Argel's stemmoside C as a novel natural remedy for mice with alcohol-induced gastric ulcer based on its molecular mechanistic pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Solenostemma argel is widely distributed in Africa & Asia with traditional usage in alleviating abdominal colic, aches, & cramps. This plant is rich in phytochemicals, which must be explored for its pharmacological effects.

PURPOSE

Peptic Ulcer Disease (PUD) is the digestion of the digestive tube. PUD not only interferes with food digestion & nutrient absorption, damages one of the largest defensive barriers against pathogenic micro-organisms, but also impedes drug absorption & bioavailability, rendering the oral route, the most convenient way, ineffective. Omeprazole, one of the indispensable cost-effective proton-pump inhibitors (PPIs) extensively prescribed to control PUD, is showing growing apprehensions toward multiple drug interactions & side effects. Hence, finding a natural alternative with Omeprazole-like activity & limited side effects is a medical concern.

STUDY DESIGN

Therefore, we present Stemmoside C as a new gastroprotective phytochemical agent isolated from Solenostemma argel to be tested in upgrading doses against ethanol-induced gastric ulcers in mice compared to negative, positive, & reference Omeprazole groups.

METHODS

We carried out in-depth pharmacological & histopathological studies to determine the possible mechanistic pathway.

RESULTS

Our results showed that Stemmoside C protected the stomach against ethanol-induced gastric ulcers parallel to Omeprazole. Furthermore, the mechanistic studies revealed that Stemmoside C produced its effect using an orchestrated array of different mechanisms. Stemmoside C stimulates stomach defense by increasing COX-2, PGE-2, NO, & TFF-1 healing factors, IL-10 anti-inflammatory cytokine, & Nrf-2 & HO-1 anti-oxidant pathways. It also suppresses stomach ulceration by inhibiting leucocyte recruitment, especially neutrophils, leading to subsequent inhibition of NF-κBp65, TNF-α, IL-1β, & iNOS pro-inflammatory cytokines & JAK-1/STAT-3 inflammation-induced carcinogenicity cascade in addition to MMP-9 responsible for tissue degradation.

CONCLUSION

These findings cast light on Stemmoside C's clinical application against gastric ulcer progression, recurrence, & tumorigenicity & concurrently with chemotherapy.

Sulforaphane alleviates lung ischemia‑reperfusion injury through activating Nrf‑2/HO‑1 signaling

Oxidative stress and inflammation are both involved in the pathogenesis of lung ischemia-reperfusion (I/R) injury. Sulforaphane (SFN) is a natural product with cytoprotective, anti-inflammatory, and antioxidant properties. The present study hypothesized that SFN may protect against lung I/R injury via the regulation of antioxidant and anti-inflammatory-related pathways. A rat model of lung I/R injury was established, and rats were randomly divided into 3 groups: Sham group, I/R group, and SFN group. It was shown that SFN protected against a pathological inflammatory response via inhibition of neutrophil accumulation and in the reduction of the serum levels of the pro-inflammatory cytokines, IL-6, IL-1β, and TNF-α. SFN treatment also significantly inhibited lung reactive oxygen species production, decreased the levels of 8-OH-dG and malondialdehyde, and reversed the decrease in the antioxidant activities of the enzymes catalase, superoxide dismutase, and glutathione peroxidase in the lungs of the I/R treated rats. In addition, SFN ameliorated I/R-induced lung apoptosis in rats by suppressing Bax and cleaved caspase-3 levels and increased Bcl-2 expression. Furthermore, SFN treatment activated an Nrf2-related antioxidant pathway, as indicated by the increased nuclear transfer of Nrf2 and the downstream HO-1 and NADPH quinone oxidoreductase-1. In conclusion, these findings suggested that SFN protected against I/R-induced lung lesions in rats via activation of the Nrf2/HO-1 pathway and the accompanied anti-inflammatory and anti-apoptotic effects.

Astaxanthin suppresses oxidative stress and calcification in vertebral cartilage endplate via activating Nrf-2/HO-1 signaling pathway

BACKGROUND

Cartilage endplate (CEP) degeneration is an important initiating factor leading to intervertebral disc degeneration (IVDD). Astaxanthin (Ast) is a natural lipid-soluble and red-orange carotenoid which possesses various biological activities, including antioxidant, anti-inflammatory, and anti-aging effects in multiple organisms. However, the effects and mechanism of Ast on endplate chondrocytes remain largely unknown. The objective of the current study was to investigate the effects and of Ast on CEP degeneration and its underlying molecular mechanisms.

METHODS

Tert-butyl hydroperoxide (TBHP) was used to mimic the IVDD pathological environment. We investigated the effects of Ast on the Nrf2 signaling pathway and damage-associated events. The IVDD model was constructed by surgical resection of L4 posterior elements to explore the role of Ast in vivo.

