Resveratrol Reduces Renal and Lung Injury Caused by Sepsis in Rats

Molecular Mechanisms of Oxidative Stress in Acute Kidney Injury: Targeting the Loci by Resveratrol

Reactive oxygen species are a group of cellular molecules that stand as double-edged swords, their good and bad being discriminated by a precise balance. Several metabolic reactions in the biological system generate these molecules that interact with cellular atoms to regulate functions ranging from cell homeostasis to cell death. A prooxidative state of the cell concomitant with decreased clearance of such molecules leads to oxidative stress, which contributes as a prime pathophysiological mechanism in various diseases including renal disorders, such as acute kidney injury. However, targeting the generation of oxidative stress in renal disorders by an antioxidant, resveratrol, is gaining considerable therapeutic importance and is known to improve the condition in preclinical studies. This review aims to discuss molecular mechanisms of oxidative stress in acute kidney injury and its amelioration by resveratrol. The major sources of data were PubMed and Google Scholar, with studies from the last five years primarily included, with significant earlier data also considered. Mitochondrial dysfunction, various enzymatic reactions, and protein misfolding are the major sources of reactive oxygen species in acute kidney injury, and interrupting these loci of generation or intersection with other cellular components by resveratrol can mitigate the severity of the condition.

ENHANCED EFFICACY OF RESVERATROL-LOADED SILVER NANOPARTICLE IN ATTENUATING SEPSIS-INDUCED ACUTE LIVER INJURY: MODULATION OF INFLAMMATION, OXIDATIVE STRESS, AND SIRT1 ACTIVATION

ABSTRACT

Sepsis-induced acute liver injury is a life-threatening condition involving inflammation, oxidative stress, and endothelial dysfunction. In the present study, the preventive effects of resveratrol (RV) alone and RV-loaded silver nanoparticles (AgNPs + RV) against sepsis-induced damage were investigated and compared in a rat model of polymicrobial sepsis induced by cecal ligation and puncture (CLP). Rats were divided into four groups: Sham, CLP, RV, and AgNPs + RV. Pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation, presepsin, procalcitonin (PCT), 8-hydroxy-2'-deoxyguanosine (8-OHDG), vascular endothelial growth factor (VEGF), and sirtuin-1 (SIRT1) levels were assessed to determine the treatments' effects. AgNPs + RV treatment significantly reduced pro-inflammatory cytokines, NF-κB activation, presepsin, PCT, 8-OHDG, and VEGF levels compared with the CLP group, indicating attenuation of sepsis-induced liver injury. Both RV and AgNPs + RV treatments increased SIRT1 levels, suggesting a potential role of SIRT1 activation in mediating the protective effects. In conclusion, AgNPs + RV treatment demonstrated extremely enhanced efficacy in alleviating sepsis-induced liver injury by modulating inflammation, oxidative stress, and endothelial dysfunction, potentially mediated through SIRT1 activation. In this study, the effect of AgNPs + RV on sepsis was evaluated for the first time, and these findings highlight AgNPs + RV as a promising therapeutic strategy for managing sepsis-induced liver injury, warranting further investigation.

A comprehensive insight into the molecular and cellular mechanisms of action of resveratrol on complications of sepsis a systematic review

Sepsis and septic shock are still one of the most important medical challenges. Sepsis is an extreme and uncontrolled response of the innate immune system to invading pathogenesis. Resveratrol (3,5,4'-trihydroxytrans-stilbene), is a phenolic and non-flavonoid compound naturally produced by some plants and fruits. The object of the current study is to systematically review the impacts of resveratrol and its mechanisms of function in the management of sepsis and its related complications. The guidelines of the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statements were applied to perform the study (PROSPERO: CRD42021289357). We searched Embase, Web of Science, Google Scholar, Science Direct, PubMed, ProQuest, and Scopus databases up to January 2023 by using the relevant keywords. Study criteria were met by 72 out of 1415 articles screened. The results of this systematic review depict that resveratrol can reduces the complications of sepsis by affecting inflammatory pathways, oxidative stress, and modulating immune responses. Future human randomized clinical trials are necessary due to the promising therapeutic effects of resveratrol on sepsis complications and the lack of clinical trials in this regard.

Plants' bioactive secondary metabolites in the management of sepsis: Recent findings on their mechanism of action

Sepsis is a severe inflammatory response to systemic infection and is a threatening cause of death in intensive care units. In recent years, a number of studies have been conducted on the protective effect of natural products against sepsis-induced organ injury. However, a comprehensive review of these studies indicating the mechanisms of action of the bioactive compounds is still lacking. In this context, this review aimed to provide an updated analysis of the mechanism of action of plants' secondary metabolites in the management of sepsis. Scopus, Science Direct, Google Scholar, and PubMed were searched from inception to July 2022. A variety of secondary metabolites were found to be effective in sepsis management including allicin, aloin, cepharanthine, chrysin, curcumin, cyanidin, gallic acid, gingerol, ginsenoside, glycyrrhizin, hesperidin, kaempferol, narciclasine, naringenin, naringin, piperine, quercetin, resveratrol, rosmarinic acid, shogaol, silymarin, sulforaphane, thymoquinone, umbelliferone, and zingerone. The protective effects exerted by these compounds can be ascribed to their antioxidant properties as well as induction of endogenous antioxidant mechanisms, and also via the downregulation of inflammatory response and reduction of biochemical and inflammatory markers of sepsis. These findings suggest that these secondary metabolites could be of potential therapeutic value in the management of sepsis, but human studies must be performed to provide strength to their potential clinical relevance in sepsis-related morbidity and mortality reduction.

Resveratrol: Potential Application in Sepsis

Sepsis is a life-threatening organ dysfunction syndrome caused by host response disorders due to infection or infectious factors and is a common complication of patients with clinical trauma, burns, and infection. Resveratrol is a natural polyphenol compound that is a SIRT-1 activator with anti-inflammatory, antiviral, antibacterial, antifungal inhibitory abilities as well as cardiovascular and anti-tumor protective effects. In recent years, some scholars have applied resveratrol in animal models of sepsis and found that it has an organ protective effect and can improve the survival time and reduce the mortality of animals with sepsis. In this study, Medline (Pubmed), embase, and other databases were searched to retrieve literature published in 2021 using the keywords “resveratrol” and “sepsis,” and then the potential of resveratrol for the treatment of sepsis was reviewed and prospected to provide some basis for future clinical research.

Phytochemicals: Potential Therapeutic Interventions Against Coronavirus-Associated Lung Injury

Since the outbreak of coronavirus disease 2019 (COVID-19) in December 2019, millions of people have been infected and died worldwide. However, no drug has been approved for the treatment of this disease and its complications, which urges the need for finding novel therapeutic agents to combat. Among the complications due to COVID-19, lung injury has attained special attention. Besides, phytochemicals have shown prominent anti-inflammatory effects and thus possess significant effects in reducing lung injury caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Also, the prevailing evidence reveales the antiviral effects of those phytochemicals, including anti-SARS-CoV activity, which could pave the road in providing suitable lead compounds in the treatment of COVID-19. In the present study, candidate phytochemicals and related mechanisms of action have been shown in the treatment/protection of lung injuries induced by various methods. In terms of pharmacological mechanism, phytochemicals have shown potential inhibitory effects on inflammatory and oxidative pathways/mediators, involved in the pathogenesis of lung injury during COVID-19 infection. Also, a brief overview of phytochemicals with anti-SARS-CoV-2 compounds has been presented.

