cTnT) and the activities of creatine kinase (CK), lactate dehydrogenase (LDH), and aspartate aminotransferase (AST) in plasma were increased 6 and 24 h after ISO treatment. The levels of malondialdehyde (MDA), diene conjugate (DC), and protein carbonyl (PC) were increased in heart tissue and plasma, while levels of erythrocyte MDA and glutathione (GSH) and plasma ferric reducing antioxidant power (FRAP) were also increased. However, GSH levels and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) decreased in heart tissue of rats with AMI. We also investigated the effects of carnosine (CAR) treatment on these parameters 24 h after the last ISO injection. CAR (250 mg/kg/day; ip) treatments were carried out either 10 days before ISO injection or 2 days concomitant with ISO. Pretreatment with CAR decreased plasma LDH and AST activities and ameliorated cardiac histopathological changes in ISO-treated rats. Cardiac MDA, DC and PC levels decreased, but GSH levels and SOD and GSH-Px activities increased. However, the increases in plasma MDA and PC levels as well as erythrocyte H₂O₂-induced MDA and GSH levels did not change due to CAR pretreatment. In conclusion, our findings indicate that CAR pretreatment may have protective effects on ISO-induced cardiac toxicity by decreasing oxidative stress.     

Protective effect of Diyarbak?r watermelon juice on carbon tetrachloride-induced toxicity in rats

The present study was designed to evaluate the effect of Diyarbak?r watermelon (Citrullus lanatus cv. Sürme) juice on lipid peroxidation states in rat liver, kidney and brain. In vivo administration of carbon tetrachloride (CCl₄) once a week for 28 days caused a significant elevation of serum markers of liver damage, aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TB) and decrease in albumin when compared to the control group. However, administration of carbon tetrachloride along with watermelon juice or ursodeoxycolic acid (UDCA) significantly reduces these changes. Increased lipid peroxide (LPO) level was observed in the liver, kidney and brain tissues after CCl₄ administration. However, watermelon juice and UDCA treatment prevented the increase in LPO. The results indicated that watermelon juice protects the liver, kidney and brain tissues from experimental CCl₄ toxicity in rats and that the protective effect of watermelon juice may be due to its antioxidant activity and inhibition of lipid peroxide formation. In conclusion, present study reveals biological evidence that supports the use of watermelon juice in the treatment of chemical-induced hepatotoxicity.     

Metformin effect in models of inflammation is associated with activation of ATP-dependent potassium channels and inhibition of tumor necrosis factor-α production

Inflammopharmacology - Metformin is an oral hypoglycemic drug widely used in the management of type 2 diabetes mellitus. We have recently demonstrated that metformin exhibits activity in models of...     

Interferon-γ reduces tumor-induced Ia− macrophage-mediated suppression: role of prostaglandin E2, Ia,and tumor necrosis factor-α

Tumor growth enhances macrophage (Mφ) suppressor activity by causing Mφ to increase synthesis of inhibitory molecules such as prostaglandin E₂ (PGE₂) or decreasing their expression of up-regulatory molecules such as the class II MHC protein Ia. Although these tumor-induced changes are correlated, it is unknownwhether tumor-bearing host (TBH) Ia⁻ Mφ become more suppressive by increasing their PGE₂ synthesis. To assess the role of PGE₂ in tumor-induced Ia⁻ Mφ-mediated suppression of CD4⁺ T-cell alloreactivity, unseparated (Ia⁺ -enriched) or Ia⁺ -depleted (Ia⁻) populations of murine normal host (NH) or TBH splenic Mφ were added to mixed lymphocyte reaction (MLR) cultures. NH or TBH Ia⁻ Mφ were significantly more suppressive than their respective unseparated populations, and TBH Ia⁻ Mφ were more suppressive than their NH counterparts. When PGE₂ production was blocked with indomethacin, TBH Ia⁻ Mφ-mediated suppression was reduced more than suppression mediated by all other Mφ populations. A PGE₂-specific ELISA showed more PGE₂ in Ia⁻ Mφ-containing cultures than in those with whole Mφ and more cultures containing TBH Ia⁻ Mφ than in their NH counterparts. Because interferon-γ (IFN-γ) is a potent Mφ activation molecule that regulates both Ia expression and PGE₂ production, the effects of IFN-γ on tumor-induced Ia⁻ Mφ-mediated suppression were investigated. Exogenous IFN-γ reduced suppression mediated by all Mφ populations except NH unseparated Mφ. IFN-γ suppressed alloreactivity without Mφ or with NH unseparated Mφ. Suppression mediated by NH or TBH Ia⁻, and TBH unseparated Mφ was also reduced when Mφ were pre-incubated with IFN-γ before their addition to MLR cultures. IFN-γ addition did not block Ia⁻ Mφ-mediated suppression by decreasing Mφ PGE₂ production. In fact, IFN-γ addition increased PGE₂ production two-fold in MLR cultures. However, IFN-γ partly reduced suppression mediated by exogenous PGE₂ added to Mφ-depleted cultures. Cytofluorometric analysis showed that IFN-γ increased the percentage of Ia⁺ Mφ in NH and TBH Ia⁻ Mφ populations. Blocking TNF-α activity with anti-TNF-α antibodies caused IFN-γ to suppress alloreactivity in all Mφ-added cultures. Collectively, these data show that tumor-induced suppression mediated by Ia⁻ Mφ is caused by increased PGE₂ synthesis. IFN-γ strongly reduces Ia⁻ Mφ-mediated suppression by blocking PGE₂-mediated suppression, enhancing Ia⁻ Mφ production of the up-regulatory molecule TNF-α, and possibly by increasing the number of Ia⁺ Mφ. These effects of IFN-γ on Ia⁻ Mφ suggest that this cytokine increases immunity and Mφ-mediated cytotoxicity during cancer.     

Protective effects of Ficus carica leaves on glucose and lipids levels,carbohydrate metabolism enzymes and β-cells in type 2 diabetic rats

Context: The decoctions of Ficus carica Linn. (Moraceae) leaves are used in the folklore treatment of diabetes.

Objective: To evaluate the effect of F. carica on glucose and lipids levels, carbohydrate metabolism enzymes and β-cells protective effects in type 2 diabetes.

Material and methods: Diabetes was induced in 15 days high-fat diet (HFD)-fed Wistar rats by intraperitoneal injection of streptozotocin (STZ) (40?mg/kg). The ethyl acetate extract (250 and 500?mg/kg) of F. carica leaves was administered for 28 days. Oral glucose tolerance (OGTT) and intraperitoneal insulin tolerance tests (ITT) were evaluated on 15th and 25th days, respectively.

Results: The ethyl acetate extract (250 and 500?mg/kg) of n F. carica leaves showed significant effect (p?F. carica (250 and 500?mg/kg) significantly (p?F. carica enhanced the glucose utilization significantly (p?<?0.005) over 30 and 60?min compared to diabetic control. Further, the altered activities of key carbohydrate metabolizing enzymes such as glucose-6-phosphatase, fructose-1,6-bisphosphatase and hexokinase in the liver tissue of diabetic rats were significantly (p?F. carica. Immumohistochemical studies of islets substantiated the cytoprotective effect on pancreatic β-cells.

Discussion and conclusions: F. carica leaves exerted significant effect on carbohydrate metabolism enzymes with promising hypoglycemic and hypolipidemic activities in type 2 diabetic rats.