Numerous studies have shown that resveratrol (RES) exerts anti-inflammatory effects but human trials evidencing these effects in vivo are limited. Furthermore, the molecular mechanisms triggered in humans following the oral intake of RES are not yet understood. Therefore, the purpose of this study was to investigate the molecular changes in peripheral blood mononuclear cells (PBMCs) associated to the one-year daily intake of a RES enriched (8 mg) grape extract (GE-RES) in hypertensive male patients with type 2 diabetes mellitus (T2DM). We used microarrays and RT-PCR to analyze expression changes in genes and microRNAs (miRs) involved in the inflammatory response modulated by the consumption of GE-RES in comparison to a placebo and GE lacking RES. We also examined the changes in several serobiochemical variables, inflammatory and fibrinolytic markers. Our results showed that supplementation with GE or GE-RES did not affect body weight, blood pressure, glucose, HbA1c or lipids, beyond the values regulated by gold standard medication in these patients. We did not find either any significant change on serum inflammatory markers except for a significant reduction of ALP and IL-6 levels. The expression of the pro-inflammatory cytokines CCL3, IL-1 beta and TNF-alpha was significantly reduced and that of the transcriptional repressor LRRFIP-1 increased in PBMCs from patients taking the GE-RES extract. Also, a group of miRs involved in the regulation of the inflammatory response: miR-21, miR-181b, miR-663, miR-30c2, miR-155 and miR-34a were found to be highly correlated and altered in the group consuming the GE-RES for 12 months. Our results provide preliminary evidence that long-term supplementation with a grape extract containing RES downregulates the expression of key pro-inflammatory cytokines with the involvement of inflammation-related miRs in circulating immune cells of T2DM hypertensive medicated patients and support a beneficial immunomodulatory effect in these patients. (C) 2013 Elsevier Ltd. All rights reserved.
The objective of the present study was to develop a rat model that replicates the natural history and metabolic characteristics of human type 2 diabetes and is also suitable for pharmacological screening. Male Sprague-Dawley rats (160-180 g) were divided into two groups and fed with commercially available normal pellet diet (NPD) (12% calories as fat) or in-house prepared high-fat diet (HFD) (58% calories as fat), respectively, for a period of 2 weeks. The HFD-fed rats exhibited significant increase in body weight, basal plasma glucose (PGL), insulin (PI), triglycerides (PTG) and total cholesterol (PTC) levels as compared to NPD-fed control rats. Besides, the HFD rats showed significant reduction in glucose disappearance rate (K-value) on intravenous insulin glucose tolerance test (IVIGTT). Hyperinsulinemia together with reduced glucose disappearance rate (K-value) suggested that the feeding of HFD-induced insulin resistance in rats. After 2 weeks of dietary manipulation, a subset of the rats from both groups was injected intraperitoneally with low dose of streptozotocin (STZ) (35 mg kg(-1)). Insulin-resistant HFD-fed rats developed frank hyperglycemia upon STZ injection that, however, caused only mild elevation in PGL in NPD-fed rats. Though there was significant reduction in PI level after STZ injection in HFD rats, the reduction observed was only to a level that was comparable with NPD-fed control rats. In addition, the levels of PTG and PTC were further accentuated after STZ treatment in HFD-fed rats. In contrast, STZ (35 mg kg(-1), i.p.) failed to significantly alter PI, PTG and PTC levels in NPD-fed rats. Thus, these fat-fed/STZ-treated rats simulate natural disease progression and metabolic characteristics typical of individuals at increased risk of developing type 2 diabetes because of insulin resistance and obesity. Further, the fat-fed/STZ-treated rats were found to be sensitive for glucose lowering effects of insulin sensitizing (pioglitazone) as well as insulinotropic (glipizide) agents. Besides, the effect of pioglitazone and glipizide on the plasma lipid parameters (PTG and PTC) was shown in these diabetic rats. The present study represents that the combination of HFD-fed and low-dose STZ-treated rat serves as an alternative animal model for type 2 diabetes simulating the human syndrome that is also suitable for testing anti-diabetic agents for the treatment of type 2 diabetes. (c) 2005 Published by Elsevier Ltd.