Resveratrol Downregulates Biomarkers of Sepsis Via Inhibition of Proteasome's Proteases

Lipopolysaccharide (LPS) is the main agonist of gram-negative bacteria and initiates inflammation. We recently reported that plasmas from sepsis patients revealed increased levels of following group of biomarkers; VCAM-1, ICAM1, CRP, resistin, and proteasome LMP subunits. Our objective here was to compare effects of resveratrol (shown to be a nonspecific proteasome inhibitor by us) and a known LMP7 inhibitor (ONX-0914, specific inhibitor) on proteasome's activities, as well as on inflammatory markers mentioned above in human blood monocytes. Using fluorescence-based assays on blood monocytes purified proteasomes, resveratrol (0-100 μM) inhibited all three protease activities, predominantly LMP7. Similarly, resveratrol inhibited all three protease activities using cell-based luminescence assay. In contrast, ONX-0914 was more selective and potent for LMP7 activity. Resveratrol and ONX-0914, both significantly inhibited expression of LPS-induced biomarkers mentioned above in CD14 monocytes. Moreover, resveratrol itself, as well as in combination with LPS, accumulated pIκBα in CD14 monocytes. Collectively, our data suggest that resveratrol is a less potent inhibitor of all three; CT-like (predominantly LMP7), T-like and PA protease activities and is less toxic to human monocytes than ONX-0914 (a selector inhibitor of only LMP7) as observed by an autophagy detection kit. Also, resveratrol reduces LPS-induced inflammatory cytokine expression by decreasing the translocation of NF-κB due to an increase in inhibitor pIκBα. Therefore, resveratrol can be used to curb inflammation in diseased states like sepsis and other disorders.

Antioxidant Supplementation in Renal Replacement Therapy Patients: Is There Evidence?

The disruption of balance between production of reactive oxygen species and antioxidant systems in favor of the oxidants is termed oxidative stress (OS). To counteract the damaging effects of prooxidant free radicals, all aerobic organisms have antioxidant defense mechanisms that are aimed at neutralizing the circulating oxidants and repair the resulting injuries. Antioxidants are either endogenous (the natural defense mechanisms produced by the human body) or exogenous, found in supplements and foods. OS is present at the early stages of chronic kidney disease, augments progressively with renal function deterioration, and is further exacerbated by renal replacement therapy. End-stage renal disease patients, on hemodialysis (HD) or peritoneal dialysis (PD), suffer from accelerated OS, which has been associated with increased risk for mortality and cardiovascular disease. During HD sessions, the bioincompatibility of dialyzers and dialysate trigger activation of white blood cells and formation of free radicals, while a significant loss of antioxidants is also present. In PD, the bioincompatibility of solutions, including high osmolality, elevated lactate levels, low pH, and accumulation of advanced glycation end-products trigger formation of prooxidants, while there is significant loss of vitamins in the ultrafiltrate. A number of exogenous antioxidants have been suggested to ameliorate OS in dialysis patients. Vitamins B, C, D, and E, coenzyme Q10, L-carnitine, a-lipoic acid, curcumin, green tea, flavonoids, polyphenols, omega-3 polyunsaturated fatty acids, statins, trace elements, and N-acetylcysteine have been studied as exogenous antioxidant supplements in both PD and HD patients.

Systematic review and meta-analysis of the protective effect of resveratrol on multiple organ injury induced by sepsis in animal models

Sepsis may directly lead to multiple organ failure, which is among the leading causes of mortality in critically ill patients. According to data released by the Global Sepsis Alliance, the number of mortalities due to sepsis exceeded the combined number for prostate cancer, breast cancer and AIDS in 2012. To date, studies have reported that resveratrol has marked positive effects including anti-inflammatory, anti-oxidative and pro-microcirculatory functions in sepsis-induced organ injury, significantly improving the survival time and mortality of sepsis animals. The present systematic review sought to further clarify the efficacy and safety of resveratrol in the treatment of sepsis. Studies on resveratrol application in the treatment of sepsis-induced organ injury in animal models were reviewed by searching various Chinese and other language databases (PubMed, Embase, CNKI, WanFang and WeiPu) and by manually searching the references of related articles. The selection and evaluation of the studies was performed by two independent reviewers. A total of 260 related studies were initially identified. Following application of the exclusion factors and inclusion criteria, 11 studies were included. Meta-analysis revealed that resveratrol exerted significant protective effect in sepsis-induced animal models of organ injury, through anti-inflammatory, anti-oxidant and pro-microcirculatory functions compared with in the placebo group. While nuclear factor κB (NF-κB) and nuclear factor E2-related factor 2 (NRF-2) are the two major signaling pathways to have been associated with the anti-inflammatory and anti-oxidative effects of resveratrol, these factors were not quantified for mean values, therefore not suitable for systematic evaluation. For related factors, the results of meta-analysis were as follows: For tumor necrosis factor-α (TNF-α), the standardized mean difference (SMD) was -13.50 [95% confidence interval (CI): -22.08, -4.91; P=0.002]; for malondialdehyde (MDA), the SMD was -3.10 (95% CI: -5.27, -0.93; P=0.005); for mean arterial pressure the SMD was 1.34 (95% CI: 0.07, 2.62; P=0.04); for interleukin (IL)-6 the SMD was -9.57 (95% CI: -20.90, 1.75; P=0.10); and for IL-10 the SMD was 0.80 (95% CI: -0.73, 2.34; P=0.31). It was concluded that resveratrol exerted significant anti-inflammatory and anti-oxidative effects through NF-κB and NRF-2 signaling pathways in animal models of sepsis-induced multiple organ injury, manifesting as significant downregulation of TNF-α and MDA expression and improved microcirculation, therefore ameliorating septic damage to the body, which may ultimately improve survival ratios.

Effect of Resveratrol on Blood Rheological Properties in LPS-Challenged Rats

Objectives: Abnormal rheological properties induce adverse effects during sepsis. This study sought to investigate the hypothesis that resveratrol (Res) improves blood rheological properties in rats following a lipopolysaccharide (LPS) challenge, and provide a novel approach for treatment of sepsis.

Methods: The rats were intraperitoneally or intramuscularly injected with vehicle, LPS (8 mg/kg), Res (30 mg/kg), or both to yield four groups: control, Res, LPS, and LPS + Res. After 6 h of LPS and/or Res injection, the mean arterial pressure (MAP), regional blood flow, erythrocyte and leukocyte parameters, and blood viscosity were observed.

Results: LPS administration had no significant effects on the erythrocyte parameters and plasma viscosity. LPS administration reduced the MAP, whole blood viscosity at low and medium shear rates, the blood flow in the spleen and kidney, and the leukocyte content in whole blood when compared to control group, and increased the myeloperoxidase (MPO) activity in lung. Treatment with Res alone had no effects on most of parameters observed except increasing the whole blood relative viscosity. However, Res treatment after LPS resulted in further decrease in whole blood viscosity at high and medium shear rates. Furthermore, Res treatment conversely decreased the red blood cell distribution width-CV, blood flow of stomach, whole blood relative viscosity and MPO activity in lung, and increased the leukocyte content, but did not restore LPS-induced decrease in MAP and the blood flow in the spleen and kidney.

Conclusion: The Res treatment partly reduce the whole blood viscosity and regional blood flow, and increase WBC content in peripheral blood following the LPS challenge, suggesting a favorable role in expanding the quasi-sympathetic effects of LPS in blood viscosity at early stages.

