Potential role of reactive oxygen species in pancreatitis-associated multiple organ dysfunction

Electro-microenvironment modulated inhibition of endogenous biofilms by piezo implants for ultrasound-localized intestinal perforation disinfection

Endogenous bacterial infections from damaged gastrointestinal (GI) organs have high potential to cause systemic inflammatory responses and life-threatening sepsis. Current treatments, including systemic antibiotic administration and surgical suturing, are difficult in preventing bacterial translocation and further infection. Here, we report a wireless localized stimulator composed of a piezo implant with high piezoelectric output serving as an anti-infective therapy patch, which aims at modulating the electro-microenvironment of biofilm around GI wounds for effective inhibition of bacterial infection if combined with ultrasound (US) treatment from outside the body. The pulsed charges generated by the piezo implant in response to US stimulation transfer into bacterial biofilms, effectively destroying their macromolecular components (e.g., membrane proteins), disrupting the electron transport chain of biofilms, and inhibiting bacterial proliferation, as proven by experimental studies and theoretical calculations. The piezo implant, in combination with US stimulation, also exhibits successful in vivo anti-infection efficacy in a rat cecal ligation and puncture (CLP) model. The proposed strategy, combining piezo implants with controllable US activation, creates a promising pathway for inhibiting endogenous bacterial infection caused by GI perforation.

Ferulic acid attenuates pancreaticobiliary duct occlusion-induced inflammation in both pancreas and liver

INTRODUCTION

Acute pancreatitis is a systemic inflammatory disorder characterized by the hyperactivation of digestion enzymes and the release of proinflammatory cytokines. Ferulic acid (FA) is a hydroxycinnamic acid derivative that has recently been shown to have antioxidant and anti-inflammatory properties.

AIM

The anti-inflammatory effects of FA were investigated in the pancreaticobiliary duct ligation (PBDL)-induced pancreatitis model.

METHODS

Wistar albino rats (250-300 g; female = male) were divided into sham operation and PBDL groups. Some PBDL-performed animals were given intragastric saline or 250 mg/kg FA or 500 mg/kg FA 30 min before the PBDL and for 3 consecutive days. Moreover, the control group received saline. Blood samples are collected at the 24th, 48th, and 72nd hours to measure serum tumor necrosis factor (TNF)-α, liver, and pancreatic enzymes. At the 72nd hour, rats were euthanized; pancreas, lung, and liver samples were collected, scored microscopically, and analyzed for myeloperoxidase activity, malondialdehyde, and glutathione levels. One-way ANOVA with Tukey-Kramer tests were used for statistical analysis.

RESULTS

FA treatment reduced myeloperoxidase activity and prevented the depletion of glutathione in all three tissues. With FA treatments, high malondialdehyde levels in the pancreas and liver were reduced, as were serum TNF- α, amylase, lipase, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, and total bilirubin levels. Additionally, FA ameliorated microscopic damage in the pancreas and liver significantly.

CONCLUSION

According to the findings, FA protects endogenous antioxidant content, prevents neutrophil infiltration, and decreases lipid peroxidation in PBDL-induced pancreatitis. Furthermore, FA improves tissue damage induced by pancreatitis with its anti-inflammatory effects.

Genistein attenuated oxidative stress, inflammation, and apoptosis in L-arginine induced acute pancreatitis in mice

Aim

Acute pancreatitis is a common and potentially serious condition. However, a specific treatment for this condition is still lacking. Genistein, with its anti-oxidant and anti-inflammatory effects, could possibly be used to tackle the underlying pathophysiology of acute pancreatitis. Therefore, the aim of this study was to investigate the effects of genistein on oxidative stress, inflammation, and apoptosis in acute pancreatitis induced by L-arginine in mice.

Methods

Twenty-four male ICR mice were equally divided into 4 groups: Control (Con); Acute pancreatitis (AP) group: Two doses of i.p. 350 mg/100 g body weight (BW) of L-arginine were administered 1 h apart; AP and low-dose genistein (LG) group: mice were given i.p. injection of 10 mg/kg genistein 2 h prior to L-arginine injection followed by once-daily dosing for 3 days; and AP and high-dose genistein (HG) group: mice were given 100 mg/kg genistein with the similar protocol as the LG group. Pancreatic tissue was evaluated for histopathological changes and acinar cell apoptosis, malondialdehyde (MDA) levels, immunohistochemical staining for myeloperoxidase (MPO), nuclear factor-kappa beta (NF-kB), and 4-hydroxynonenal (4-HNE). Serum levels of amylase (AMY), c-reactive protein (CRP), and interleukin (IL)-6 were measured.

Results

Significant increases in the degree of acinar cell apoptosis, pancreatic MDA, serum IL-6 and amylase, MPO, NF-kB and 4-HNE positivity were observed in the AP group. All these parameters declined after low- and high-dose genistein treatment. Severe pancreatic inflammation, edema, and acinar cell necrosis were observed in the AP group. Significant improvement of histopathological changes was seen in both low- and high-dose genistein groups. There were no significant differences in any parameters between low and high doses of genistein.

Conclusion

Genistein could attenuate the severity of histopathological changes in acute pancreatitis through its anti-oxidant, anti-inflammatory, and anti-apoptotic properties.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03689-9.

Angiotensin-(1-7) Restores Microcirculation Profiles in Acute Pancreatitis: Secret of Telomerase Reverse Transcriptase

OBJECTIVES

The aim of this study was to investigate whether angiotensin (Ang)-(1-7)-mediated restoration of pancreatic microcirculation profiles and endothelial injury is associated with the expression of telomerase reverse transcriptase (TERT).

METHODS

Wild-type, TERT transgene, and TERT knockdown mice were used in this study, and acute pancreatitis model was induced by intraperitoneal injection of cerulein and lipopolysaccharide (LPS). Pancreatitis was confirmed by histopathology and serum amylase levels. Pancreatic microcirculation function was assessed by laser Doppler. Endothelial injury model was established by exposing endothelial cells to LPS. Proinflammatory cytokines were detected using enzyme-linked immunosorbent assay, endothelial permeability was detected using transwell assay, and mitochondrial dysfunction and mitochondrial reactive oxygen species (mtROS) were determined by performing confocal microscopy.

RESULTS

The effects of Ang-(1-7) in the treatment of pancreatic microcirculation dysfunction were associated with TERT expression. In addition, Ang-(1-7) protected against endothelial cell lesions via inhibiting the increase in endothelial cell permeability and release of proinflammatory cytokines in a TERT-dependent manner. Furthermore, TERT was involved in Ang-(1-7)-mediated attenuation of mitochondrial dysfunction and mtROS in LPS-induced endothelial cells.

CONCLUSIONS

Angiotensin-(1-7) restores pancreatic microcirculation profiles and reverses endothelial injury by inhibiting mtROS production and mitochondrial dysfunction in a TERT-dependent manner.

Dietary glucose oxidase and/or catalase supplementation alleviates intestinal oxidative stress induced by diquat in weaned piglets

This study investigated the effects of dietary exogenous glucose oxidase (GOD) and/or catalase (CAT) on the intestinal antioxidant capacity and barrier function in piglets under oxidative stress. Sixty pigs assigned randomly to five treatment groups-CON: basal diet; DIQ: basal diet; GOD: basal diet + 40-U GOD/kg diet; CAT: basal diet + 50-U CAT/kg diet; and GC: basal diet + 40-U GOD/kg diet + 50-U CAT/kg diet-were analyzed. On Day 14, the CON group was injected with saline, and the others were treated with diquat. The results showed that in diquat-treated piglets, supplementation of dietary GOD and CAT elevated the superoxide dismutase and CAT activities and attenuated the malondialdehyde level in plasma and intestinal mucosa, enhanced the duodenal villus height and villus height/crypt depth ratio, upregulated ZO-1 mRNA level, and attenuated the apoptosis of the epithelial cells and caspase-3 mRNA level in the intestine. Additionally, the supplementation upregulated mRNA expression of the intestinal NF-E2-related factor 2-regulated genes in diquat-treated piglets. However, GOD combined with CAT could not alleviate oxidative damage better than supplementation of CAT or GOD alone under oxidative stress. Overall, the study provides a potential alternative that could relieve the weaning stress in piglets and help formulate antibiotic-free diets.

