Apocynin Attenuates Acute Kidney Injury and Inflammation in Rats with Acute Hypertriglyceridemic Pancreatitis

Analyzing chemical composition of Sargentodoxae caulis water extract and their hypouricemia effect in hyperuricemic mice

Hyperuricemia (HUA) is a metabolic disease characterized by the increase of serum uric acid (UA) level. Sargentodoxae Caulis (SC) is a commonly used herbal medicine for the treatment of gouty arthritis, traumatic swelling, and rheumatic arthritis in clinic. In this study, a total of fifteen compounds were identified in SC water extract using UHPLC-Q-TOF-MS/MS, including three phenolic acids, seven phenolic glycosides, four organic acids, and one lignan. Then, to study the hypouricemia effect of SC, a HUA mouse model was induced using a combination of PO, HX, and 20% yeast feed. After 14 days of treatment with the SC water extract, the levels of serum UA, creatinine (CRE), blood urea nitrogen (BUN) were reduced significantly, and the organ indexes were restored, the xanthine oxidase (XOD) activity were inhibited as well. Meanwhile, SC water extract could ameliorate the pathological status of kidneys and intestine of HUA mice. Additionally, quantitative real-time PCR (qRT-PCR) and western blotting results showed that SC water extract could increase the expression of ATP binding cassette subfamily G member 2 (ABCG2), organic cation transporter 1 (OCT1), organic anion transporter 1 (OAT1) and organic anion transporter 3 (OAT3), whereas decrease the expression of glucose transporter 9 (GLUT9). This study provided a data support for the clinical application of SC in the treatment of HUA.

Nicotinamide adenine dinucleotide phosphate oxidase in pancreatic diseases: Mechanisms and future perspectives

Pancreatitis and pancreatic cancer (PC) stand as the most worrisome ailments affecting the pancreas. Researchers have dedicated efforts to unraveling the mechanisms underlying these diseases, yet their true nature continues to elude their grasp. Within this realm, oxidative stress is often believed to play a causal and contributory role in the development of pancreatitis and PC. Excessive accumulation of reactive oxygen species (ROS) can cause oxidative stress, and the key enzyme responsible for inducing ROS production in cells is nicotinamide adenine dinucleotide phosphate hydrogen oxides (NOX). NOX contribute to pancreatic fibrosis and inflammation by generating ROS that injure acinar cells, activate pancreatic stellate cells, and mediate macrophage polarization. Excessive ROS production occurs during malignant transformation and pancreatic carcinogenesis, creating an oxidative microenvironment that can cause abnormal apoptosis, epithelial to mesenchymal transition and genomic instability. Therefore, understanding the role of NOX in pancreatic diseases contributes to a more in-depth exploration of the exact pathogenesis of these diseases. In this review, we aim to summarize the potential roles of NOX and its mechanism in pancreatic disorders, aiming to provide novel insights into understanding the mechanisms underlying these diseases.

Comprehensive review on the pathogenesis of hypertriglyceridaemia-associated acute pancreatitis

It is well known, that the inflammatory process that characterizes acute pancreatitis (AP) can lead to both pancreatic damage and systemic inflammatory response syndrome (SIRS). During the last 20 years, there has been a growing incidence of episodes of acute pancreatitis associated with hypertriglyceridaemia (HTAP). This review provides an overview of triglyceride metabolism and the potential mechanisms that may contribute to developing or exacerbating HTAP. The article comprehensively discusses the various pathological roles of free fatty acid, inflammatory response mechanisms, the involvement of microcirculation, serum calcium overload, oxidative stress and the endoplasmic reticulum, genetic polymorphism, and gut microbiota, which are known to trigger or escalate this condition. Future perspectives on HTAP appear promising, with ongoing research focused on developing more specific and effective treatment strategies.

Apocynin, an NADPH Oxidase Enzyme Inhibitor, Prevents Amebic Liver Abscess in Hamster

Amebiasis is an intestinal infection caused by Entamoeba histolytica. Amebic liver abscess (ALA) is the most common extraintestinal complication of amebiasis. In animal models of ALA, neutrophils have been shown to be the first cells to come into contact with Entamoeba histolytica during the initial phase of ALA. One of the multiple mechanisms by which neutrophils exhibit amebicidal activity is through reactive oxygen species (ROS) and the enzyme NADPH oxidase (NOX2), which generates and transports electrons to subsequently reduce molecular oxygen into superoxide anion. Previous reports have shown that ROS release in the susceptible animal species (hamster) is mainly stimulated by the pathogen, in turn provoking such an exacerbated inflammatory reaction that it is unable to be controlled and results in the death of the animal model. Apocynin is a natural inhibitor of NADPH oxidase. No information is available on the role of NOX in the evolution of ALA in the hamster, a susceptible model. Our study showed that administration of a selective NADPH oxidase 2 (NOX2) enzyme inhibitor significantly decreases the percentage of ALA, the size of inflammatory foci, the number of neutrophils, and NOX activity indicated by the reduction in superoxide anion (O2-) production. Moreover, in vitro, the apocynin damages amoebae. Our results showed that apocynin administration induces a decrease in the activity of NOX that could favor a decrease in ALA progression.