RESULTS

We found that the activation of the Nrf-2/HO-1 signaling pathway was enhanced by Ast, thus promoted mitophagy process, inhibited oxidative stress and CEP chondrocytes ferroptosis, eventually ameliorated extracellular matrix (ECM) degradation, CEP calcification and endplate chondrocytes apoptosis. Knockdown of Nrf-2 using siRNA inhibited Ast induced mitophagy process and its protective effect. Moreover, Ast inhibited oxidative stimulation-induced NF-κB activity and could ameliorate the inflammation response. The results also were confirmed by experiments in vivo, Ast alleviated IVDD development and CEP calcification.

CONCLUSIONS

Ast could protect vertebral cartilage endplate against oxidative stress and degeneration via activating Nrf-2/HO-1 pathway. Our results imply that Ast may serve as a potential therapeutic agent for IVDD progression and treatment.

Protective effect of Saxagliptin on diabetic rats with renal ischemia reperfusion injury by targeting oxidative stress and mitochondrial apoptosis pathway through activating Nrf-2/HO-1 signaling

Oxidative stress and apoptosis play vital role in diabetic rats suffering from renal ischemia reperfusion injury (IRI). As a dipeptidyl dipeptidase-4 (DPP-4) inhibitor, Saxagliptin(SAX)has been confirmed in the regulation of inflammation and apoptosis by targeting Nrf-2/HO-1signalling. The study was designed to explore the efficacy and potential mechanisms of SAX on inflammation and apoptosis for treating of IRI in diabetic rats. Through testing the expressions of Nrf-2, HO-1, Cleaved-Caspase9, Cleaved-Caspase3, Bax, BCL-2, Bak, Apaf-1, cytochrome C (Cytc), Cystatin C (CysC), β2-microglobulin (β2-MG), creatinine (Cr), urea nitrogen (BUN), TUNEL and pathological morphology, the effects of SAX on IRI diabetic rats have been investigatedg. The results has displayed SAX treatment significantly attenuate the cell apoptosis and pathological damage of kidney as well as lessening the expression of cleaved-caspase-9, cleaved-caspase3, Bax, cytoplasmic-Cytc, MDA, Bak, and Apaf-1 molecules, and the contents of ROS, Cr, CysC, β2-MG, and BUN. Furthermore, SAX therapy also increased the expression of Nrf-2, BCL-2, HO-1 and mitochondrial cytochrome Cytc, and enhanced the activity of SOD, CAT and GPx. Therefore, our study has indicated that SAX treatment alleviated IRI in diabetic rats by suppressing oxidative stress and mitochondrial apoptotic pathways by activating the Nrf-2/HO-1 signaling.

Targeting endoplasmic reticulum stress, Nrf-2/HO-1, and NF-κB by myristicin and its role in attenuation of ulcerative colitis in rats

AIMS

Ulcerative colitis (UC) is characterized by the up-regulation of pro-inflammatory mediators, apoptotic signals, and oxidative stress that can lead to an increased risk of colorectal cancer. The present study aims to investigate the possible role of myristicin in modulating endoplasmic reticulum stress (ERS) and risk-associated conditions in acetic acid (AA)-induced UC.

MATERIALS AND METHODS

Adult male rats were treated with 150 mg/kg body weight of myristicin or mesalazine orally either as pre/post treatment or post-treatment only. The gene expression of glucose-related protein 78 (GRP78), CCAAT/enhancer-binding protein homologous protein (CHOP), and nuclear factor kappa B (NF-κB), percentage of DNA fragmentation, and serum levels of some oxidative and inflammatory markers were measured.

KEY FINDINGS

The results indicated the potential upregulation of ERS, pro-apoptotic, lipid peroxidation, and pro-inflammatory cascades by induction of UC in rats. However, myristicin could effectively reverse the deteriorated effects of ulceration in colonic mucosa. It was mediated through downregulation of the ERS markers GRP78 and CHOP genes expression, reduction of NF-κB mRNA expression, DNA fragmentation, reduced lipid peroxidation, myeloperoxidase (MPO) activity and pro-inflammatory markers (Tumor necrosis factor-α (TNF-α), Interleukin-1β (IL-1β) and cyclo‑oxygenase (COX-2) activity). Accompanied by elevated levels of IL-10, colonic Nuclear erythroid factor (Nrf-2) and Heme oxygenase (HO-1) activity as well as blood antioxidant enzymes activity. Results of docking might confirm the biological results of our study.

SIGNIFICANCE

Myristicin could effectively modulate important stress, and inflammatory effectors and protect mucosal DNA from oxidative damage which can serve as a promising candidate for the treatment of ulcerative colitis.

