The natural flavonoid quercetin ameliorates cerulein-induced acute pancreatitis in mice

Isorhamnetin Alleviates Mitochondrial Injury in Severe Acute Pancreatitis via Modulation of KDM5B/HtrA2 Signaling Pathway

Severe acute pancreatitis (SAP), a widespread inflammatory condition impacting the abdomen with a high mortality rate, poses challenges due to its unclear pathogenesis and the absence of effective treatment options. Isorhamnetin (ISO), a naturally occurring flavonoid, demonstrates robust antioxidant and anti-inflammatory properties intricately linked to the modulation of mitochondrial function. However, the specific protective impact of ISO on SAP remains to be fully elucidated. In this study, we demonstrated that ISO treatment significantly alleviated pancreatic damage and reduced serum lipase and amylase levels in the mouse model of SAP induced by sodium taurocholate (STC) or L-arginine. Utilizing an in vitro SAP cell model, we found that ISO co-administration markedly prevented STC-induced pancreatic acinar cell necrosis, primarily by inhibiting mitochondrial ROS generation, preserving ATP production, maintaining mitochondrial membrane potential, and preventing the oxidative damage and release of mitochondrial DNA. Mechanistically, our investigation identified that high-temperature requirement A2 (HtrA2) may play a central regulatory role in mediating the protective effect of ISO on mitochondrial dysfunction in STC-injured acinar cells. Furthermore, through an integrated approach involving bioinformatics analysis, molecular docking analysis, and experimental validation, we uncovered that ISO may directly impede the histone demethylation activity of KDM5B, leading to the restoration of pancreatic HtrA2 expression and thereby preserving mitochondrial function in pancreatic acinar cells following STC treatment. In conclusion, this study not only sheds new light on the intricate molecular complexities associated with mitochondrial dysfunction during the progression of SAP but also underscores the promising value of ISO as a natural therapeutic option for SAP.

Study on the mechanism of Shugan Lidan Xiaoshi granule in preventing acute pancreatitis based on network pharmacology and molecular docking

Background

Shugan Lidan Xiaoshi granules (SLXG) is a herbal granule formulation developed by extensively modifying multiple traditional Chinese medicine compound prescriptions known for their ability to dissolve stones. It is primarily used for the prevention and treatment of cholelithiasis and possesses significant therapeutic potential in both preventing and treating acute pancreatitis. However, the preventive effects of SLXG on cholelithiasis-related complications, such as acute pancreatitis (AP), have been inadequately researched.

Methods

TCMSP database was searched to identify the active components and targets of SLXG's action. The disease gene databases (GeneCards, OMMI, PharmGKB, DrugBank) were used to retrieve the targets associated with AP. A TCM ingredient target network was then constructed by using the intersection of these two datasets. The overlapping targets underwent network analyses, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG)and Protein-Protein Interaction (PPI) analyses. Molecular docking was performed to examine the interaction patterns between the active ingredients and central targets.

Results

A "Traditional Chinese Medicine-Component-Target" complex network consisting of 10 traditional Chinese medicines, 114 compounds, and 164 targets was constructed. GO and KEGG analysis showed that SLXG has the potential to regulate the response of oxygen-containing compounds, apoptosis, and inflammatory factors. Nine central genes were identified by the PPI network and subnetwork. IL6 was chosen as the most significant gene for molecular docking. The three active compounds of SLXG: quercetin, luteolin, and paeoniflorin, along with the active site of IL6 have a good binding ability and thus play a preventive role in AP.

Conclusion

This study provides evidence of the effective preventive role of SLXG against AP, as indicated by bioinformatics analysis. The preventive effect of SLXG is attributed to its multi-component, multi-target, and multi-pathway mechanisms. This finding provides a solid foundation for future research on the clinical application and mechanism of action of drugs.

Network pharmacology-based investigation and experimental validation of the therapeutic potential and molecular mechanism of Danshen Chuanxiongqin injection in acute pancreatitis

BACKGROUND

Danshen Chuanxiong Injection (DCI) has demonstrated significant clinical efficacy in the treatment of acute pancreatitis (AP); however, the precise molecular mechanisms underlying its therapeutic effects remain incompletely understood.

OBJECTIVE

In this study, we employed network pharmacology analysis to comprehensively investigate the active components, potential targets, and signaling pathways involved in DCI-mediated treatment of AP.

METHODS

We utilized the mouse pancreatic acinar cell line 266-6 to establish an cholecystokinin (CCK)-induced AP cell injury model and evaluated cell viability using the Cell counting kit-8 assay. Western blotting and quantitative PCR were employed to determine the expression levels of key target proteins and genes.

RESULTS

Network pharmacology analysis identified a total of 144 active components and 430 potential targets within DCI. By integrating data from public databases, we identified 762 AP-related genes. Among these, we identified 93 potential targets that may be involved in the therapeutic effects of DCI for AP. These targets were significantly enriched in biological processes such as oxidative stress, regulation of cytokine production, leukocyte migration, and the TNF signaling pathway. Molecular docking studies revealed a high binding affinity between the active components and the key targets AKT1 and NFKBA, indicative of potential interaction. Additionally, CCK-induced acinar cell injury led to upregulation of AKT1, NFKBA, and P53 proteins, as well as TNF, IL6, and MMP9 genes. Conversely, treatment with DCI dose-dependently attenuated CCK-induced acinar cell injury and restored the expression levels of the aforementioned proteins and genes.

CONCLUSION

Overall, this study provides a comprehensive understanding of the molecular mechanisms underlying the therapeutic effects of DCI in the treatment of AP. Our findings confirm the protective effect of DCI against CCK-induced acinar cell injury and its regulation of key targets.

Quercetin alleviates gliotoxin-induced duckling tissue injury by inhibiting oxidative stress, inflammation and increasing heterophil extracellular traps release

Aspergillus fumigatus causes aspergillosis with high morbidity and mortality in the duck industry. As a vital virulence factor produced by A. fumigatus, gliotoxin (GT) is widely present in food and feed, threatening duck industry and human health. Quercetin is a polyphenol flavonoid compound from natural plants with anti-inflammatory and antioxidant functions. However, the effects of quercetin on ducklings with GT poisoning are unknown. The model of ducklings with GT poisoning was established, and the protective effects and molecular mechanisms of quercetin on ducklings with GT poisoning were investigated. Ducklings were divided into control, GT, and quercetin groups. A model of GT (2.5 mg/kg) poisoning in ducklings was successfully established. Quercetin protected GT-induced liver and kidney functions and alleviated GT-induced alveolar wall thickening in lungs, cell fragmentation, and inflammatory cell infiltration in liver and kidney. Quercetin decreased malondialdehyde (MDA) and increased superoxide dismutase (SOD) and catalase (CAT) after GT treatment. Quercetin significantly reduced GT-induced mRNA expression levels of inflammatory factors. Furthermore, quercetin increased GT-reduced heterophil extracellular traps (HETs) in serum. These results indicated that quercetin protected ducklings against GT poisoning by inhibiting oxidative stress, inflammation and increasing HETs release, which confirms the potential applicability of quercetin in treating GT-induced duckling poisoning.