Ampelopsis grossedentata, a medicinal and edible plant, has been widely used in China for hundreds of years, and dihydromyricetin is the main active ingredient responsible for its various biological actions. We investigated the effects of dihydromyricetin on glucose and lipid metabolism, inflammatory mediators and several biomarkers in nonalcoholic fatty liver disease. In a double-blind clinical trial, sixty adult nonalcoholic fatty liver disease patients were randomly assigned to receive either two dihydromyricetin or two placebo capsules (150 mg) twice daily for three months. The serum levels of alanine, aspartate aminotransferase, gamma-glutamyl transpeptidase, glucose, low-density lipoprotein-cholesterol and apolipoprotein B, and the homeostasis model assessment of insulin resistance (HOMA-IR) index were significantly decreased in the dihydromyricetin group compared with the placebo group. In the dihydromyricetin group, the serum levels of tumor necrosis factor-alpha, cytokeratin-18 fragment and fibroblast growth factor 21 were decreased, whereas the levels of serum adiponectin were increased at the end of the study. We conclude that dihydromyricetin supplementation improves glucose and lipid metabolism as well as various biochemical parameters in patients with nonalcoholic fatty liver disease, and the therapeutic effects of dihydromyricetin are likely attributable to improved insulin resistance and decreases in the serum levels of tumor necrosis factor-alpha, cytokeratin-18, and fibroblast growth factor 21. (C) 2015 Elsevier Ltd. All rights reserved.
Statin therapy may lower plasma coenzyme Q10 (CoQ10) concentrations, but the evidence as to the significance of this effect is unclear. We assessed the impact of statin therapy on plasma CoQ10 concentrations through the meta-analysis of available RCTs. The literature search included selected databases up to April 30, 2015. The meta-analysis was performed using either a fixed-effects or random-effect model according to I-2 statistic. Effect sizes were expressed as weighted mean difference (WMD) and 95% confidence interval (CI). The data from 8 placebo-controlled treatment arms suggested a significant reduction in plasma CoQ10 concentrations following treatment with statins (WMD: 0.44 mu mol/L, 95%Cl: -0.52, -0.37,p = 12 weeks (WMD: -0.40 mu mol/L, 95%Cl: -0.50, - 0.30, p < 0.001). The meta-analysis showed a significant reduction in plasma CoQ10 concentrations following treatment with statins. Further well-designed trials are required to confirm our findings and elucidate their clinical relevance. (C) 2015 Elsevier Ltd. All rights reserved.
Previous epidemiological and feeding studies have observed that adherence to Mediterranean diet (Med-Diet) is associated with reduced cardiovascular risk. However, the molecular mechanisms involved are not fully understood. Since atherosclerosis is nowadays considered a low-grade inflammatory disease, recent studies have explored the anti-inflammatory effects of a Med-Diet intervention on serum and cellular biomarkers related to atherosclerosis. In two sub-studies of the PREDIMED (PREvencion con DIeta MEDiterranea) trial, we analyzed the effects at 3 months of two Med-Diet interventions supplemented with either virgin olive oil (VOO) or nuts compared with a control low-fat diet (LFD). Both Med-Diets showed an anti-inflammatory effect reducing serum C-reactive protein, interleukin-6 (IL6) and endothelial and monocytary adhesion molecules and chemokines (P < 0.05; all), whereas these parameters increased after the LFD intervention (P < 0.05; all). In another substudy, we evaluated the long-term (1 year) effects of these interventions on vascular risk factors in 516 high-risk subjects, as well as the effect of different Med-Diet components in the reduction of these biomarkers. At 1 year, the Med-Diet groups had significant decreases in the plasma concentrations of IL6, tumor necrosis factor receptor (TNFR) 60 and TNFR80 (P < 0.05), while intercellular adhesion molecule 1 (ICAM-1), TNFR60 and TNFR80 concentrations increased in the LFD group (P < 0.002). In addition, those allocated in the highest tertile of VOO and vegetables consumption had a significant diminution of plasma TNFR60 concentration compared with those in tertile 1 (P < 0.02). In conclusion, Med-Diet exerts an anti-inflammatory effect on cardiovascular system since it down-regulates cellular and circulating inflammatory biomarkers related to atherogenesis in subjects at high cardiovascular risk. (C) 2012 Elsevier Ltd. All rights reserved.