Design of Diselenide-Bridged Hyaluronic Acid Nano-antioxidant for Efficient ROS Scavenging to Relieve Colitis

Overproduction of reactive oxygen species (ROS), a key characteristic of inflammatory bowel disease (IBD), is responsible for dysregulation of signal transduction, inflammatory response, and DNA damage, which ultimately leads to disease progression and deterioration. Thus, ROS scavenging has become a promising strategy to navigate IBD. Inspired by the targeting capability of hyaluronic acid (HA) to CD44-overexpressed inflammatory cells together with the redox regulation capacity of diselenide compounds, we developed an oral nanoformulation, i.e., diselenide-bridged hyaluronic acid nanogel (SeNG), with a view to treat colitis through a ROS scavenging mechanism. Our data demonstrated that SeNG specifically accumulated in colitis tissue that was mediated by highly efficient CD44-HA interaction. This has allowed us to demonstrate a significant anti-inflammatory effect in an acute colitis mouse model induced by dextran sulfate sodium and trinitrobenzenesulfonic acid. Mechanistically, we continued to show SeNG reduced the ROS level via both direct elimination and up-regulation of the Nrf2/HO-1 signal pathway. Collectively, our work provides proof-of-principle evidence for a SeNG-mediated nano-antioxidant strategy, by which colitis could be effectively managed.

Curculigoside mitigates hepatic ischemia/reperfusion-induced oxidative stress, inflammation, and apoptosis via activation of the Nrf-2/HO-1 pathway

Curculigoside has been shown to decrease oxidative stress and inflammatory reactions in many disorders, but its effects during hepatic ischemia-reperfusion injury (IRI) remain unknown. This research aims to determine the protective role and the potential mechanism of action of curculigoside in hepatic IRI. Here, a well-established rat model of partial warm IRI was constructed; serum ALT/AST and H&E staining were employed to assay the extent of liver injury; the superoxide dismutase, malondialdehyde, IL-6, and TNF-α contents were determined using the corresponding kits; the apoptosis index was evaluated by TUNEL staining; and the expression of Nrf-2, HO-1, and apoptosis-associated proteins was detected by qRT-PCR and Western blotting. The results showed that curculigoside pretreatment effectively mitigated hepatic IRI, as demonstrated by decreases in the levels of serum aminotransferases, hepatocellular necrosis and apoptosis, oxidative stress markers, infiltration of inflammatory cells, and secretion of proinflammatory cytokines. Mechanistically, the expression of Nrf-2 and HO-1 was greatly suppressed by hepatic IRI and reactivated by curculigoside. Furthermore, cotreatment with ML-385, an inhibitor of Nrf-2, counteracted the protective effect of curculigoside against hepatic IRI. The results of our study show that curculigoside plays a protective role in hepatic IRI by inhibiting oxidative stress, inflammation, and apoptosis and that its effects may be associated with activation of the Nrf-2/HO-1 pathway.

Yixin-Fumai granules improve sick sinus syndrome in aging mice through Nrf-2/HO-1 pathway: A new target for sick sinus syndrome

ETHNOPHARMACOLOGICAL RELEVANCE

Yixin-Fumai granules (YXFMs)-composed of Ginseng quinquefolium (L.) Alph. Wood, Ophiopogon japonicus (Thunb.) Ker Gawl, Schisandra arisanensis Hayata, Astragalus aaronsohnianus Eig, Salvia cryptantha Montbret & Aucher ex Benth, and Ligusticum striatum DC-are compound granules used in traditional Chinese medicine to increase heart rate and thus treat bradyarrhythmia. It may be effective in treating sick sinus syndrome (SSS).

AIM

To observe the effect of YXFMs on aging-induced SSS in mice and explore whether this effect is related to the Nrf-2/HO-1 signaling pathway.

MATERIALS AND METHODS

Mice with a significant decrease in the heart rate due to natural aging were selected to construct an SSS model. After the mice were administered YXFMs, the damage to their sinoartrial node (SAN) was assessed through electrocardiography, Masson's trichrome staining, and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL). Dihydroethidium staining and immunofluorescence staining were used to assay reactive oxygen species (ROS) content and HCN4, respectively. Moreover, to observe the effects of YXFMs in vitro, the HL-1 cell line, derived from mouse atrial myocytes, was used to simulate SAN pacemaker cells, with H₂O₂ used as the cellular oxidative stress (OS) inducer. 2,7-Dichlorodihydrofluorescein diacetate staining was used to assay ROS content, whereas immunofluorescence staining and Western blotting were used to elucidate the related protein expression. Finally, mice were injected the Nrf-2 inhibitor ML385 to reversely verify the effects of YXFMs.

RESULTS

In our in vivo experiments, YXFMs significantly inhibited aging-induced SSS, shortened the R-R interval, increased heart rate, alleviated fibrosis, reduced apoptosis rate and ROS content, and promote HCN4 expression in the SAN. In our in vitro experiments, YXFMs significantly inhibited H₂O₂-induced cell peroxidation damage, promoted Nrf-2 activation and nuclear metastasis, increased HO-1 expression- thereby inhibiting ROS accumulation-and finally, upregulated HCN4 expression through the inhibition of histone deacetylase 4 (HDAC4) expression and its nuclear metastasis. Finally, injection of the Nrf-2 inhibitor ML385 after YXFMs administration inhibited their protective effect in the mice.

