Effect of dexamethasone on peripheral blood leukocyte immune response in bile-pancreatic duct obstruction-induced acute pancreatitis

Vitamin E protects against the modulation of TNF-α-AMPK axis and inhibits pancreas injury in a rat model of L-arginine-induced acute necrotising pancreatitis

BACKGROUND

Acute pancreatitis (AP) associated with the modulation of TNF-α-AMPK axis in the presence and absence of vitamin E has not been investigated before.

MATERIAL AND METHODS

Rats were either injected with L-arginine (2.5 gm/kg) before being sacrificed after 48 h or were pre-treated with vitamin E (60 mg/kg) and continued receiving vitamin E until the end of the experiment.

RESULTS

AP was developed as demonstrated by infiltration of inflammatory cells and profound pancreas tissue damage, which were substantially protected by vitamin E. In addition, L-arginine injections significantly (p < .0001) increased the expression of TNF-α mRNA and protein, and decreased phospho-AMPK and IL-10 mRNA and protein that was significantly (p < .0001) protected by vitamin E. Furthermore, vitamin E inhibited L-arginine-induced blood levels of LDH, amylase, and myeloperoxidase.

CONCLUSIONS

L-arginine-induced acute pancreatitis modulates TNF-α-AMPK axis, IL-10 and other AP biomarkers, which is protected by vitamin E; thus, may offer therapeutic potential in humans.

Pharmacological prevention of post-operative pancreatitis: systematic review and meta-analysis of randomized controlled trials on animal studies

BACKGROUND

Postoperative pancreatic fistula (POPF) remains a significant complication of pancreatic resection with recent evidence showing a strong association between post-operative pancreatitis and subsequent development of POPF. Incidence and severity of pancreatitis following endoscopic therapy has been effectively reduced with indomethacin prophylaxis, however further agents require evaluation. We present a systematic literature review and meta-analysis of the prophylactic treatment with corticosteroids or n-acetyl cysteine (NAC) of induced pancreatitis in rodent models.

METHODS

A systematic literature search was conducted using Pubmed, Medline, Embase and Cochrane library to identify eligible randomized control trials (RCT) involving animal models that examined NAC or corticosteroids. The primary outcome was the subsequent effect on serum amylase and IL-6 and the histopathological markers of severity such as pancreatic oedema and necrosis.

RESULTS

Four RCTs (n = 178) met inclusion criteria examining NAC and eight RCTs (n = 546) examining corticosteroid agents (dexamethasone, hydrocortisone, methylprednisolone). Prophylactic administration of all corticosteroid agents showed a net effect in favour of reducing markers of severity of pancreatitis. NAC showed a significant reduction in severity of amylase and necrosis.

CONCLUSION

The RCTs examined suggest that prophylactic administration of corticosteroid agents and NAC can reduce the severity of pancreatitis as indicated by histopathologic markers, serum amylase and IL-6 levels.

Corticosteroid treatment for acute/acute-on-chronic experimental and naturally occurring pancreatitis in several species: a scoping review to inform possible use in dogs

Acute pancreatitis in dogs is a prevalent disease characterised by mild to severe inflammation. Treatment with anti-inflammatory corticosteroids has been widely debated but is not generally recommended in veterinary medicine. The objective of the present study was to present current evidence on the effect of corticosteroid treatment for acute/acute-on-chronic pancreatitis across species. These findings were then used to evaluate if and how corticosteroid treatment could influence disease outcome in canine acute/acute-on-chronic pancreatitis. A scoping review was performed by searching the Agricola, CAB Abstracts, MEDLINE and Embase databases to identify relevant articles published before June 24, 2021. The inclusion criteria were English language, original research published in a peer-reviewed journal, and investigation of corticosteroid treatment effects on acute/acute-on-chronic pancreatitis by the outcome parameters clinical score, circulating CRP level, hospitalisation duration, mortality and pancreas histopathology. Research on any species was considered. Studies were rated based on the level of evidence, and methodological quality was evaluated based on similarity between groups at baseline, risk of bias and study group size. The reporting method was based on the PRISMA extension for scoping reviews. One thousand nine hundred fifty-four studies were identified, and 31 met the inclusion criteria. Five were canine studies, with 4 investigating experimentally induced pancreatitis; 5 were human clinical studies; and 21 were rodent studies of experimentally induced pancreatitis. The level of evidence ranged between randomised controlled trials and case series, the estimated risk of bias ranged from low to high, and the sample sizes ranged from very small to moderate. Evidence indicates that adding corticosteroid to symptomatic treatment of acute/acute-on-chronic canine pancreatitis could have a positive influence on disease outcome. However, the analysed evidence was based on several species, including both naturally occurring and experimentally induced pancreatitis; thus, the authors suggest that large randomised controlled studies should be performed in dogs with spontaneously occurring acute/acute-on-chronic pancreatitis to further elucidate a potential benefit of corticosteroid treatment.