Accumulation of amyloid-beta peptides (A beta) within brain is a major pathogenic hallmark of Alzheimer's disease (AD). Emerging evidence suggests that autophagy, an important intracellular catabolic process, is involved in A beta clearance. Here, we investigated whether temsirolimus, a newly developed compound approved by Food and Drug Administration and European Medicines Agency for renal cell carcinoma treatment, would promote autophagic clearance of A beta and thus provide protective effects in cellular and animal models of AD. HEK293 cells expressing the Swedish mutant of APP695 (HEK293-APP695) were treated with vehicle or 100 nM temsirolimus for 24 h in the presence or absence of 3-methyladenine (5mM) or Atg5-siRNA, and intracellular A beta levels as well as autophagy biomarkers were measured. Meanwhile, APP/PS1 mice received intraperitoneal injection of temsirolimus (20 mg/kg) every 2 days for 60 days, and brain A beta burden, autophagy biomarkers, cellular apoptosis in hippocampus, and spatial cognitive functions were assessed. Our results showed that temsirolimus enhanced A beta clearance in HEK293-APP695 cells and in brain of APP/PSI mice in an autophagy-dependent manner. Meanwhile, temsirolimus attenuated cellular apoptosis in hippocampus of APP/PSI mice, which was accompanied by an improvement in spatial learning and memory abilities. In conclusion, our study provides the first evidence that temsirolimus promotes autophagic A beta clearance and exerts protective effects in cellular and animal models of AD, suggesting that temsirolimus administration may represent a new therapeutic strategy for AD treatment. Meanwhile, these findings emphasize the notion that many therapeutic agents possess pleiotropic actions aside from their main applications. (C) 2014 Elsevier Ltd. All rights reserved.
The nuclear factor erythroid derived 2-related factor 2 (Nrf2) and the antioxidant protein heme oxygenase-1 (HO-1) are crucial components of the cellular stress response. These two systems work together to combat oxidative stress and inflammation and are attractive drug targets for counteracting different pathologies, including neuroinflammation. We aimed to identify the most effective Nrf2/HO-1 activators that modulate the inflammatory response in microglia cells. In the present study, we searched the literature and selected 56 compounds reported to activate Nrf2 or HO-1 and analyzed them for HO-1 induction at 6 and 24 h and cytotoxicity in BV2 microglial cells in vitro. Approximately 20 compounds up-regulated HO-1 at the concentrations tested (5-20 mu M) with carnosol, supercurcumin, cobalt protoporphyrin-IX and dimethyl fumarate exhibiting the best induction/low cytotoxicity profile. Upregulation of HO-1 by some compounds resulted in increased cellular bilirubin levels but did not augment the expression of proteins involved in heme synthesis (ALAS 1) or biliverdin reductase. Bilirubin production by HO-1 inducers correlated with their potency in inhibiting nitrite production after challenge with interferon-gamma (INF-gamma) or lipopolysaccharide (LPS). The compounds down-regulated the inflammatory response (TNF-alpha, PGE2 and nitrite) more strongly in cells challenged with INF-gamma than LPS, and silencing HO-1 or Nrf2 with shRNA differentially affected the levels of inflammatory markers. These findings indicate that some small activators of Nrf2/HO-1 are effective modulators of microglia inflammation and highlight the chemical scaffolds that can serve for the synthesis of potent new derivatives to counteract neuroinflammation and neurodegeneration. (C) 2013 Elsevier Ltd. All rights reserved.
Mammalian cells can utilize hydrogen sulfide (H2S) to support mitochondrial respiration. The aim of our study was to explore the potential role of S-sulfhydration (a H2S-induced posttranslational modification, also known as S-persulfidation) of the mitochondrial inner membrane protein ATP synthase (FIFO ATP synthase/Complex V) in the regulation of mitochondrial bioenergetics. Using a biotin switch assay, we have detected S-sulfhydration of the alpha subunit (ATP5A1) of ATP synthase in response to exposure to H2S in vitro. The H2S generator compound NaHS induced S-sulfhydration of ATP5A1 in HepG2 and HEK293 cell lysates in a concentration-dependent manner (50-300 mu M). The activity of immunocaptured mitochondrial ATP synthase enzyme isolated from HepG2 and HEK293 cells was stimulated by NaHS at low concentrations (10-100 nM). Site-directed mutagenesis of ATP5A1 in HEK293 cells demonstrated that cysteine residues at positions 244 and 294 are subject to S-sulfhydration. The double mutant ATP synthase protein (C244S/C294S) showed a significantly reduced enzyme activity compared to control and the single-cysteine-mutated recombinant proteins (C244S or C294S). To determine whether endogenous H2S plays a role in the basal S-sulfhydration of ATP synthase in vivo, we compared liver tissues harvested from wild-type mice and mice deficient in cystathionine-gamma-lyase (CSE, one of the three principal mammalian H2S-producing enzymes). Significantly reduced S-sulfhydration of ATP5A1 was observed in liver homogenates of CSE-/- mice, compared to wild-type mice, suggesting a physiological role for CSE-derived endogenous H2S production in the S-sulfhydration of ATP synthase. Various forms of critical illness (including burn injury) upregulate H2S-producing enzymes and stimulate H2S biosynthesis. In liver tissues collected from mice subjected to burn injury, we detected an increased S-sulfhydration of ATP5A1 at the early time points post-burn. At later time points (when systemic H2S levels decrease) S-sulfhydration of ATP5A1 decreased as well. In conclusion, H2S induces S-sulfhydration of ATP5A1 at C244 and C294. This post-translational modification may be a physiological mechanism to maintain ATP synthase in a physiologically activated state, thereby supporting mitochondrial bioenergetics. The sulfhydration of ATP synthase may be a dynamic process, which may be regulated by endogenous H2S levels under various pathophysiological conditions. (C) 2016 Elsevier Ltd. All rights reserved.