Inhibition of TRAF6 improves hyperlipidemic acute pancreatitis by alleviating pyroptosis in vitro and in vivo rat models

OBJECTIVE

Hypertriglyceridemia (HTG) is one of the common causes of acute pancreatitis (AP). Hyperlipidemic acute pancreatitis (HTG-AP) is associated with higher mortality owing to its tendency for greater severity and rapid progression. The purpose of this study was to explore the mechanism of involvement of tumor necrosis factor receptor-related factor 6 (TRAF6) in pyroptosis during HTG-AP.

METHODS

The HTG environment was simulated with palmitic acid treatment in vitro and a high-fat diet in vivo. Cerulein was used to establish the HTG-AP model, followed by genetic and pharmacological inhibition of TRAF6. Pyroptosis activation, inflammatory reaction, and the interaction between TRAF6 and pyroptosis in HTG-AP were assessed.

RESULTS

HTG was found to aggravate the development of pancreatitis, accompanied by increased pyroptosis and enhanced inflammatory response in HTG-AP models. Mechanistically, TRAF6 downregulation decreased the activation of pyroptosis in cerulein-induced HTG-AP.

CONCLUSION

Collectively, inhibition of TRAF6 improved HTG-AP and the associated inflammation by alleviating pyroptosis.

Ferroptosis inhibition attenuates inflammatory response in mice with acute hypertriglyceridemic pancreatitis

BACKGROUND

Ferroptosis is involved in developing inflammatory diseases; yet, its role in acute hypertriglyceridemic pancreatitis (HTGP) remains unclear.

AIM

To explore whether ferroptosis is involved in the process of HTGP and elucidate its potential mechanisms.

METHODS

An HTGP mouse model was induced using intraperitoneal injection of P-407 and caerulein (CAE). Then, pancreatic tissues from the model animals were subjected to proteome sequencing analysis. The pathological changes and scores of the pancreas, lung, and kidney were determined using hematoxylin-eosin staining. The levels of serum amylase (AMY), triglyceride, and total cholesterol were measured with an automatic blood cell analyzer. Additionally, the serum levels of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β were determined by enzyme linked immunosorbent assay. Malonaldehyde (MDA), glutathione (GSH), and Fe²⁺ were detected in the pancreas. Finally, immunohistochemistry was performed to assess the expression of ferroptosis-related proteins.

RESULTS

Proteome sequencing revealed that ferroptosis was involved in the process of HTGP and that NADPH oxidase (NOX) 2 may participate in ferroptosis regulation. Moreover, the levels of serum AMY, TNF-α, IL-6, and IL-1β were significantly increased, MDA and Fe²⁺ were upregulated, GSH and ferroptosis-related proteins were reduced, and the injury of the pancreas, lung, and kidney were aggravated in the P407 + CAE group compared to CAE and wild type groups (all P < 0.05). Notably, the inhibition of ferroptosis and NOX2 attenuated the pathological damage and the release of TNF-α, IL-6, and IL-1β in the serum of the mice.

CONCLUSION

Ferroptosis was found to have an important role in HTGP and may be considered a potential target for clinical treatment.

Dysregulated B7H4/JAK2/STAT3 Pathway Involves in Hypertriglyceridemia Acute Pancreatitis and Is Attenuated by Baicalin

BACKGROUND

Patients with hypertriglyceridemia (HTG) are prone to develop more severe acute pancreatitis (AP). However, the specific molecular mechanism still has not been elaborated clearly, and effective drugs for treating HTG-AP are not yet readily available. Baicalin is an ingredient isolated from a natural product that with potential to attenuate inflammation and pain in AP.

AIMS

The aim of the present study was to explore the effect of baicalin on HTG-AP and the possible mechanism involved.

METHODS

A mouse model of HTG-AP was successfully established by administering Poloxamer 407 and L-arginine intraperitoneally. We analyzed pathological changes, and performed TUNEL staining, DHE staining, and western blot to detect apoptosis, inflammation, oxidative stress, and B7H4/JAK2/STAT3 signaling in the pancreas.