Resveratrol protects against early polymicrobial sepsis-induced acute kidney injury through inhibiting endoplasmic reticulum stress-activated NF-κB pathway

Resveratrol, a polyphenol compound derived from various edible plants, protects against sepsis-induced acute kidney injury (AKI) via its anti-inflammatory activity, but the underlying mechanisms remain largely unknown. In this study, a rat model of sepsis was established by cecal ligation and puncture (CLP), 30 mg/kg resveratrol was intraperitoneally administrated immediately after the CLP operation. HK-2 cells treated by 1 μg/ml lipopolysaccharide, 0.2 μM tunicamycin, 2.5 mM irestatin 9389 and 20 μM resveratrol were used for in vitro study. The results demonstrated that resveratrol significantly improved the renal function and tubular epithelial cell injury and enhanced the survival rate of CLP-induced rat model of sepsis, which was accompanied by a substantial decrease of the serum content and renal mRNA expressions of TNF-α, IL-1β and IL-6. In addition, resveratrol obviously relieved the endoplasmic reticulum stress, inhibited the phosphorylation of inositol-requiring enzyme 1(IRE1) and nuclear factor-κB (NF-κB) in the kidney. In vitro studies showed that resveratrol enhanced the cell viability, reduced the phosphorylation of NF-κB and production of inflammatory factors in lipopolysaccharide and tunicamycin-induced HK-2 cells through inhibiting IRE1 activation. Taken together, administration of resveratrol as soon as possible after the onset of sepsis could protect against septic AKI mainly through inhibiting IRE1-NF-κB pathway-triggered inflammatory response in the kidney. Resveratrol might be a readily translatable option to improve the prognosis of sepsis.

Resveratrol enhances vascular reactivity in mice following lipopolysaccharide challenge via the RhoA-ROCK-MLCP pathway

The aim of the present study was to identify whether sepsis-induced vascular hyporeactivity is associated with microcirculation disturbance and multiple organ injuries. The current study assessed the impact of resveratrol (Res) treatment on lipopolysaccharide (LPS) challenge mediated vascular hyporeactivity. Effects of Res treatment (30 mg/kg; i.m.) at 1 h following LPS stimulation (5 mg/kg; i.v.) on the survival time, mean arterial pressure (MAP), and maximal difference of MAP (ΔMAP) to norepinephrine (NE; 4.2 µg/kg) in mice were observed. The reactivity to gradient NE of isolated mesenteric arterioles and the association with the RhoA-RhoA kinase (ROCK)-myosin light chain phosphatase (MLCP) pathway were investigated by myography, and the signaling molecule protein levels were assessed using ELISA. Res treatment prolonged the survival time of mice subjected to LPS challenge, but did not prevent the LPS-induced hypotension and increase in ΔMAP. Res treatment and RhoA agonist U-46619 incubation prevented LPS-induced vascular hyporeactivity ex vivo, which were suppressed by incubation with ROCK inhibitor Y-27632. LPS-induced vascular hyporeactivity was not affected by the MLCP inhibitor okadaic acid incubation, but was further downregulated by the co-incubation of OA plus Y-27632. The inhibiting effect of Y-27632 on Res treatment was eradicated by incubation with U-46619. Furthermore, RhoA inhibitor C3 transferase did not significantly inhibit the enhancing role of Res treatment, which was further increased by U-46619 plus C3 transferase co-incubation. In addition, Res treatment eradicated the LPS-induced decreases in p-RhoA and p-Mypt1 levels and increases in MLCP levels. The results of the present study indicate that post-treatment of Res significantly ameliorates LPS-induced vascular hyporeactivity, which is associated with the activation of the RhoA-ROCK-MLCP pathway.

Resveratrol Protects Sepsis-Induced Oxidative DNA Damage in Liver and Kidney of Rats

BACKGROUND

The increases of free radicals have been proposed to be involved in the pathogenesis of sepsis, which leads to multiple-organ dysfunction syndromes. The uses of antioxidants as a complementary tool in the medical care of oxidative stress-related diseases have attracted attention of researchers. Resveratrol (RV) has suggested being antioxidant, anti-proliferative, and anti-inflammatory effects in various experimental models and clinical settings.

AIMS

This study was undertaken to evaluate the protective effects of RV on oxidative DNA damage induced by sepsis in the liver and kidney tissues of Wistar albino rats.

STUDY DESIGN

Animal experimentation.

METHODS

Four experimental groups consisting of eight animals for each was created using a total of thirty-two male Wistar albino rats. Sham group was given 0.5 mL of saline intra-peritoneal (ip) only following laparatomy. Sepsis group was given 0.5 mL saline ip only following the induction of sepsis. RV-treated group was given a dose of 100 mg/kg ip RV in 0.5 mL saline following laparatomy. RV-treated sepsis group was given 100 mg/kg ip RV in 0.5 mL saline following the induction of sepsis. A model of sepsis was created by cecal ligation and puncture technique. In the liver and kidney tissues, oxidative stress parameters (malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPX)) and a proinflammatory cytokine (tumor necrosis factor alpha (TNF-alpha)), were evaluated spectrophotometrically and DNA damage was determined by the alkaline single cell gel electrophoresis (comet assay) technique using formamidopyrimidine DNA glycosylase protein.

RESULTS

In the RV-treated sepsis group, the levels of MDA and TNF-alpha were lower and GSH levels, SOD and GPX activities were higher than in the septic rats (p<0.05). RV treatment significantly reduced the sepsis-induced oxidative DNA damage in the liver and kidney cells (p<0.05).

CONCLUSION

It is suggested that RV treatment might reduce the sepsis-induced oxidative DNA damages in sepsis-related diseases; however, there is a need for more studies to clear up the protective mechanisms of RV against sepsis.

Does rosmarinic acid treatment have protective role against sepsis-induced oxidative damage in Wistar Albino rats?

Reactive oxygen species are believed to be involved in the development of sepsis. Plant-derived phenolic compounds are thought to be possible therapeutic agents against sepsis because of their antioxidant properties. Rosmarinic acid (RA) is a phenolic compound commonly found in various plants, which has many biological activities including antioxidant activity. The aim of this study was to investigate the effects of RA on sepsis-induced DNA damage in the lymphocytes and liver and kidney cells of Wistar albino rats by alkaline comet assay with and without formamidopyrimidine DNA glycosylase protein. The oxidative stress parameters such as superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities and total glutathione (GSH) and malondialdehyde (MDA) levels in the liver and kidney tissues and an inflammatory cytokine, tumor necrosis factor α (TNF-α) level in plasma were also evaluated. It is found that DNA damage in the lymphocytes, livers, and kidneys of the RA-treated rats was significantly lower than that in the sepsis-induced rats. RA treatment also decreased the MDA levels and increased the GSH levels and SOD and GSH-Px activities in the livers and kidneys of the sepsis-induced rats. Plasma TNF-α level was found to be decreased in the RA-treated rats. It seems that RA might have a role in the attenuation of sepsis-induced oxidative damage not only by decreasing the DNA damage but also by increasing the antioxidant status and DNA repair capacity of the animals.

Resveratrol Rescues Kidney Mitochondrial Function Following Hemorrhagic Shock

OBJECTIVE

Hemorrhagic shock may contribute to acute kidney injury (AKI) by profoundly altering renal mitochondrial function. Resveratrol (RSV), a naturally occurring sirtuin 1 (SIRT1) activator, has been shown to promote mitochondrial function and reduce oxidative damage in a variety of aging-related disease states. We hypothesized that RSV treatment during resuscitation would ameliorate kidney mitochondrial dysfunction and decrease oxidative damage following hemorrhagic shock.

METHODS

Using a decompensated hemorrhagic shock model, male Long-Evans rats (n = 6 per group) were killed prior to hemorrhage (sham), at severe shock, and following either lactated Ringer's (LR) resuscitation or LR + RSV resuscitation (RSV: 30 mg/kg). At each time point, blood samples were assayed for arterial blood gases, lactate, blood urea nitrogen, and serum creatinine. Mitochondria were also isolated from kidney samples in order to assess individual electron transport complexes (complexes I, II, and IV) using high-resolution respirometry. Total mitochondria reactive oxygen species were measured using fluorometry, and lipid peroxidation was assessed by measuring 4-hydroxynonenal by Western blot. Quantitative polymerase chain reaction was used quantify mRNA from peroxisome proliferator-activated receptor γ coactivator 1-α (PGC1-α) SIRT1, and proteins known to mitigate oxidative damage and promote mitochondrial biogenesis.

