Honokiol attenuates the severity of acute pancreatitis and associated lung injury via acceleration of acinar cell apoptosis. Shock. 2012;37:478-484. [PMID: 22258232 DOI: 10.1097/shk.0b013e31824653be]

Rhein Protects Against Severe Acute Pancreatitis In vitro and In vivo by Regulating the JAK2/STAT3 Pathway

Rhein is widely used in inflammation treatment in China, but its effects on severe acute pancreatitis (SAP) have not been studied closely. This study investigated rhein’s protective effects against SAP using in vitro and in vivo models to determine whether its protective mechanism regulated the Janus kinase two and signal transducer and activator of transcription 3 (JAK2/STAT3) signalling pathway. Thirty-six male Sprague–Dawley rats were randomised into sham operation, SAP and rhein groups. The SAP model was induced by retrograde pancreatic bile duct injection of sodium taurocholate. Serum TNF-α and interleukin (IL)-6 levels were determined by ELISA, whereas serum amylase and lipase concentrations were measured using test kits. Western blot and/or immunohistochemistry quantified JAK2 and STAT3 expression. Furthermore, histopathological pancreatic changes were detected by haematoxylin and eosin staining. AR42J cells were randomly divided into the control, cerulein and rhein groups. Amylase activity was assessed using an amylase test kit; the tumour necrosis factor-α (TNF-α) expression was determined by enzyme-linked immunosorbent assay (ELISA). JAK2 and STAT3 protein expression were evaluated by western blot. SAP was concomitant with increased JAK2 and STAT3 expressions in vivo. Pre-treatment with rhein attenuated serum TNF–α and IL-6 levels effectively, and notably reduced p-JAK2, p-STAT3, JAK2 and STAT3 protein expression. Rhein significantly alleviated pancreatic histopathology. Compared to untreated groups, rhein significantly reduced amylase activity in supernatants of AR42J cells induced by cerulein in vitro. Furthermore, rhein altered JAK2 and STAT3 protein levels in AR42J cells after cerulein induction. Overall, rhein exerted protective effect on SAP in vitro and in vivo, possibly through the JAK2/STAT3 signalling pathway.

Drug discovery and formulation development for acute pancreatitis

Acute pancreatitis is a sudden inflammation and only last for a short time, but might lead to a life-threatening emergency. Traditional drug therapy is an essential supportive method for acute pancreatitis treatment, yet, failed to achieve satisfactory therapeutic outcomes. To date, it is still challenging to develop therapeutic medicine to redress the intricate microenvironment promptly in the inflamed pancreas, and more importantly, avoid multi-organ failure. The understanding of the acute pancreatitis, including the causes, mechanism, and severity judgment, could help the scientists bring up more effective intervention and treatment strategies. New formulation approaches have been investigated to precisely deliver therapeutics to inflammatory lesions in the pancreas, and some even could directly attenuate the pancreatic damages. In this review, we will briefly introduce the involved pathogenesis and underlying mechanisms of acute pancreatitis, as well as the traditional Chinese medicine and the new drug option. Most of all, we will summarize the drug delivery strategies to reduce inflammation and potentially prevent the further development of pancreatitis, with an emphasis on the bifunctional nanoparticles that act as both drug delivery carriers and therapeutics.

Honokiol Reduces Fungal Load, Toll-Like Receptor-2, and Inflammatory Cytokines in Aspergillus fumigatus Keratitis

Purpose

We characterized the effects of Honokiol (HNK) on Aspergillus fumigatus-caused keratomycosis and the underlying mechanisms. HNK is known to have anti-inflammatory and antifungal properties, but the influence on fungal keratitis (FK) remains unknown.

Methods

In ex vivo, minimum inhibitory concentration and Cell Count Kit-8 assay were carried out spectrophotometrically to provide preferred concentration applied in vivo. Time kill assay pointed that HNK was fungicidal and fungistatic chronologically. Adherence assay, crystal violet staining, and membrane permeability assay tested HNK effects on different fungal stages. In vivo, clinical scores reflected the improvement degree of keratitis outcome. Myeloperoxidase (MPO) assay, flow cytometry (FCM), and immunohistofluorescence staining (IFS) were done to evaluate neutrophil infiltration. Plate count detected HNK fungicidal potentiality. RT-PCR, Western blot, and enzyme-linked immunosorbent assay (ELISA) verified the anti-inflammatory activity of HNK collaboratively.

Results

In vitro, MIC90 HNK was 8 µg/mL (no cytotoxicity), and Minimal Fungicidal Concentration (MFC) was 12 µg/mL for A. fumigatus. HNK played the fungistatic and fungicidal roles at 6 and 24 hours, respectively, inhibiting adherence at the beginning, diminishing biofilms formation, and increasing membrane permeability all the time. In vivo, HNK improved C57BL/6 mice outcome by reducing disease severity (clinical scores), neutrophil infiltration (MPO, FCM, and IFS), and fungal loading (plate count). RT-PCR, Western blot, and ELISA revealed that HNK downregulated mRNA and protein expression levels of Toll-like receptor-2 (TLR-2), high mobility group box 1 (HMGB1), IL-1β, and TNF-α.