CONCLUSION

Here, we elaborated on the relationship between aging-induced SSS and the Nrf-2/HO-1 pathway for the first time and proposed that YXFMs improve SSS via the Nrf-2/HO-1 axis. Specifically, YXFMs promoted Nrf-2 activation and plasma-nuclear transfer to enhance HO-1 expression via the Nrf-2/HO-1 axis. This inhibited OS and reduced ROS accumulation in the SAN, and then, through the ROS/HDAC4 axis, reduced HDAC4 expression and plasma-nuclear transfer. Thereby, the OS-induced HCN4 loss in the SAN was inhibited-improving the function of I_f channel and thus producing SAN protection effect against SSS and improving the heart rate and R-R interval. In the future, we plan to use bioinformatics analysis technology to execute the next step of our research, namely to determine the effect of isolated, purified components of YXFMs in SSS, to increase its efficiency and reduce the toxicity of YXFMs.

Sulforaphane alleviates hepatic ischemia-reperfusion injury through promoting the activation of Nrf-2/HO-1 signaling

BACKGROUND

Sulforaphane (SFN)displays both anti-oxidative stress and anti-inflammatory activity. Given that inflammation and oxidative stress play important roles in hepatic ischemia-reperfusion injury (HI/RI), we examined the protective effect and potential mechanism of SFN on HI/RI.

METHODS

The maneuver of Pringle's was used to establish the mode of HI/RI and 60 SD rats were randomly divided into Sham, HI/RI, SFN and ML385 Groups. The expression of aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), Nuclear factor-E2-related factor 2(Nrf-2), heme oxygenase 1(HO-1), nitric oxide (NO), Cyclooxygenase2 (COX-2), NADPH quinone oxidoreductase 1 (NQO1), malondialdehyde (MDA), tumor necrosis factor-a (TNF-a), interleukin-6 (IL-6) and monocyte chemotactic protein 1(MCP-1) were measured. Moreover, hepatic pathological morphology and the activity of glutathione (GSH), Catalase (CAT), superoxide dismutase (SOD) of the liver were also examined.

RESULTS

SFN treatment can significantly decrease the hepatic pathological injury and down-regulate the expression of ALT, AST, ALP, COX-2, TNF-a, IL-6, MCP-1, NO and MDA in HI/RI with increasing the expression of Nrf2, NQO1 and HO-1, and up-regulating the activity of GSH, CAT and SOD. Moreover, Nrf-2 inhibitor, ML385 can obliviously reverse the protective effect of SFN on HI/RI.

CONCLUSION

Sulforaphane can inhibit the inflammatory response and oxidative stress induced by HI/RI through promoting the activation of the Nrf-2 / HO-1 signal pathway.

Mechanistic interplay of various mediators involved in mediating the neuroprotective effect of daphnetin

Daphnetin is a 7, 8 dihydroxy coumarin isolated from different medicinal plants of the Thymelaeaceae family and exhibits copious pharmacological activities including neuroprotection, anti-cancer, anti-malarial, anti-inflammatory, anti-parasitic and anti-arthritic activity. It has been proved to be an effective neuroprotective agent in several preclinical animal studies and cell line examinations. It is found to interact with different cellular mediators and signaling pathways to confer protection against neurodegeneration. The reactive oxygen species and inflammatory mediators are the major culprits of different neurodegenerative diseases. Oxidative stress activates the pro-apoptotic proteins and inhibits anti-apoptotic proteins, leading to neuronal cell death. Daphnetin restores cellular redox balance by upregulating the antioxidants level (GSH and SOD), anti-apoptotic protein (Bcl-2), as well as by reducing the levels of proinflammatory cytokines, executioner caspase-3, pro-apoptotic-Bax, and oxidative stress markers. Furthermore, activation of Nrf-2/HO-1 signaling and upregulation of HSP-70 governs the protection elicited by daphnetin against oxidative stress-induced neuronal apoptosis. Daphnetin modulated inhibition of JNK-MAPK, JAK-STAT, and TLR-4/NF-κB signaling pathways also contributed to its neuroprotective effect. The positive effects of daphnetin have been also related to its AChE, BChE, and BACE-1 inhibitory potential. The present review has been designed to explore the mechanistic interplay of various mediators in mediating the neuroprotective effects of daphnetin.

Geniposide attenuates dextran sulfate sodium-induced colitis in mice via Nrf-2/HO-1/NF-κB pathway

BACKGROUND

Geniposide (GE) is the main component in gardenia fruit. This study aimed to investigate the protective effects and potential mechanisms of GE on dextran sulfate sodium (DSS)-induced colitis in mice and lipopolysaccharide (LPS)-induced RAW 264.7 cells.

METHODS

The in vivo acute colitis experimental model was established by administering drinking water containing 3% DSS to the mice for 7 days. GE was administered to the mice via oral gavage at 20 and 40 mg/kg for 7 days. Colon length, colon myeloperoxidase (MPO) level, serum and colon malondialdehyde (MDA) levels, and superoxide dismutase (SOD) activity were determined, and histological evaluation was performed. The levels of interleukin-6 (IL-6), IL-1β, and tumor necrosis factor-α (TNF-α) in the serum and colon were detected. The expression of proteins of the nuclear factor E2 related factor 2 (Nrf-2)/HO-1/ NF-κB pathway in the colon was detected. The in vitro model of LPS-induced RAW 264.7 cells to simulate enteritis model. Cell viability, IL-6, IL-1β, and TNF-α levels in the cell supernatant were measured. The MPO levels in RAW 264.7 cells and DSS-induced mice and MDA and SOD levels in the cell supernatant were measured. The expression of proteins of the Nrf-2/HO-1/NF-κB pathway in RAW 264.7 cells was determined.