Quercetin and vitamin E ameliorate cardio-apoptotic risks in diabetic rats

Apoptosis is upregulated in all forms of diabetes, and the mitochondria act as target in diabetes pathophysiology. Quercetin and vitamin E have both shown usefulness in the delay of progression of diabetes-induced complications. However, their effect on the apoptotic process in diabetes mellitus is unknown. We hypothesize that quercetin treatment in diabetes may decrease the propensity for cardiomyocytic death via regulation of the mitochondria permeability transition (mPT) pore opening. Hearts from normal and streptozotocin-induced diabetic rats were used for the study. Low ionic strength heart mitochondria were used for swelling assay and mitochondrial lipid peroxidation (mLPO) activity was spectrophotometrically assessed. Levels of cytochrome c and caspase 3 and 9 were determined by immunohistochemistry, while lesions assessed by histology. Diabetic heart mPT pore showed larger amplitude swelling than control, while mLPO levels were increased in diabetic rats relative to control, this resulted in cytochrome c release. This initiated increased caspase 3 and 9 activity in diabetic rats (p < 0.05). Histology showed hemorrhagic lesions in diabetic rat hearts. Quercetin and vitamin E treatment reversed these effects, suggestive of their anti-apoptotic effect. Quercetin and vitamin E protection in diabetes is mediated by mPT pore inhibition and modulation of mitochondrial-mediated apoptosis.

Natural product-based Radiopharmaceuticals:Focus on curcumin and its analogs, flavonoids, and marine peptides

Natural products provide a bountiful supply of pharmacologically relevant precursors for the development of various drug-related molecules, including radiopharmaceuticals. However, current knowledge regarding the importance of natural products in developing new radiopharmaceuticals remains limited. To date, several radionuclides, including gallium-68, technetium-99m, fluorine-18, iodine-131, and iodine-125, have been extensively studied for the synthesis of diagnostic and therapeutic radiopharmaceuticals. The availability of various radiolabeling methods allows the incorporation of these radionuclides into bioactive molecules in a practical and efficient manner. Of the radiolabeling methods, direct radioiodination, radiometal complexation, and halogenation are generally suitable for natural products owing to their simplicity and robustness. This review highlights the pharmacological benefits of curcumin and its analogs, flavonoids, and marine peptides in treating human pathologies and provides a perspective on the potential use of these bioactive compounds as molecular templates for the design and development of new radiopharmaceuticals. Additionally, this review provides insights into the current strategies for labeling natural products with various radionuclides using either direct or indirect methods.

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Potential use of natural products for the development of diagnostic and therapeutic radiopharmaceuticals.

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Profile of potential natural products as molecular templates for the synthesis of new radiopharmaceuticals: Focus on curcumin and its closely related substances, flavonoids, and marine peptides.

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Radiolabeling strategies, challenges, and examples of natural product-based radiopharmaceuticals under investigation.

Uncovering the Pharmacology of Xiaochaihu Decoction in the Treatment of Acute Pancreatitis Based on the Network Pharmacology

Background

Xiaochaihu decoction (XD) has demonstrated the pharmacodynamics on acute pancreatitis. This study was aimed at investigating the material and molecular basis of Xiaochaihu decoction.

Methods

Firstly, compounds of seven herbs containing XD were collected from the TCMSP, ETCM, and BATMAN-TCM databases, and the putative targets of pancreatitis were obtained from the OMIM, TTD, and GeneCards databases. Then, the PPI network was constructed according to the matching results between XD potential targets and pancreatic neoplasm targets. Furthermore, enrichment analysis on GO and KEGG by DAVID utilized bioinformatics resources. Finally, molecular docking was performed to simulate the interaction between the active compound of XD and putative targets. In an in vitro experiment, AR42J cells were induced by LPS and then treated with Quercetin (25, 50, and 100 μM) or XCHD. The IL-6, TNF-α, and IL-1β levels were detected by ELISA kit, MAPK3 and TP53 mRNA expressions were measured by qRT-PCR, and the proteins of MAPK3 and TP53 expressions were measured by WB.

Results

A total of 196 active ingredients and 91 putative targets were selected. The PPI network analysis demonstrated that Quercetin was the candidate agent and MAPK3, IL-6, and TP53 were the potential targets for the XD treatment of acute pancreatitis. The KEGG analysis revealed that pathways in cancers, TNF signaling way, and MAPK signaling way might play an important role in pancreatitis therapy. And molecular docking results showed that Quercetin combined well with MAPK3, IL-6, and TP53. An in vitro experiment indicated that XCHD and Quercetin inhibited the IL-6, TNF-α, and IL-1β levels and MAPK3 and TP53.

Conclusion

This study illustrated that XCHD and Quercetin contained in XD played an important role in the treatment of acute pancreatitis by acting on the key genes of MPAK3, IL-6, and TP53 which were associated with inflammation and apoptosis.

MiR-146b-3p protects against AR42J cell injury in cerulein-induced acute pancreatitis model through targeting Anxa2

Background

Acute pancreatitis (AP) is a common inflammatory disorder. MicroRNAs play crucial roles in the pathogenesis of AP. In this article, we explored the detailed role and molecular mechanisms of miR-146b-3p in AP progression.

Methods

The rat AR42J cells were treated with cerulein to establish the AP model in vitro. The miR-146b-3p and Annexin A2 (Anxa2) mRNA levels were assessed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Cell viability and apoptosis were tested using the Cell Counting Kit-8 (CCK-8) and flow cytometry assays, respectively. Caspase-3 activity and the production of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-α (TNF-α) were measured by enzyme-linked immunosorbent assay and qRT-PCR. Targeted interaction between miR-146b-3p and Anxa2 was verified by the dual-luciferase reporter and RNA immunoprecipitation assays. Western blot analysis was performed to detect the expression of Anxa2 protein.

Results

Our data revealed that miR-146b-3p was significantly downregulated in AP samples. The enforced expression of miR-146b-3p alleviated cerulein-induced injury in AR42J cells, as evidenced by the promotion in cell viability and the repression in cell apoptosis, as well as the reduction in IL-1β, IL-6, and TNF-α production. Anxa2 was directly targeted and inhibited by miR-146b-3p. Moreover, the alleviative effect of miR-146b-3p overexpression on cerulein-induced AR42J cell injury was mediated by Anxa2.

Conclusions

The current work had led to the identification of miR-146b-3p overexpression that protected against cerulein-induced injury in AR42J cells at least in part by targeting Anxa2, revealing a promising target for AP diagnosis and treatment.

A multi-strategy platform for quality control and Q-markers screen of Chaiqin chengqi decoction

BACKGROUND

Acute pancreatitis (AP) is an inflammatory disorder of the pancreas that is associated with substantial morbidity and mortality. Chaiqin chengqi decoction (CQCQD) has been proven clinically to be an effective treatment for AP for decades in West China Hospital. Quality control for CQCQD containing many hundreds of characteristic phytochemicals poses a challenge for developing robust quality assessment metrics.

PURPOSE

To evaluate quality consistency of CQCQD with a multi-strategy based analytical method, identify potential quality-markers (Q-markers) based on drug properties and effect characteristics, and endeavor to establish CQCQD as a globally-accepted medicine.