Inflammatory capacity of exosomes released in the early stages of acute pancreatitis predicts the severity of the disease

As acute pancreatitis progresses to the severe form, a life-threatening systemic inflammation is triggered. Although the mechanisms involved in this process are not yet well understood, it has been proposed that circulating exosomes may be involved in the progression of inflammation from the pancreas to distant organs. Here, the inflammatory capacity and protein profile of plasma exosomes obtained during the first 24 h of hospitalization of patients diagnosed with acute pancreatitis were characterized and compared with the final severity of the disease. We found that the final severity of the disease strongly correlates with the inflammatory capacity of exosomes in the early stages of acute pancreatitis. Exosomes isolated from patients with mild pancreatitis had no effect on macrophages, while exosomes isolated from patients with severe pancreatitis triggered NFκB activation, TNFα and IL1β expression, and free radical generation. To delve deeper into the mechanism involved, we performed a proteomic analysis of the different exosomes that allowed us to identify different groups of proteins whose concentration was also correlated with the clinical classification of pancreatitis. In particular, an increase in the amount of S100A8 and S100A9 carried by exosomes of severe pancreatitis suggests that the mechanism of action of exosomes is mediated by the effect of these proteins on NADPH oxidase. This enzyme is activated by S100A8/S100A9, thus generating free radicals and promoting an inflammatory response. Along these lines, we observed that inhibition of this enzyme abolished all the pro-inflammatory effects of exosomes from severe pancreatitis. All this suggests that the systemic effects, and therefore the final severity of acute pancreatitis, are determined by the content of circulating exosomes generated in the early hours of the process. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Liver Transplantation for Acute-on-Chronic Liver Failure Associated With Acute Necrotizing Pancreatitis: A Case Report

Liver transplantation (LT) for acute-on-chronic liver failure (ACLF) accompanied by acute necrotizing pancreatitis is still unclear. We have a reported case of LT for ACLF associated with acute necrotizing pancreatitis. The postoperative multiorgan dysfunction and secondary infection were successfully managed under close supervision. The patient was a 47-year-old man with chronic hepatitis B virus infection presented with ACLF and acute necrotizing pancreatitis. After receiving LT from a deceased donor, the patient's liver functioning rapidly reverted to a normal level, and the acute pancreatitis was simultaneously stabilized. However, the patient later developed multiorgan dysfunction secondary to multidrug resistant bacteria infection, which was treated successfully with repeated percutaneous drainage, sensitive antibiotics, continuous renal replacement therapy, microbial balance, and best supportive care. LT can be considered for ACLF associated with acute necrotic pancreatitis without absolute contraindication. Moreover, we recommend a close observation of possible postoperative severe infection, and cautious multidisciplinary management was needed for the prevention of organ dysfunction.

Superoxide Dismutase Predicts Persistent Circulation Failure and Mortality in the Early Stage of Acute Pancreatitis

OBJECTIVES

Oxidative stress is an important event in the pathogenesis of acute pancreatitis. Superoxide dismutase is a major antioxidant enzyme in the body. The aim of this study was to investigate the changes in superoxide dismutase activity early in the onset of acute pancreatitis and its value in predicting the risk of organ failure and mortality.

METHODS

Data for 2549 patients hospitalized from 2013 to 2017 were extracted from the prospective database, and we selected 854 adult patients who were admitted within 24 h of disease onset with complete data. Serum superoxide dismutase activities on the first, second, and third days of hospital admission for patients with different severities, organ failure, and mortality were compared. The areas under the curve for the prediction of organ failure, pancreatic necrosis, and mortality were estimated using receiver operating characteristic curves.

RESULTS

Among the 854 adult patients, superoxide dismutase activities were significantly different among patients with mild acute pancreatitis, moderately severe acute pancreatitis, and severe acute pancreatitis (P = 0.005). Superoxide dismutase activity was significantly decreased in patients with persistent renal failure (77.8 ± 37.2), persistent circulatory failure (66.2 ± 14.9), and mortality (64.3 ± 16.0). The accuracy of superoxide dismutase with regard to predicting persistent circulatory failure and mortality was high, and the areas under the receiver operating characteristic curves were 0.83 and 0.84, respectively.

CONCLUSIONS

Superoxide dismutase activity was negatively correlated with the severity and clinical outcome of AP. Superoxide dismutase activity is highly accurate at predicting persistent circulation failure and mortality in the early stage of AP.

Selenium-Enriched Yeast Alleviates Oxidative Stress-Induced Intestinal Mucosa Disruption in Weaned Pigs

To explore the effect of selenium-enriched yeast (SeY) on intestinal barrier functions in weaned pigs upon oxidative stress, a 2 × 2 factorial design was utilized and thirty-two pigs were randomly assigned into four groups. Pigs with or without exposure to oxidative stress (diquat challenge) were fed with a basal diet or a SeY-containing diet. The trial lasted for 21 days, and result showed that SeY supplementation attenuated body-weight reduction and significantly decreased the serum concentrations of diamine oxidase (DAO) and D-lactic acid in pigs upon diquat challenge (P < 0.05). Diquat challenge decreased the villus height and the ratio of villus height to crypt depth (V/C) in the jejunum and ileum (P < 0.05). However, SeY supplementation not only elevated the villus height and the ratio of V/C (P < 0.05) but also improved the distribution and abundance of tight-junction protein ZO-1 in the jejunum epithelium. Interestingly, SeY supplementation acutely decreased the total apoptosis rate of intestinal epithelial cells in pigs upon diquat challenge (P < 0.05). Moreover, SeY elevated the content of antioxidant molecules such as glutathione peroxidase (GSH-Px) and catalase (CAT) but significantly decreased the content of malondialdehyde (MDA) in the intestinal mucosa (P < 0.05). Importantly, SeY elevated the expression levels of critical functional genes such as the nuclear factor erythroid-2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), sodium/glucose cotransporter 1 (SGLT1), and B-cell lymphoma-2 (BCL-2) in the intestinal mucosa upon diquat challenge (P < 0.05). Moreover, the expression of caspase-3 was downregulated by SeY in the duodenum and jejunum mucosa (P < 0.05). These results indicated that SeY attenuated oxidative stress-induced intestinal mucosa disruption, which was associated with elevated mucosal antioxidative capacity and improved intestinal barrier functions.

Effects of curcumin on oxidative stress, inflammation and apoptosis in L-arginine induced acute pancreatitis in mice

Background and purpose

Curcumin, an active constituent of rhizomes of Curcuma longa Linn, exhibits a variety of biological activities such as anti-inflammation and anti-oxidant. The present study aims to examine the effects of curcumin on oxidative stress, inflammation and apoptosis in L-arginine induced acute pancreatitis (AP) in mice.

Methods

Male ICR mice were randomly divided into 4 groups. Control group received intraperitoneal injection (i.p.) of 1% DMSO as a vehicle. AP group received two doses of i.p. L-arginine (L-Arg) 450 mg/100 g body weight (BW) at 1-hour interval. AP plus low-dose curcumin group received i.p. curcumin 50 mg/kg BW 1 hour before L-Arg injection and then once daily for 3 days. AP plus high-dose curcumin group received i.p. curcumin 200 mg/kg BW 1 hour before L-Arg injection and then once daily for 3 days. All mice were sacrificed at 72 hours. Pancreatic tissue was obtained for histological evaluation, immunohistochemical studies for nuclear factor-kappa beta (NF-kβ), apoptosis and myeloperoxidase (MPO), and Western blot analyses for 4-Hydroxynonenal (4-HNE). Blood samples were collected for amylase analysis.