Conclusions

Our study suggested HNK played antifungal and anti-inflammatory roles on keratomycosis by reducing survival of fungi, infiltration of leucocytes, and expression of HMGB1, TLR-2, and proinflammatory cytokines, providing a potential treatment for FK.

Aqueous extraction from dachengqi formula granules reduces the severity of mouse acute pancreatitis via inhibition of pancreatic pro-inflammatory signalling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Dachengqi decoction (DCQD) belongs to a family of purgative herbal formulas widely used in China for the treatment of acute pancreatitis (AP). AP is a prevalent digestive disease currently without an effective pharmacological intervention. Formula granules have become the preferred method for delivery of herbal formulation in China given its benefit of potency retention, dosing precision and ease of use. The efficacy of DCQD formula granules (DFGs) in experimental AP models has not been investigated.

AIM OF THE STUDY

To analyse and compare the differences in chemical composition of DFGs, with their aqueous extraction (AE) and chloroform extraction (CE) derivatives. To assess their efficacy on severity and targeted pancreatic pro-inflammatory signalling pathways in freshly isolated acinar cells and two models of experimental AP.

MATERIAL AND METHODS

UPLC-Q-TOF-MS was used to analyse chemical components of DFGs and their extractions. Freshly isolated mouse pancreatic acinar cells were treated with taurolithocholic acid 3-sulphate disodium salt (TLCS, 500 μM) with or without DFGs, AE and CE. Apoptotic and necrotic cell death pathway activation was measured by caspase 3/7 (10 μl/mL) and propidium iodide (PI, 1 μM), respectively, using a fluorescent plate reader. Necrotic acinar cells were also counted by epifluorescence microscopy. Mice received either 7 intraperitoneal injections of caerulein (50 μg/kg) at hourly intervals or retrograde infusion of TLCS (3 mM, 50 μl) to induce AP (CER-AP and TLCS-AP, respectively). In CER-AP, mice received oral gavage of DFGs (2.1, 4.2 and 5.2 g/kg), AE (0.6, 1.2, and 2.4 g/kg) and CE (4, 9 and 17 mg/kg), or matched DFGs (1.8 g/kg) and AE (1 g/kg) for 3 times at 2-hourly intervals, or a single intraperitoneal injection of DCQD-related monomers rhein (20 mg/kg), narigeinine (25 mg/kg), and honokiol (5 mg/kg) begun at the 3rd injection of caerulein. In TLCS-AP, DFGs (4.2 g/kg) were given orally at 1, 3 and 5 h post-surgery. Disease severity and pancreatic pro-inflammatory markers were determined.

RESULTS

The main effective anthraquinones and their glycosides, flavonoids and their glycosides, polyphenols and lignans were found in the DFGs. A higher proportion of polar components including glycosides attached to anthraquinones, phenols and flavonoids was found in AE. Conversely, lower polar components containing methoxy substituted flavonoids and anthraquinones were more abundant in CE. DFGs were given at 4.2 g/kg, a consistent reduction in the pancreatic histopathology score and severity indices was observed in both CER-AP and TLCS-AP. In vitro, AE significantly reduced both apoptotic and necrotic cell death pathway activation, while CE increased TLCS-induced acinar cell necrosis. In vivo, AE at dose of 1.2 g/kg consistently reduced pancreatic histopathological scores and myeloperoxidase in the CER-AP that were associated with suppressed expression of pro-inflammatory meditator mRNAs and proteins. CE increased lung myeloperoxidase and failed to protect against CER-AP in all dosages. AE was demonstrated to be more effective than DFGs in reducing pancreatic histopathological scores and myeloperoxidase.

CONCLUSIONS

AE from DFGs alleviated the severity of mouse AP models via an inhibition of pancreatic pro-inflammatory signalling pathways. Efficacy of AE on experimental AP was more potent than its original DFGs and DCQD monomers.

miR-375 Inhibits Autophagy and Further Promotes Inflammation and Apoptosis of Acinar Cells by Targeting ATG7

OBJECTIVES

MicroRNAs have been considered to be closely related with the development of severe acute pancreatitis (SAP), and microRNA-375 (miR-375) was believed to be a marker of SAP. We aim to investigate the role of miR-375 in regulating SP.

METHODS

Cerulein and lipopolysaccharide were used to establish the models of SAP. AR42J cell line was chosen for study in vitro. Flow cytometry was applied for assessing apoptosis. The contents of inflammatory factors were detected with related enzyme-linked immunosorbent assay and quantitative real-time polymerase chain reaction assays. Hematoxylin and eosin staining was applied to observe the pathological changes of pancreatic tissues. Immunohistochemistry analysis was conducted for investigating the expression of light chain 3.