METHODS

A typical analysis of constitutive medicinal plant materials was performed following the Chinese Pharmacopoeia. The extraction process was optimized through an orthogonal array (L₉(3⁴)) to evaluate three levels of liquid to solid ratio, soaking time, duration of extraction, and the number of extractions. An ultra-high-performance liquid chromatography (UHPLC) fingerprinting combined with absolute quantitation of multi chemical marker compounds, coupled with similarity, hierarchical clustering analysis (HCA), and principal component analyses (PCA) were performed to evaluate 10 batches of CQCQD. On the basis of systematic analysis of fundamental features of CQCQD in treating AP, the potential Q-marker screen was proposed through detection of quality transfer and efficacy for chemical markers. UHPLC coupled with quadrupole orbitrap mass spectrometry were used to determine compounds in medicinal materials, decoctions and plasma. Network pharmacology and taurolithocholic acid 3-sulfate induced pancreatic acinar cell death were used to evaluate the correlation between chemical markers and anti-pancreatitis activity. A cerulein induced AP murine model was used to validate quality assessed CQCQD batches at clinically-equivalent dose. The effective content of chemical markers was predicted using linear regression analysis on quantitative information between validated batches and the other batches.

RESULTS

The chemical markers and other physical and chemical indices in the original materials met Chinese Pharmacopoeia standards. A total of 22 co-existing fingerprint peaks were selected and the similarity varied between 0.946 and 0.990. Batch D10 possessed the highest similarity index. HCA classified the 10 batches into 2 main groups: 7 batches represented by D10 and 3 batches represented by D1. During the initial Q-marker screen stage, 22 compounds were detected in both plant materials and decoctions, while 13 compounds were identified in plasma. Network pharmacology predicted the potential targets and pathway of AP related to the 22 compounds. All 10 batches showed reduced necrosis below 60% with the best effect achieved by D10 (~40%). The spectrum-efficacy relationship analyzed by Pearson correlation analysis indicated that emodin, rhein, aloe emodin, geniposide, hesperridin, chrysin, syringin, synephrine, geniposidic acid, magnolol, physcion, sinensetin, and baicalein showed positive correlation with pancreatic acinar cell death protection. Similar to the in vitro evaluation, batch D10 significantly reduced total histopathological scores and biochemical severity indices at a clinically-equivalent dose but batch D1 did not. The content of naringin, narirutin and baicalin in batches D1, D5 and D9 consistently exceeds the upper limit of the predicted value. Eight markers whose lower limit is predicted to be close to 0 contributed less to the material basis for AP protection.

CONCLUSION

Despite qualified materials used for CQCQD preparation, the clinical effect depends on appropriate content range of Q-markers. Emodin, rhein, aloe emodin, magnolol, hesperidin, synephrine, baicalein, and geniposide are considered as vital Q-markers in the primary screen. This study proposed a feasible platform for producing highly consistent batches of CQCQD in future study.

Cilostazol protects against cyclophosphamide-induced ovarian toxicity in female rats: role of cAMP and HO-1

Purpose: Cancer rates have been increased among women of reproductive age nowadays. Hence, many young female will be exposed to chemotherapeutic agents as cyclophosphamide (CP), carrying the hazards on female fertility. Cilostazol is a selective phosphodiesterase-3 inhibitor drug which exhibits antioxidant, anti-inflammatory, and anti-apoptotic activities. We aimed in this study to explore the possible protective effects of cilostazol against CP-induced ovarian damage in female rats.Methods: Cilostazol (10 mg/kg/day) was administered orally for 10 days in presence and absence of CP (150 mg/kg IP single dose) treatment. Serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), estrogen (E2), and anti-Müllerian hormone (AMH) levels were determined. Ovarian oxidative stress parameters along with inflammatory biomarkers were measured. 3,5-Cyclic adenosine monophosphate (cAMP) ovarian level was detected. Ovarian histopathological examination and caspase-3 immunohistochemical study were evaluated.Results: CP-treated rats showed a significant increase in serum levels of FSH and LH with decreased serum E2 and AMH levels with an increase in the ovarian inflammatory and oxidative stress biomarkers besides a significant decrease in cAMP ovarian level with an evident histopathological picture of ovarian damage and a high caspase-3 immunoexpression. Cilostazol pretreatment significantly restored the distributed hormonal levels, the oxidative stress and inflammatory biomarkers to their normal levels with marked improvement in histopathological picture of ovarian damage with a significant decrease in caspase-3 immunoexpression.Conclusions: These data suggest that cilostazol protects against CP- induced ovarian damage, which may be related to an increase in cAMP with subsequent anti-inflammatory, antioxidant, and anti-apoptotic properties.

Serotonin receptors 5-HTR2A and 5-HTR2B are involved in cigarette smoke-induced airway inflammation, mucus hypersecretion and airway remodeling in mice

BACKGROUND

Cigarette smoke plays an important role in the pathogenesis of chronic obstructive pulmonary disease (COPD). Recently, elevated serotonin (5-HT) levels were found in the plasma of COPD patients. The role of 5-HT and its receptors in airway inflammation and remodeling induced by cigarette smoke is unclear.

METHODS

BALB/c mice received the 5-HTR2A inhibitor ketanserin, the 5-HTR2B inhibitor RS-127445 or the natural 5-HTR2A/2B inhibitor quercetin intraperitoneally, then were exposed to cigarette smoke for 6 or 12 weeks. Control mice received placebo and were exposed to room air or cigarette smoke. Mice were sacrificed and bronchial alveolar lavage fluid (BALF) and lung tissue samples were collected.

RESULTS

Immunohistochemistry and western blot confirmed an increase in both 5-HTR2A and 5-HTR2B expression in mouse lungs after exposure to cigarette smoke for 6 and 12 weeks. Cigarette smoke induced accumulation of macrophages and neutrophils and increased levels of inflammatory cytokines, including IL-1β and TNF-ɑ, in BALF and lung tissue; these effects were inhibited by ketanserin, RS-127445 and quercetin. Pretreatment with 5-HT receptor antagonists suppressed the goblet cell hyperplasia induced by 6- or 12-week exposure to cigarette smoke, based on Alcian blue-periodic acid Schiff staining. After 12 weeks of cigarette smoke exposure, Masson's staining showed fibrosis surrounding the mouse airways, and inhibitor pretreatment significantly attenuated the thickening and collagen deposition around the small airways.

CONCLUSIONS

Our results suggest that cigarette smoke-induced airway inflammation and small airway remodeling are partially mediated by 5-HTR2A and 5-HTR2B, which could be a new therapeutic target for airway remodeling in COPD.

Myrtus communis leaf extract protects against cerulein-induced acute pancreatitis in rats

In this study, the aim was to examine the potential protective effects of Myrtus communis subsp. communis leaf ethanol extract (MC) treatment against acute pancreatitis (AP) in rats. Thirty-two rats were grouped as the saline-pretreated control (C), MC-pretreated control (MC), saline-pretreated AP (AP), and MC-pretreated AP (MC + AP) groups. To induce AP, cerulein was administered (50 µg/kg) two times. The rats were given MC for 14 days before cerulein injection. Six hours after the final cerulein injection, the rats were sacrificed. Pancreatic damage was associated with an increase in the serum activity of lipase and amylase, the pancreatic activity of myeloperoxidase, and the pancreatic level of malondialdehyde, interleukin-1β, and interleukin-6. AP also led to a decrease in the pancreatic level of anti-inflammatory interleukin-10 and glutathione. Pretreatment with MC before the induction of AP significantly reduced the pancreatic damage observed during the histological examination as well as reversed the biochemical changes evoked by AP. PRACTICAL APPLICATIONS: Acute pancreatitis is characterized by high mortality (average about 5%; severe cases may reach about 30%). The current treatment for acute pancreatitis is mainly symptomatic. The introduction of herbal drugs may lead to the development of a new strategy in the treatment of this disease. This study revealed that MC reduced pancreatic injury by decreasing pro-inflammatory cytokines, increasing antioxidant capacity and anti-inflammatory cytokine, IL-10. To the authors' knowledge, this research is the first report showing that MC inhibits the development of AP. This observation suggests that MC may be useful in the prevention and the treatment of AP in clinical settings.