Results

Mean body weight was significantly lower in AP group than in control group, while in curcumin group, body weight was maintained. The serum amylase, number of MPO positive cells, NF-kB positive cells, TUNEL positive cells, and 4-HNE expression significantly increased in AP group when compared with control group, but decreased in low and high-dose curcumin groups. Mice in AP group developed severe pancreatic inflammation, edema and fat necrosis. While mice in low and high-dose curcumin groups showed a significant improvement in histopathological scores. There was no significant difference between low and high doses of curcumin.

Conclusion

Curcumin could attenuate acute pancreatitis via anti-oxidant, anti-inflammation and anti-apoptosis property leading to the improvement in pancreatic damage.

Inflammatory stimuli promote oxidative stress in pancreatic acinar cells via Toll-like receptor 4/nuclear factor-κB pathway

The Toll‑like receptor 4/nuclear factor‑κB (TLR4/NF‑κB) pathway is vital to the pathogenesis of acute pancreatitis (AP). The aim of the present study was to identify the mechanism of the activation of the TLR4/NF‑κB signaling pathway in the viability of primary pancreatic cells. The cells were stimulated with lipopolysaccharide (LPS) for the activation of NF‑κB signaling. Next, the reactive oxygen species (ROS) level was evaluated by detecting the concentration of malondialdehyde and glutathione peroxidase. Cell viability was measured by Cell Counting Kit‑8 and MTT assays, while the percentage of apoptosis was detected by flow cytometry. Quantitative polymerase chain reaction was used to detect TLR4, B‑cell lymphoma 2 (Bcl2), Bcl2‑associated X protein (Bax) and phorbol‑12‑myristate‑13‑acetate‑induced protein 1 (PMAIP1) expression levels. Western blot assay was also conducted to detect TLR4 protein expression, while the activity of NF‑κB signaling was measured by determining the p65 and phosphorylated p65 protein levels. In addition, the effect of TLR4 overexpression or treatment with TLR4 antagonists in the presence of LPS stimulation was investigated. The results revealed that ROS levels were increased and cell viability was decreased in LPS‑stimulated pancreatic acinar cells. TLR4, Bax and PMAIP1 levels were increased, Bcl2 expression was decreased and NF‑κB signaling was activated in LPS‑stimulated pancreatic acinar cells. Furthermore, pancreatic cells with TLR4 overexpression exhibited increased ROS level and decreased viability. Finally, the effect caused by LPS stimulation was partially reversed by treatment of pancreatic acinar cells with TLR4 antagonists. In conclusion, the current study investigated a novel regulatory mechanism of the TLR4/NF‑κB pathway in LPS‑stimulated pancreatic cells, which may contribute to pancreatitis. The damage of these cells due to increased ROS levels was observed to occur through activation of the TLR4/NF‑κB pathway.

Effect of Endotoxemia in Suckling Rats on Pancreatic Integrity and Exocrine Function in Adults: A Review Report

Background. Endotoxin (LPS), the component of Gram-negative bacteria, is responsible for sepsis and neonatal mortality, but low concentrations of LPS produced tissue protection in experimental studies. The effects of LPS applied to the suckling rats on the pancreas of adult animals have not been previously explored. We present the impact of neonatal endotoxemia on the pancreatic exocrine function and on the acute pancreatitis which has been investigated in the adult animals. Endotoxemia was induced in suckling rats by intraperitoneal application of LPS from Escherichia coli or Salmonella typhi. In the adult rats, pretreated in the early period of life with LPS, histological manifestations of acute pancreatitis have been reduced. Pancreatic weight and plasma lipase activity were decreased, and SOD concentration was reversed and accompanied by a significant reduction of lipid peroxidation products (MDA + 4 HNE) in the pancreatic tissue. In the pancreatic acini, the significant increases in protein signals for toll-like receptor 4 and for heat shock protein 60 were found. Signal for the CCK1 receptor was reduced and pancreatic secretory responses to caerulein were diminished, whereas basal enzyme secretion was unaffected. These pioneer studies have shown that exposition of suckling rats to endotoxin has an impact on the pancreas in the adult organism.

Screening and validation of differentially expressed extracellular miRNAs in acute pancreatitis

The present study aimed to screen for differentially expressed extracellular microRNAs (miRNAs) during the development of acute pancreatitis (AP) and validate the miRNA expression in the plasma of patients with AP. The culture medium of taurolithocholic acid‑3 sulfate‑treated rat pancreatic acinar AR42J cells was collected to extract total RNA for miRNA microarray analysis. Compared with the miRNA test results of the AP rats in the GEO databases, the differentially expressed extracellular miRNAs were screened. The TargetScan, miRanda, and PicTar programs were used for target gene prediction of the identified miRNAs, and gene ontology‑biological processes (GO‑BP) functional annotation was performed. Finally, the results from the combined microarray analyses (in vitro cell line and in vivo rat samples) were validated using plasma samples from patients with mild and moderately severe AP by reverse transcription‑polymerase chain reaction. The results demonstrated that extracellular miR‑24 was differentially expressed by microarray and bioinformatics analysis in both the cell line and the animal model of AP. Bioinformatics prediction analysis revealed that downstream target genes of miR‑24 included Vav2, Syk, Lhcgr, Slc9a3r1, Cacnb1, Cacna1b, Bcl10, and Fgd3. Functional enrichment analysis revealed that the main GO‑BP predicted functional presentations were positive regulation of calcium‑mediated signaling, activation of c‑Jun N‑terminal kinase activity, calcium ion transport, regulation of Rho protein signal transduction, negative regulation of the protein kinase B signaling cascade, and the T cell receptor signaling pathway. Validation analysis for the plasma miR‑24 expression in humans revealed a significant upregulation of miR‑24 in the plasma samples of AP patients compared with the healthy controls, while no significant difference was observed in the miR‑24 expression between the mild and the moderately severe AP groups. The present study confirmed the high expression of miR‑24 in peripheral blood during AP, suggesting that miR‑24 might have an intercellular communication role contributing to the AP‑associated distant organ injury.

Mangiferin protects against ‭intestinal ischemia/reperfusion-induced ‭liver injury: ‬‬Involvement of PPAR-‭γ, GSK-3β and Wnt/β-catenin pathway‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬

AIM

Mangiferin (MF), a xanthonoid from Mangifera indica, possesses anti-inflammatory, immunomodulatory, and potent antioxidant effects; however, its protective effect against mesenteric ischemia/reperfusion (I/R)-induced liver injury has not been fully clarified. The study was designed to assess the possible mechanism of action of MF against mesenteric I/R model.

MAIN METHODS

Male Wister rats were treated with MF (20mg/kg, i.p) or the vehicle for 3 days before I/R, which was induced by clamping the superior mesenteric artery for 30min followed by declamping for 60min.

KEY FINDINGS

The mechanistic studies revealed that MF protected the 2 organs studied, viz., liver and intestine partly via increasing the content of β-catenin and PPAR-γ along with decreasing that of GSK-3β and the phosphorylated NF-қB-p65. MF antioxidant effect was evidenced by increasing contents of total antioxidant capacity and GST, besides normalizing that of MDA. Regarding the anti-inflammatory effect, MF reduced IL-1β and IL-6, effects that were mirrored on the tissue content of MPO. Moreover, MF possessed anti-apoptotic character evidenced by elevating Bcl-2 content and reducing that of caspase-3. In the serum, intestinal I/R increased the activity of ALT, AST, and creatine kinase.

SIGNIFICANCE

The intimated protective mechanisms of MF against mesenteric I/R are mediated, partially, by modulation of oxidative stress, inflammation, and apoptosis possibly via the involvement of Wnt/β-catenin/NF-қβ/ PPAR-γ signaling pathways.