RESULTS

The level of miR-375 in pancreatitis tissues and cell lines was upregulated. Overexpression of miR-375 promoted inflammation and the apoptosis of acinar cells through inhibiting autophagy. The binding site between miR-375 and ATG7 was identified, and miR-375 could directly regulate the ATG7. microRNA-375 suppressed autophagy and promoted inflammation and the apoptosis of acinar cells via targeting ATG7.

CONCLUSIONS

We proved that miR-375 could inhibit autophagy and promote inflammation and the apoptosis of acinar cells through regulating ATG7. This study first proves that miR-375 modulates the development of SAP through targeting ATG7.

Chaiqin chengqi decoction alleviates severe acute pancreatitis associated acute kidney injury by inhibiting endoplasmic reticulum stress and subsequent apoptosis

BACKGROUND

Acute kidney injury (AKI), characterized by an increase of serum creatinine and urea, is a severe complication of severe acute pancreatitis (SAP) with high mortality. Endoplasmic reticulum (ER) stress has been considered as a key pathologic process in AKI. Chaiqin chengqi decoction (CQCQD) is an effective Chinese medicine formula for SAP treatment in China and has been used for many years. Our goal is to explore the role of CQCQD on ER stress of AKI in experimental SAP.

MATERIALS & METHODS

SAP was induced in rats by retrograde duct injection of 5% sodium taurocholate (NaTC, 1 ml/kg), sham operation (SO) rats simultaneously received saline infusion. Intraperitoneal injection of 4-PBA (50 mg/kg, once a day for three days before the surgery) or intragastric gavage of CQCQD (1 g/kg, 2 hourly × 3 after disease induction) was used to treat SAP rats. All animals were humanely sacrificed 12 h after disease induction. Histopathology scores of kidney and pancreas; serum biochemical indices and kidney protein levels of ER stress and apoptosis markers were assessed. Tubular epithelial cell line (HK-2) was treated either with TNF-α (10 ng/ml) or IL-6 (10 ng/ml) for 12 h plus either 4-PBA (0.1 M) or CQCQD (1 mg/ml) for in vitro study. Cell viability and markers of ER stress and apoptosis were measured.

RESULTS

Ductal perfusion of NaTC caused significant increases in serum lipase, amylase and pancreatic histopathology (inflammatory cell infiltration, interstitial edema, and acinar cell necrosis). Kidney histopathology (tubular dilation, brush border loss, little tubular necrosis, and cast formation), serum creatine and urea levels were raised when compared with the SO group. Moreover, apoptotic cell death markers (caspase-9, cleaved-caspase-3, and TUNEL) and kidney ER stress proteins (BIP, IRE1-α, XBP1s, and CHOP) were elevated after NaTC administration. 4-PBA and CQCQD significantly alleviated histopathological changes of kidney and pancreas, inflammatory cytokines, biochemical markers of AKI, ER stress proteins and apoptotic cell death markers. They also protected HK-2 cells from injury of TNF-α and IL-6, and alleviated both ER stress and apoptosis proteins in vitro.

CONCLUSION

CQCQD may alleviate SAP-related AKI by inhibiting ER stress-related apoptosis.

The Role of the ER-Induced UPR Pathway and the Efficacy of Its Inhibitors and Inducers in the Inhibition of Tumor Progression

Cancer is the second most frequent cause of death worldwide. It is considered to be one of the most dangerous diseases, and there is still no effective treatment for many types of cancer. Since cancerous cells have a high proliferation rate, it is pivotal for their proper functioning to have the well-functioning protein machinery. Correct protein processing and folding are crucial to maintain tumor homeostasis. Endoplasmic reticulum (ER) stress is one of the leading factors that cause disturbances in these processes. It is induced by impaired function of the ER and accumulation of unfolded proteins. Induction of ER stress affects many molecular pathways that cause the unfolded protein response (UPR). This is the way in which cells can adapt to the new conditions, but when ER stress cannot be resolved, the UPR induces cell death. The molecular mechanisms of this double-edged sword process are involved in the transition of the UPR either in a cell protection mechanism or in apoptosis. However, this process remains poorly understood but seems to be crucial in the treatment of many diseases that are related to ER stress. Hence, understanding the ER stress response, especially in the aspect of pathological consequences of UPR, has the potential to allow us to develop novel therapies and new diagnostic and prognostic markers for cancer.