RESULTS

GE treatment resulted in significant histological changes and reduced the expression of inflammatory mediators IL-6, IL-1β, and TNF-α the in serum, colon, and cell supernatant effectively. Parenteral nutrition reduced MPO content in the colon and RAW 264.7 cells. GE treatment increased SOD levels in the serum, colon, and cell supernatant. GE restored the protein expression of the Nrf-2/HO-1/ NF-κB pathway in RAW 264.7 cells and nude mice, and these changes were blocked significantly by Nrf-2 siRNA.

CONCLUSIONS

These findings demonstrated that GE ameliorated inflammation and oxidative stress in experimental colitis via modulation of the Nrf-2/HO-1/NF-κB pathway. Thus, GE could serve as a potential therapeutic agent for the treatment of ulcerative colitis (UC).

Erdosteine salvages cardiac necrosis: Novel effect through modulation of MAPK and Nrf-2/HO-1 pathway

Isoproterenol (ISO) induced oxidative stress and inflammation is involved in the pathogenesis of myocardial necrosis. To optimize the effect of erdosteine against myocardial necrosis, male albino Wistar rats were divided into eight groups (n = 6), that is, normal, ISO-control, erdosteine pretreatment with ISO. Rats were administered erdosteine orally for 28 days. Two doses of ISO (85 mg/kg), s.c. were given to ISO-C and erdosteine treatment groups on the 27th and 28th day. On the 29th day, hemodynamic parameters were recorded and the heart was excised for further parameters. In ISO-C rats, significantly increased levels of inflammatory markers, pro-oxidants, and structural damage were observed as compared with normal group. Furthermore, immunohistochemistry and terminal deoxynucleotidyl transferase dUTP nick end labeling revealed an increased expression of apoptotic proteins. Erdosteine at 80 mg/kg reversed the deleterious effects of ISO and normalized myocardium. Erdosteine showed anti-inflammatory, antiapoptotic, and antioxidant activities through inhibition of MAPK and Nrf-2/HO-1 pathways. To conclude, erdosteine was found protective in ISO-induced myocardial necrosis through MAPK and Nrf-2/HO-1 pathway.

Asiaticoside inhibits TGF-β1-induced mesothelial-mesenchymal transition and oxidative stress via the Nrf2/HO-1 signaling pathway in the human peritoneal mesothelial cell line HMrSV5

Background

Peritoneal fibrosis (PF) is a frequent complication caused by peritoneal dialysis (PD). Peritoneal mesothelial cells (PMCs), the first barrier of the peritoneum, play an important role in maintaining structure and function in the peritoneum during PD. Mesothelial-mesenchymal transition (MMT) and oxidative stress of PMCs are two key processes of PF.

Purpose

To elucidate the efficacy and possible mechanism of asiaticoside inhibition of MMT and ROS generation in TGF-β1-induced PF in human peritoneal mesothelial cells (HPMCs).

Methods

MMT and ROS generation of HPMCs were induced by TGF-β1. To explain the anti-MMT and antioxidant role of asiaticoside, varied doses of asiaticoside, oxygen radical scavenger (NAC), TGF-β receptor kinase inhibitor (LY2109761) and Nrf2 inhibitor (ML385) were used separately. Immunoblots were used to detect the expression of signaling associated proteins. DCFH-DA was used to detect the generation of ROS. Transwell migration assay and wound healing assay were used to verify the capacity of asiaticoside to inhibit MMT. Immunofluorescence assay was performed to observe the subcellular translocation of Nrf2 and expression of HO-1.

Results

Asiaticoside inhibited TGF-β1-induced MMT and suppressed Smad signaling in a dose-dependent manner. Migration and invasion activities of HPMCs were decreased by asiaticoside. Asiaticoside decreased TGF-β1-induced ROS, especially in a high dose (150 μM) for 6 h. Furthermore, ML385 partly abolished the inhibitory effect of asiaticoside on MMT, ROS and p-Smad2/3.

Conclusions

Asiaticoside inhibited the TGF-β1-induced MMT and ROS via Nrf2 activation, thus protecting the peritoneal membrane and preventing PF.