RESULTS

Treatment with baicalin decreased serum triglyceride, cholesterol, lipase, amylase levels, and attenuated pancreatic edema. After intervention with baicalin, apoptosis and inflammation in HTG-AP mice were alleviated, as indicated by the decrease of Bax, cleaved-caspase-3, IL-6, TNF-α, and IL-1β. Baicalin also alleviated oxidative stress by decreasing NOX2, increasing SOD2 protein expression, and regulating Nrf2/Keap1 signaling in HTG-AP mice. Furthermore, baicalin decreased the upregulated B7H4/JAK2/STAT3 pathway in HTG-AP.

CONCLUSIONS

In conclusion, our data suggested that baicalin could attenuate HTG-AP, possibly through regulating B7H4/JAK2/STAT3 signaling.

Self-assembled hyaluronic acid-coated nanocomplexes for targeted delivery of curcumin alleviate acute kidney injury

Acute kidney injury (AKI) is a pathological process with high morbidity, and drug resistance is easy to occur due to untargeted drug therapy. Curcumin can repair acute kidney injury. The expression of the CD44 receptor in renal tubular epithelial cells is abnormally elevated during AKI, and hyaluronic acid (HA) has the ability to bind specifically to the CD44 receptor. In this study, we developed a hyaluronic acid-coated liposome (HALP) nanocomplexes that targeted renal epithelial cells and its effect of relieving AKI was investigated. HALP was formed by self-assembly through the electrostatic interaction of curcumin-loaded cationic liposomes (LP) with hyaluronic acid and responds to the release of curcumin in the acidic microenvironment of lesions to treat AKI. HALP had good stability and biocompatibility. The in vitro results showed that compared to LP, HALP exhibited higher antioxidant, anti-inflammatory, and anti-apoptotic capacities. The AKI model suggested that HALP could not only target and accumulate in the injured kidney but also had an excellent ability to reduce the inflammatory response, which decreased tubular necrosis and restored kidney function.

Ginsenoside Rg1 attenuates LPS-induced chronic renal injury by inhibiting NOX4-NLRP3 signaling in mice

Chronic renal injury (CRI) is a common pathological damage in chronic renal disease, and the therapeutic options for preventing its progression are limited at present. Ginsenoside Rg1 (Rg1) is reported to have a protective effect on renal injury by improving oxidative stress and inflammation. Lipopolysaccharide (LPS) plays important roles in inducing inflammatory and high-dose LPS is often used to perform acute renal injury. However, little is known about the effect of low-dose LPS on CRI, and the protective effect of Rg1 against chronic LPS-induced CRI. Here, we reported the protective effect and mechanism of Rg1 against LPS-induced CRI in mice. In this study, the results demonstrated that low-dose LPS (0.25 mg/kg) exposure for 14 days significantly induced renal function impairment and renal injury and fibrosis. Meanwhile, LPS exposure significantly increased reactive oxygen species (ROS) generation, NADPH oxidase 4 (NOX4) and NLRP3 inflammasome expression in renal cortex. However, treatment with Rg1, tempol (a superoxide dismutase mimetic), and apocynin (a NOX inhibitor) significantly improved renal function impairment and renal fibrosis, and significantly decreased the levels of TGF-β, IL-1β, KIM-1, β-Gal, and collagen IV in the kidneys. And Rg1 treatment also significantly reduced ROS generation and inhibited the activation of NOX4 and NLRP3 inflammasome. Overall, these results suggest that Rg1 treatment can ameliorate LPS-induced chronic kidney injury and renal fibrosis, the mechanisms may be involved in reducing NOX2-mediated oxidative stress and inhibiting NLRP1 inflammasome.

Hypertriglyceridemia Acute Pancreatitis: Animal Experiment Research

In recent years, the number of acute pancreatitis cases caused by hypertriglyceridemia has increased gradually, which has caught the attention of the medical community. However, because the exact mechanism of hypertriglyceridemic acute pancreatitis (HTG-AP) is not clear, treatment and prevention in clinical practice face enormous challenges. Animal models are useful for elucidating the pathogenesis of diseases and developing and testing novel interventions. Therefore, animal experiments have become the key research means for us to understand and treat this disease. We searched almost all HTG-AP animal models by collecting many studies and finally collated common animals such as rats, mice and included some rare animals that are not commonly used, summarizing the methods to model spontaneous pancreatitis and induce pancreatitis. We sorted them on the basis of three aspects, including the selection of different animals, analyzed the characteristics of different animals, different approaches to establish hypertriglyceridemic pancreatitis and their relative advantages and disadvantages, and introduced the applications of these models in studies of pathogenesis and drug therapy. We hope this review can provide relevant comparisons and analyses for researchers who intend to carry out animal experiments and will help researchers to select and establish more suitable animal experimental models according to their own experimental design.