Modern diets can cause modern diseases. Research has linked a metabolite of sugar, methylglyoxal (MG), to the development of diabetic complications, but the exact mechanism has not been fully elucidated. The present study was designed to investigate whether MG could directly influence endothelial function, oxidative stress and inflammation in Wistar and Goto-Kakizaki (GK) rats, an animal model of type 2 diabetes. Wistar and GK rats treated with MG in the drinking water for 3 months were compared with the respective control rats. The effects of MG were investigated on NO-dependent vasorelaxation in isolated rat aortic arteries from the different groups. Insulin resistance, NO bioavailability, glycation, a pro-inflammatory biomarker monocyte chemoattractant protein-1 (MCP-1) and vascular oxidative stress were also evaluated. Methylglyoxal treated Wistar rats significantly reduced the efficacy of NO-dependent vasorelaxation (p < 0.001). This impairment was accompanied by a three fold increase in the oxidative stress marker nitrotyrosine. Advanced glycation endproducts (AGEs) formation was significantly increased as well as MCP-1 and the expression of the receptor for AGEs (RAGE). NO bioavailability was significantly attenuated and accompanied by an increase in superoxide anion immunofluorescence. Methylglyoxal treated GK rats significantly aggravated endothelial dysfunction, oxidative stress, AGEs accumulation and diminished NO bioavailability when compared with control GK rats. These results indicate that methylglyoxal induced endothelial dysfunction in normal Wistar rats and aggravated the endothelial dysfunction present in GK rats. The mechanism is at least in part by increasing oxidative stress and/or AGEs formation with a concomitant increment of inflammation and a decrement in NO bioavailability. The present study provides further evidence for methylglyoxal as one of the causative factors in the pathogenesis of atherosclerosis and development of macrovascular diabetic complication. (C) 2012 Elsevier Ltd. All rights reserved.
Metabolic syndrome and oxidative stress are common complications of type 2 diabetes mellitus. The present study was designed to determine whether resveratrol, a widely used nutritional supplement, can improve insulin sensitivity, metabolic complication as well as hepatic oxidative stress in fructose-fed rats. Male Sprague Dawley rats (180-200 g) were divided into four groups with 8 animals each. Fructose-fed insulin resistant group (Dia) animals were fed 65% fructose (Research diet, USA) for a period of 8 weeks, whereas control group (Con) animals were fed 65% cornstarch (Research Diet, USA). Resveratrol, 10 mg/kg/day (Dia + Resv) or metformin 300 mg/kg/day (Dia + Met) were administered orally to the 65% fructose-fed rats for 8 weeks. At the end of the feeding schedule, Dia group had insulin resistance along with increased blood glucose, triglyceride, uric acid and nitric oxide (NO) levels. Significant (p < 0.05) increase in hepatic TBARS and conjugated dienes, and significant (p < 0.05) decrease in hepatic SOD and vitamin C was observed in Dia group compared to Con group. Administration of metformin or resveratrol significantly (p < 0.05) normalized all the altered metabolic parameters. However, a marked insulin sensitizing action was only observed in the Dia + Resv group. Similarly, while metformin administration failed to normalize the increased TBARS levels and decreased SOD activity, resveratrol showed a more promising effect of all oxidative stress parameters measured in the present study. Attenuation of hepatic oxidative stress in fructose-fed rat liver after resveratrol administration was associated with significant (p < 0.05) increase in nuclear level of NRF2 compared with other groups. The present study demonstrates that resveratrol is more effective than metformin in improving insulin sensitivity, and attenuating metabolic syndrome and hepatic oxidative stress in fructose-fed rats. (c) 2012 Elsevier Ltd. All rights reserved.