Nobiletin attenuates acetaminophen-induced hepatorenal toxicity in rats

The study aimed to examine the effects of nobiletin on the toxicity model induced with acetaminophen (APAP). For this purpose, 24 adult male rats were equally divided into four groups. The groups were the control group (group 1); dimethyl sulfoxide only, the APAP group (group 2) received a single dose of APAP 1000 mg/kg on the 10th day of experiment; the Nobiletin group (group 3), nobiletin (10 mg/kg) for 10 days; and the APAP + Nobiletin group (group 4), nobiletin (10 mg/kg) for 10 days with a single dose of APAP (1000 mg/kg) administered on the 10th day and the experiment ended after 48 hours. At the end of the study, a significant increase in malondialdehyde, interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) levels and a significant decrease in glutathione levels, glutathione peroxidase activities and nuclear factor erythroid-derived 2-like 2 (Nrf-2) and heme oxygenase-1 (HO-1) expressions were observed with APAP application in liver and kidney tissues. Serum aspartate transaminase (AST), alanine transaminase (ALT), urea, and creatinine levels were also significantly increased in the APAP group. However, nobiletin treatment in group 4 reversed oxidative stress and inflammatory and histopathological signs caused by APAP. It is concluded that nobiletin may be a beneficial substance that confers hepatorenal protection to APAP-induced toxicity via antioxidant and anti-inflammatory mechanisms.

Piceatannol alleviates inflammation and oxidative stress via modulation of the Nrf2/HO-1 and NF-κB pathways in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is one of the leading causes of morbidity and mortality in diabetic patients. Piceatannol (PIC) has protective effects against cardiovascular disease; however, it remains unknown whether it also protects against DCM. A Cell Counting Kit-8 (CCK-8) assay was used to evaluate the effects of PIC on the viability of high glucose (HG)-induced H9C2 cells. Protein expression and mRNA levels were detected by western blotting and real-time polymerase chain reaction (RT-PCR), respectively. In vivo, physical and biochemical analyses, together with transthoracic echocardiography and hemodynamic measurements, were used to detect the effects of PIC treatment on cardiac function in DCM rats. Reactive oxygen species production was determined using an ELISA kit, and inflammatory cytokines were detected by RT-PCR. Pathological changes were assessed by hematoxylin-eosin staining, immunohistochemical staining, and TUNEL staining. According to the results, PIC treatment improved cell viability and inhibited cell apoptosis in HG-induced H9C2 cardiac myoblasts. In addition, PIC not only attenuated the over-production of interleukin-6 (IL-6) (P < 0.05) and tumor necrosis factor alpha (TNF-α) (P < 0.05), but also improved the expression of nuclear factor E2-related factor 2 (Nrf2) (P < 0.05) and heme oxygenase-1 (HO-1) (P < 0.01). Importantly, knockdown of Nrf2 suppressed PIC-mediated activation of the Nrf2/HO-1 pathway and abolished its anti-inflammatory effects. In vivo, oral administration of PIC suppressed STZ-induced inflammation, oxidative stress hypertrophy, fibrosis(myocardial collagen volume fraction in 5 mg/kg and 10 mg/kg PIC group was decreased 25.83% and 55.61% compared with the DM group), and apoptosis(Caspase-3 level in 5 mg/kg and 10 mg/kg PIC group was decreased 13.21% and 33.91% compared with the DM group), thereby relieving cardiac dysfunction and improving both fibrosis and pathological changes in cardiac tissues of diabetic rats. These findings define for the first time that the effects of PIC against DCM can be attributed to its role in inflammation and oxidative stress inhibition.

Oleocanthal Modulates LPS-Induced Murine Peritoneal Macrophages Activation via Regulation of Inflammasome, Nrf-2/HO-1, and MAPKs Signaling Pathways

The present study was designed to investigate the role of the canonical and noncanonical inflammasome, MAPKs and NRF-2/HO-1, signaling pathways involved in the antioxidant and anti-inflammatory activities of oleocanthal in lipopolysaccharide (LPS)-stimulated murine peritoneal macrophages. Isolated cells were treated with oleocanthal in the presence or absence of LPS (5 μg mL^-1) for 18 h. Oleocanthal showed a potent reduction of reactive oxygen species (ROS) (25 μM, 50. 612 ± 0.02; 50 μM, 53. 665 ± 0.09; 100 μM, 52. 839 ± 0.02), nitrites (25 μM, 0.631 ± 0.07; 50 μM, 0.652 ± 0.07; 100 μM, 0.711 ± 0.08), and pro-inflammatory cytokines levels when compared with LPS-DMSO-treated control cells. In terms of enzymes protein expression, oleocanthal was able to downregulate iNOS (25 μM, 0.173 ± 0.02; 50 μM, 0.149 ± 0.01; 100 μM, 0.150 ± 0.01; p < 0.001), COX-2 (25 μM, 0.482 ± 0.08; 50 μM, 0.469 ± 0.05; 100 μM, 0.418 ± 0.06; p < 0.001), and mPGES-1 (25 μM, 0.185 ± 0.11; 50 μM, 0.218 ± 0.13; 100 μM, 0.161 ± 0.15; p < 0.001) as well as p38 (25 μM, 0.366 ± 0.11; 50 μM, 0.403 ± 0.13; 100 μM, 0.362 ± 0.15; p < 0.001), JNK (25 μM, 0.443 ± 0.11; 50 μM, 0.514 ± 0.13; 100 μM, 0.372 ± 0.15; p < 0.001), and ERK (25 μM, 0.294 ± 0.01; 50 μM, 0.323 ± 0.01; 100 μM, 0.274 ± 0.01; p < 0.001) protein phosphorylation, which was accompanied by an upregulation of Nrf-2 (25 μM, 1.57 ± 0.01; 50 μM, 1.54 ± 0.01; 100 μM, 1.63 ± 0.05; p < 0.05) and HO-1(25 μM, 2.12 ± 0,03; 50 μM, 2.24 ± 0.01; 100 μM, 1.92 ± 0.05; p < 0.01) expression in comparison with LPS-DMSO cells. Moreover, oleocanthal inhibited canonical and noncanonical inflammasome signaling pathways. Thus, oleocanthal might be a promising natural agent for future treatment of immune-inflammatory diseases.