The protective mechanism of QGC in feline esophageal epithelial cells by interleukin-1β treatment

In a previous study, Quercetin-3-O-β-D-glucuronopyranoside (QGC) has anti-oxidative and anti-inflammatory effects in vivo. QGC is a flavonoid glucoside extracted from Rumex Aquaticus. We investigated the downstream target proteins involved in IL-1β-stimulated ROS production and the ability of QGC to inhibit ROS production. Cell viability was determined using the MTT reduction assay. Western blot analysis was performed with antibodies to investigate the activation of three MAPKs, NF-κB, and phosphorylated IκB-α (pIB), and the expression of COX-2. 2',7'-dichlorofluorescin diacetate was used to detect the generation of intracellular ROS species. When the cells were exposed to media containing IL-1β for 18 h, cell viability was not affected. QGC did not reduce the COX-2 expression induced by IL-1β. However; QGC attenuated the production of intracellular ROS induced by IL-1β. IL-1β increased the expression of ERK, p38 MAPK, and pIB, and nuclear translocation of NF-κB were recovered by the ROS scavenger N-acetyl-L-cysteine (NAC) and QGC, but not by the NADPH oxidase inhibitor diphenylene iodonium. Pretreatment of cells with the ERK inhibitor PD98059, the p38 MAPK inhibitor SB202190, NAC, and QGC attenuated nuclear translocation of NF-κB and activation of pIB. QGC has a scavenging effect on cytokine-induced ROS production, thereby preventing its downstream effects, nuclear translocation of NF-κB, and activation of pIB is mediated by activation of ERK and p38 MAPK, although QGC does not inhibit IL-1β-stimulated COX-2 expression in feline esophageal epithelial cells. The data suggest that QGC exerts anti-oxidative effects and inhibitory effects against esophageal epithelial cells signals by the action of IL-1β treatment.

Alteration of the renin-angiotensin system in caerulein induced acute pancreatitis in the mouse

BACKGROUND

The objective of this study was to determine if RAS bioactive enzymes and peptides are perturbed in acute pancreatitis and associated lung injury.

METHODS

The intervention group of mice were treated with ten hourly intraperitoneal (i.p.) injections of caerulein (50 μg/kg) to induce acute pancreatitis. Animals were euthanized, samples of pancreas, lung and blood were collected, and plasma was prepared and stored for subsequent analysis. ACE and ACE2 activities were determined by spectrofluorometric assay. ACE, ACE2, Ang II and Ang-(1-7) levels were quantified by ELISA.

RESULTS

There was a significant decrease in ACE2 enzymatic activity in pancreatic and lung tissues of mice with acute pancreatitis. In contrast, there were no significant changes in measured levels of ACE and ACE2 in the pancreas, and lung or activity of ACE in pancreatic and lung tissue following acute pancreatitis. There were no significant differences in the activities and levels of circulating ACE and ACE2 following acute pancreatitis. The ACE to ACE2 activity ratio was markedly increased in pancreatic and lung tissues of mice with acute pancreatitis. No significant changes were observed in the levels of Ang II except for a decrease in lung tissue. No changes were observed in Ang-(1-7) levels in pancreas, lung and plasma between the groups. The Ang II to Ang-(1-7) ratio was increased in the pancreas but was decreased in the lung following caerulein treatment.

CONCLUSION

These data suggest dysregulation of RAS in acute pancreatitis as evidenced by altered Ang II/Ang-(1-7) levels induced by the imbalance of ACE/ACE2 activity.

Are gastric mucosal macrophages responsible for gastric injury in acute pancreatitis?

AIM: To investigate the protective effect of clodronate-containing liposomes against severe acute pancreatitis (SAP)-triggered acute gastric mucosal injury (AGMI) in rats.

METHODS: Clodronate- and phosphate-buffered saline (PBS)-containing liposomes were prepared by reverse-phase evaporation. The SAP rat model was established by injecting sodium taurocholate into the pancreatic subcapsular space. Sprague-Dawley rats were randomly divided into three groups: control (C), SAP plus PBS-containing liposome (P) and SAP plus clodronate-containing liposome (T). Serum tumor necrosis factor (TNF)-α levels were estimated by ELISA. Pathological changes in the gastric mucosa and pancreas were observed by hematoxylin and eosin (HE) staining. Apoptotic cells were detected by terminal deoxynucleotidyl transferase dUTP nick end labeling staining. The numbers of macrophages in the gastric mucosa were analyzed by CD68 immunohistochemical staining.

RESULTS: The liposomes had a mean diameter of 150 ± 30 nm. The TNF-α levels were significantly higher in the P group than that in the C group (2 h, 145.13 ± 11.50 vs 23.2 ± 2.03; 6 h, 245.06 ± 12.11 vs 30.28 ± 6.07, P < 0.05), and they were significantly lower in the T group than that in the P group (2 h, 93.24 ± 23.11 vs 145.13 ± 11.50; 6 h, 135.18 ± 13.10 vs 245.06 ± 12.11, P < 0.05). The pathological scores of the pancreas were lower in the T group than in the P group (2 h, 1.88 ± 0.83 vs 4.13 ± 0.83; 6 h, 2.87 ± 0.64 vs 6.25 ± 0.88, P < 0.01). The pathological scores of the gastric mucosa were also lower in the T group than in the P group (2 h, 1.12 ± 0.64 vs 2 ± 0.75; 6 h, 1.58 ± 0.53 vs 3 ± 1.31, P < 0.05). In addition, increased CD68 levels were observed in the gastric mucosa of the P group compared with the C group. Clodronate-containing liposomes decreased the CD68 levels in the mucosa of the T group. The apoptotic indexes of the gastric mucosa were higher in the T group than in the P group (2 h, 15.7 ± 0.92 vs 11.5 ± 1.64; 6 h, 21.12 ± 1.06 vs 12.6 ± 2.44, P < 0.01).

CONCLUSION: Gastric macrophages contribute to the pathogenesis of gastric injury in SAP. Clodronate-containing liposomes have protective effects against AGMI in rats with SAP.

Redox signaling in acute pancreatitis

Acute pancreatitis is an inflammatory process of the pancreatic gland that eventually may lead to a severe systemic inflammatory response. A key event in pancreatic damage is the intracellular activation of NF-κB and zymogens, involving also calcium, cathepsins, pH disorders, autophagy, and cell death, particularly necrosis. This review focuses on the new role of redox signaling in acute pancreatitis. Oxidative stress and redox status are involved in the onset of acute pancreatitis and also in the development of the systemic inflammatory response, being glutathione depletion, xanthine oxidase activation, and thiol oxidation in proteins critical features of the disease in the pancreas. On the other hand, the release of extracellular hemoglobin into the circulation from the ascitic fluid in severe necrotizing pancreatitis enhances lipid peroxidation in plasma and the inflammatory infiltrate into the lung and up-regulates the HIF-VEGF pathway, contributing to the systemic inflammatory response. Therefore, redox signaling and oxidative stress contribute to the local and systemic inflammatory response during acute pancreatitis.

Hormonal protection in acute pancreatitis by ghrelin, leptin and melatonin

Acute pancreatitis is a nonbacterial disease of the pancreas. The severe form of this ailment is characterized by high mortality. Whether acute pancreatitis develops as the severe type or resolves depends on the intensity of the inflammatory process which is counteracted by the recruitment of innate defense mechanisms. It has been shown that the hormones ghrelin, leptin and melatonin are able to modulate the immune function of the organism and to protect the pancreas against inflammatory damage. Experimental studies have demonstrated that the application of these substances prior to the induction of acute pancreatitis significantly attenuated the intensity of the inflammation and reduced pancreatic tissue damage. The pancreatic protective mechanisms of the above hormones have been related to the mobilization of non-specific immune defense, to the inhibition of nuclear factor kappa B and modulation of cytokine production, to the stimulation of heat shock proteins and changes of apoptotic processes in the acinar cells, as well as to the activation of antioxidant system of the pancreatic tissue. The protective effect of ghrelin seems to be indirect and perhaps dependent on the release of growth hormone and insulin-like growth factor 1. Leptin and ghrelin, but not melatonin, employ sensory nerves in their beneficial action on acute pancreatitis. It is very likely that ghrelin, leptin and melatonin could be implicated in the natural protection of the pancreatic gland against inflammatory damage because the blood levels of these substances increase in the initial phase of pancreatic inflammation. The above hormones could be a part of the innate resistance system which might remove noxious factors and could suppress or attenuate the inflammatory process in the pancreas.

