Nonsteroidal anti-inflammatory drug induces proinflammatory damage in gastric mucosa through NF-κB activation and neutrophil infiltration: anti-inflammatory role of heme oxygenase-1 against nonsteroidal anti-inflammatory drug

Induction of mitochondrial toxicity by non-steroidal anti-inflammatory drugs (NSAIDs): The ultimate trade-off governing the therapeutic merits and demerits of these wonder drugs

Non-steroidal anti-inflammatory drugs (NSAIDs) are most extensively used over-the-counter FDA-approved analgesic medicines for treating inflammation, musculoskeletal pain, arthritis, pyrexia and menstrual cramps. Moreover, aspirin is widely used against cardiovascular complications. Owing to their non-addictive nature, NSAIDs are also commissioned as safer opioid-sparing alternatives in acute trauma and post-surgical treatments. In fact, therapeutic spectrum of NSAIDs is expanding. These "wonder-drugs" are now repurposed against lung diseases, diabetes, neurodegenerative disorders, fungal infections and most notably cancer, due to their efficacy against chemoresistance, radio-resistance and cancer stem cells. However, prolonged NSAID treatment accompany several adverse effects. Mechanistically, apart from cyclooxygenase inhibition, NSAIDs directly target mitochondria to induce cell death. Interestingly, there are also incidences of dose-dependent effects where NSAIDs are found to improve mitochondrial health thereby suggesting plausible mitohormesis. While mitochondria-targeted effects of NSAIDs are discretely studied, a comprehensive account emphasizing the multiple dimensions in which NSAIDs affect mitochondrial structure-function integrity, leading to cell death, is lacking. This review discusses the current understanding of NSAID-mitochondria interactions in the pathophysiological background. This is essential for assessing the risk-benefit trade-offs of NSAIDs for judiciously strategizing NSAID-based approaches to manage pain and inflammation as well as formulating effective anti-cancer strategies. We also discuss recent developments constituting selective mitochondria-targeted NSAIDs including theranostics, mitocans, chimeric small molecules, prodrugs and nanomedicines that rationally optimize safer application of NSAIDs. Thus, we present a comprehensive understanding of therapeutic merits and demerits of NSAIDs with mitochondria at its cross roads. This would help in NSAID-based disease management research and drug development.

The protective effects of Gamma-linolenic acid against indomethacin-induced gastric ulcer in rats

The primary goal of the investigation was to analyse the anti-inflammatory and antioxidant properties of Gamma-linolenic acid (GLA) on rats with indomethacin (IND)-induced gastric ulcers. Thirty rats were divided into five groups: Control, IND (50 mg/kg, p.o.), IND pretreated with GLA 100 mg/kg (p.o. for 14 d), IND pretreated with GLA 150 mg/kg (p.o. for 14 d) and IND pretreated with omeprazole (20 mg/kg, p.o. for 14 d). The stomach tissues were examined to calculate the ulcer index and pH and analyse biochemical markers (prostaglandin E2 (PGE2), cyclooxygenase 1 (COX1), TNF-1, IL-6 and intercellular adhesion molecule-1 (ICAM1)) and oxidative stress parameters (malondialdehyde: (MDA), superoxide dismutase (SOD), glutathione (GSH) and CAT (catalase)) as well as undergo histopathological assessment. GLA 100 and 150 mg/kg showed a protective effect against IND-induced gastric damage. It reduced levels of COX1, TNF-1, IL-6 and ICAM and increased PGE2 levels. GLA also normalised antioxidant function by modulating MDA, SOD, GSH and CAT. GLA intervention protects against IND-induced gastric ulcers by restoring oxidant/antioxidant balance and reducing inflammation.

Probiotic bacteria protect against indomethacin-induced gastric ulcers through modulation of oxidative stress, inflammation, and apoptosis

BACKGROUND

Indomethacin is an anti-inflammatory drug that causes ulcers on the gastric mucosa due to its use. Probiotic bacteria are live microorganisms, and it has been stated by various studies that these bacteria have antioxidant and anti-inflammatory effects. In this study, we investigated the possible protective effect of various types of probiotic bacteria (Lactobacillus rhamnosus, Lactobacillus fermentum, and Lactobacillus brevis) against acute gastric mucosal damage caused by indomethacin.