Broccoli consumption may reduce the risk of various cancers and many broccoli supplements are now available. The bioavailability and excretion of the mercapturic acid pathway metabolites isothiocyanates after human consumption of broccoli supplements has not been tested. Two important isothiocyanates from broccoli are sulforaphane and erucin. We employed a cross-over study design in which 12 subjects consumed 40 g of fresh broccoli sprouts followed by a 1 month washout period and then the same 12 subjects consumed 6 pills of a broccoli supplement. As negative controls for isothiocyanate consumption four additional subjects consumed alfalfa sprouts during the first phase and placebo pills during the second. Blood and urine samples were collected for 48 h during each phase and analyzed for sulforaphane and erucin metabolites using LC-MS/MS. The bioavailability of sulforaphane and erucin is dramatically lower when subjects consume broccoli supplements compared to fresh broccoli sprouts. The peaks in plasma concentrations and urinary excretion were also delayed when subjects consumed the broccoli supplement. GSTP1 polymorphisms did not affect the metabolism or excretion of sulforaphane or erucin. Sulforaphane and erucin are able to interconvert in vivo and this interconversion is consistent within each subject but variable between subjects. This study confirms that consumption of broccoli supplements devoid of myrosinase activity does not produce equivalent plasma concentrations of the bioactive isothiocyanate metabolites compared to broccoli sprouts. This has implications for people who consume the recommended serving size (1 pill) of a broccoli supplement and believe they are getting equivalent doses of isothiocyanates. Published by Elsevier Ltd.
Dysregulation in signaling of the endocannabinoid 2-arachidonoylglycerol (2-AG) is implicated in hyper-responsiveness to stress. We hypothesized that blockade of monoacylglycerol lipase (MGL), the primary enzyme responsible for 2-AG deactivation in vivo, would produce context-dependent anxiolytic effects in rats. Environmental aversiveness was manipulated by varying illumination of an elevated plus maze. Percentage open arm time and numbers of open and closed arm entries were measured in rats receiving a single intraperitoneal (i.p.) injection of either vehicle, the MGL inhibitor JZL184 (1-8 mg/kg), the benzodiazepine diazepam (1 mg/kg), the cannabinoid CBI receptor antagonist rimonabant (1 mg/kg), or JZL184 (8 mg/kg) coadministered with rimonabant (1 mg/kg). JZL184 (8 mg/kg) produced anxiolytic-like effects (i.e., increased percentage open arm time and number of open arm entries) under high, but not low, levels of environmental aversiveness. Diazepam produced anxiolytic effects in either context. Rimonabant blocked the anxiolytic-like effects of JZL184, consistent with mediation by CB1. Anxiolytic effects of JZL184 were preserved following chronic (8 mg/kg per day x 6 days) administration. Chronic and acute JZL184 treatment similarly enhanced behavioral sensitivity to an exogenous cannabinoid (WIN55,212-2; 2.5 mg/kg i.p.) 24 or 72 h following the terminal injection, suggesting a pervasive effect of MGL inhibition on the endocannabinoid system. We attribute our results to alterations in emotion rather than locomotor activity as JZL184 did not alter the number of closed arm entries in the plus maze or produce motor ataxia in the bar test. Our results demonstrate that JZL184 has beneficial, context-dependent effects on anxiety in rats, presumably via inhibition of MGL-mediated hydrolysis of 2-AG. These data warrant further testing of MGL inhibitors to elucidate the functional role of 2-AG in controlling anxiety and stress responsiveness. Our data further implicate a role for 2-AG in the regulation of emotion and validate MGL as a therapeutic target. (C) 2011 Elsevier Ltd. All rights reserved.