Evidence for a role of mitogen-activated protein kinases in the treatment of experimental acute pancreatitis

Acute pancreatitis (AP) is an inflammatory disease characterized by acute inflammation and necrosis of the pancreatic parenchyma. AP is often associated with organ failure, sepsis, and high mortality. The pathogenesis of AP is still not well understood. In recent years several papers have highlighted the cellular and molecular events of acute pancreatitis. Pancreatitis is initiated by activation of digestive enzymes within the acinar cells that are involved in autodigestion of the gland, followed by a massive infiltration of neutrophils and macrophages and release of inflammatory mediators, responsible for the local and systemic inflammatory response. The hallmark of AP is parenchymal cell necrosis that represents the cause of the high morbidity and mortality, so that new potential therapeutic approaches are indispensable for the treatment of patients at high risk of complications. However, not all factors that determine the onset and course of the disease have been explained. Aim of this article is to review the role of mitogen-activated protein kinases in pathogenesis of acute pancreatitis.

Cell death and DAMPs in acute pancreatitis

Cell death and inflammation are key pathologic responses of acute pancreatitis (AP), the leading cause of hospital admissions for gastrointestinal disorders. It is becoming increasingly clear that damage-associated molecular pattern molecules (DAMPs) play an important role in the pathogenesis of AP by linking local tissue damage to systemic inflammation syndrome. Endogenous DAMPs released from dead, dying or injured cells initiate and extend sterile inflammation via specific pattern recognition receptors. Inhibition of the release and activity of DAMPs (for example, high mobility group box 1, DNA, histones and adenosine triphosphate) provides significant protection against experimental AP. Moreover, increased serum levels of DAMPs in patients with AP correlate with disease severity. These findings provide novel insight into the mechanism, diagnosis and management of AP. DAMPs might be an attractive therapeutic target in AP.

Src as the link between inflammation and cancer

Although a causal link between chronic inflammation and cancer has been established, the exact molecular mechanism linking inflammation to cancer remains largely unknown. It was previously postulated that molecular switches responsible for cancer cell development, and for infiltration of inflammatory cells into cancer, were divided into a distinct set of intracellular proteins and signaling pathways. However, recent evidence suggests that both tumor cells and tumor-infiltrating immune cells utilize the same kinases, mostly that of Src family, to facilitate cancer development and progression. In the past few years several groups have found that Src activation both in cancer and inflammatory cells is mainly driven by pro-inflammatory cytokines within the tumor microenvironment. Here we evaluate the cross talks between Src kinase pathways in immune cells and cancer cells. We conclude that Src might serve as a critical mechanistic link between inflammation and cancer, mediating and propagating a cycle between immune and tissue cells that can ultimately lead to the development and progression of cancer.

Effect of L-cysteine on remote organ injury in rats with severe acute pancreatitis induced by bile-pancreatic duct obstruction

BACKGROUND

Remote organ failure occurs in cases of acute pancreatitis (AP); however, the reports on AP induced by pancreatic duct obstruction are rare. In this study we determined the effect of L-cysteine on pancreaticobiliary inflammation and remote organ damage in rats after pancreaticobiliary duct ligation (PBDL).

METHODS

AP was induced by PBDL in rats with 5/0 silk. Sixty rats were randomly divided into 4 groups. Groups A and B were sham-operated groups that received injections of saline or L-cysteine (10 mg/kg) intraperitoneally (15 rats in each group). Groups C and D were PBDL groups that received injections of saline or L-cysteine (10 mg/kg) intraperitoneally (15 rats in each group). The tissue samples of the pancreas and remote organs such as the lung, liver, intestine and kidney were subsequently examined for pathological changes under a light microscope. The samples were also stored for the determination of malondialdehyde and glutathione levels. Blood urea nitrogen (BUN), plasma amylase, ALT and AST levels were determined spectrophotometrically using an automated analyzer. Also, we evaluated the effect of L-cysteine on remote organ injury in rats with AP induced by retrograde infusion of 3.5% sodium taurocholate (NaTc) into the bile-pancreatic duct.

RESULTS

Varying degrees of injury in the pancreas, lung, liver, intestine and kidney were observed in the rats 24 hours after PBDL. The severity of injury to the lung, liver and intestine was attenuated, while injury status was not changed significantly in the pancreas and kidney after L-cysteine treatment. Oxidative stress was also affected by L-cysteine in PBDL-treated rats. The concentration of tissue malondialdehyde decreased in the pancreas and remote organs of PBDL and L-cysteine administrated rats, and the concentration of glutathione increased more significantly than that of the model control group. However, L-cysteine administration reduced the severity of injury in remote organs but not in the pancreas in rats with NaTc-induced AP.

CONCLUSION

L-cysteine treatment attenuated multiple organ damage at an early stage of AP in rats and modulated the oxidant/antioxidant imbalance.

Blood modulates the kinetics of reactive oxygen release in pancreatic ischemia-reperfusion injury

OBJECTIVES

Reason for the unsuccessful use of antioxidants in transplantation might be the unknown kinetics of reactive oxygen species (ROS) release. In this study, we compared the kinetics of ROS release from rat pancreata in the presence and absence of blood.

METHODS

In vivo, ischemia-reperfusion injury (IRI) was induced in pancreata of male Wistar rats by occlusion of the arterial blood supply for 1 or 2 hours. In vitro, isolated pancreata were single-pass perfused with Krebs-Henseleit bicarbonate solution. Reactive oxygen species were quantified by electron spin resonance spectroscopy using CMH (1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine) as spin label. Thiols (glutathione), nicotinamide adenine dinucleotide phosphate-oxidase activity, myeloperoxidase activity, and adenosine triphosphate content were measured.

RESULTS

During reperfusion, an increase in IRI-induced ROS in arterial blood was noted after 2 hours of warm ischemia. In sharp contrast, ROS release was immediate and short lived in blood-free perfused organs. The degree of tissue damage correlated with nicotinamide adenine dinucleotide phosphate-oxidase activity and adenosine triphosphate content. Antioxidative capacity of tissues was reduced.

CONCLUSIONS

Electron spin resonance spectroscopy in conjunction with spin labels allows for the detection of ROS kinetics in pancreatic IRI. Reactive oxygen species kinetics are dependent on the length of the ischemic period and the presence or absence of blood.

Beneficial effects of the ethanol extract of Caesalpinia pyramidalis on the inflammatory response and abdominal hyperalgesia in rats with acute pancreatitis

ETHNOPHARMACOLOGICAL RELEVANCE

Caesalpinia pyramidalis Tul. (Fabaceae) is a plant found in the Northeast of Brazil that is popularly used to treat inflammation. Acute pancreatitis (AP) is an inflammatory disease for which abdominal pain is a relevant symptom. As there is no specific therapy for AP, we investigated the effect of the ethanol extract from the inner bark of C. pyramidalis (EECp) on the AP induced by common bile duct obstruction (CBDO) in rats.

MATERIAL AND METHODS

AP was induced in male Wistar rats (200-250 g, n=6-8) through laparotomy and subsequent CBDO. Animals were euthanized after 6 (G6h) or 24 h (G24h) of induction. In the G6h protocol, animals were pretreated with EECp (100-400 mg/kg, p.o.) or vehicle (Tween 80; 0.2%) 1h before CBDO or sham surgery. For the G24h protocol, rats were pretreated with EECp (400mg/kg, 1h before CBDO or 1 h before and 12 h after CBDO) or vehicle. The following parameters were measured: inflammatory/oxidative (myeloperoxidase activity and malondialdehyde formation in the pancreas and lung, leukocyte counts in the blood and serum nitrate/nitrite), enzymatic (serum amylase and lipase levels) and nociceptive (abdominal hyperalgesia).