Centaurium erythraea extract improves survival and functionality of pancreatic beta-cells in diabetes through multiple routes of action

ETHNOPHARMACOLOGICAL RELEVANCE

Centaurium erythraea Rafn (CE) is used as a traditional medicinal plant in Serbia to treat different ailments due to its antidiabetic, antipyretic, antiflatulent and detoxification effects.

AIM OF THE STUDY

Elucidation of the mechanisms that underlie the antioxidant and pro-survival effects of the CE extract (CEE) in beta-cells and pancreatic islets from streptozotocin (STZ)-treated diabetic rats.

MATERIAL AND METHODS

Diabetes was induced in rats by multiple applications of low doses of STZ (40 mg/kg intraperitoneally (i.p.), for five consecutive days). CEE (100 mg/kg) was administered orally, in the pre-treated group for two weeks before diabetes induction, during the treatments with STZ and for four weeks after diabetes onset, and in the post-treatment group for four weeks after diabetes induction. The impact of CEE on diabetic islets was estimated by histological and immunohistochemical examination of the pancreas. Molecular mechanisms of the effects of CEE were also analyzed in insulinoma Rin-5F cells treated with STZ (12 mM) and CEE (0.25 mg/mL). Oxidative stress was evaluated by assessing the levels of DNA damage, lipid peroxidation, protein S-glutathionylation and enzymatic activities and expression of CAT, MnSOD, CuZnSOD, GPx and GR in beta-cells. The presence and activities of the redox-sensitive and islet-enriched regulatory proteins were also analyzed.

RESULTS

Treatment with CEE ameliorated the insulin level and glycemic control in STZ-induced diabetic rats by improving the structural and functional properties of pancreatic islets through multiple routes of action. The disturbance of islet morphology and islet cell contents in diabetes was reduced by the CEE treatment and was associated with a protective effect of CEE on the levels of insulin, GLUT-2 and p-Akt in diabetic islets. The antioxidant effect of CEE on STZ-treated beta-cells was displayed as reduced DNA damage, lipid peroxidation, protein S-glutathionylation and alleviation of STZ-induced disruption in MnSOD, CuZnSOD and CAT enzyme activities. The oxidative stress-induced disturbance of the transcriptional regulation of CAT, MnSOD, CuZnSOD, GPx and GR enzymes in beta-cells was improved after the CEE treatment, and was observed as readjustment of the presence and activities of redox-sensitive NFκB-p65, FOXO3A, Sp1 and Nrf-2 transcription factors. The observed CEE-mediated induction of proliferative and pro-survival pathways and insulin expression/secretion after STZ-induced oxidative stress in beta-cells could be partially attributed to a fine-tuned modulation of the activities of pro-survival Akt, ERK and p38 kinases and islet-enriched Pdx-1 and MafA regulatory factors.

CONCLUSIONS

The results of this study provide evidence that CEE improves the structural and functional properties of pancreatic beta-cells by correcting the endogenous antioxidant regulatory mechanisms and by promoting proliferative and pro-survival pathways in beta-cells.

Differential Impact of Flavonoids on Redox Modulation, Bioenergetics, and Cell Signaling in Normal and Tumor Cells: A Comprehensive Review

SIGNIFICANCE

Flavonoids can interact with multiple molecular targets to elicit their cellular effects, leading to changes in signal transduction, gene expression, and/or metabolism, which can, subsequently, affect the entire cell and organism. Immortalized cell lines, derived from tumors, are routinely employed as a surrogate for mechanistic studies, with the results extrapolated to tissues in vivo. Recent Advances: We review the activities of selected flavonoids on cultured tumor cells derived from various tissues in comparison to corresponding primary cells or tissues in vivo, mainly using quercetin and flavanols (epicatechin and (-)-epigallocatechin gallate) as exemplars. Several studies have indicated that flavonoids could retard cancer progression in vivo in animal models as well as in tumor cell models.

CRITICAL ISSUES

Extrapolation from in vitro and animal models to humans is not straightforward given both the extensive conjugation and complex microbiota-dependent metabolism of flavonoids after consumption, as well as the heterogeneous metabolism of different tumors.

FUTURE DIRECTIONS

Comparison of data from studies on primary cells or in vivo are essential not only to validate results obtained from cultured cell models, but also to highlight whether any differences may be further exploited in the clinical setting for chemoprevention. Tumor cell models can provide a useful mechanistic tool to study the effects of flavonoids, provided that the limitations of each model are understood and taken into account in interpretation of the data.

Withaferin A, a novel compound of Indian ginseng (Withania somnifera), ameliorates Cerulein-induced acute pancreatitis: Possible role of oxidative stress and inflammation

Acute pancreatitis is an inflammatory disorder of the pancreas that may precipitate due to various reasons such as chronic alcoholism, gall stone obstruction, and life style. Current treatment options offer limited efficacy, as they provide only symptomatic relief. This study is an attempt to study the effects of Withaferin A (WFA) against Cerulein-induced acute pancreatitis in mice. Animals were pretreated with WFA via intraperitoneal route, for 7 days. Plasma amylase and lipase, tissue malondialdehyde (MDA), and glutathione were evaluated for all groups. Western blot analysis; haematoxylin and eosin staining of the liver, lung, and pancreas; immunohistochemistry for nitrotyrosine; and myeloperoxidase activity were performed. Haematoxylin and eosin stained sections significantly revealed the altered architecture and thereby damage in the pancreas, lungs, and liver that has been low in treatment groups. Increased myeloperoxidase and nitrotyrosine have also been reduced upon treatment with WFA. Increased levels of MDA, NO, and expression of myeloperoxidase and nitrotyrosine in the parameters estimated add evidence to the role of oxidative stress and inflammation in acute pancreatitis. WFA evidently altered these conditions upon pretreatment. Our study shows that this novel steroidal compound has potent anti-inflammatory property. Natural compounds can therefore be good remedies against many diseases if incorporated in routine diet as dietary supplement.

Protective effects of flavonoids from Coreopsis tinctoria Nutt. on experimental acute pancreatitis via Nrf-2/ARE-mediated antioxidant pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Oxidative stress is a prominent feature of clinical acute pancreatitis (AP). Coreopsis tinctoria has been used traditionally to treat pancreas disorders like diabetes mellitus in China and Portugal and its flavonoid-rich fraction contain the main phytochemicals that have antioxidant and anti-inflammatory activities.

AIM OF THE STUDY

To investigate the effects of flavonoids isolated from C. tinctoria on experimental AP and explore the potential mechanism.

MATERIALS AND METHODS

LC-MS based online technique was used to analyse and isolate targeted flavonoids from C. tinctoria. Freshly isolated mouse pancreatic acinar cells were treated with taurocholic acid sodium salt hydrate (NaT, 5 mM) with or without flavonoids. Fluorescence microscopy and a plate reader were used to determine necrotic cell death pathway activation (propidium iodide), reactive oxygen species (ROS) production (H2-DCFDA) and ATP depletion (luminescence) where appropriate. AP was induced by 7 repeated intraperitoneal caerulein injections (50 μg/kg) at hourly interval in mice or retrograde infusion of taurolithocholic acid 3-sulfate disodium salt (TLCS; 5 mM, 50 μL) into the pancreatic duct in mice or infusion of NaT (3.5%, 1 mL/kg) in rats. A flavonoid was intraperitoneally administered at 0, 4, and 8 h after the first caerulein injection or post-operation. Disease severity, oxidative stress and antioxidant markers were determined.