RESULTS

Resveratrol supplementation during resuscitation restored mitochondrial respiratory capacity and decreased mitochondrial reactive oxygen species and lipid peroxidation. Compared with standard LR resuscitation, RSV treatment significantly increased SIRT1 and PGC1-α expression and significantly increased both superoxide dismutase 2 and catalase expression. Although RSV was associated with decreased lactate production, pH, blood urea nitrogen, and serum creatinine values did not differ between resuscitation strategies.

CONCLUSIONS

Resuscitation with RSV significantly restored renal mitochondrial function and decreased oxidative damage following hemorrhagic shock.

Resveratrol attenuates renal injury and fibrosis by inhibiting transforming growth factor-β pathway on matrix metalloproteinase 7

Renal injury has a strong relationship to the subsequent development of renal fibrosis. In developing renal fibrosis, tubular epithelial cells in the kidney underwent epithelial-mesenchymal transition (EMT). Matrix metalloproteinase 7 (MMP7) was reported to reduce E-cadherin and induce EMT by up-regulation of β-catenin/lymphoid enhancer-binding factor 1 (LEF1) signaling. In this research, we tried to evaluate the role of resveratrol (RSV) on EMT process in renal injury and fibrosis. Human tubular epithelial cell HK-2 cells were treated with aristolochic acid (AAs) and transforming growth factor-β(TGF-β) to induce EMT with or without the administration of RSV. The inhibitory role of RSV on EMT in renal injury and fibrosis was determined by Western blotting, real-time PCR, and immunofluorescence staining. The EMT repressing role of RSV was also evaluated in vivo by renal ischemia-reperfusion (I/R) injury and unilateral ureteral obstruction (UUO) models. The underlying mechanism was investigated by shRNA interfering MMP7 and sirtuin 1 (SIRT1) expression. The results indicated that RSV reversed human kidney 2 (HK-2) cell EMT, renal I/R injury, and renal fibrosis. MMP7 inhibition was responsible for RSV-induced EMT repression. SIRT1 was up-regulated by RSV inhibited TGF-β pathway on MMP7 via deacetylating Smad4. In conclusion, RSV attenuated renal injury and fibrosis by inhibiting EMT process which was attributed to the fact that the up-regulated SIRT1 by RSV deacetylated Smad4 and inhibited MMP7 expression.

Resveratrol attenuates microvascular inflammation in sepsis via SIRT-1-Induced modulation of adhesion molecules in ob/ob mice

OBJECTIVE

Obesity, a sirtuin-1 (SIRT-1) -deficient state, increases morbidity and resource utilization in critically ill patients. SIRT-1 deficiency increases microvascular inflammation and mortality in early sepsis. The objective of the study was to study the effect of resveratrol (RSV), a SIRT-1 activator, on microvascular inflammation in obese septic mice.

METHODS

ob/ob and C57Bl/6 (WT) mice were pretreated with RSV versus dimethyl sulfoxide (DMSO) (vehicle) prior to cecal ligation and puncture (sepsis). We studied (1) leukocyte/platelet adhesion, (2) E-selectin, ICAM-1, and SIRT-1 expression in small intestine, and (3) 7-day survival. A group of RSV-treated mice received SIRT-1 inhibitor (EX-527) with sepsis induction, and leukocyte/platelet adhesion and E-selectin/ICAM-1 expression were studied. We treated endothelial (HUVEC) cells with RSV to study E-selectin/ICAM-1 and p65-acetylation (AC-p65) in response to lipopolysaccharide (LPS).

RESULTS

RSV treatment decreased leukocyte/platelet adhesion and E-selectin/ICAM-1 expression with increased SIRT-1 expression in septic ob/ob and WT mice, decreased E-selectin/ICAM-1 expression via increased SIRT-1 expression, and decreased AC-p65 expression in HUVEC. EX-527 abolished RSV-induced attenuation of microvascular inflammation in ob/ob septic mice. Finally, ob/ob mice in the sepsis+RSV group had significantly increased 7-day survival versus the sepsis+vehicle group.

CONCLUSIONS

RSV increases SIRT-1 expression in ob/ob septic mice to reduce microvascular inflammation and improves survival.

Protective effects of caffeoylxanthiazonoside isolated from fruits of Xanthium strumarium on sepsis mice

CONTEXT

The fruit of Xanthium strumarium L. (Asteraceae) has been used for the treatment of various inflammatory diseases.

OBJECTIVE

This study investigates the protective effect of caffeoylxanthiazonoside (CYXD) isolated from fruits of X. strumarium on sepsis mice in vitro and in vivo.

MATERIALS AND METHODS

Cecal ligation and puncture (CLP) operation was used to establish the sepsis mice model, and sham mice were also performed. CYXD was administered by intraperitoneal injection (10, 20, and 40 mg/kg/d), then the survival rate was measured in 96 h. Additionally, sepsis mice were induced by injection LPS (2 mg/kg); CYXD was administered by intraperitoneal injection (10, 20, and 40 mg/kg/d), then mice were sacrificed, and serum levels of TNF-α and IL-6 were determined by ELISA assay. Furthermore, the ability of CYXD to neutralize LPS was measured by using the LAL test, and expressions of TNF-α, IL-6 were determined by using real-time fluorogenic PCR.

RESULTS

Results indicated that CYXD significantly elevated survival rates of sepsis mice induced by CLP (p < 0.05) with survival rates of 35%, 45%, and 65%. Furthermore, the LPS level was decreased obviously by CYXD (1, 2, and 4 mg/L) (p < 0.05). Additionally, CYXD (10, 20, and 40 mg/kg) can not only significantly decrease TNF-α and IL-6 levels induced by LPS in mice's serum (p < 0.05), but also inhibit mRNA expressions of TNF-α and IL-6 induced by LPS in RAW 264.7 cells at doses of 20, 40, and 80 μg/mL (p < 0.05).

CONCLUSION

Our study demonstrated that CYXD has significant protective effects on sepsis mice.

The effects of resveratrol on hyperoxia-induced lung injury in neonatal rats

BACKGROUND

Bronchopulmonary dysplasia (BPD) is a chronic lung disease that causes significant morbidity and mortality in premature infants. Inflammation and oxidative injury play an important role in the pathogenesis of BPD. Resveratrol is an antioxidant and anti-inflammatory agent. In this study, the histopathological and biochemical effects of resveratrol on a hyperoxia-induced lung injury model in newborn rats were investigated.

METHODS

The experiment was performed on newborn rat pups from the 3(rd) to 13(th) postnatal day and they were randomly divided into four groups: Group 1 (air-exposed + saline, n = 10), Group 2 (air-exposed + resveratrol, n = 11), Group 3 (hyperoxia-exposed + saline, n = 6) and Group 4 (hyperoxia-exposed + resveratrol, n = 7). Resveratrol was administered (30 mg/kg/day) intraperitoneally. The histopathological effects of resveratrol on lung tissue were assessed by alveolar surface area, fibrosis, and smooth muscle actin (SMA) score, and the biochemical effects on lung tissue were assessed by glutathione (GSH), superoxide dismutase (SOD), nitric oxide (NO), tumor necrosis factor-α (TNF-α), and nuclear factor kappa B (NF-κB) levels.

RESULTS

The alveolar surface area, fibrosis, SMA score, and NO levels were found to be significantly higher in Group 3 compared with Group 1 (p < 0.05). In addition, it was found that resveratrol treatment significantly reduced the SMA score and the NO and TNF-α levels, and increased the GSH and SOD levels in the hyperoxia group (p < 0.05).

CONCLUSION

This experimental study showed that oxidative stress and NO contributed to the pathogenesis of hyperoxia-induced lung injury, and that resveratrol had a preventive effect on hyperoxic lung injury through its anti-inflammatory and antioxidant properties.

Therapeutic targeting of the mitochondrial dysfunction in septic acute kidney injury

PURPOSE OF REVIEW

Acute kidney injury (AKI) is a common and serious complication of severe sepsis. No targeted therapies exist for sepsis-associated AKI, suggesting a pressing need for elucidation of the underlying pathogenic mechanisms.