Anti-aging effect of fullerenol on skin aging through derived stem cells in a mouse model

Fullerenol is similar to graphite in terms of structure. In the present study, the anti-aging effect of fullerenol on skin through derived stem cells in a mouse model was assessed and the potential mechanism of fullerenol was investigated. The anti-aging effect of fullerenol effectively inhibited the retention rate of transplanted adipose-derived stem cells and increased the thickness of the dermal portion of skin and collagen ratio in mice. The effect of fullerenol on the proliferation of stem cells was observed. Treatment with fullerenol effectively promoted the mRNA expression of Runt-related transcription factor 2, alkaline phosphatase and osteocalcin in a mouse model of skin aging induced by D-galactose. However, fullerenol treatment effectively suppressed the protein expression of peroxisome proliferator-activated receptor-γ (PPAR-γ) and increased forkhead box protein O1 (FoxO1) protein expression in the mice model of skin aging induced by D-galactose. These results demonstrate that the anti-aging effect of fullerenol on skin through derived stem cells may be mediated in mice via the PPAR-γ/FoxO1 signaling pathway.

Chinese Herbal Medicines Attenuate Acute Pancreatitis: Pharmacological Activities and Mechanisms

Acute pancreatitis (AP) is a commonly occurring gastrointestinal disorder. An increase in the annual incidence of AP has been observed, and it causes acute hospitalization and high mortality. The diagnosis and treatment guidelines for AP recommend conservative medical treatments focused on reducing pancreatic secretion and secondary injury, as a primary therapeutic approach. Unfortunately, the existing treatment options have limited impact on the incidence and severity of AP due to the complex and multifaceted pathological process of this disease. In recent decades, Chinese herbal medicines (CHMs) have been used as efficient therapeutic agents to attenuate AP in Asian countries. Despite early cell culture, animal models, and clinical trials, CHMs are capable of interacting with numerous molecular targets participating in the pathogenesis of AP; however, comprehensive, up-to-date communication in this field is not yet available. This review focuses on the pharmacological activities of CHMs against AP in vitro and in vivo and the underlying mechanisms. A computational prediction of few selected and promising plant-derived molecules (emodin, baicalin, resveratrol, curcumin, ligustrazine, and honokiol) to target numerous proteins or networks involved in AP was initially established based on a network pharmacology simulation. Moreover, we also summarized some potential toxic natural products for pancreas in order to more safe and reasonable medication. These breakthrough findings may have important implications for innovative drug research and the future development of treatments for AP.

The Natural Occurring Compounds Targeting Endoplasmic Reticulum Stress

ER stress has been implicated in pathophysiological development of many diseases. Persistent overwhelming stimuli trigger ER stress to initiate apoptosis, autophagy, and cell death. IRE1-JNK and eIF2α-CHOP signaling pathways are the two important players of ER stress, which is also modulated by ROS production, calcium disturbance, and inflammatory factors. ER stress has been developed as a novel strategy for diseases management. Recently, a vast of research focuses on the natural occurring compounds targeting ER stress, which results in medical benefits to human diseases. These small reported molecules mainly include polyphenols, alkaloids, and saponins. Many of them have been developed for use in clinical applications. To better understand the pharmacological mechanism of these molecules in ER stress in diseases, efforts have been made to discover and deliver medical merits. In this paper, we will summarize the natural occurring compounds targeting ER stress.

Endoplasmic reticulum stress is activated in acute pancreatitis

Endoplasmic reticulum (ER) is one of the most important cell organelles in the body, regulating protein synthesis, folding and aggregation. Endoplasmic reticulum stress (ERS) is a particular subcellular pathological process involving an imbalance of homeostasis and ER disorder. In the early stage of ERS, cells show a protective unfolded protein response that changes the cellular transcriptional and translational programs to alleviate the process. Therefore, a certain degree of ERS can activate the protective adaptation of cells, whereas sustained severe ERS triggers an apoptotic signal and leads to apoptosis. Acute pancreatitis is a disease caused by trypsin digestion of the pancreas, although the pathogenesis is not completely understood. However, a close association has been suggested between pancreatitis and ERS. This article reviewed relevant research advances and discussed the effect of ERS on the development and progression of acute pancreatitis.

The mechanism underlying alpinetin-mediated alleviation of pancreatitis-associated lung injury through upregulating aquaporin-1

Characterized by its acute onset, critical condition, poor prognosis, and high mortality rate, severe acute pancreatitis (SAP) can cause multiple organ failure at its early stage, particularly acute lung injury (ALI). The pathogenesis of ALI is diffuse alveolar damage, including an increase in pulmonary microvascular permeability, a decrease in compliance, and invasion of many inflammatory cells. Corticosteroids are the main treatment method for ALI; however, the associated high toxicity and side effects induce pain in patients. Recent studies show that the effective components in many traditional Chinese medicines can effectively inhibit inflammation with few side effects, which can decrease the complications caused by steroid consumption. Based on these observations, the main objective of the current study is to investigate the effect of alpinetin, which is a flavonoid extracted from Alpinia katsumadai Hayata, on treating lung injury induced by SAP and to explore the mechanism underlying the alpinetin-mediated decrease in the extent of ALI. In this study, we have shown through in vitro experiments that a therapeutic dose of alpinetin can promote human pulmonary microvascular endothelial cell proliferation. We have also shown via in vitro and in vivo experiments that alpinetin upregulates aquaporin-1 and, thereby, inhibits tumor necrosis factor-α expression as well as reduces the degree of lung injury. Overall, our study shows that alpinetin alleviates SAP-induced ALI. The likely molecular mechanism includes upregulated aquaporin expression, which inhibits tumor necrosis factor-α and, thus, alleviates SAP-induced ALI.