Caffeine Modulates Cadmium-Induced Oxidative Stress, Neuroinflammation, and Cognitive Impairments by Regulating Nrf-2/HO-1 In Vivo and In Vitro

Cadmium (Cd), a nonbiodegradable heavy metal and one of the most neurotoxic environmental and industrial pollutants, promotes disturbances in major organs and tissues following both acute and chronic exposure. In this study, we assessed the neuroprotective potential of caffeine (30 mg/kg) against Cd (5 mg/kg)-induced oxidative stress-mediated neuroinflammation, neuronal apoptosis, and cognitive deficits in male C57BL/6N mice in vivo and in HT-22 and BV-2 cell lines in vitro. Interestingly, our findings indicate that caffeine markedly reduced reactive oxygen species (ROS) and lipid peroxidation (LPO) levels and enhanced the expression of nuclear factor-2 erythroid-2 (Nrf-2) and hemeoxygenase-1 (HO-1), which act as endogenous antioxidant regulators. Also, 8-dihydro-8-oxoguanine (8-OXO-G) expression was considerably reduced in the caffeine-treated group as compared to the Cd-treated group. Similarly, caffeine ameliorated Cd-mediated glial activation by reducing the expression of glial fibrillary acidic protein (GFAP), ionized calcium-binding adapter molecule 1 (Iba-1), and other inflammatory mediators in the cortical and hippocampal regions of the mouse brain. Moreover, caffeine markedly attenuated Cd-induced neuronal loss, synaptic dysfunction, and learning and cognitive deficits. Of note, nuclear factor-2 erythroid-2 (Nrf-2) gene silencing and nuclear factor-κB (NF-κB) inhibition studies revealed that caffeine exerted neuroprotection via regulation of Nrf-2- and NF-κB-dependent mechanisms in the HT-22 and BV-2 cell lines, respectively. On the whole, these findings reveal that caffeine rescues Cd-induced oxidative stress-mediated neuroinflammation, neurodegeneration, and memory impairment. The present study suggests that caffeine might be a potential antioxidant and neuroprotective agent against Cd-induced neurodegeneration.

Loss of RIP3 initiates annihilation of high-fat diet initialized nonalcoholic hepatosteatosis: A mechanism involving Toll-like receptor 4 and oxidative stress

Non-alcoholic fatty liver disease (NAFLD) is a prevalent and complex disease that confers a high risk of severe liver disorders. Although such public and clinical health importance, very few effective therapies are presently available for NAFLD. Here, we showed that receptor-interacting kinase-3 (RIP3) was up-regulated in liver of mouse with hepatic steatosis induced by high fat diet (HFD). After 16 weeks on a HFD, obesity, insulin resistance, metabolic syndrome, hepatic steatosis, inflammatory response and oxidative stress were significantly alleviated in liver of mice with the loss of RIP3. We provided mechanistic evidence that RIP3 knockdown attenuated hepatic dyslipidemia through preventing the expression of lipogenesis-associated genes. Furthermore, in the absence of RIP3, the transcription factor of nuclear factor-κB (NF-κB) signaling pathway activated by HFD was blocked, accompanied with the inhibition of NLRP3 inflammasome. We also found that RIP3 knockdown-induced activation of nuclear factor-erythroid 2 related factor 2/heme oxygenase-1 (Nrf-2/HO-1) led to the inhibition of oxidative stress. The detrimental effects of RIP3 on hepatic steatosis and related pathologies were confirmed in palmitate (PAL)-treated mouse liver cells. Of note, lipopolysaccharide (LPS)- or PAL-activated TLR-4 resulted in the up-regulation of RIP3 that was accompanied by the elevated inflammation and lipid deposition, and these effects were reversed in TLR-4 knockdown cells. Furthermore, promoting Nrf-2 pathway activation effectively reduced reactive oxygen species (ROS) generation and RIP3 expression in PAL-stimulated cells, consequently leading to the suppression of cellular inflammation and lipid accumulation. In contrast, blocking Nrf-2/HO-1 signaling abrogated RIP3 knockdown-reduced reactive oxygen species (ROS), inflammatory response and lipid deposition in PAL-stimulated cells. Taken together, the present study helped to elucidate how HFD-induced hepatic steatosis was regulated by RIP3, via the TLR-4/NF-κB and Nrf-2/HO-1 signaling pathways.