RECENT FINDINGS

Emerging studies of human and experimental septic AKI kidneys have affirmed the longstanding observation that cell death in the tubule is uncommon despite often severe impairment of filtration. Rather than cell death, there appears to be widespread sublethal injury to tubular epithelial mitochondria. These organelles efficiently harness energy through controlled oxidation of metabolic fuels, they house pro-apoptotic proteins, and they produce reactive oxygen species. Derangement in one or more of these functions may contribute to the large reduction in renal function in septic AKI despite only scant cell death. In experimental septic AKI, molecular markers of mitochondrial biogenesis and function - whose renal expression dips during injury - rebound to normal levels as kidney function improves. Results from knockout mice suggest that restoration of mitochondrial function within the nephron may be critical to functional recovery.

SUMMARY

Recent findings from human and experimental septic AKI studies strongly implicate the mitochondrion as an important target for sublethal kidney injury. Stimulating the natural pathways through which mitochondrial function is normally recovered following sepsis represents a promising strategy for the development of novel therapies.

Statins, fibrates, thiazolidinediones and resveratrol as adjunctive therapies in sepsis: could mitochondria be a common target?

Through their pleiotropic actions, statins, fibrates, thiazolidinediones and resveratrol can target multiple mechanisms involved in sepsis. Their actions on mitochondrial function are of interest in a pathological state where bioenergetic failure may play a key role in the development of organ dysfunction. We review these four drug groups as potential adjunctive therapies in sepsis with a particular focus upon mitochondria. Systematic review of clinical and experimental trials was done with a literature search using the PubMed database. Search terms included statins, fibrates, thiazolidinediones, resveratrol, mitochondria, sepsis, peroxisome proliferator-activated receptors, inflammation, oxidative stress and organ dysfunction. With the exception of statins, most of the compelling evidence for the use of these agents in sepsis comes from the experimental literature. The agents all exert anti-inflammatory and anti-oxidant properties, plus protective effects against mitochondrial dysfunction and stimulation of mitochondrial biogenesis. Improved outcomes (organ dysfunction, survival) have been reported in a variety of sepsis models. Notably, positive outcome effects were more commonly seen when the agents were given as pre- rather than post-treatment of sepsis. Statins, fibrates, thiazolidinediones and resveratrol prevent sepsis-induced injury to organs and organelles with outcome improvements. Their effects on mitochondrial function may be integral in offering this protection. Definitive clinical trials are needed to evaluate their utility in septic patients or those at high risk of developing sepsis.

Ursolic acid attenuates lipopolysaccharide-induced acute lung injury in a mouse model

AIM

To assess whether ursolic acid (UA) can attenuate lipopolysachharide (LPS)-induced acute lung injury and improve the survival time in a mouse model.

MATERIALS & METHODS

The mice were challenged with LPS and survival time was monitored from 0-96 h after LPS treatment. TNF-α, IL-6, IL-1β, HMGB1, nitric oxide (NO) and IL-10 concentration in serum were measured by ELISA. Myeloperoxidase activity, malondialdehyde, lung wet:dry weight ratio and lung permeability in lung tissues were detected. NF-κB, HMGB1 and inducible NO synthase in the lungs were detected by western blot.

RESULTS

UA markedly rescued lethality, improved survival time and lung pathological changes, inhibited TNF-α, IL-6, IL-1β, HMGB1 and NO, and increased IL-10 expression. In addition, UA can also decrease myeloperoxidase, malondialdehyde, lung wet:dry weight ratio and lung permeability. UA attenuated NF-κB, HMGB1 and inducible NO synthase protein expression in the lungs.

CONCLUSION

The results suggest that UA is capable of improving survival time and LPS-induced acute lung injury. UA has a potentially therapeutic role in septic shock.

Protective effects of resveratrol on sepsis-induced DNA damage in the lymphocytes of rats

Sepsis, often initiated by an infection, is a state of disrupted inflammatory homeostasis. There is increasing evidence that oxidative stress has an important role in the development of sepsis-induced multiorgan failure. Resveratrol (RV) is a polyphenolic compound found in the skin of red fruits, such as mulberries and red grapes, and in peanuts. RV has been reported to have an antioxidant, antiproliferative, and anti-inflammatory properties in various models. It has also been found to inhibit the proliferation of a variety of human cancer cell lines, including breast, prostate, colon, pancreatic, and thyroid. This study has been undertaken to assess the role of RV on the sepsis-induced oxidative DNA damage in the lymphocytes of Wistar albino rats by the standard and formamidopyrimidine DNA glycosylase (Fpg)-modified comet assays. The parameters of tail length, tail intensity, and tail moment were evaluated for the determination of DNA damage. According to the study, the DNA damage was found to be significantly higher in the sepsis-induced rats when compared with the control rats (p < 0.05). The parameters were significantly decreased in the RV-treated sepsis-induced group when compared with the sepsis-induced group. The parameters in the sepsis-induced rats were found to be significantly higher in the Fpg-modified comet assay when compared with the standard comet assay (p < 0.05), and RV treatment decreases the DNA damage in the sepsis-induced rats, suggesting that the oxidative stress is likely to be responsible for DNA damage and RV might have a role in the prevention of sepsis-induced oxidative DNA damage.

Resveratrol has antiinflammatory and antifibrotic effects in the peptidoglycan-polysaccharide rat model of Crohn's disease

BACKGROUND

Resveratrol has antiinflammatory and antifibrotic effects. Resveratrol decreases proliferation and collagen synthesis by intestinal smooth muscle cells. We hypothesized that resveratrol would decrease inflammation and fibrosis in an animal model of Crohn's disease.

METHODS

Peptidoglycan-polysaccharide (PG-PS) or human serum albumin (HSA) was injected into the bowel wall of Lewis rats at laparotomy. Resveratrol or vehicle was administered daily by gavage 1-27 days postinjection. On day 28, gross abdominal and histologic findings were scored. Cecal collagen content was measured by colorimetric analysis of digital images of trichrome-stained sections. Cecal levels of procollagen, cytokine, and growth factor mRNAs were determined.

RESULTS

PG-PS-injected rats (vehicle-treated) developed more fibrosis than HSA-injected rats by all measurements: gross abdominal score (P < 0.001), cecal collagen content (P = 0.04), and procollagen I and III mRNAs (P ≤ 0.0007). PG-PS-injected rats treated with 40 mg/kg resveratrol showed a trend toward decreased gross abdominal score, inflammatory cytokine mRNAs, and procollagen mRNAs. PG-PS-injected rats treated with 100 mg/kg resveratrol had lower inflammatory cytokine mRNAs (IL-1β [3.50 ± 1.08 vs. 10.79 ± 1.88, P = 0.005], IL-6 [17.11 ± 9.22 vs. 45.64 ± 8.83, P = 0.03], tumor necrosis factor alpha (TNF-α) [0.80 ± 0.14 vs. 1.89 ± 0.22, P = 0.002]), transforming growth factor beta 1 (TGF-β1) mRNA (2.24 ± 0.37 vs. 4.06 ± 0.58, P = 0.01), and histologic fibrosis score (6.4 ± 1.1 vs. 9.8 ± 1.0; P = 0.035) than those treated with vehicle. There were trends toward decreased gross abdominal score and decreased cecal collagen content. Procollagen I, procollagen III, and IGF-I mRNAs also trended downward.

CONCLUSIONS

Resveratrol decreases inflammatory cytokines and TGF-β1 in the PG-PS model of Crohn's disease and demonstrates a promising trend in decreasing tissue fibrosis. These findings may have therapeutic applications in inflammatory bowel disease.