Dihydro-Resveratrol Ameliorates Lung Injury in Rats with Cerulein-Induced Acute Pancreatitis

Acute pancreatitis is an inflammatory process originated in the pancreas; however, it often leads to systemic complications that affect distant organs. Acute respiratory distress syndrome is indeed the predominant cause of death in patients with severe acute pancreatitis. In this study, we aimed to delineate the ameliorative effect of dihydro-resveratrol, a prominent analog of trans-resveratrol, against acute pancreatitis-associated lung injury and the underlying molecular actions. Acute pancreatitis was induced in rats with repetitive injections of cerulein (50 µg/kg/h) and a shot of lipopolysaccharide (7.5 mg/kg). By means of histological examination and biochemical assays, the severity of lung injury was assessed in the aspects of tissue damages, myeloperoxidase activity, and levels of pro-inflammatory cytokines. When treated with dihydro-resveratrol, pulmonary architectural distortion, hemorrhage, interstitial edema, and alveolar thickening were significantly reduced in rats with acute pancreatitis. In addition, the production of pro-inflammatory cytokines and the activity of myeloperoxidase in pulmonary tissues were notably repressed. Importantly, nuclear factor-kappaB (NF-κB) activation was attenuated. This study is the first to report the oral administration of dihydro-resveratrol ameliorated acute pancreatitis-associated lung injury via an inhibitory modulation of pro-inflammatory response, which was associated with a suppression of the NF-κB signaling pathway.

Honokiol protects against renal ischemia/reperfusion injury via the suppression of oxidative stress, iNOS, inflammation and STAT3 in rats

Honokiol is the predominant active ingredient in the commonly used traditional Chinese medicine, Magnolia, which has been confirmed in previous studies to exhibit anti-oxidation, antimicrobial, antitumor and other pharmacological effects. However, its effects on renal ischemia/reperfusion injury (IRI) remain to be elucidated. The present study aimed to examine the effects of honokiol on renal IRI, and to investigate its potential protective mechanisms in the heart. Male adult Wistar albino rats were induced into a renal IRI model. Subsequently, the levels of serum creatinine, blood urea nitrogen (BUN), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and alkaline phosphatase (ALP), and the levels of serum nitrite and the kidney nitrite were examined in the IRI group. The levels of oxidative stress, inducible nitric oxide synthase (iNOS), inflammatory factors and caspase-3 were evaluated using a series of commercially available kits. The levels of phosphorylated signal transducer and activator of transcription 3 (p-STAT3) and the protein expression levels of STAT3 were determined using western blotting. Pretreatment with honokiol significantly reduced the levels of serum creatinine, BUN, ALT, AST and ALP, and the level of nitrite in the kidney of the IRI group, compared with the control group. The levels of malondialdehyde, the activity of myeloperoxidase, and the gene expression and activity of iNOS were reduced in the IRI rats, compared with the sham-operated rats, whereas the levels of superoxide dismutase and catalase were increased following treatment with honokiol in the IRI rats. In addition, the expression levels of tumor necrosis factor-α and interleukin-6 in the IRI rats were increased by honokiol. Treatment with honokiol suppressed the protein expression levels of p-STAT3 and caspase-3 in the IRI rats. These findings indicated that honokiol protects against renal IRI via the suppression of oxidative stress, iNOS, inflammation and STAT3 in the rat.

Anticancer drugs for the modulation of endoplasmic reticulum stress and oxidative stress

Prior research has demonstrated how the endoplasmic reticulum (ER) functions as a multifunctional organelle and as a well-orchestrated protein-folding unit. It consists of sensors which detect stress-induced unfolded/misfolded proteins and it is the place where protein folding is catalyzed with chaperones. During this folding process, an immaculate disulfide bond formation requires an oxidized environment provided by the ER. Protein folding and the generation of reactive oxygen species (ROS) as a protein oxidative byproduct in ER are crosslinked. An ER stress-induced response also mediates the expression of the apoptosis-associated gene C/EBP-homologous protein (CHOP) and death receptor 5 (DR5). ER stress induces the upregulation of tumor necrosis factor-related apoptosis inducing ligand (TRAIL) receptor and opening new horizons for therapeutic research. These findings can be used to maximize TRAIL-induced apoptosis in xenografted mice. This review summarizes the current understanding of the interplay between ER stress and ROS. We also discuss how damage-associated molecular patterns (DAMPs) function as modulators of immunogenic cell death and how natural products and drugs have shown potential in regulating ER stress and ROS in different cancer cell lines. Drugs as inducers and inhibitors of ROS modulation may respectively exert inducible and inhibitory effects on ER stress and unfolded protein response (UPR). Reconceptualization of the molecular crosstalk among ROS modulating effectors, ER stress, and DAMPs will lead to advances in anticancer therapy.