RESULTS

Induction of AP by CBDO significantly increased all the parameters evaluated in both G6h and G24h protocols when compared with the respective sham group. In the G6h protocol, the EECp pretreatment (400 mg/kg) significantly reduced all these parameters, besides completely inhibiting abdominal hyperalgesia. The same profile of reduction was observed from two administrations of EECp in the G24h protocol, while one single dose of EECp was able to significantly reduce pancreatic MDA, serum lipase levels, leukocyte counts in the blood and abdominal hyperalgesia without affecting the other parameters in the G24h protocol. Furthermore, rutin was found in the EECp.

CONCLUSIONS

Our results demonstrated that EECp decreases inflammation, lipoperoxidation and hyperalgesia in CBDO-induced AP, making it of interest in future approaches to treat this condition.

Altered levels of trace elements in acute lung injury after severe trauma

Trace element (TE) supplementation can reduce the incidence of multiple organ failure after severe trauma. The lung plays a main role in post-injury multiple organ failure. In the present study, the relationship between TEs and acute lung injury (ALI) post-injury was investigated in a rabbit model of severe trauma with an injury severity score of 27. New Zealand white rabbits were randomly assigned to trauma-control, trauma-TE groups, and a control group. During days 1-5 post-trauma, each rabbit in the trauma-TE group received 0.1 ml multi-TE compound intraperitoneally to give a daily dose of 32.50 mg/kg of Zn, 6.35 mg/kg of Cu, 1.38 mg/kg of Mn, and 0.16 mg/kg of Se. Concentrations of blood and lung selenium (Se), copper (Cu), zinc (Zn), and manganese (Mn) were measured at 6 and 24 h, as well as 3, 6, 9, and 14 days after trauma. Levels of glutathione peroxidase (GPx), total superoxide dismutase (SOD), Cu/Zn superoxide dismutase (Cu/Zn-SOD), and malondialdehyde (MDA) in serum and lung tissue and the level of intercellular adhesion molecular-1 (ICAM-1) in serum were detected simultaneously. In addition, the lung coefficient (LC) and the lung permeation index (LPI) were measured. Serum and lung Zn, Se, and Mn levels decreased dramatically by 6 h after trauma in both experimental groups. Cu showed no significant changes after trauma. The serum and lung GPx and SOD levels in the experimental group decreased significantly on days 1 and 3, respectively. Serum and lung MDA began to increase on day 3 in the trauma group but increased less after TE supplementation. Serum ICAM-1 peaked on day 6 in the experimental group. LC and LPI increased gradually post-trauma, peaking on days 6 and 9, respectively. In conclusion, an acute lung injury causes declines of the levels of TEs in serum and lung which can be significantly prevented by TE supplementation and which can also mitigate some of the morphological and biomechanical changes in ALI.

Protective effect of melatonin on acute pancreatitis

Melatonin, a product of the pineal gland, is released from the gut mucosa in response to food ingestion. Specific receptors for melatonin have been detected in many gastrointestinal tissues including the pancreas. Melatonin as well as its precursor, L-tryptophan, attenuates the severity of acute pancreatitis and protects the pancreatic tissue from the damage caused by acute inflammation. The beneficial effect of melatonin on acute pancreatitis, which has been reported in many experimental studies and supported by clinical observations, is related to: (1) enhancement of antioxidant defense of the pancreatic tissue, through direct scavenging of toxic radical oxygen (ROS) and nitrogen (RNS) species, (2) preservation of the activity of antioxidant enzymes; such as superoxide dismutase (SOD), catalase (CAT), or glutathione peroxidase (GPx), (3) the decline of pro-inflammatory cytokine tumor necrosis α (TNFα) production, accompanied by stimulation of an anti-inflammatory IL-10, (4) improvement of pancreatic blood flow and decrease of neutrophil infiltration, (5) reduction of apoptosis and necrosis in the inflamed pancreatic tissue, (6) increased production of chaperon protein (HSP60), and (7) promotion of regenerative process in the pancreas. Conclusion. Endogenous melatonin produced from L-tryptophan could be one of the native mechanisms protecting the pancreas from acute damage and accelerating regeneration of this gland. The beneficial effects of melatonin shown in experimental studies suggest that melatonin ought to be employed in the clinical trials as a supportive therapy in acute pancreatitis and could be used in people at high risk for acute pancreatitis to prevent the development of pancreatic inflammation.

Thioredoxin, thioredoxin-interacting protein and digestive diseases

The thioredoxin system is an antioxidative and redox-regulating system that consists of several small proteins, including thioredoxin (TRX), reduced coenzyme II (NADPH) and thioredoxin reductase (TRX-R). It can function to regulate oxidation-reduction state of cells, resist oxidative stress, activate transcription factors NF-κB and AP-1 to promote the growth and proliferation of cells, and interact with ASK-1 to inhibit apoptosis. Thioredoxin-interacting protein (TXNIP) is a member of the thioredoxin-binding protein family and plays a role in mediating oxidative stress, resisting cell proliferation and inducing apoptosis, acting as a negative regulator of the TRX system. Since oxidative stress and apoptosis are often involved in the pathogenesis of digestive diseases, TRX and TXNIP may play roles in the pathogenesis of digestive diseases. This paper gives an overview of the structure and functions of TRX and TXNIP and reviews the recent advances in understanding the relationship between the two proteins and digestive diseases.

Effects of reactive oxygen species scavenger on the protective action of 100% oxygen treatment against sterile inflammation in mice

Sepsis/multiple organ dysfunction syndrome (MODS) is a major cause of high mortality in the intensive care unit. We have recently reported that 100% oxygen treatment is beneficial to mice with zymosan-induced sterile inflammation by increasing antioxidant enzymatic activities. Yet, the use of hyperoxia is hindered by concerns that it could exacerbate organ injury by increasing free radical formation. It is believed that systemic inflammation and overproduction of reactive oxygen species (ROS) contribute to the mechanism underlying sepsis/MODS. A ROS scavenger has been proven to protect against sepsis/MODS in some animal models. Therefore, we hypothesized that ROS scavenger pretreatment might enhance the protective action of 100% oxygen treatment against zymosan-induced sterile inflammation in mice. In the present study, we showed that 100% oxygen treatment prevented the abnormal changes in serum biochemical parameters, tissue oxygenation, and organ histopathology, and improved the 14-day survival rate in zymosan-stimulated mice, indicating that 100% oxygen treatment had a protective action on sterile inflammation. We found that pretreatment with a ROS scavenger (N-acetylcysteine, vitamin C, or dimethylthiourea) abolished this protective action of 100% oxygen treatment. We also showed that 100% oxygen treatment decreased the levels of serum proinflammatory cytokines (TNF-alpha, IL-6, and high-mobility group box 1), increased the level of serum anti-inflammatory cytokine (IL-10), and upregulated the activities of serum and tissue antioxidant enzymes (superoxide dismutase, catalase, and glutathione peroxidase) in zymosan-stimulated mice, which were reversed by the pretreatment with a ROS scavenger (N-acetylcysteine, vitamin C, or dimethylthiourea). We thus conclude that ROS scavenger pretreatment partly abolishes the protective effects of 100% oxygen treatment on sterile inflammation in mice by regulating inflammatory cytokines as well as antioxidant enzymes.

Effect of salvia miltiorrhizae on pulmonary apoptosis of rats with severe acute pancreatitis or obstructive jaundice

To investigate the effect of apoptosis about Salvia miltiorrhizae injection on the lungs of SAP and OJ rats. Total 288 rats were used for SAP-associated experiments and OJ-associated experiments, respectively. The rats were randomly divided into sham-operated, model control and treated group. According to the difference of time points after operation, the SAP rats in each group were subdivided into 3, 6 and 12 h groups while the OJ rats were divided into 7, 14, 21 and 28 days groups. The pathological changes, expression levels of Bax protein and apoptotic indexes in the lungs of SAP or OJ rats were observed, and the mortality rates of SAP or OJ rats were recorded, respectively. The numbers of dead SAP and OJ rats in treated groups declined. The pathological changes in the lungs of SAP or OJ rats in treated groups were relieved to varying degrees. There was no marked difference in pathological severity scores and the positive staining intensity of Bax protein between treated groups and model control groups (all P > 0.05). Salvia miltiorrhizae has some protective effect on the lungs of rats with SAP or OJ which may be related apoptosis although our results can not find significant difference between treated groups and model control groups.