Effects of diphenyl diselenide on oxidative stress induced by sepsis in rats

Sepsis is a potentially deadly complication that can be caused by different factors. Actually, it is known that oxidative stress is involved in the pathogenesis of sepsis. Thus, the aim of this study was to evaluate the effect of diphenyl diselenide (PhSe)(2), an emergent compound, on oxidative stress parameters induced by sepsis in rats. Animals were pre-injected with (PhSe)(2) or vehicle. Twenty-four hours later, sepsis was induced by cecal ligation puncture (CLP). After 12 h, liver was taken for thiobarbituric acid reactive species (TBARS) measurement, δ-aminolevunic acid dehydratase (δ-ALA-D), Cu/Zn superoxide dismutase (Cu/Zn SOD) and catalase (CAT) activities assay. The sepsis increased TBARS, inhibited δ-ALA-D, activated Cu/Zn SOD and had a tendency to decrease CAT activity. However, (PhSe)(2) prevented the TBARS formation, but did not prevent the inhibition of δ-ALA-D activity in the animals with damage. Thus, this study showed that (PhSe)(2) partially prevents the oxidative stress induced by sepsis, indicating the potential of this compound as a treatment for this pathology. Nevertheless, more tests should be performed to confirm the hypothesis suggested here.

Resveratrol causes cell cycle arrest, decreased collagen synthesis, and apoptosis in rat intestinal smooth muscle cells

One of the most difficult and treatment-resistant complications of Crohn's disease is the development of fibrotic intestinal strictures due to mesenchymal cell hyperplasia and collagen deposition. Resveratrol, a phytoalexin found in berries, peanuts, grapes, and red wine, has been shown to inhibit fibrosis in vasculature, heart, lung, kidney, liver, and esophagus in animal models. Resveratrol has also been shown to inhibit oxidation, inflammation, and cell proliferation and to decrease collagen synthesis in several cell types or animal models. The aim of this study was to determine whether resveratrol has antifibrotic effects on intestinal smooth muscle cells. Responses to resveratrol by cultured smooth muscle cells isolated from colons of untreated Lewis rats were examined; this rat strain is used in a model of Crohn's disease with prominent intestinal fibrosis. A relative decrease in cell numbers following treatment with 50 and 100 μM resveratrol was evident at 24 h (P ≤ 0.005). This effect was largely due to cell cycle arrest, with an increase in the percent of cells in S phase from 8 to 25-35% (P < 0.05). Cell viability was unchanged until 2-3 days of treatment when there was a 1.2- to 5.0-fold increase in the percent of apoptotic cells, depending on the assay (P < 0.05). Expression of collagen type I protein was decreased following treatment with resveratrol for 24 h (to 44 and 25% of control levels with 50 and 100 μM resveratrol, respectively; P < 0.05). Expression of procollagen types I and III mRNA was also decreased with resveratrol treatment. Resveratrol (50 μM) diminished the proliferative response to TGF-β₁ (P = 0.02) as well as IGF-I-stimulated collagen production (P = 0.02). Thus resveratrol decreases intestinal smooth muscle cell numbers through its effects on cell cycle arrest and apoptosis and also decreases collagen synthesis by the cells. These effects could be useful in preventing the smooth muscle cell hyperplasia and collagen deposition that characterize stricture formation in Crohn's disease.

Pharmacological targets in the renal peritubular microenvironment: implications for therapy for sepsis-induced acute kidney injury

One of the most frequent and serious complications to develop in septic patients is acute kidney injury (AKI), a disorder characterized by a rapid failure of the kidneys to adequately filter the blood, regulate ion and water balance, and generate urine. AKI greatly worsens the already poor prognosis of sepsis and increases cost of care. To date, therapies have been mostly supportive; consequently there has been little change in the mortality rates over the last decade. This is due, at least in part, to the delay in establishing clinical evidence of an infection and the associated presence of the systemic inflammatory response syndrome and thus, a delay in initiating therapy. A second reason is a lack of understanding regarding the mechanisms leading to renal injury, which has hindered the development of more targeted therapies. In this review, we summarize recent studies, which have examined the development of renal injury during sepsis and propose how changes in the peritubular capillary microenvironment lead to and then perpetuate microcirculatory failure and tubular epithelial cell injury. We also discuss a number of potential therapeutic targets in the renal peritubular microenvironment, which may prevent or lessen injury and/or promote recovery.

Resveratrol improves renal microcirculation, protects the tubular epithelium, and prolongs survival in a mouse model of sepsis-induced acute kidney injury

The mortality rate of patients who develop acute kidney injury during sepsis nearly doubles. The effectiveness of therapy is hampered because it is usually initiated only after the onset of symptoms. As renal microvascular failure during sepsis is correlated with the generation of reactive nitrogen species, the therapeutic potential of resveratrol, a polyphenol vasodilator that is also capable of scavenging reactive nitrogen species, was investigated using the cecal ligation and puncture (CLP) murine model of sepsis-induced acute kidney injury. Resveratrol when given at 5.5 h following CLP reversed the decline in cortical capillary perfusion, assessed by intravital microscopy, at 6 h in a dose-dependent manner. Resveratrol produced the greatest improvement in capillary perfusion and increased renal blood flow and the glomerular filtration rate without raising systemic pressure. A single dose at 6 h after CLP was unable to improve renal microcirculation assessed at 18 h; however, a second dose at 12 h significantly improved microcirculation and decreased the levels of reactive nitrogen species in tubules, while improving renal function. Moreover, resveratrol given at 6, 12, and 18 h significantly improved survival. Hence, resveratrol may have a dual mechanism of action to restore the renal microcirculation and scavenge reactive nitrogen species, thus protecting the tubular epithelium even when administered after the onset of sepsis.

Protective effects of pycnogenol against ischemia reperfusion-induced oxidative renal injury in rats

INTRODUCTION

Oxygen free radicals are involved in pathophysiology of ischemia/reperfusion (I/R) injury. This study was designed to assess the possible protective effect of pycnogenol (PYC) against I/R-induced oxidative renal damage.

MATERIALS AND METHODS

Wistar albino rats were unilaterally nephrectomized and subjected to 45 min of renal pedicle occlusion followed by 3 h of reperfusion. PYC (10 mg kg(-1), i.p.) or saline was administered at 15 min prior to ischemia and immediately before the reperfusion period. At the end of the 3 h, rats were decapitated and trunk blood was collected. Creatinine, blood urea nitrogen (BUN), and lactate dehydrogenase (LDH) activity were measured in the serum samples, while proinflammatory cytokines, TNF-alpha, IL-1beta, and IL-6 levels were assayed in plasma samples. Kidney samples were taken for the determination of tissue malondialdehyde (MDA), glutathione (GSH) levels, Na+, K+-ATPase, and myeloperoxidase (MPO) activities, and the extent of tissue injury was analyzed microscopically.

RESULTS

Ischemia/reperfusion caused a significant decrease in tissue GSH level and Na+, K+-ATPase activity, which was accompanied with significant increases in the renal MDA level and MPO activity. Similarly, serum creatinine and BUN levels, as well as LDH and IL-1beta, IL-6, and TNF-alpha levels, were elevated in the saline-treated I/R group as compared to saline-treated control group. On the other hand, PYC treatment reversed all these biochemical indices, as well as histopathological alterations that were induced by I/R.

CONCLUSIONS

Findings of the present study suggest that pycnogenol exerts renoprotective effects, via its free radical scavenging and antioxidant activities, that appear to involve the inhibition of tissue neutrophil infiltration.

The effect of resveratrol in tracheal tissue of rats exposed to cigarette smoke

OBJECTIVE

The aim of this study was to evaluate the effect of resveratrol on the tracheal tissue of rats exposed to cigarette smoke.