Therapeutic implications of innate immune system in acute pancreatitis

INTRODUCTION

Acute pancreatitis (AP) is an inflammatory disorder of the pancreas encompassing a cascade of cellular and molecular events. It starts from premature activation of zymogens with the involvement of innate immune system to a potential systemic inflammatory response and multiple organ failure. Leukocytes are the major cell population that participate in the propagation of the disease. Current understanding of the course of AP is still far from complete, limiting treatment options mostly to conservative supportive care. Emerging evidence has pointed to modulation of the immune system for strategic therapeutic development, by mitigating the inflammatory response and severity of AP. In the current review, we have focused on the role of innate immunity in the condition and highlighted therapeutics targeting it for treatment of this challenging disease.

AREAS COVERED

The current review has aimed to elaborate in-depth understanding of specific roles of innate immune cells, derived mediators and inflammatory pathways that are involved in AP. Summarizing the recent therapeutics and approaches applied experimentally that target immune responses to attenuate AP.

EXPERT OPINION

The current state of knowledge on AP, limitations of presently available therapeutic approaches and the promise of therapeutic implications of innate immune system in AP are discussed.

Localized delivery of dexamethasone-21-phosphate via microdialysis implants in rat induces M(GC) macrophage polarization and alters CCL2 concentrations

Microdialysis sampling probes were implanted into the subcutaneous space on the dorsal side of male Sprague Dawley rats to locally deliver dexamethasone-21-phosphate (Dex) with the aim of altering in vivo macrophage polarization. Macrophage polarization is of significant interest in the field of biomaterials since wound-healing macrophages are a possible means to extend implant life as well as improve tissue remodeling to an implant. Quantitative analysis of CCL2 in collected dialysates, gene expression and immunohistochemistry performed on the tissue surrounding the microdialysis implant were used to evaluate if Dex polarized macrophages. Dex infusion down-regulated IL-6 and CCL2 gene expression and decreased CCL2 concentrations in dialysates collected at the implant site. Dex appeared to have no significant effect on the gene regulation of CD163, a commonly used M2c macrophage surface marker; Arg2; and iNOS2. However, Dex infusion was effective at increasing the number of CD163(+) cells surrounding the implanted microdialysis probe. This work demonstrates the use of microdialysis sampling to deliver agents such as Dex to alter macrophage polarization in vivo while allowing the ability to collect cytokines in the surrounding microenvironment.

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.

Dexamethasone down-regulates the inflammatory mediators but fails to reduce the tissue injury in the lung of acute pancreatitis rat models

Pulmonary complications are frequent in the course of acute pancreatitis. We investigate the effects of dexamethasone on lung injury in mild and severe AP. Mild and severe acute pancreatitis was induced in rats by bile-pancreatic duct obstruction and infusion of 3.5% sodium taurocholate into the bile-pancreatic duct, respectively. Dexamethasone (1 mg/kg) was given by intramuscular injection 1 h after acute pancreatitis. Plasma amylase activity was measured to evaluate the pancreas damage. Lungs were harvested for analysing mRNA expression of monocyte chemoattractant protein-1 (MCP-1), cytokine-induced neutrophil chemoattractant (CINC), P-selectin and intercellular adhesion molecule-1 (ICAM-1), myeloperoxidase (MPO) activity (as index of neutrophil infiltration) and histological examination. Dexamethasone reduced the hyperamylasemia and hindered the pulmonary upregulation of MCP-1, CINC, P-selectin and ICAM-1, in both mild and severe acute pancreatitis. Despite this, dexamethasone treatment failed to reduce MPO activity and histological alterations developed in lungs during acute pancreatitis, either in bile-pancreatic duct obstruction or sodium taurocholate model. We conclude that pulmonary local factors different from inflammatory mediators contribute to leukocyte recruitment, so that although dexamethasone down-regulated the lung expression of chemokines and adhesion molecules during acute pancreatitis it was not able to prevent leukocyte infiltration, which could be responsible for maintaining the lung injury in either mild or severe acute pancreatitis.

Comparative evaluation of blood markers and extrapancreatic inflammatim on CT score in the early prediction of the severity of acute panereatitis

AIM: To compare the value of blood markers and extrapancreatic inflammation on CT score (EPIC) in early prediction of the severity of acute pancreatitis (AP).

METHODS: The clinical, laboratory and CT data obtained on admission (within 24 h of hospitalization) for 96 patients with AP who were hospitalized from September 2010 to September 2011 were analyzed. Severe AP (SAP) was defined as the presence of one or more of the following signs: mortality, persistent organ failure and/or admission ICU, and/or operation. Blood markers and EPIC were compared between SAP group and mild AP (MAP) using the t test. The correlation between blood markers, EPIC and severity of AP was analyzed. The value of blood markers and EPIC in predicting the severity of AP was assessed using receiver operation curve analysis. The sensitivity, positive predictive value and accuracy were also studied.