RESULTS

Total flavonoids extract and flavonoids 1-6 (C1-C6) exhibited different capacities in reducing necrotic cell death pathway activation with 0.5 mM C1, (2 R,3 R)-taxifolin 7-O-β-D-glucopyranoside, having the best effect. C1 also significantly reduced NaT-induced ROS production and ATP depletion. C1 at 12.5 mg/kg and 8.7 mg/kg (equivalent to 12.5 mg/kg for mice) significantly reduced histopathological, biochemical and immunological parameters in the caerulein-, TLCS- and NaT-induced AP models, respectively. C1 administration increased pancreatic nuclear factor erythroid 2-related factor 2 (Nrf2) and Nrf2-medicated haeme oxygenase-1 expression and elevated pancreatic antioxidant enzymes superoxide dismutase and glutathione peroxidase levels.

CONCLUSIONS

Flavonoid C1 from C. tinctoria was protective in experimental AP and this effect may at least in part be attributed to its antioxidant effects by activation of Nrf2-mediated pathways. These results suggest the potential utilisation of C. tinctoria to treat AP.

Astaxanthin ameliorates cerulein-induced acute pancreatitis in mice

BACKGROUND

A various of pharmacological effects of astaxanthin has been confirmed. However, the mechanism underlying protective effect of astaxanthin on acute pancreatitis (AP) induced by cerulein still unclear. The present study is to investigate the mechanism underlying the effect of astaxanthin on autophagy and apoptosis via the JAK/STAT3 pathway.

METHODS

Intraperitoneal injection of cerulein at hourly intervals followed by lipopolysaccharide injection were used in Balb/C mice. Vehicle or astaxanthin, which intraperitoneal injected in two doses (20 mg/kg and 40 mg/kg), were injected in mice 1 h before the first cerulein injection. At 3 h after the last injection, when the pathological changes were most severe, pancreatic tissue was analyzed by pathologically scored and hematoxylin and eosin (H&E) staining. The severity of AP was assessed by histological grading, proinflammatory cytokine levels, biochemistry, myeloperoxidase (MPO) activity, and analysis of JAK/STAT3 activity.

RESULTS

Astaxanthin administration markedly reduced serum digestive enzyme activities, pancreatic histological scores, proinflammatory cytokine levels (tumor necrosis factor-α (TNF-α), Interleukin-1β (IL-1β), and Interleukin-6 (IL-6)), MPO and JAK/STAT3 activity.

CONCLUSION

Collectively, these results indicate that astaxanthin inhibits pancreatic injury in AP by targeting JAK/STAT3-mediated apoptosis and autophagy.

Quercetin alleviates generalized hyperalgesia in mice with induced adenomyosis

Adenomyosis is a common gynecologic disorder characterized by the presence of endometrial glands and stroma within the myometrium. The present study investigated the effect of quercetin in neonatal Imprinting Control Region mice with tamoxifen-induced adenomyosis. The body weight and hotplate response latency of all mice was examined at 4, 8, 12 and 16 weeks after birth. The mice dosed with tamoxifen were divided into four groups: high- or low-quercetin group, valproic acid (VPA) group and untreated group. The group of mice that were neonatally administrated with the solvent only (no tamoxifen), received no treatment and served as a blank control group. After 3 weeks of drug treatment, the potential ability of quercetin to improve the generalized hyperalgesia in mice with induced adenomyosis was evaluated by determining the body weight, pain modulation, examining the myometrial infiltration by histology examination of the uterus and detecting the expression of transient receptor potential cation channel subfamily V member 1 (Trpv-1), phospho (p)-p38 mitogen activated protein kinase p-extracellular signal-regulated kinase (p-ERK) in DRG neurons via immunohistochemistry. The results demonstrated that treatment with quercetin improved the generalized hyperalgesia by extending the hotplate response latency, reduced myometrial infiltration and decreased the expression levels Trpv-1, p-p38 and p-ERK in dorsal root ganglion neurons. The results indicated that quercetin decreases the incidence of hyperalgesia in mice with tamoxifen-induced adenomyosis, and the potential mechanism is through reduced central sensitization, which may be a promising treatment for adenomyosis.

A relation between osteoclastogenesis inhibition and membrane-type estrogen receptor GPR30

Disruption of the cooperative balance between osteoblasts and osteoclasts causes various bone disorders, some of which are because of abnormal osteoclast recruitment. Osteoporosis, one of the bone disorders, is not effectively treated by currently available medicines. In addition to the development of novel drugs for palliative treatment, the exploitation of novel compounds for preventive treatment is important in an aging society. Quercetin, a major flavonoid found in many fruits and vegetables, has been expected to inhibit cancer and prevent several diseases because of its anti-inflammatory and estrogenic functions. It has been reported that quercetin has the potential to reduce bone resorption, but the mechanism by which this compound affects the differentiation of osteoclasts remains unknown. Here, using a bone marrow cell-based in vitro osteoclast differentiation system from bone marrow cells, we found that the ability of quercetin to inhibit osteoclastogenesis was related to its estrogenic activity. The inhibition was partially blocked by a specific antagonist for the nuclear receptor estrogen receptor α, but a specific antagonist of the membrane-type receptor GPR30 completely ablated this inhibition. Furthermore, quercetin suppressed the transient increase of Akt phosphorylation induced by the stimulation of macrophage colony-stimulating factor and receptor activator of NF-κB ligand with no effect on MAPK phosphorylation, suggesting exquisite crosstalk between cytokine receptor and G-protein coupled receptor signaling. These results indicate the important role of GPR30 in osteoclast differentiation and provide new insights to the development of new treatments for osteoporosis.

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Flavonoids can prevent osteoporosis, but the precise mechanism remains unknown.

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The major flavonoid quercetin inhibited osteoclastogenesis.

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The inhibition was entirely rescued by GPR30 antagonism.

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GPR30 has a key role in mechanism of osteoclastogenesis prevention by quercetin.

Therapeutic effects of quercetin on early inflammation in hypertriglyceridemia-related acute pancreatitis and its mechanism

OBJECTIVE

To investigate the therapeutic effects of quercetin on early-stage inflammation in hypertriglyceridemia (HTG)-related acute pancreatitis (AP) both in vivo and in vitro, and its possible mechanism.

METHODS

In vivo, rats were fed a high-fat diet to induce HTG, and AP was induced by intraperitoneal injection of cerulein (50 μg/kg × 2). Quercetin (100, 150 and 200 mg/kg) was administered by intraperitoneal injection after AP induction. In vitro, rat exocrine acinar cells were preincubated with palmitic acid (PA, 0.1 mmol/L, 6 h) with quercetin (5, 10, 20 and 40 μM) prior to a cholecystokinin analog CCK-8 (20pM). Injury of the pancreas was assessed by amylase secretion and pancreatic histological evaluation. Inflammation was estimated by measuring IL-1β, IL-6, TNFα and NF-kB expression. Dynamic expression of IRE1α, sXBP1, C/EBPα and C/EBPβ was monitored by real-time PCR, immunofluorescence (IF) and western blot (WB).