MATERIALS AND METHODS

40 adult Wistar albino rats were divided into four groups for an experiment of 6 weeks. Animals in group 1 were controls (n = 10). Rats in group 2 were exposed to cigarette smoke only, and rats in group 3 received daily intraperitoneal injections of resveratrol (10 mg/kg/d). Animals in group 4 were exposed to both cigarette smoke and intraperitoneal injections of resveratrol. Rats of all groups were sacrificed using cervical dislocation. The tracheas were removed and embedded in paraffin blocks. Sections of 4-5 mum thickness were prepared from the blocks. These sections were stained with hematoxylin and eosin, periodic acid-Schiff, and Alcian blue and viewed with a Leica DFC 280 light microscope.

RESULTS

Tracheal sections showed that, in group 2 (cigarette smoke group), there was desquamation of epithelial cells into the tracheal lumen, loss of cilia in the epithelial layer, an increase of goblet cells, activation of serous glands at the submucosa, and cell infiltration. In group 4 (cigarette smoke + resveratrol group), all these findings also existed but only a few sections were affected. It was observed that cigarette smoking caused morphological changes such as epithelial degeneration in the upper airway. These morphological changes were correlated with the amount of toxic substances in the cigarette smoke.

CONCLUSION

We found that resveratrol had a preventive role in the histopathological changes caused by cigarette smoking in the rat trachea.

Effect of resveratrol on tubular damage and interstitial fibrosis in kidneys of rats exposed to cigarette smoke

The aim of this study was to evaluate the effect of resveratrol on kidney tissue of rats exposed to cigarette smoke. Forty adult male Wistar Albino rats were divided into four groups. Animals in group 1 was the control group. For 6 weeks, group 2 was exposed to cigarette smoke; group 3 received daily intraperitoneal injections of resveratrol (10 mg/kg/d); and group 4 was exposed to both cigarette smoke and intraperitoneal resveratrol. All rats were sacrificed with cervical dislocation. The kidney tissues were obtained, fixed in Bouin's fixative and embeded in paraffin blocks. Samples were sectioned to 4-5 microns thickness, stained with hematoxylin/eosin (H/E), Masson's trichromic, periodic acid-schiff (PAS) and were examined by light microscopy for tubular injury and interstitial fibrosis. Results were compared by non-parametric tests. Hydropic degeneration, tubular atrophy, tubulo-interstitial fibrosis, interstitial cell infiltration, vacuolar degeneration and desquamation were prominent in group 2. In group 4, hydropic degeneration, epithelial cell vacuolization and desquamation was not observed, but occasional tubular atrophy and dilation were observed. Our study suggests that, some morphological alterations in the rat kidney, due to cigarette smoke may be prevented by resveratrol.

The effect of β-glucan on trace element levels in intra-abdominal sepsis in rats

Sepsis is associated with the development of progressive damage in multiple organ systems. The beneficial effect of glucans has been attributed to modulation of immune function and enhances defense against bacterial, viral, fungal, and parasitic infections. The aim of this study was to investigate the putative protective effect of ß-glucan on changes of trace element levels in various tissues after experimental sepsis in rats. Sepsis was induced by cecal ligation and perforation (CLP) in 28 male Wistar albino rats. To evaluate this, rats were divided into four groups as sham operated, ß-glucan treated sham operated, CLP, and ß-glucan treated CLP. Sixteen hours after operation, rats were decapitated and zinc (Zn) and copper (Cu) levels were determined in the liver, kidney, heart, diaphragm, and lung tissues. The results demonstrate that sepsis significantly decreased zinc and copper levels of all tissues. The decrease in tissue zinc and copper levels demonstrates the role of trace elements in sepsis-induced tissue damage. Our results indicated that ß-glucan administration did not return the zinc and copper levels to the control group level, and it seems likely that the given dose of ß-glucan was insufficient to prevent sepsis-induced organ injury.

Protective and therapeutic effects of resveratrol on acetic acid-induced gastric ulcer

Sprague Dawley rats of both sexes were injected with either saline or RVT (10 mg/kg) either before or after acetic acid ulcer induction and decapitated 3, 5 or 10 days after ulcer. In the saline-treated ulcer groups, macroscopically evident ulcers were observed, while RVT-pretreated or RVT-treated groups had lower macroscopic ulcer scores. Likewise, the microscopic damage scores were lower for the RVT-administered groups. Gastric myeloperoxidase activity, malondialdehyde, collagen and tumour necrosis factor-alpha levels, as well as luminol- and lucigenin-enhanced chemiluminescence levels that were elevated in the saline-administered ulcer groups, were depressed with both RVT-pretreatment and RVT-treatment. Moreover, depleted glutathione levels in the ulcer groups were increased back to control levels by both pre- and post-treatments of RVT. Results demonstrate that resveratrol has both protective and therapeutic effects on oxidative gastric damage by suppressing pro-inflammatory cascades, including the activation of pro-inflammatory cytokines, accumulation of neutrophils and release of oxygen-derived free radicals.

NF-kappaB signaling pathway and its therapeutic implications in human diseases

The nuclear factor-kappaB (NF-kappaB) pathway is one of the most important cellular signal transduction pathways involved in both physiologic processes and disease conditions. It plays important roles in the control of immune function, inflammation, stress response, differentiation, apoptosis, and cell survival. Moreover, NF-kappaB is critically involved in the processes of development and progression of cancers. More importantly, recent studies have shown that NF-kappaB signaling also plays critical roles in the epithelial-mesenchymal transition (EMT) and cancer stem cells. Therefore, targeting of NF-kappaB signaling pathway could be a potent strategy for the prevention and/or treatment of human cancers and inflammatory diseases.

Role of oxidants in lung injury during sepsis

The role of oxidative stress has been well appreciated in the development of sepsis-induced acute lung injury (ALI). Oxidative stress in sepsis-induced ALI is believed to be initiated by products of activated lung macrophages and infiltrated neutrophils, promptly propagating to lung epithelial and endothelial cells. This leads to tissue damage and organ dysfunction. On stimulation, neutrophils (PMNs) enable their migration machinery. The lung undergoes changes favoring adhesion and transmigration of PMNs, resulting in PMN accumulation in lung, which is a characteristic of sepsis-induced ALI. Oxidative stress turns on the redox-sensitive transcription factors (NF-kappaB, AP-1), resulting in a large output of proinflammatory cytokines and chemokines, which further aggravate inflammation and oxidative stress. During the process, transcription factor nuclear factor-erythroid 2-p45-related factor 2 (Nrf2) and heme oxygenase (HO) appear to play the counterbalancing roles to limit the propagation of oxidative stress and inflammatory responses in lung. Many antioxidants have been tested to treat sepsis-induced ALI in animal models and in patients with sepsis. However, the results are inconclusive. In this article, we focus on the current understanding of the pathogenesis of sepsis-induced ALI and novel antioxidant strategies for therapeutic purposes.

Recombinant activated protein C induces dose-dependent changes in inflammatory mediators, tissue damage, and apoptosis in in vivo rat model of sepsis

BACKGROUND

Sepsis is the tenth leading cause of death in the U.S. and creates a $16.7 billion burden on the healthcare system every year. Sepsis is characterized by a severe uncontrolled inflammatory response to the infection. Various cells and mediators are activated, and the result is a complex interaction between the inflammation and coagulation cascades leading to capillary leakage and end-organ ischemia. Current therapeutic strategies, such as recombinant human activated protein C, focus on this interplay. However, this drug's precise mechanism of action is not well understood. The aim of this study was to assess cytokine production, tissue damage, and apoptosis in a rat model of sepsis in response to various doses of this drug.

METHODS

Sprague-Dawley rats were divided into eight groups, including negative control, sham, sepsis only, and five treatment groups. The sepsis and treatment groups were given Escherichia coli. Each of the treatment groups received a different dose of recombinant activated protein C to complete 30-min or 270-min infusion times from the onset of sepsis. Serum and tissue samples were collected. Interleukin (IL)-6 concentrations were measured, and serum malondialdehyde (MDA) concentrations were determined to assess generalized tissue damage. Apoptosis in the lung was evaluated using a semi-quantitative ligation-mediated polymerase chain reaction assay.