TUNEL staining combined with cell morphologic characteristics for identifying acinar cell death mode in rats with acute pancreatitis

AIM: To detect acinar cell death in rats with acute pancreatitis (AP) by TdT-mediated dUTP nick labeling (TUNEL) staining and to study the correlation between the morphology of TUNEL positive cells and their death modes.

METHODS: Acute necrotizing pancreatitis (ANP) was induced in rats by injection of 4% sodium taurocholate in the pancreaticobiliary duct, and the pathological changes in pancreatic tissue were observed. Pancreatic tissue sections were stained by TUNEL, and the morphological changes of TUNEL positive cells were evaluated under a light microscope.

RESULTS: Compared to the sham operated group, the pancreas of ANP rats exhibited typical pathological changes of AP, and had a large number of TUNEL positive acinar cells. The TUNEL positive cells showed various morphologic characteristics, which included the manifestations of both apoptosis and necrosis. The apoptotic morphology was characterized by nuclear condensation and karyorrhexis followed by the formation of apoptotic bodies, while necrotic cells demonstrated nuclear swelling, karyolysis and cytoplasmic vacuolization. There were significant differences between the morphologic characteristics of the two cell death modes.

CONCLUSION: TUNEL staining itself cannot well differentiate the apoptosis and necrosis of acinar cells in AP. However, when combined with the morphologic characteristics of TUNEL positive cells, TUNEL staining can preliminarily identify the two modes of cell death.

Paeoniflorin inhibits human gastric carcinoma cell proliferation through up-regulation of microRNA-124 and suppression of PI3K/Akt and STAT3 signaling

AIM: To examine the potential anti-tumor activity of paeoniflorin in the human gastric carcinoma cell line MGC-803.

METHODS: Cell viability and cytotoxic effects in MGC-803 cells were analyzed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and lactate dehydrogenase assay, respectively. Cell apoptosis of MGC-803 cells was measured using flow cytometry, DAPI staining assay and caspase-3 activity assay. Quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to measure the expression of microRNA-124 (miR-124) in response to paeoniflorin. The expression of phosphatidylinositol 3-kinase (PI3K), protein kinase B (Akt), phospho-Akt (p-Akt) and phospho-signal transducer and activator of transcription 3 (p-STAT3) were also measured by quantitative RT-PCR and Western blot analysis in normal, miR-124 and anti-miR-124 over-expressing MGC-803 cells, treated with paeoniflorin.

RESULTS: Paeoniflorin was found to inhibit MGC-803 cell viability in a dose-dependent manner. Paeoniflorin treatment was associated with the induction of apoptosis and caspase-3 activity in MGC-803 cells. Paeoniflorin treatment significantly increased miR-124 levels and inhibited the expression of PI3K, Akt, p-Akt and p-STAT3 in MGC-803 cells. Interestingly, the over-expression of miR-124 inhibits PI3K/Akt and phospho-STAT3 expressions in MGC-803 cells. PI3K agonist (IGF-1, 1 μg/10 μL) or over-expression of STAT3 reversed the effect of paeoniflorin on the proliferation of MGC-803 cells. Over-expression of anti-miR-124 in MGC-803 cells reversed paeoniflorin-induced up-regulation.

CONCLUSION: In summary, the in vitro data suggest that paeoniflorin is a potential novel therapeutic agent against gastric carcinoma, which inhibits cell viability and induces apoptosis through the up-regulation of miR-124 and suppression of PI3K/Akt and STAT3 signaling.

Effects of honokiol on sepsis-induced acute kidney injury in an experimental model of sepsis in rats

Acute kidney injury (AKI) is a severe complication of sepsis, which largely contributes to the high mortality rate of sepsis. Honokiol, a natural product isolated from Magnolia officinalis (Houpo), has been shown to exhibit anti-inflammatory and antioxidant properties. Here, we investigated the effects of honokiol on sepsis-associated AKI in rats subjected to cecal ligation and puncture (CLP). We found that the administration of honokiol improved the survival of septic rats. Periodic acid-Schiff stain revealed that the morphological changes of kidney tissues in CLP rats were restored after honokiol treatment. Furthermore, honokiol reduced CLP-induced oxidative stress and inflammatory cytokine production. The levels of nitric oxide (NO) and inducible NO synthetase (iNOS) were attenuated by honokiol in septic rats. Finally, honokiol inhibited CLP-induced activation of NF-κB signaling in CLP rats. Our findings suggest that honokiol might be used as a potential therapeutic agent for complications of sepsis, especially for sepsis-induced AKI.