Inflammatory Response and Oxidative Stress as Mechanism of Reducing Hyperuricemia of Gardenia jasminoides-Poria cocos with Network Pharmacology

Hyperuricemia (HUA) is a metabolic disease, closely related to oxidative stress and inflammatory responses, caused by reduced excretion or increased production of uric acid. However, the existing therapeutic drugs have many side effects. It is imperative to find a drug or an alternative medicine to effectively control HUA. It was reported that Gardenia jasminoides and Poria cocos could reduce the level of uric acid in hyperuricemic rats through the inhibition of xanthine oxidase (XOD) activity. But there were few studies on its mechanism. Therefore, the effective ingredients in G. jasminoides and P. cocoa extracts (GPE), the active target sites, and the further potential mechanisms were studied by LC-/MS/MS, molecular docking, and network pharmacology, combined with the validation of animal experiments. These results proved that GPE could significantly improve HUA induced by potassium oxazine with the characteristics of multicomponent, multitarget, and multichannel overall regulation. In general, GPE could reduce the level of uric acid and alleviate liver and kidney injury caused by inflammatory response and oxidative stress. The mechanism might be related to the TNF-α and IL-7 signaling pathway.

Baicalein alleviates pyroptosis and inflammation in hyperlipidemic pancreatitis by inhibiting NLRP3/Caspase-1 pathway through the miR-192-5p/TXNIP axis

OBJECTIVE

Hyperlipidemia is a main reason of pancreatitis. Baicalein can ameliorate the pathological manifestations of pancreatitis. This study evaluated underlying molecular mechanism of baicalein in hyperlipidemic pancreatitis (HP).

METHODS

HP rat model was successfully established and treated with baicalein. Amylase (AMY) activity and concentrations of triglyceride (TG) and total cholesterol (TC) were detected. Levels of pyroptosis-related proteins (GSDMD, IL-1β, IL-18) were detected by Western blot. Expressions of inflammatory factors (IL-6, TNF-α, IL-4) were detected by ELISA. Toxicity of baicalein on pancreatic acinar cells (PACs) was detected by MTT assay. HP cell model was established by 0.1 mM palmitic acid and CCK-8 stimulation. Target relation of miR-192-5p and TXNIP was predicted and verified by RNA22 v2 database and dual-luciferase reporter assay. Expressions of miR-192-5p and TXNIP were detected by RT-qPCR. Pyroptosis and inflammation in PACs were detected after baicalein treatment combined with silencing miR-192-5p or TXNIP overexpression. Protein levels of NLRP3/Caspase-1 pathway in vivo and vitro were detected.

RESULTS

Baicalein reduced concentrations of TG and TC, AMY activity, and pathological scores in HP rat model, reduced LDH activity, pyroptosis and alleviated inflammation in vivo and in vitro. Mechanically, miR-192-5p targeted TXNIP, and baicalein inhibited pyroptosis and inflammation by up-regulating miR-192-5p and down-regulating TXNIP. Silencing miR-192-5p or TXNIP overexpression partially abolished the anti-pyroptosis and anti-inflammatory effect of baicalein on PACs. Baicalein attenuated HP by inhibiting the NLRP3/Caspase-1 pathway.

CONCLUSION

Baicalein alleviated pyroptosis and inflammation in HP by inhibiting the NLRP3/Caspase-1 pathway through miR-192-5p upregulation and TXNIP inhibition.

Phillyrin ameliorates diabetic nephropathy through the PI3K/Akt/GSK-3β signalling pathway in streptozotocin-induced diabetic mice

Diabetic nephropathy is a progressive kidney disease resulting from long-term hyperglycaemia in diabetic patients, and the underlying mechanism is complex and lacks effective treatments. Various active ingredients in Chinese herbs have been shown to alleviate renal injury and improve DN in recent years. Phillyrin, a natural medicinal active compound extracted from the Oleaceae family, has various pharmacological effects, including antioxidative, antiapoptotic and antiobesity effects. However, the role of phillyrin and its underlying mechanism in DN have not yet been explored. To investigate the effects of phillyrin on DN and its potential mechanisms of action, we performed experiments using streptozotocin (STZ)-induced DN mice as models. Phillyrin significantly reduced the levels of fasting blood glucose (FBG) and glycosylated haemoglobin A1c (HbA1c), downregulated the levels of serum blood urea nitrogen (BUN), serum creatinine (Scr), serum and urine β2-microglobulins (β2-MG) and improved the pathological changes of the kidney in a DN mouse model. Phillyrin also increased the level of antioxidants and attenuated oxidative damage in DN model mice. In addition, phillyrin inhibited Glycogen synthase kinase-3β (GSK-3β) activity by activating the PI3K/Akt signalling pathway, increased the Bcl-2/Bax ratio, reduced the release of cytochrome c from the mitochondria to the cytoplasm, subsequently inhibited the activation of caspase-3 and ultimately suppressed renal cell apoptosis. These findings suggested that phillyrin could be a new promising therapeutic strategy for DN, and this protective effect might be related to suppressing oxidative stress and apoptosis via the PI3K/Akt/GSK-3β pathway.