RESULTS

Quercetin intervention reduced plasma amylase level (P < 0.001) in a dose-dependent manner, attenuated pancreatic histopathological damage (P < 0.05), and reduced the mRNA and protein expression of NF-kB, IL-1β, IL-6, TNFα (P < 0.05) more significantly in HTG-related AP rats than in normal-lipid AP rats. Quercetin also down-regulated gene and protein expression levels of IRE1α, sXBP1, C/EBPα and C/EBPβ in a dose-dependent manner.

CONCLUSIONS

Quercetin attenuates early-stage inflammation in HTG-related AP, probably by reducing IRE1α, sXBP1, C/EBPα and C/EBPβ expression.

Effect of different doses of quercetin on pancreatic pathology in rats with hypertriglyceridemia related acute pancreatitis

AIM: To investigate the effect of different doses of quercetin on the pancreatic pathology in rats with cerulein-induced acute pancreatitis (AP) associated with hypertriglyceridemia (HTG).

METHODS: Seventy-two male SD rats were randomly divided into 12 groups: HTG group (n = 6, fed a high-fat diet for 2 wk: 77% normal chow + 3% cholesterol + 20% lard), HTG + AP group (n = 6, after 2 wk of a high-fat diet, AP was induced by peritoneal injection of 50 μg/kg cerulein twice at 1-h interval), HTG + AP + quercetin groups [n = 24, divided into 4 groups (6 rats each), quercetin (50, 100, 150, 200 mg/kg) was administered to rats by peritoneal injection after AP induction], normal blood lipid group (n = 6, fed normal chow for 2 wk), normal blood lipid + AP group (n = 6, after 2 wk of normal chow, AP was induced by peritoneal injection of 50 μg/kg cerulein twice at 1-h interval), normal blood lipid + AP + quercetin groups [n = 24, divided into 4 groups (6 rats each), quercetin (50, 100, 150, 200 mg/kg) was administered to rats by peritoneal injection after AP induction]. All rats were sacrificed 9 h after AP induction. Plasma levels of amylase were tested and the pathological changes of pancreatic tissues were observed.

RESULTS: After two weeks of a high-fat diet, serum levels of triglyceride and total cholesterol were much higher than those in rats given normal chow (P < 0.001). Compared with the normal blood lipid + AP group, plasma level of amylase was significantly higher (23670.00 U/L ± 2053.13 U/L vs 13136.00 U/L ± 3536.95 U/L) and pancreatic tissue injury was significantly more serious in the HTG + AP group (9.75 ± 0.94 vs 5.92 ± 1.32) (P = 0.022; P < 0.001). Quercetin intervention groups showed significantly lower levels of amylase and less serious pancreatic tissue injury; the effect was dose-dependent. This protective effect of quercetin was more obvious in the HTG + AP group than in the AP group (HTG + AP + 100, 150, 200 mg/kg quercetin group vs HTG + AP group total histopathological scores: P < 0.001 for all; normal blood lipid + AP + 100, 150, 200 mg/kg quercetin group vs normal blood lipid + AP group total histopathological scores: P = 0.084, P = 0.003, P < 0.001), particularly in acinar necrosis and inflammatory infiltration (HTG + AP + 100, 150, 200 mg/kg quercetin group vs HTG + AP group necrosis score: P < 0.001 for all; inflammatory infiltration: P = 0.008, P = 0.006, P = 0.001).

CONCLUSION: Quercetin could significantly ameliorate the pancreatic pathology in rats with HTG related AP, especially acinar necrosis and inflammatory infiltration. The protective effect is dose-dependent.

The flavonoid quercetin ameliorates Alzheimer's disease pathology and protects cognitive and emotional function in aged triple transgenic Alzheimer's disease model mice

Alzheimer's disease (AD) is the most common senile dementia in the world. Although important progress has been made in understanding the pathogenesis of AD, current therapeutic approaches provide only modest symptomatic relief. In this study, we evaluated the neuroprotective effect of quercetin (25 mg/kg) administration via i.p. injection every 48 h for 3 months on aged (21-24 months old) triple transgenic AD model (3xTg-AD) mice. Our data show that quercetin decreases extracellular β-amyloidosis, tauopathy, astrogliosis and microgliosis in the hippocampus and the amygdala. These results were supported by a significant reduction in the paired helical filament (PHF), β-amyloid (βA) 1-40 and βA 1-42 levels and a decrease in BACE1-mediated cleavage of APP (into CTFβ). Additionally, quercetin induced improved performance on learning and spatial memory tasks and greater risk assessment behavior based on the elevated plus maze test. Together, these findings suggest that quercetin reverses histological hallmarks of AD and protects cognitive and emotional function in aged 3xTg-AD mice.

Effects of melatonin on the oxidative damage and pancreatic antioxidant defenses in cerulein-induced acute pancreatitis in rats

BACKGROUND

Oxidative stress is recognized as a pivotal effector of several pathogenic processes, including acute pancreatitis. Reactive oxygen species not just cause damage on the main cellular components, but also influence the expression of antioxidant system genes. Antioxidant molecules, such as melatonin, could be good candidates for the treatment of this multidimensional disease. The present study was to evaluate the chemopreventive effect of melatonin in a rat model of cerulein-induced acute pancreatitis.

METHODS

Four subcutaneous injections of cerulein (20 μg/kg body weight) were given to Wistar rats at two hours intervals; melatonin was injected intraperitoneally (25 mg/kg body weight) 30 minutes before each injection of cerulein. Lipid peroxidation, protein oxidation (carbonyl groups), total antioxidant status, and glutathione peroxidase activity were determined in pancreatic tissue using commercial kits.

RESULTS

The chemopreventive administration of melatonin caused a reduction in lipid peroxidation and protein oxidation due to injections of cerulein. Additionally, melatonin treatment was also able to revert glutathione peroxidase activity and total antioxidant status near to control levels, suggesting that melatonin could prevent from oxidative phenomena in the pancreas, such as lipid peroxidation and protein oxidation, and could stimulate, directly or indirectly, the expression of antioxidant enzymes.

CONCLUSION

Melatonin, a polyvalent antioxidant, protected the pancreatic damage via the decrease of oxidative stress and increase of the activities of antioxidant enzymes in cerulein-induced acute pancreatitis.

Opuntia humifusa ameliorated cerulein-induced acute pancreatitis

OBJECTIVE

The aim of this study was to evaluate the effects of Opuntia humifusa (OH) on cerulein-induced acute pancreatitis (AP).

METHODS

Acute pancreatitis was induced via intraperitoneal injection of cholecystokinin analog cerulein (50 μg/kg). In the OH pretreatment group, OH was administered intraperitoneally (100, 250, or 500 mg/kg) 1 hour before first cerulein injection. In the posttreatment group, OH was administered intraperitoneally (500 mg/kg) 1 hour after the first cerulein injection. Furthermore, we isolated the pancreatic acinar cells using collagenase method, then investigated the acinar cell viability, cytokine productions, and the regulating mechanisms.

RESULTS

The both pretreatment and posttreatment of OH treatment attenuated the severity of AP, as shown by the histology of the pancreas and lung, and inhibited neutrophil infiltration; serum amylase and lipase activities; proinflammatory cytokine expression such as interleukin 1, interleukin 6, and tumor necrosis factor α; and cell death including apoptosis and necrosis. Furthermore, OH inhibited the activation of c-Jun N-terminal kinases.

CONCLUSIONS

These results suggest that OH reduces the severity of AP by inhibiting acinar cell death through c-Jun N-terminal kinases.