HMGB1 in health and disease

Complex genetic and physiological variations as well as environmental factors that drive emergence of chromosomal instability, development of unscheduled cell death, skewed differentiation, and altered metabolism are central to the pathogenesis of human diseases and disorders. Understanding the molecular bases for these processes is important for the development of new diagnostic biomarkers, and for identifying new therapeutic targets. In 1973, a group of non-histone nuclear proteins with high electrophoretic mobility was discovered and termed high-mobility group (HMG) proteins. The HMG proteins include three superfamilies termed HMGB, HMGN, and HMGA. High-mobility group box 1 (HMGB1), the most abundant and well-studied HMG protein, senses and coordinates the cellular stress response and plays a critical role not only inside of the cell as a DNA chaperone, chromosome guardian, autophagy sustainer, and protector from apoptotic cell death, but also outside the cell as the prototypic damage associated molecular pattern molecule (DAMP). This DAMP, in conjunction with other factors, thus has cytokine, chemokine, and growth factor activity, orchestrating the inflammatory and immune response. All of these characteristics make HMGB1 a critical molecular target in multiple human diseases including infectious diseases, ischemia, immune disorders, neurodegenerative diseases, metabolic disorders, and cancer. Indeed, a number of emergent strategies have been used to inhibit HMGB1 expression, release, and activity in vitro and in vivo. These include antibodies, peptide inhibitors, RNAi, anti-coagulants, endogenous hormones, various chemical compounds, HMGB1-receptor and signaling pathway inhibition, artificial DNAs, physical strategies including vagus nerve stimulation and other surgical approaches. Future work further investigating the details of HMGB1 localization, structure, post-translational modification, and identification of additional partners will undoubtedly uncover additional secrets regarding HMGB1's multiple functions.

Antioxidative phytoceuticals to ameliorate pancreatitis in animal models: An answer from nature

Despite enthusiastic efforts directed at elucidating critical underlying mechanisms towards the identification of novel therapeutic targets for severe acute pancreatitis (SAP), the disease remains without a specific therapy to be executed within the first hours to days after onset of symptoms. Although earlier management for SAP should aim to either treat organ failure or reduce infectious complications, the current standard of care for the general management of AP in the first hours to days after onset of symptoms include intravenous fluid replacement, nutritional changes, and the use of analgesics with a close monitoring of vital signs. Furthermore, repeated evaluation of severity is very important, as the condition is particularly unstable in the early stages. In cases where biliary pancreatitis is accompanied by acute cholangitis or in cases where biliary stasis is suspected, an early endoscopic retrograde cholangiopancreatography is recommended. However, practice guidelines regarding the treatment of pancreatitis are suboptimal. In chronic pancreatitis, conservative management strategies include lifestyle modifications and dietary changes followed by analgesics and pancreatic enzyme supplementation. Recently, attention has been focused on phytoceuticals or antioxidants as agents that could surpass the limitations associated with currently available therapies. Because oxidative stress has been shown to play an important role in the pathogenesis of pancreatitis, antioxidants alone or combined with conventional therapy may improve oxidative-stress-induced organ damage. Interest in phytoceuticals stems from their potential use as simple, accurate tools for pancreatitis prognostication that could replace older and more tedious methods. Therefore, the use of antioxidative nutrition or phytoceuticals may represent a new direction for clinical research in pancreatitis. In this review article, recent advances in the understanding of the pathogenesis of pancreatitis are discussed and the paradigm shift underway to develop phytoceuticals and antioxidants to treat it is introduced. Despite the promise of studies evaluating the effects of antioxidants/phytoceuticals in pancreatitis, translation to the clinic has thus far been disappointing. However, it is expected that continued research will provide solid evidence to justify the use of antioxidative phytoceuticals in the treatment of pancreatitis.

Rhein induces a necrosis-apoptosis switch in pancreatic acinar cells

Objectives. The Chinese herbal medicine Da-Cheng-Qi decoction can regulate a necrosis-apoptosis switch in injured pancreatic acinar cells. This study investigated the effects of rhein, a component of this medicine, on a necrosis-apoptosis switch in pancreatic rat AR42J cells. Methods. Cerulein-treated AR42J cells were used. After pretreatment with 479, 119.8, or 29.9  μ g/L rhein, cells were cocultured with rhein and cerulein (10(-8) M) for 4, 8, or 16 h. Apoptosis and necrosis were examined using annexin V and propidium iodide costaining. Mitochondria-dependent apoptosis-associated proteins were examined using enzyme-linked immunosorbent assays and western blotting. Results. Few cells died in untreated samples. The number was significantly higher in 16-h-cerulein-treated samples and treatment with 479  μ g/L rhein most effectively increased the apoptotic-to-necrotic cell ratio (P < 0.05). In cerulein-treated cells, rhein increased the concentrations of p53, cytochrome C, and caspase-3, and increased the Bax/Bcl-2 ratio in a time- and dose-dependent manner, with the maximum effect in cells treated with 479  μ g/L rhein for 16 h (P < 0.05). Conclusions. Rhein induces the necrosis-apoptosis switch in injured pancreatic acinar cells in a time- and dose-dependent manner. Mitochondria-dependent apoptosis signaling pathways might play an important role in this effect.