RESULTS: There were 20 patients with SAP and 76 patients with MAP. The levels of blood markers and EPIC in the SAP group were significantly higher than those in the MAP group [white blood cell (WBC): (15.16 ± 5.06) × 10⁹/L vs (11.05 ± 1.76) × 10⁹/L, neutrophil-lymphocyte ratio (NLR): 18.95 ± 12.13 vs 6.63 ± 3.44, high-sensitivity C-reactive protein (hs-CRP): 58.35 mg/L ± 20.47 mg/L vs 28.59 mg/L ± 12.92 mg/L, D-dimer (DD): 1596.95 μg/L ± 1409.05 μg/L vs 412.52 μg/L ± 316.66 μg/L, EPIC: 3.30 ± 0.86 vs 1.50 ± 0.96, all P = 0.000]. The Spearman correlation coefficients (rs) between severity of AP and WBC, NLR, hs-CRP, DD and EPIC were 0.419, 0.571, 0.568, 0.434 and 0.613, respectively (all P = 0.000). The area under the curve (AUC) of WBC, NLR, hs-CRP, DD and EPIC in predicting the severity of AP were 0.798 (0.670-0.925), 0.906 (0.830-0.981), 0.904 (0.838-0.970), 0.808 (0.638-0.938) and 0.917 (0.851-0.983), respectively. The predictive sensitivities were 70.00%, 85.00%, 85.00%, 75.00% and 85.00%; the positive predictive values were 58.33%, 73.91%, 51.52%, 48.39% and 72.00%; and the accuracies were 83.33%, 90.63%, 80.21%, 78.13% and 90.63%, respectively.

CONCLUSION: WBC and DD have a moderate value in predicting the severity of AP, while NLR, hs-CRP, and EPIC have a much higher value.

δ-Tocotrienol and quercetin reduce serum levels of nitric oxide and lipid parameters in female chickens

BACKGROUND

Chronic, low-grade inflammation provides a link between normal ageing and the pathogenesis of age-related diseases. A series of in vitro tests confirmed the strong anti-inflammatory activities of known inhibitors of NF-κB activation (δ-tocotrienol, quercetin, riboflavin, (-) Corey lactone, amiloride, and dexamethasone). δ-Tocotrienol also suppresses β-hydroxy-β-methylglutaryl coenzyme A (HMG-CoA) reductase activity (the rate-limiting step in de novo cholesterol synthesis), and concomitantly lowers serum total and LDL cholesterol levels. We evaluated these compounds in an avian model anticipating that a dietary additive combining δ-tocotrienol with quercetin, riboflavin, (-) Corey lactone, amiloride, or dexamethasone would yield greater reductions in serum levels of total cholesterol, LDL-cholesterol and inflammatory markers (tumor necrosis factor-α [TNF-α], and nitric oxide [NO]), than that attained with the individual compounds.

RESULTS

The present results showed that supplementation of control diets with all compounds tested except riboflavin, (-) Corey lactone, and dexamethasone produced small but significant reductions in body weight gains as compared to control. (-) Corey lactone and riboflavin did not significantly impact body weight gains. Dexamethasone significantly and markedly reduced weight gain (>75%) compared to control. The serum levels of TNF-α and NO were decreased 61% - 84% (P < 0.001), and 14% - 67%, respectively, in chickens fed diets supplemented with δ-tocotrienol, quercetin, riboflavin, (-) Corey lactone, amiloride, or dexamethasone as compared to controls. Significant decreases in the levels of serum total and LDL-cholesterol were attained with δ-tocotrienol, quercetin, riboflavin and (-) Corey lactone (13% - 57%; P < 0.05), whereas, these levels were 2-fold higher in dexamethasone treated chickens as compared to controls. Parallel responses on hepatic lipid infiltration were confirmed by histological analyses. Treatments combining δ-tocotrienol with the other compounds yielded values that were lower than individual values attained with either δ-tocotrienol or the second compound. Exceptions were the significantly lower total and LDL cholesterol and triglyceride values attained with the δ-tocotrienol/(-) Corey lactone treatment and the significantly lower triglyceride value attained with the δ-tocotrienol/riboflavin treatment. δ-Tocotrienol attenuated the lipid-elevating impact of dexamethasone and potentiated the triglyceride lowering impact of riboflavin. Microarray analyses of liver samples identified 62 genes whose expressions were either up-regulated or down-regulated by all compounds suggesting common impact on serum TNF-α and NO levels. The microarray analyses further identified 41 genes whose expression was differentially impacted by the compounds shown to lower serum lipid levels and dexamethasone, associated with markedly elevated serum lipids.

CONCLUSIONS

This is the first report describing the anti-inflammatory effects of δ-tocotrienol, quercetin, riboflavin, (-) Corey lactone, amiloride, and dexamethasone on serum TNF-δ and NO levels. Serum TNF-δ levels were decreased by >60% by each of the experimental compounds. Additionally, all the treatments except with dexamethasone, resulted in lower serum total cholesterol, LDL-cholesterol and triglyceride levels. The impact of above mentioned compounds on the factors evaluated herein was increased when combined with δ-tocotrienol.