The susceptibility of fatty acids to oxidation is thought to be directly dependent on their degree of unsaturation. However, some in vitro and in vivo studies suggest that the relation between chemical structure and susceptibility to oxidation is not as straightforward as hypothesized from theoretical viewpoints. Indeed, long chain polyunsaturated fatty acids (LC-PUFAs) might be less oxidizable than others under specific experimental conditions. We investigated the free radical-scavenging potential of PUFA and the production of reactive oxygen/nitrogen (ROS/RNS) species by human aortic endothelial cells (HAECs) supplemented with different fatty acids. Fatty acid micelles scavenged superoxide in an unsaturation-dependent manner, up to eicosapentaenoic acid, which was the most effective fatty acid. Supplementation of HAEC with polyunsaturated fatty acids of the omega 3 series resulted in lower formation of ROS, as compared with cells supplemented with saturates, monounsaturates, or polyunsaturates of the omega 6 series. This effect was maximal at concentrations of 10 mu M. The effects of omega 3 fatty acids on reactive species production appear to be stronger when ROS were evaluated, as a milder, albeit significant effect was observed on RNS generation. Based on in vivo data showing reduced excretion of lipid peroxidation products after omega 3 intake and our data on ROS production and direct superoxide scavenging by LC-PUFAs, notably those of the omega 3 series, we propose that this series of fatty acid might act as indirect anti- rather than pro-oxidant in vascular endothelial cells, hence diminishing inflammation and, in turn, the risk of atherosclerosis and cardiovascular disease. (C) 2008 Elsevier Ltd. All rights reserved.
A pharmacokinetic study of the metabolic profile of resveratrol has been performed in healthy men after moderate red wine (RW) consumption. The bioavailability of resveratrol is highly influenced by several factors such as the food matrix and, therefore, this study has been compared with a pilot study in which men ingested grape extract (GE) tablets as a nutraceutical, containing similar total amounts of resveratrol than RW. Blood and urine samples were taken before and at several time points after intervention and then analyzed by SPE and LC-ESI-MS/MS. Up to 17 resveratrol and piceid derivatives were identified, including those formed by the intestinal microbiota. Resveratrol glucosides were found in plasma as intact forms and reached the lowest maximum concentrations 1 h after both interventions. Higher plasma concentrations and longer times (t(max)) were observed for resveratrol glucuronides due to phase II metabolism and even higher values for conjugates derived from microbiota, such as dihydroresveratrol-glucuronides. The same trend was observed for total excreted amounts in urine samples. When both treatments were compared, statistically significant differences for some metabolites were obtained, which may be due to the different composition of resveratrol and piceid in both sources. However. GE formulation seems to delay resveratrol absorption, staying longer in the gut where could be metabolized to a greater degree, since 2.1-3.6-fold higher urinary concentrations of microbial metabolites were observed after GE intervention at 12-24 h urinary fraction. Therefore, supplement intake could be also a way to bring resveratrol benefits to human health. (C) 2012 Elsevier Ltd. All rights reserved.
We previously reported the effect of dioscin against hepatic ischemia/reperfusion injury (IRI) in rats. However, little is known concerning the role of dioscin in renal IRI. In the present study, rats were subjected to IRI and dioscin was intragastrically administered for seven consecutive days before surgery. In vitro models of hypoxia/reoxygenation were developed in NRK-52E and HK-2 cells, which were prophylactically treated with or without dioscin. The results showed that dioscin significantly decreased serum BUN and Cr levels, and markedly attenuated cell injury. Mechanistic studies showed that dioscin significantly increased HSP70 levels, decreased the levels of TLR4, MyD88, TRAF6, COX-2, JNK, ERIC and p38 MAPK phosphorylation, suppressed the nuclear translocation of NF-kappa B and HMGB1, and subsequently decreased the mRNA levels of IL-1 beta, 1L-6, TNF-alpha, ICAM-1 and IFN-gamma. Moreover, HSP70 siRNA or TLR4 DNA reversed the nephroprotective effects of dioscin, while dioscin still significantly down-regulated the TLR4 signaling pathway. Furthermore, by inhibiting MyD88 with ST2825 (a MyD88 inhibitor), renal IRI was significantly attenuated, suggesting that the effect of dioscin against renal IRI depended on MyD88. Our results suggested that dioscin had a potent effect against renal IRI through suppressing the TLR4/MyD88 signaling pathway by up-regulating HSP70. These data provide new insights for investigating the natural product with the nephroprotective effect against IRI, which should be developed as a new therapeutic agent for the treatment of acute kidney injury in the future. (C) 2015 Elsevier Ltd. All rights reserved.