Protective effects of edaravone on rats with severe acute pancreatitis

AIM: To investigate the therapeutic effects and mechanism of edaravone on rats with severe acute pancreatitis (SAP) induced by L-arginine.

METHODS: A total of 60 rats were randomly and equally divided into three groups, namely control group, SAP model group and edaravone treatment group (n = 20). A SAP model was established by injecting intraperitoneally with L-arginine at a dose of 2.5 g/kg twice at an interval of 1 h, and injecting intravenously with edaravone 3 mg/kg, bid × 3 d (edaravone treatment group). The characteristics and volume of ascites, the pathological changes of pancreatic tissue and the serum levels of amylase (AMY), tumor necrosis factor-α (TNF-α), interleukin (IL)-6 and the contents of malonaldehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) in pancreatic tissue of rats and prognosis were compared after 72 h following administration of L-arginine.

RESULTS: Compared with control group, 72 h after administration of L-arginine, SAP model group showed typical histopathological changes of SAP, elevated the volume of ascites (5.16 ± 1.52 vs 0.50 ± 0.10, P < 0.01), and significantly higher serum levels of AMY, TNF-α, IL-6 and content of MDA of pancreatic tissue (8967.5 ± 298.4 vs 720.1 ± 119.7I; 103.98 ± 10.56 vs 41.59 ± 3.79; 548.57 ± 10.45 vs 198.34 ± 2.10; 35.6 ± 3.8 vs 7.9 ± 2.2, all P < 0.01), and lower GSH and SOD in pancreatic tissue (7.2 ± 0.6 vs 17.1 ± 2.1; 7300 ± 1800 vs 28 400 ± 2700, both P < 0.01). Compared with SAP model group, 72 h after administration of L-arginine, significantly alleviated pathological lesions of SAP, decreased volume of ascites (4.05 ± 1.22 vs 53.16 ± 1.52, P < 0.05), lower pathological scores (P < 0.05), lower serum levels of AMY, TNF-α, IL-6 and MDA in pancreatic tissue (7809.5 ± 158.3 vs 8967.5 ± 298.4; 79.80 ± 14.23 vs 103.98 ± 10.56; 467 ± 6.64 vs548.57 ± 10.45; 29.1 ± 2.6 vs 35.6 ± 3.8, all P < 0.05), and higher GSH and SOD in pancreatic tissue were observed in edaravone treatment group (8.7 ± 1.3 vs 7.2 ± 0.6; 114 000 ± 27 000 vs 7300 ± 1800, both P < 0.05).

CONCLUSION: Edaravone can scavenge oxygen-derived free radicals, upgrade the contents of SOD and GSH in pancreatic tissue, decrease the serum levels of proinflammatory cytokines and, ameliorate the pathological lesions of pancreatic tissue in rats, and has a possibility of decreasing death rate.

Pathophysiological role of platelets and platelet system in acute pancreatitis

The most successful approach for restoring normal long-term glucose homeostasis in type I diabetes mellitus is whole-organ pancreas transplantation. Graft pancreatitis is observed in up to 20% of patients and may lead to loss of the transplanted organ. Several pathophysiological events have been implicated in this form of pancreatitis. The most important cause of early graft pancreatitis is ischemia/reperfusion (I/R)-related disturbance of microvascular perfusion with subsequent hypoxic tissue damage. Recently, considerable evidence accumulated that, among a variety of other pathophysiological events, the activation of platelets can contribute to I/R injury in the course of acute pancreatitis experimentally and clinically. This review summarizes the events affecting platelet function and, therefore, pancreatic microcirculation leading to acute pancreatitis. Therapeutic approaches and own results are presented.

Advances in research of severe acute pancreatitis complicated by lung injury

Lung injury is one of the most common complications of severe acute pancreatitis (SAP). At present, the pathogenesis of SAP complicated by lung injury still remains unclear. However, great attention has been paid to it at home and abroad. Many factors such as pancreatic enzyme, polymorphonuclear neutrophil, oxygen free radical, cytokine, microcirculatory disturbance, complement, kinin, NO and ET play an important role in the pathogenesis of SAP by interacting with each other. This paper reviews the advances in the pathogenesis of SAP complicated by lung injury and related studies in order to provide the theoretical basis for its effective prevention and treatment.

Nutrition support in severe acute pancreatitis

Nutritional support can improve the outcome from severe acute pancreatitis in two ways: first by providing the building blocks for tissue repair and recovery, and second, by modulating the inflammatory response and preventing organ failure, both of which are responsible for most of the morbidity and mortality associated with the disease. This review discusses the evidence on which these statements are based.

Relationship between acute pancreatitis and oxidative stress

Under the imbalance between generation of reactive oxygen species and inadequate antioxidant defense systems, oxidative stress can cause cell damage either directly or indirectly through altering signaling pathways. It is the etiopathogenisis and also the consequence of many diseases. Oxidative injury plays an important role not only in the pathogenesis of acute pancreatitis (AP) but also in pancreatitis-induced damages of other organs such as heart, liver, lung, kidney, alimentary canal and so on. Oxidative stress can produce a higher level of reactive oxygen species (ROS) and reactive nitrogen species (RNS), which induce inflammatory reaction and microcirculation disturbance, and cell necrosis or apoptosis, leading to pancreatic inflammation and multiple organ dysfunction syndromes. The antioxidants can decrease the production of oxygen free radicals (or directly scavenge them), protect the antioxidant enzyme activity, reinforce the antioxidative capacity of bodies, and consequently play an obvious therapeutic effect on AP.

Influence of dexamethasone on inflammatory mediators and NF-kappaB expression in multiple organs of rats with severe acute pancreatitis

AIM

To observe the therapeutic effects of dexamethasone on rats with severe acute pancreatitis (SAP) and investigate the influences of dexamethasone on the inflammatory mediators and NF-kappaB expression in multiple organs of SAP rats as well as the mechanisms involved.

METHODS

Ninety Sprague-Dawley (SD) rats with SAP were randomly divided into the model group (n = 45) and dexamethasone treatment group (n = 45), and another 45 rats were selected for the sham operation group. All groups were randomly subdivided into the 3 h, 6 h and 12 h groups, each group containing 15 rats. The survival of all groups and pathological changes of multiple organs (liver, kidney and lung) were observed at different time points after the operation. The pathological score of multiple organs was carried out, followed by the determination of amylase, endotoxin and TNF-alpha contents in blood. The tissue microarray was used to detect the expression levels of NF-kappaB p65 protein in multiple organs.

RESULTS

There was no marked difference between the model group and treatment group in the survival rate. The amylase content of the treatment group was significantly lower compared to the model group at 12 h (P < 0.01, 7791.00 vs 9195.00). Moreover, the endotoxin and TNF-alpha levels of the treatment group were significantly lower than that of the model group at 6 h and 12 h (P < 0.01, 0.040 vs 0.055, 0.042 vs 0.059 and P < 0.05, 58.30 vs 77.54, 38.70 vs 67.30, respectively). Regarding the changes in liver NF-kappaB expression, the model group significantly exceeded the sham operation group at 3 h (P < 0.01, 1.00 vs 0.00), and the treatment group significantly exceeded the sham operation group at 12 h (P < 0.01, 1.00 vs 0.00), whereas no marked difference was observed between the model group and treatment group at all time points. The kidney NF-kappaB expression level in the treatment group significantly exceeded the model group (P < 0.05, 2.00 vs 0.00) and the sham operation group (P < 0.01, 2.00 vs 0.00) at 12 h. No NF-kappaB expression in the lung was found in any group.