C/EBP homologous protein deficiency aggravates acute pancreatitis and associated lung injury

AIM: To investigate the pathophysiological role of C/EBP homologous protein (CHOP) in severe acute pancreatitis and associated lung injury.

METHODS: A severe acute pancreatitis model was induced with 6 injections of cerulein (Cn, 50 μg/kg) at 1-h intervals, then intraperitoneal injection of lipopolysaccharide (LPS, 7.5 mg/kg) in CHOP-deficient (Chop^-/-) mice and wild-type (WT) mice. Animals were sacrificed under anesthesia, 3 h or 18 h after LPS injection. Serum amylase, lipase, and cytokines [interleukin (IL)-6 and tumor necrosis factor (TNF)-α], pathological changes, acute lung injury, and apoptosis in the pancreas were evaluated. Serum amylase and lipase activities were detected using a medical automatic chemical analyzer. Enzyme-linked immunosorbent assay kits were used to evaluate TNF-α and IL-6 levels in mouse serum and lung tissue homogenates. Apoptotic cells in sections of pancreatic tissues were determined by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) analysis. The mouse carotid arteries were cannulated and arterial blood samples were collected for PaO₂ analysis. The oxygenation index was expressed as PaO₂/FiO₂.

RESULTS: Administration of Cn and LPS for 9 and 24 h induced severe acute pancreatitis in Chop^-/- and WT mice. When comparing Chop^-/- mice and WT mice, we observed that CHOP-deficient mice had greater increases in serum TNF-α (214.40 ± 19.52 pg/mL vs 150.40 ± 16.70 pg/mL; P = 0.037), amylase (4236.40 ± 646.32 U/L vs 2535.30 ± 81.83 U/L; P = 0.041), lipase (1678.20 ± 170.57 U/L vs 1046.21 ± 35.37 U/L; P = 0.008), and IL-6 (2054.44 ± 293.81 pg/mL vs 1316.10 ± 108.74 pg/mL; P = 0.046) than WT mice. The histopathological changes in the pancreases and lungs, decreased PaO₂/FiO₂ ratio, and increased TNF-α and IL-6 levels in the lungs were greater in Chop^-/- mice than in WT mice (pancreas: Chop^-/-vs WT mice, hemorrhage, P = 0.005; edema, P = 0.005; inflammatory cells infiltration, P = 0.005; total scores, P = 0.006; lung: hemorrhage, P = 0.017; edema, P = 0.017; congestion, P = 0.017; neutrophil infiltration, P = 0.005, total scores, P = 0.001; PaO₂/FiO₂ ratio: 393 ± 17.65 vs 453.8, P = 0.041; TNF-α: P = 0.043; IL-6, P = 0.040). Results from TUNEL analysis indicated increased acinar cell apoptosis in mice following the induction of acute pancreatitis. However, Chop^-/- mice displayed significantly reduced pancreatic apoptosis compared with the WT mice (201.50 ± 31.43 vs 367.00 ± 47.88, P = 0.016).

CONCLUSION: These results suggest that CHOP can exert protective effects against acute pancreatitis and limit the spread of inflammatory damage to the lungs.

Effect of honokiol on erythrocytes

Honokiol ((3,5-di-(2-propenyl)-1,1-biphenyl-2,2-diol), a component of Magnolia officinalis, stimulates apoptosis and is thus considered for the treatment of malignancy. In analogy to apoptosis of nucleated cells, erythrocytes may enter eryptosis, a suicidal death characterized by cell shrinkage and by breakdown of cell membrane phosphatidylserine asymmetry with phosphatidylserine-exposure at the erythrocyte surface. Eryptosis may be triggered following increase of cytosolic Ca(2+)-activity ([Ca(2+)]i). The present study explored, whether honokiol elicits eryptosis. Cell volume has been estimated from forward scatter, phosphatidylserine-exposure from annexin V binding, hemolysis from hemoglobin release, [Ca(2+)]i from Fluo3-fluorescence, and ceramide from fluorescent antibodies. As a result, a 48 h exposure to honokiol was followed by a slight but significant increase of [Ca(2+)]i (15 μM), significant decrease of forward scatter (5 μM), significant increase of annexin-V-binding (5 μM) and significant increase of ceramide formation (15 μM). Honokiol further induced slight, but significant hemolysis. Honokiol (15 μM) induced annexin-V-binding was significantly blunted but not abrogated in the nominal absence of extracellular Ca(2+). In conclusion, honokiol triggers suicidal erythrocyte death or eryptosis, an effect at least in part due to stimulation of Ca(2+) entry and ceramide formation.