dThe aim of the present study was the evaluation of possible protective effects of quercetin (QE) against beta-cell damage in experimental streptozotocin (STZ)-induced diabetes in rats. STZ was injected intraperitoneally at a single dose of 50 mg kg(-1) for diabetes induction. QE (15 mg kg-1 day, intraperitoneal (i.p.) injection) was injected for 3 days prior to STZ administration; these injections were continued to the end of the study (for 4 weeks). It has been believed that oxidative stress plays a role in the pathogenesis of diabetes mellitus (DM). In order to determine the changes of cellular antioxidant defense system, antioxidant enzymes such as glutathione peroxidase (GSHPx), superoxide dismutase (SOD) and catalase (CAT) activities were measured in pancreatic homogenates. Moreover we also measured serum nitric oxide (NO) and erythrocyte and pancreatic tissue malondialdehyde (MDA) levels, a marker of lipid peroxidation, if there is an imbalance between oxidant and antioxidant status. Pancreatic p-cells were examined by inummohistochemical methods. STZ induced a significant increase lipid peroxidation, serum NO concentrations and decreased the antioxidant enzyme activity. Erythrocyte MDA, serum NO and pancreatic tissue MDA significantly increased (P < 0.05) and also the antioxidant levels significantly decreased (P < 0.05) in diabetic group. QE treatment significantly decreased the elevated MDA and NO (P < 0.05), and also increased the antioxidant enzyme activities (P < 0.05). QE treatment has shown protective effect possibly through decreasing lipid peroxidation, NO production and increasing antioxidant enzyme activity. Islet cells degeneration and weak insulin immurrohistochemical staining was observed in STZ induced diabetic rats. Increased staining of insulin and preservation of islet cells were apparent in the QE-treated diabetic rats. These findings suggest that QE treatment has protective effect in diabetes by decreasing oxidative stress and preservation of pancreatic beta-cell integrity. (C) 2004 Elsevier Ltd. All rights reserved.
Cisplatin, a platinum-derived chemotherapeutic agent, produces mechanical and coldallodynia reminiscent of chemotherapy-induced neuropathy in humans. The endocannabinoid system represents a novel target for analgesic drug development. The endocannabinoid signaling system consists of endocannabinoids (e.g. anandamide (AEA) and 2-arachidonoylglycerol (2-AG)), cannabinoid receptors (e.g. CB1 and CB2) and the enzymes controlling endocannabinoid synthesis and degradation. AEA is hydrolyzed by fatty-acid amide hydrolase (FAAH) whereas 2-AG is hydrolyzed primarily by monoacylglycerol lipase (MGL). We compared effects of brain permeant (URB597) and impermeant (URB937) inhibitors of FAAH with an irreversible inhibitor of MGL (JZL184) on cisplatin-evoked behavioral hypersensitivities. Endocannabinoid modulators were compared with agents used clinically to treat neuropathy (i.e. the opioid analgesic morphine, the anticonvulsant gabapentin and the tricyclic antidepressant amitriptyline). Cisplatin produced robust mechanical and cold allodynia but did not alter responsiveness to heat. After neuropathy was fully established, groups received acute intraperitoneal (i.p.) injections of vehicle, amitriptyline (30 mg/kg), gabapentin (100 mg/kg), morphine (6 mg/kg), URB597 (0.1 or 1 mg/kg), URB937 (0.1 or 1 mg/kg) or JZL184 (1, 3 or 8 mg/kg). Pharmacological specificity was assessed by coadministering each endocannabinoid modulator with either a CB1 (AM251 3 mg/kg), CB2 (AM630 3 mg/kg), TRPV1 (AMG98103 mg/kg) or TRPA1 (HC030031 8 mg/kg) antagonist. Effects of cisplatin on endocannabinoid levels and transcription of receptors (CB1, CB2, TRPV1, TRPA1) and enzymes (FAAH, MGL) linked to the endocannabinoid system were also assessed. URB597, URB937, JZL184 and morphine reversed cisplatin-evoked mechanical and cold allodynia to pre-cisplatin levels. By contrast, gabapentin only partially reversed the observed allodynia while amitriptyline, administered acutely, was ineffective. CB1 or CB2 antagonists completely blocked the anti-allodynic effects of both FAAH (URB597, URB937) and MGL (JZL184) inhibitors to mechanical and cold stimulation. By contrast, the TRPV1 antagonist AMG9810 blocked the anti-allodynic efficacy of both FAAH inhibitors, but not the MGL inhibitor. By contrast, the TRPA1 antagonist HC30031 did not attenuate anti-allodynic efficacy of any endocannabinoid modulator. When the levels of endocannabinoids were examined, cisplatin increased both anandamide (AEA) and 2-arachidonoylglycerol (2-AG) levels in the lumbar spinal cord and decreased 2-AG levels (but not AEA) in dorsal hind paw skin. RT-PCR showed that mRNA for FAAH, but not other markers, was upregulated by cisplatin treatment in lumbar spinal cord. The present studies demonstrate that cisplatin alters endocannabinoid tone and that inhibition of endocannabinoid hydrolysis alleviates chemotherapy-induced mechanical and cold allodynia. The anti-allodynic effects of FAAH and MGL inhibitors are mediated by CB1 and CB2 cannabinoid receptors, whereas TRPV1, but not TRPA1, -dependent mechanisms contribute to the anti-allodynic efficacy of FAAH (but not MGL) inhibitors. Strikingly, endocannabinoid modulators potently suppressed cisplatin-evoked allodynia with a rapid onset and showed efficacy that equaled or exceeded that of major classes of anti-neuropathic pain medications used clinically. Thus, inhibition of endocannabinoid hydrolysis, via FAAH or MGL inhibitors, represents an efficacious pharmacological approach for suppressing chemotherapy-induced neuropathic pain. (c) 2012 Elsevier Ltd. All rights reserved.