CONCLUSION

Dexamethasone can lower the amylase, endotoxin and TNF-alpha levels as well as mortality of SAP rats. NF-kappaB plays an important role in multiple organ injury. Further studies should be conducted to determine whether dexamethasone can ameliorate the pathological changes of multiple organs by reducing the NF-kappaB expression in the liver and kidney. The advantages of tissue microarrays in pancreatitis pathological examination include time- and energy- saving, and are highly efficient and representative. The restriction of tissue microarrays on the representation of tissues to various extents due to small diameter may lead to the deviation of analysis.

Ligustrazine alleviates acute renal injury in a rat model of acute necrotizing pancreatitis

AIM: To evaluate the effect of ligustrazine, a traditional Chinese medicine, on renal injury in a rat model of acute necrotizing pancreatitis (ANP).

METHODS: A total of 192 rats were randomly divided into three groups: control (C group), ANP without treatment (P group), and ANP treated with ligustrazine (T group). Each group was further divided into 0.5, 2, 6, 12 h subgroups. All rats were anesthetized with an intraperitoneal injection of sodium pentobarbital. Sodium taurocholate was infused through the pancreatic membrane to induce ANP. T group was infused sodium taurocholate as above, and 0.6% ligustrazine was then administered via the femoral vein. Serum urea nitrogen (BUN) and creatinine (Cr) concentrations were measured for the evaluation of renal function. The effects of ligustrazine on the severity of renal injury were assessed by renal function, TXA₂/PGI₂ and histopathological changes. Renal blood flow was determined by the radioactive microsphere technique (RMT).

RESULTS: Compared with control group, the renal blood flow in P group was decreased significantly. Serious renal and pancreatic damages were found in P group, the BUN and Cr levels were elevated significantly, and the ratio of TXA₂ to PGI₂ was increased at 2, 6 and 12 h. Compared with P group, the blood flow of kidney was elevated significantly at 6 and 12 h after induction of ANP, the renal and pancreatic damages were attenuated, and the BUN and Cr levels were decreased significantly, and the ratio of TXA₂ to PGI₂ was decreased at 6 and 12 h in T group.

CONCLUSION: Microcirculatory disorder (MCD) is an important factor for renal injury in ANP. Ligustrazine can ameliorate the condition of MCD and the damage of pancreas and kidney.

Effect of Ginkgolide B on plasma levels of cytokines in severe acute pancreatitis in rats

AIM: To observe the level changes of tumor necrosis factor-alpha (TNF-α), platelet activating factor (PAF), interleukin-10 (IL-10), interleukin-12 (IL-12) and soluble TNF receptors (sTNFR) in rats with severe acute pancreatitis (SAP) and the influences of Ginkgolide B (BN52021) on the changes.

METHODS: Male Wistar rats were randomly divided into 3 groups: SAP model group (SAP, n = 15), BN52021 treatment group (BN, n = 15) and negative control group (NC, n = 15). SAP was induced by retrograde infusion of 50 g/L sodium taurocholate into the pancreatic duct of rats. Sham operation was performed in the rats of NC group, while the rats in SAP and NC groups received the femoral vein injection of normal saline (5 mL/kg) 15 min after induction of SAP. Moreover, the rats in BN group received BN52021 injection instead of normal saline. After operation, the animals were sacrificed at 1^st, 6^th and 12^th h for plasma cytokines detection with enzyme-linked immunosorbent assay (ELISA).

RESULTS: The levels of plasma TNF-α and PAF were significantly higher in SAP group than those in NC group (746.2 ± 374.1 ng/L vs 385.1 ± 86.3 ng/L, P<0.05; 82.5 ± 35.4 ng/L vs 1.1 ± 1.9 ng/L, P<0.05), but they were significantly decreased in BN group (503.7 ± 177.9, 39.9 ± 29.9 ng/L)(both P<0.05). The levels of plasma sTNFR were 50.0 ± 21.0, 488.7 ± 363.8, and 883.4 ± 552.5 ng/L in NC, SAP and BN group, respectively, and there were significant differences among them (P<0.05). Plasma IL-12 level was markedly increased in SAP group as compared with that in NC group (97.1 ± 55.9 ng/L vs 20.4 ± 19.4 ng/L, P<0.05), while it was further increased at the 1^st h in BN group as compared with that in SAP group (133.5 ± 33.4 ng/L vs 55.9 ± 14.7 ng/L, P<0.05). The level of IL-10 was not significant different among the three groups (P > 0.05).

CONCLUSION: The plasma levels of pro- and anti-cytokines are increased in SAP rats, and BN52021 can inhibit the production of pro-cytokines and promote the secretion of anti-cytokines such as IL-12 and sTNFR to some extent.

Hypericum perforatum attenuates the development of cerulein-induced acute pancreatitis in mice

A considerable body of recent evidence suggests that oxidative stress and exaggerated production of reactive oxygen species play a major role in several aspects of inflammation and shock. Hypericum perforatum is a medicinal plant species containing many polyphenolic compounds, namely flavonoids and phenolic acids. Because polyphenolic compounds have high antioxidant potential, in this study we evaluated the effect of Hypericum perforatum extract on acute pancreatitis induced by cerulein administration in male CD mice. Intraperitoneal injection of cerulein in mice resulted in a severe, acute pancreatitis, which was characterized by edema, neutrophil infiltration, tissue hemorrhage, and cell necrosis as well as increases in the serum levels of amylase and/or lipase in comparison to sham-treated mice. The infiltration of the pancreatic tissue of these animals with neutrophils (measured as increase in myeloperoxidase activity) was associated with expression of the adhesion molecule ICAM-1. Immunohistochemical examination demonstrated a marked increase in the staining (immunoreactivity) for nitrotyrosine and poly(ADP-ribose) (PAR) in the pancreas of cerulein-treated mice in comparison to sham-treated mice. In contrast, the degree of (a) pancreatic inflammation and tissue injury (histological score), (b) expression of ICAM-1, (c) the staining for nitrotyrosine and PAR, and (d) myeloperoxidase activity was markedly reduced in pancreatic tissue sections obtained from cerulein-treated mice administered Hypericum perforatum extract (30 mg/kg, suspended in 0.2 mL of saline solution, o.s.). Moreover, the treatment with Hypericum perforatum extract significantly reduced the mortality rate at 5 days after cerulein administration. Taken together, our results indicate that Hypericum perforatum extract reduces the development of acute pancreatitis.

Clinical significance of serum thioredoxin 1 levels in patients with acute pancreatitis

OBJECTIVE

Thioredoxin 1 (TRX-1), a redox-regulating protein with antioxidant activity, is induced by oxidative stress, and serum TRX-1 levels are recognized as an oxidative-stress marker. The aim of this study was to clarify the clinical significance of serum TRX-1 levels in patients with acute pancreatitis (AP) and evaluate the usefulness of this measurement in assessing disease severity.

METHODS

Serum TRX-1 levels were determined on admission in 18 patients with severe AP and 36 patients with mild AP. We also investigated the relationship between serum TRX-1 levels and clinical and laboratory data.

RESULTS

The median serum TRX-1 levels on admission were 54.9 ng/mL in mild AP and 118.8 ng/mL in severe AP. When the cutoff value for TRX-1 in predicting severe AP was determined to be 100 ng/mL, its sensitivity, specificity, and accuracy were 83.3%, 94.4%, and 90.7%, respectively. A significant correlation was observed between serum TRX-1 levels and Ranson score (r = 0.674), C-reactive protein (r = 0.718), interleukin 6 (r = 0.712), leukocyte count (r = 0.642), and serum amylase (r = 0.436).

CONCLUSIONS

Serum TRX-1 levels significantly correlate with AP severity. TRX-1 should constitute a reliable oxidative-stress marker for the evaluation of AP severity in relation to oxidative stress.

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