Unc-51 like autophagy activating kinase 1 accelerates angiotensin II-induced cardiac hypertrophy through promoting oxidative stress regulated by Nrf-2/HO-1 pathway

Unc-51 like autophagy activating kinase 1 (ULK1) is a serine/threonine kinase and the mammalian functional homolog of yeast Atg1, and plays an essential role in regulating various cellular processes. However, whether ULK1 can influence cardiac hypertrophy is unclear. In the study, we investigated the role of ULK1 in the pathogenesis of pathological cardiac hypertrophy and the molecular mechanism. We showed that ULK1 levels were increased in human dilated cardiomyopathic hearts and in mouse hypertrophic hearts. ULK1 knockout conferred resistance to angiotensin II (Ang II) infusion through markedly repressing hypertrophic growth, cardiac function and the deposition of fibrosis. In ULK1 transgenic (TG) mice with ULK1 over-expression, accelerated hypertrophy, reduced cardiac function and promoted fibrosis deposition were observed compared with non-transgenic mice following AngII challenge. In addition, mice lacking ULK1 showed alleviated oxidative stress by improving nuclear erythroid factor 2-related factor 2 (Nrf-2) and heme oxygenase-1 (HO-1) expression, whereas mice with ULK1 over-expression developed an accelerated reactive oxygen species (ROS) production. In vitro, we found that ULK1 knockdown-attenuated oxidative stress, inflammation and fibrosis deposition in AngII-exposed cardiomyocytes were significantly blunted by the inhibition of Nrf-2/HO-1 signaling. However, ULK1 overexpression-accelerated oxidative stress, inflammatory response and fibrosis were markedly ameliorated by the inhibition of ROS production. Our results indicated that ULK1 was a potential therapeutic target in pathological cardiac hypertrophy.

Ligustrazine attenuates inflammation and oxidative stress in a rat model of arthritis via the Sirt1/NF-κB and Nrf-2/HO-1 pathways

Inflammation responses and oxidative stress are closely involved in the pathogenesis of arthritis. Ligustrazine (Lig), a natural four methyl which is isolated from Chinese herb ligusticum chuanxiong hort, has been proved significantly anti-inflammation and anti-oxidative stress effects. The present study aimed to evaluate the effect of Lig on inflammation and oxidative stress in Freund's complete adjuvant (FCA)-induced arthritis in rats. The treatment of Lig significantly decreased the hind-paw volume change and alleviated the histopathological changes in sections of rat paws induced by arthritis. Lig also reduced the serum levels of pro-inflammatory cytokines (interleukin [IL]-6, IL-1 beta, and tumor necrosis factor-alpha), increased the activity of superoxide dismutase (SOD) and reduced the concentration of malondialdehyde (MDA). Besides that, the protein expressions of the sirtuin 1 (Sirt1)/nuclear factor kappa B (NF-κB) and nuclear factor (erythroid-derived 2)-like-2 factor (Nrf-2)/heme oxygenase (HO)-1 pathways determined by western bolt further confirmed that Lig effectively inhibited the Sirt1/NF-κB pathway and activated the Nrf-2/HO-1 pathway. Taken together, our results suggest Lig has therapeutic potential for arthritis, which might be via the regulation of Sirt1/NF-κB and Nrf-2/HO-1 pathways.

Glycyrrhizic acid ameliorates myocardial ischemic injury by the regulation of inflammation and oxidative state

Background

Glycyrrhizic acid (GA), a bioactive triterpenoid saponin isolated from the roots of licorice plants (Glycyrrhiza glabra), has been shown to exert a variety of pharmacological activities and is considered to have potential therapeutic applications. The purpose of the present study was to investigate the cardioprotective effect of GA on myocardial ischemia (MI) injury rats induced by isoproterenol (ISO), and explore the potential mechanisms underlying these effects.

Materials and methods

The rats were randomized into five groups: control, ISO, ISO+diltiazem (10 mg/kg), ISO+GA (10 mg/kg), and ISO+GA (20 mg/kg). Electrocardiogram and histopathological examination were performed. Markers of cardiac marker enzymes (creatine kinase-MB, lactate dehydrogenase), oxidative stress (superoxide dismutase, malondialdehyde [MDA]), and inflammation (TNF-α, IL-1β, and IL-6) were also measured in each group. Proteins involved in NF-κB and Nrf-2/HO-1 pathway were detected by Western blot.

Results

GA decreased the ST elevation induced by MI, decreased serum levels of creatine kinase, lactate dehydrogenase, malondialdehyde, IL-6, IL-1β, and TNF-α, and increased serum superoxide dismutase and malondialdehyde activities. Furthermore, GA increased the protein levels of Nrf-2 and HO-1 and downregulated the phosphorylation of IκB, and NF-κB p65 in ISO-induced MI.

Conclusion

These observations indicated that GA has cardioprotective effects against MI, and these effects might be related to the activation of Nrf-2/HO-1 and inhibition of NF-κB signaling pathway in the myocardium.