Apocynin ameliorates NADPH oxidase 4 (NOX4) induced oxidative damage in the hypoxic human retinal Müller cells and diabetic rat retina

NADPH oxidase (NOX) is a main producers of reactive oxygen species (ROS) that may contribute to the early pathogenesis of diabetic retinopathy (DR). ROS has harmful effects on endogenous neuro-survival factors brain-derived neurotrophic factor (BDNF) and sirtuin 1 (SIRT1) are necessary for the growth and survival of the retina. The role of NOX isoforms NOX4 in triggering ROS in DR is not clear. Here we determine the protective effects of a plant-derived NOX inhibitor apocynin (APO) on NOX4-induced ROS production which may contribute to the depletion of survival factors BDNF/SIRT1 or cell death in the diabetic retinas. Human retinal Müller glial cells (MGCs) were treated with hypoxia mimetic agent cobalt chloride (CoCl₂) in the absence or presence of APO. Molecular analysis demonstrates that NOX4 is upregulated in CoCl₂-treated MGCs and in the diabetic retinas. Increased NOX4 was accompanied by the downregulation of BDNF/SIRT1 expression or in the activation of apoptotic marker caspase-3. Whereas, APO treatment downregulates NOX4 and subsequently upregulates BDNF/SIRT1 or alleviate caspase-3 expression. Accordingly, in the diabetic retina we found a positive correlation in NOX4 vs ROS (p = 0.025; R² = 0.488) and caspase-3 vs ROS (p = 0.04; R² = 0.428); whereas a negative correlation in BDNF vs ROS (p = 0.009; R² = 0.596) and SIRT1 vs ROS (p = 0.0003; R² = 0.817) respectively. Taken together, NOX4-derived ROS could be a main contributor in downregulating BDNF/SIRT1 expression or in the activation of caspase-3. Whereas, APO treatment may minimize the deleterious effects occurring due to hyperglycemia and/or diabetic mimic hypoxic condition in early pathogenesis of DR.

Apocynin and catalase prevent hypertension and kidney injury in Cyclosporine A-induced nephrotoxicity in rats

Oxidative stress is involved in the pathogenesis of a number of diseases including hypertension and renal failure. There is enhanced expression of nicotinamide adenine dinucleotide (NADPH oxidase) and therefore production of hydrogen peroxide (H2O2) during renal disease progression. This study investigated the effect of apocynin, an NADPH oxidase inhibitor and catalase, an H2O2 scavenger on Cyclosporine A (CsA) nephrotoxicity in Wistar-Kyoto rats. Rats received CsA (25mg/kg/day via gavage) and were assigned to vehicle, apocynin (2.5mmol/L p.o.), catalase (10,000U/kg/day i.p.) or apocynin plus catalase for 14 days. Renal functional and hemodynamic parameters were measured every week, and kidneys were harvested at the end of the study for histological and NADPH oxidase 4 (NOX4) assessment. Oxidative stress markers and blood urea nitrogen (BUN) were measured. CsA rats had higher plasma malondialdehyde (by 340%) and BUN (by 125%), but lower superoxide dismutase and total antioxidant capacity (by 40%, all P<0.05) compared to control. CsA increased blood pressure (by 46mmHg) and decreased creatinine clearance (by 49%, all P<0.05). Treatment of CsA rats with apocynin, catalase, and their combination decreased blood pressure to near control values (all P<0.05). NOX4 mRNA activity was higher in the renal tissue of CsA rats by approximately 63% (P<0.05) compared to controls but was reduced in apocynin (by 64%), catalase (by 33%) and combined treatment with apocynin and catalase (by 84%) compared to untreated CsA rats. Treatment of CsA rats with apocynin, catalase, and their combination prevented hypertension and restored renal functional parameters and tissue Nox4 expression in this model. NADPH inhibition and H2O2 scavenging is an important therapeutic strategy during CsA nephrotoxicity and hypertension.