RESULTS

The physiologic effects of recombinant activated protein C are dose dependent and determined by the duration of infusion. Higher doses of the drug were associated with less inflammation, apoptosis, and generalized tissue damage. Sepsis increased the mean concentration of MDA (2.1 vs. 10.9 pmol/mg of protein) and IL-6 (0 vs. 10,763 pg/mL) compared with sham-treated animals, as well as the magnitude of apoptosis in lung (2,037 vs. 8,709 pixels) (all p < 0.05). Infusion of recombinant activated protein C attenuated these responses in a dose-response manner. Interleukin-6 and MDA concentrations were increased by lower-dose therapy, but attenuated significantly by the higher-dose infusion at 5 mg/kg/h. Apoptosis was attenuated by both the lower and the higher dose, but more so with the higher dose.

CONCLUSIONS

These data can assist in establishing an optimal dose and infusion time of this drug for extrapolation to therapy of human beings. The goal now is to elucidate these findings further so that the maximum benefit of the drug may be achieved with the least possible harmful effects.

Glucan and resveratrol complex - possible synergistic effects on immune system

BACKGROUND

Recent data showing that glucan elicited defense responses in grapevine and induced protection via induction of resveratrol production led us to evaluate the possible synergetic effects of glucan and resveratrol complex on immune reactions.

METHODS

We measured phagocytosis using HEMA particles, expression of cell surface markers via fl ow cytometry, expression of cytokines using ELISA, recovery after fluorouracil-induced leucopenia and effects on gene expression via RT-PCR.

RESULTS

Our results showed that both glucan and resveratrol complex stimulated phagocytosis of blood leukocytes, caused increase in surface expression of CD(+) splenocytes and showed higher restoration of spleen recovery after experimentally induced leucopenia. In all these cases, strong synergetic effects were observed. When we measured the effects of these substances on expression level of NF-kappaB2, Cdc42 and Bcl-2 in breast cancer cells, upregulation of Cdc42 expression was evident only using both immunomodulators in combination.

CONCLUSIONS

In conclusion, our data suggest significant synergy in stimulation of immune reactions and support further studies of these natural immunomodulators.

Resveratrol improves ifosfamide-induced Fanconi syndrome in rats

Regarding the mechanisms of ifosfamide (IFO)-induced urinary toxicity, several hypotheses have been put forward, among which oxidative stress and depletion of glutathione are suggested. This investigation elucidates the role of free radicals in IFO-induced toxicity and the protection by resveratrol, a natural phytoalexin. Wistar albino rats were injected intraperioneally with saline (0.9% NaCl; control), saline+resveratrol (RVT; 10 mg/kg/day), ifosfamide (IFO; 50 mg/kg/day) or IFO+RVT for 5 days. Urine was collected for 24 h during the 5th day, and at the 120th h after the first injections, animals were killed by decapitation and trunk blood was collected. Lactate dehydrogenase (LDH) activity, total antioxidant capacity (AOC) and pro-inflammatory cytokines TNF-alpha, IL-beta and IL-6 were assayed in plasma samples. Kidney and bladder tissues were obtained for biochemical and histological analysis. Formation of reactive oxygen species in the tissue samples was monitored by using chemiluminescence (CL) technique with luminol and lucigenin probes. The results demonstrated that IFO induced a Fanconi syndrome characterized by increased urinary sodium, phosphate, glucose and protein, along with increased serum creatinine and urea levels. On the other hand, RVT markedly ameliorated the severity of renal dysfunction induced by IFO. Furthermore IFO caused a significant decrease in plasma AOC, which was accompanied with significant increases in the levels of the pro-inflammatory mediators and LDH activity, while RVT treatment reversed all these biochemical indices. In the saline-treated IFO group, glutathione levels were decreased significantly, while the malondialdehyde levels, myeloperoxidase activity and collagen content were increased in both tissues, which were in parallel with the increases in CL values. In the RVT-treated IFO group, all of these oxidant responses were prevented significantly. Our results suggest that IFO causes oxidative damage in the renal and bladder tissues and resveratrol, via its antioxidant effects, protects these tissues. Therefore, its therapeutic role in preventing the development of chemotherapeutic drug-induced major toxicity in the urinary system requires further elucidation.

Resveratrol Improves Ischemia/Reperfusion-Induced Oxidative Renal Injury in Rats

BACKGROUND

The present study was designed to examine whether resveratrol, a potent antioxidant, protects against renal ischemia-reperfusion (I/R) injury.

METHODS

Wistar albino rats were unilaterally nephrectomized and subjected to 45 min of renal pedicle occlusion followed by 6 h of reperfusion. Resveratrol (RVT, 30 mg/kg, i.p.) or vehicle was administered twice, at 30 min prior to ischemia and immediately before the reperfusion period. At the end of the reperfusion period, rats were decapitated and kidney samples were taken for histological examination or determination of levels of renal malondialdehyde (MDA), an end product of lipid peroxidation; glutathione (GSH), a key antioxidant; and myeloperoxidase (MPO) activity, an index of tissue neutrophil infiltration. Formation of reactive oxygen species in hepatic tissue samples was monitored by using chemiluminescence (CL) technique with luminol and lucigenin probes. Renal tissue collagen content as a fibrosis marker was also determined, while serum creatinine and urea concentrations were measured for the evaluation of renal function. Tumor necrosis factor-alpha (TNF-alpha ) and lactate dehydrogenase (LDH) were also assayed in serum samples.

RESULTS

Ischemia/reperfusion caused a significant decrease in tissue GSH level, which was accompanied by significant increases in the renal luminol and lucigenin CL values, MDA level, MPO activity and collagen content. Similarly, serum creatinine and BUN levels, as well as LDH and TNF-alpha, were elevated in the I/R group as compared to control group. On the other hand, resveratrol treatment reversed all these biochemical indices, as well as histopathological alterations that were induced by I/R.

CONCLUSIONS

Findings of the present study suggest that resveratrol exerts renoprotective effects via its radical scavenging and antioxidant activities, which appear to involve the inhibition of tissue neutrophil infiltration.

Resveratrol alleviates bleomycin-induced lung injury in rats

Antioxidant therapy may be useful in diseases with impaired oxidant-antioxidant balance such as pulmonary fibrosis. This study was designed to examine the effects of resveratrol, an antioxidant agents, against bleomycin-induced pulmonary fibrosis and oxidative damage. Wistar albino rats were administered a single dose of bleomycin (5 mg/kg; via the tracheal cannula) followed by either saline or resveratrol (10 mg/kg; orally) for 14 days. The effect of resveratrol on pulmonary oxidative damage was studied by cell count and analysis of cytokine levels (TGF-beta, TNF-alpha, IL-1beta and IL-6) in the bronchoalveolar lavage fluid (BALF) and biochemical measurements of malondialdehyde (MDA), an end product of lipid peroxidation; glutathione (GSH), a key antioxidant; and myeloperoxidase (MPO) activity, an index of neutrophil infiltration, in the lung tissue. Bleomycin-induced lung fibrosis was determined by lung collagen contents and also microscopically. Bleomycin caused a significant decrease in lung GSH, which was accompanied with significant increases in MDA level, MPO activity, and collagen contents of the lung tissue concomitant with increased levels of the pro-inflammatory mediators and cell count in BALF. On the other hand, resveratrol treatment reversed all these biochemical indices as well as histopathological alterations induced by bleomycin. The results demonstrate the role of oxidative mechanisms in bleomycin-induced pulmonary fibrosis, and resveratrol, by its antioxidant properties, ameliorates oxidative injury and fibrosis due to bleomycin. Thus, an effective supplement with resveratrol as an adjuvant therapy may be a very promising agent in alleviating the side effects of bleomycin, an effective chemotherapeutic agent.