Dietary polyphenols present in Punica granatum (pomegranate), such as ellagitannins and ellagic acid (EA) have shown to exert anti-inflammatory and antioxidant properties. This study was designed to evaluate the effects of a dietary EA-enriched pomegranate extract (PE) in a murine chronic model of Cronh's disease (CD). Colonic injury was induced by intracolonic instillation of trinitrobenzensulfonic acid (TNBS). Rats were fed with different diets during 30 days before TNBS instillation and 2 weeks before killing: (i) standard, (ii) PE 250 mg/kg/day, (iii) PE 500 mg/kg/day, (iv) EA 10 mg/kg/day and (v) EA 10 mg/kg/day enriched-PE 250 mg/kg/day. Inflammation response was assessed by histology and MPO activity and TNF-alpha production. Besides, colonic expressions of iNOS, COX-2, p38, JNK, pERK1/2 MAPKs, IKB alpha and nuclear p65 NF-kappa B were studied by western blotting. MPO activity and the TNF-alpha levels were significantly reduced in dietary fed rats when compared with TNBS group. Similarly, PE and an EA-enriched PE diets drastically decreased COX-2 and iNOS overexpression, reduced MAPKs phosporylation and prevented the nuclear NF-kappa B translocation. Dietary supplementation of EA contributes in the beneficial effect of PE in this experimental colitis model and may be a novel therapeutic strategy to manage inflammatory bowel disease (IBD). (c) 2012 Elsevier Ltd. All rights reserved.
Major Depressive Disorder (MDD, ICD-10: F-33) is a prevalent illness in which the pathogenic mechanism remains elusive. Recently an important role has been attributed to neuro-inflammation, and specifically the NLRP3-inflammasome complex, in the pathogenesis of MDD. This suggests a key role for immunomodulation as a key pathway in the treatment of this disorder. This study evaluates the involvement of nine common antidepressants in the NLRP3-inflammasome complex (fluoxetine, paroxetine, mianserin, mirtazapine, venlafaxine, desvenlafaxine, amitriptyline, imipramine and agomelatine), both in in vitro THP-1 cells stimulated by ATP, and in a stress-induced depressive animal or MDD patients. Antidepressant treatment induced inflammasome inhibition was observed by decreased serum levels of IL-1 and IL-18 and decrease of NLRP3 and IL-1 beta (p17) protein expression. This was also observed under stress induced depressive behaviour and inflammasome activation in C57Bl/6 mice in vivo. Deletion of key autophagy mediator Atg5 in embryonic fibroblasts (MEF cells) showed an autophagy dependent-NLRP3-inflammasome inhibition by antidepressant treatment. These results suggest the NLRP3-inflammasome could be a biomarker for antidepressant treatment response in MDD patients, and therefore the monitoring of NLRP3 expression levels and/or IL-1 beta/IL-18 release may have clinical value in drug selection. Existing evidence suggests an anti-inflammatory effect of some antidepressants shown by IL-1 beta, IL-6 and TNF-alpha. Our data have shown that antidepressant-mediated autophagy may have a role in restoration of certain metabolic and immunological pathways in MDD patients. (C) 2017 Elsevier Ltd. All rights reserved.