Beneficial effect of the bioflavonoid quercetin on cholecystokinin-induced mitochondrial dysfunction in isolated rat pancreatic acinar cells

The pathogenesis of acute pancreatitis (AP) is still poorly understood. Thus, a reliable pharmacological therapy is currently lacking. In recent years, an impairment of the energy metabolism of pancreatic acinar cells, caused by Ca(2+)-mediated depolarization of the inner mitochondrial membrane and a decreased ATP supply, has been implicated as an important pathological event. In this study, we investigated whether quercetin exerts protection against mitochondrial dysfunction. Following treatment with or without quercetin, rat pancreatic acinar cells were stimulated with supramaximal cholecystokinin-8 (CCK). CCK caused a decrease in the mitochondrial membrane potential (MMP) and ATP concentration, whereas the mitochondrial dehydrogenase activity was significantly increased. Quercetin treatment before CCK application exerted no protection on MMP but increased ATP to a normal level, leading to a continuous decrease in the dehydrogenase activity. The protective effect of quercetin on mitochondrial function was accompanied by a reduction in CCK-induced changes to the cell membrane. Concerning the molecular mechanism underlying the protective effect of quercetin, an increased AMP/ATP ratio suggests that the AMP-activated protein kinase system may be activated. In addition, quercetin strongly inhibited CCK-induced trypsin activity. The results indicate that the use of quercetin may be a therapeutic strategy for reducing the severity of AP.

Chemopreventive effects of resveratrol in a rat model of cerulein-induced acute pancreatitis

In the past decades, a greater understanding of acute pancreatitis has led to improvement in mortality rates. Nevertheless, this disease continues to be a health care system problem due to its economical costs. Future strategies such as antioxidant supplementation could be very promising, regarding to beginning and progression of the disease. For this reason, this study was aimed at assessing the effect of exogenous administration of resveratrol during the induction process of acute pancreatitis caused by the cholecystokinin analog cerulein in rats. Resveratrol pretreatment reduced histological damage induced by cerulein treatment, as well as hyperamylasemia and hyperlipidemia. Altered levels of corticosterone, total antioxidant status, and glutathione peroxidase were significantly reverted to control levels by the administration of resveratrol. Lipid peroxidation was also counteracted; nevertheless, superoxide dismutase enzyme was overexpressed due to resveratrol pretreatment. Related to immune response, resveratrol pretreatment reduced pro-inflammatory cytokine IL-1β levels and increased anti-inflammatory cytokine IL-10 levels. In addition, pretreatment with resveratrol in cerulein-induced pancreatitis rats was able to reverse, at least partially, the abnormal calcium signal induced by treatment with cerulein. In conclusion, this study confirms antioxidant and immunomodulatory properties of resveratrol as chemopreventive in cerulein-induced acute pancreatitis.

Oxidative stress in acute pancreatitis: lost in translation?

Oxidative stress has been implicated in the pathogenesis of acute pancreatitis, a severe and debilitating inflammation of the pancreas that carries a significant mortality, and which imposes a considerable financial burden on the health system due to patient care. Although extensive efforts have been directed towards the elucidation of critical underlying mechanisms and the identification of novel therapeutic targets, the disease remains without a specific therapy. In experimental animal models of acute pancreatitis, increased oxidative stress and decreased antioxidant defences have been observed, changes also detected in patients clinically. However, despite the promise of studies evaluating the effects of antioxidants in these model systems, translation to the clinic has thus far been disappointing. This may reflect many factors involved in the design of both preclinical and clinical evaluations of antioxidant therapy, not least the fact that most experimental studies have focussed on pre-treatment rather than post-injury assessment. This review has examined evidence relating to the involvement of oxidative stress in the pathophysiology of acute pancreatitis, focussing on experimental models and the clinical experience, including the experimental techniques employed and potential of antioxidant therapy.

Quercetin-loaded microcapsules ameliorate experimental colitis in mice by anti-inflammatory and antioxidant mechanisms

Quercetin (1) is an anti-inflammatory and antioxidant flavonoid. However, the oral administration of 1 did not lead to beneficial effects in experimental animal colitis models, which involve cytokines and oxidative stress. A possible explanation is that the absorption profile of 1 prevents its activity. Therefore, it was reasoned that the controlled release of 1 would improve its therapeutic effect. Thus, the therapeutic effect and mechanisms of 1-loaded microcapsules in acetic acid-induced colitis in mice were evaluated. Microcapsules were prepared using pectin/casein polymer and 1. The oral administration of 1-loaded microcapsules decreased neutrophil recruitment, attenuated histological alterations, and reduced macroscopical damage, edema, and IL-1β and IL-33 production in the colon samples. Microcapsules loaded with 1 also prevented the reduction of anti-inflammatory cytokine IL-10 and the antioxidant capacity of the colon. These preclinical data indicate that pectin/casein polymer microcapsules loaded with 1 improved the anti-inflammatory and antioxidant effects of 1 compared to the nonencapsulated drug. Therefore, quercetin seems to be a promising active molecule in inflammatory bowel disease if provided with adequate controlled release.

The novel cytokine interleukin-33 activates acinar cell proinflammatory pathways and induces acute pancreatic inflammation in mice

Background

Acute pancreatitis is potentially fatal but treatment options are limited as disease pathogenesis is poorly understood. IL-33, a novel IL-1 cytokine family member, plays a role in various inflammatory conditions but its role in acute pancreatitis is not well understood. Specifically, whether pancreatic acinar cells produce IL-33 when stressed or respond to IL-33 stimulation, and whether IL-33 exacerbates acute pancreatic inflammation is unknown.

Methods/Results

In duct ligation-induced acute pancreatitis in mice and rats, we found that (a) IL-33 concentration was increased in the pancreas; (b) mast cells, which secrete and also respond to IL-33, showed degranulation in the pancreas and lung; (c) plasma histamine and pancreatic substance P concentrations were increased; and (d) pancreatic and pulmonary proinflammatory cytokine concentrations were increased. In isolated mouse pancreatic acinar cells, TNF-α stimulation increased IL-33 release while IL-33 stimulation increased proinflammatory cytokine release, both involving the ERK MAP kinase pathway; the flavonoid luteolin inhibited IL-33-stimulated IL-6 and CCL2/MCP-1 release. In mice without duct ligation, exogenous IL-33 administration induced pancreatic inflammation without mast cell degranulation or jejunal inflammation; pancreatic changes included multifocal edema and perivascular infiltration by neutrophils and some macrophages. ERK MAP kinase (but not p38 or JNK) and NF-kB subunit p65 were activated in the pancreas of mice receiving exogenous IL-33, and acinar cells isolated from the pancreas of these mice showed increased spontaneous cytokine release (IL-6, CXCL2/MIP-2α). Also, IL-33 activated ERK in human pancreatic tissue.

Significance

As exogenous IL-33 does not induce jejunal inflammation in the same mice in which it induces pancreatic inflammation, we have discovered a potential role for an IL-33/acinar cell axis in the recruitment of neutrophils and macrophages and the exacerbation of acute pancreatic inflammation.

Conclusion

IL-33 is induced in acute pancreatitis, activates acinar cell proinflammatory pathways and exacerbates acute pancreatic inflammation.

Experimental and clinical evidence of antioxidant therapy in acute pancreatitis

Oxidative stress has been shown to play an important role in the pathogenesis of acute pancreatitis (AP). Antioxidants, alone or in combination with conventional therapy, should improve oxidative-stress-induced organ damage and therefore accelerate the rate of recovery. In recent years, substantial amounts of data about the efficiency of antioxidants against oxidative damage have been obtained from experiments with rodents. Some of these antioxidants have been found beneficial in the treatment of AP in humans; however, at present there is insufficient clinical data to support the benefits of antioxidants, alone or in combination with conventional therapy, in the management of AP in humans. Conflicting results obtained from experimental animals and humans may represent distinct pathophysiological mechanisms mediating tissue injury in different species. Further detailed studies should be done to clarify the exact mechanisms of tissue injury in human AP. Herein I tried to review the existing experimental and clinical studies on AP in order to determine the efficiency of antioxidants. The use of antioxidant enriched nutrition is a potential direction of clinical research in AP given the lack of clues about the efficiency and safety of antioxidant usage in patients with AP.

Protective effects of alpha-pinene in mice with cerulein-induced acute pancreatitis

AIMS

Acute pancreatitis (AP) is a complicated inflammatory disease that has an unknown underlying pathogenesis. Because alpha-pinene can modulate inflammation, we examined whether alpha-pinene plays a role in AP.

MAIN METHODS

Alpha-pinene was administered intraperitoneally 1h prior to the first injection of cerulein. Once AP developed, cerulein, a stable cholecystokinin analog, was injected hourly over a 6-h period. Blood samples were taken 6h later to determine serum amylase and lipase levels. The pancreas and lungs were rapidly removed for morphological examination, myeloperoxidase assay, and real-time reverse transcription polymerase chain reaction. We also isolated the pancreatic acinar cells using a collagenase solution. Cell viability, and cytokine productions were measured in pancreatic acini.

KEY FINDINGS

Intraperitoneal administration of alpha-pinene reduced the pancreatic weight (PW) to body weight (BW) ratio and the serum levels of amylase and lipase. Alpha-pinene treatment also reduced histological damage and myeloperoxidase activity in the pancreas and lungs. Furthermore, alpha-pinene pretreatment reduced the production of pancreatic tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 during cerulein-induced AP. In vitro, alpha-pinene inhibited cerulein-induced cell death and cytokine production in isolated cerulein-treated pancreatic acinar cells.

SIGNIFICANCE

These findings suggest that alpha-pinene has an anti-inflammatory effect during cerulein-induced AP.

Involvement of inflammatory factors in pancreatic carcinogenesis and preventive effects of anti-inflammatory agents

Chronic inflammation is known to be a risk for many cancers, including pancreatic cancer. Heavy alcohol drinking and cigarette smoking are major causes of pancreatitis, and epidemiological studies have shown that smoking and chronic pancreatitis are risk factors for pancreatic cancer. Meanwhile, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) are elevated in pancreatitis and pancreatic cancer tissues in humans and in animal models. Selective inhibitors of iNOS and COX-2 suppress pancreatic cancer development in a chemical carcinogenesis model of hamsters treated with N-nitrosobis(2-oxopropyl)amine (BOP). In addition, hyperlipidemia, obesity, and type II diabetes are also suggested to be associated with chronic inflammation in the pancreas and involved in pancreatic cancer development. We have shown that a high-fat diet increased pancreatic cancer development in BOP-treated hamsters, along with aggravation of hyperlipidemia, severe fatty infiltration, and increased expression of adipokines and inflammatory factors in the pancreas. Of note, fatty pancreas has been observed in obese and/or diabetic cases in humans. Preventive effects of anti-hyperlipidemic/anti-diabetic agents on pancreatic cancer have also been shown in humans and animals. Taking this evidence into consideration, modulation of inflammatory factors by anti-inflammatory agents will provide useful data for prevention of pancreatic cancer.

Effect of biologically active fraction of Nardostachys jatamansi on cerulein-induced acute pancreatitis

AIM: To determine if the fraction of Nardostachys jatamansi (NJ) has the potential to ameliorate the severity of acute pancreatitis (AP).

METHODS: Mice were administered the biologically active fraction of NJ, i.e., the 4th fraction (NJ4), intraperitoneally, and then injected with the stable cholecystokinin analogue cerulein hourly for 6 h. Six hours after the last cerulein injection, the pancreas, lung, and blood were harvested for morphological examination, measurement of cytokine expression, and examination of neutrophil infiltration.

RESULTS: NJ4 administration attenuated the severity of AP and lung injury associated with AP. It also reduced cytokine production and neutrophil infiltration and resulted in the in vivo up-regulation of heme oxygenase-1 (HO-1). Furthermore, NJ4 and its biologically active fraction, NJ4-2 inhibited the cerulein-induced death of acinar cells by inducing HO-1 in isolated pancreatic acinar cells.

CONCLUSION: These results suggest that NJ4 may be a candidate fraction offering protection in AP and NJ4 might ameliorate the severity of pancreatitis by inducing HO-1 expression.

Protective effects of lycopene on cerulein-induced experimental acute pancreatitis in rats

BACKGROUND

The purpose of our study was to evaluate the protective effect of the strong antioxidant and anti-inflammatory agent, lycopene, on oxidative stress in a rat model of cerulein-induced acute edematous pancreatitis.

METHODS

Sprague-Dawley rats were pretreated with lycopene (50 mg/kg, i.p.) or saline 15 min before cerulein was given 20 μg/kg (i.p.) at 1-h intervals within 4 h. Twelve hours after cerulein or saline injections, the animals were killed by decapitation. Blood samples were collected to analyze amylase, lipase, and proinflammatory cytokines (TNF-α and IL-1ß). Pancreatic tissues were taken for the determination of tissue glutathione (GSH) and malondialdehyde (MDA) levels, Na(+)/K(+)-ATPase, and myeloperoxidase (MPO) activities. Tissue samples were also examined histologically.

RESULTS

Acute pancreatitis caused significant decrease in tissue GSH levels and Na(+)/K(+)-ATPase activity, while pancreatic MDA levels and MPO activity were increased. Furthermore, TNF-α, IL-1ß, and amylase lipase levels were also significantly increased. On the other hand, lycopene pretreatment reserved all these biochemical indices as well as histopathologic alterations that were induced by cerulein.

CONCLUSIONS

According to the results, lycopene protects the pancreatic tissues from oxidative damage induced by cerulein, and this effect possibly involves the inhibition of neutrophil infiltration and lipid peroxidation. These results suggest that high dietary intake of tomatoes may have protective effects against acute pancreatitis.

Molecular mechanisms of pancreatic injury

PURPOSE OF REVIEW

Despite being a subject of much scientific scrutiny, the pathogenesis of acute pancreatitis is still not well understood. This article reviews recent advances in our understanding of acute pancreatitis.

RECENT FINDINGS

Zymogen activation, observed within acini early during acute pancreatitis for a long time, was shown to be sufficient to induce acute pancreatitis. Another key early event, NFκB activation, has previously been shown to induce acute pancreatitis. The relationship between these two key early steps is beginning to be clarified. Mechanisms of zymogen activation - pathologic calcium signaling, pH changes, colocalization and autophagy, and of NFκB activation have been investigated intensively along with potential therapeutic targets both upstream and downstream of these key events. Additional key findings have been elucidation of the role of bioenergetics and the dual role of oxidative stress in acute pancreatitis, recognition of endoplasmic reticulum stress as an early step and the status of duct cells as important entities in pancreatic injury.

SUMMARY

Current findings have provided further insight into the roles and mechanisms of zymogen activation and inflammatory pathways in pancreatic injury. Future studies, which will be of great importance in identifying therapeutic targets, are being undertaken to establish the relative contributions of these pathways during acute pancreatitis.