METHODS

Control group - Physiological saline was administered daily for 10 days. Indo group-Physiological saline was administered daily for 10 days. Ranitidine + Indo group 5 mg/kg ranitidine dose was administered daily for 5 days. On day 11, a single dose of 100 mg/kg of indomethacin was given to the same group. Probiotic + Indo group 1 ml/kg of oral probiotic bacteria was administered daily for 10 days. On day 11, a single 100 mg/kg dose of indomethacin was given. After the application, the rats were anesthetized with ketamine xylazine, killed under appropriate conditions, the abdominal cavity was opened and the stomach tissues were removed. The obtained gastric tissues were used in the biochemical and histopathological analyses discussed below. All data were statistically evaluated by one-way ANOVA using SPSS 20.00, followed by Duncan Post hoc test. The data were expressed as mean ± SD. P < 0.05 was considered statistically significant.

RESULTS

As a result, the administration of indomethacin caused gastric damage, stimulating oxidative stress, inflammation, and apoptosis. We found that the use of probiotic bacteria reduces oxidative stress (TOC), increases the activity of antioxidant enzymes (TAC), suppresses inflammation (IL-6 and Tnf-α), and inhibits apoptosis (Bax and Bcl-2) (P < 0.05).

CONCLUSION

Probiotic treatment can mitigate gastric damage and apoptosis caused by indomethacin-induced gastric damage in rats. Probiotic also enhances the restoration of biochemical oxidative enzymes as it has anti-inflammatory, antioxidant, and antiapoptotic properties.

Natural sporopollenin microcapsules: biological evaluation and application in regulating hepatic toxicity of diclofenac sodium in vivo

Diclofenac sodium (DIC) is a pain reliever and anti-nociceptive medication. Significant limitations of DIC treatment stem from its adverse effects. This study investigates the feasibility of using natural Lycopodium clavatum sporopollenin (LCS) microcapsules loaded with DIC to mitigate the hepatotoxicity associated with DIC treatment. In addition, LCS microcapsules were tracked in the blood, stomach, small intestine, and feces of rats to demonstrate their morphological integrity and uptake behavior. Four groups (6 per group) of adult male albino rats were administered normal saline (control), empty LCS (30 mg kg-1), plain DIC (10 mg kg-1), and DIC-loaded LCS (40 mg kg-1) orally for seven consecutive days. The first comprehensive histological examination of the rat stomach demonstrated the robustness and bioadhesion ability of LCS under severe conditions. The findings suggested that these versatile microcapsules are unlikely to be digested in the gastrointestinal tract (GIT). The administration of DIC-loaded LCS was found to play a potential protective role in regulating DIC-induced substantially increased serum levels of transaminases, alkaline phosphatase, total bilirubin, and pro-inflammatory cytokines. In addition, DIC-loaded LCS restored the antioxidant enzymes, DNA damage, and liver histological architecture abnormalities caused by DIC. Microencapsulation of DIC into pollen-derived biomaterials could be employed as an efficient platform with enough safety coverage on rat liver, pending further clinical studies.

Honokiol, an inducer of sirtuin-3, protects against non-steroidal anti-inflammatory drug-induced gastric mucosal mitochondrial pathology, apoptosis and inflammatory tissue injury

BACKGROUND AND PURPOSE

Mitochondrial oxidative stress, inflammation and apoptosis primarily underlie gastric mucosal injury caused by the widely used non-steroidal anti-inflammatory drugs (NSAIDs). Alternative gastroprotective strategies are therefore needed. Sirtuin-3 pivotally maintains mitochondrial structural integrity and metabolism while preventing oxidative stress; however, its relevance to gastric injury was never explored. Here, we have investigated whether and how sirtuin-3 stimulation by the phytochemical, honokiol, could rescue NSAID-induced gastric injury.

EXPERIMENTAL APPROACH

Gastric injury in rats induced by indomethacin was used to assess the effects of honokiol. Next-generation sequencing-based transcriptomics followed by functional validation identified the gastroprotective function of sirtuin-3. Flow cytometry, immunoblotting, qRT-PCR and immunohistochemistry were used measure effects on oxidative stress, mitochondrial dynamics, electron transport chain function, and markers of inflammation and apoptosis. Sirtuin-3 deacetylase activity was also estimated and gastric luminal pH was measured.

KEY RESULTS

Indomethacin down-regulated sirtuin-3 to induce oxidative stress, mitochondrial hyperacetylation, 8-oxoguanine DNA glycosylase 1 depletion, mitochondrial DNA damage, respiratory chain defect and mitochondrial fragmentation leading to severe mucosal injury. Indomethacin dose-dependently inhibited sirtuin-3 deacetylase activity. Honokiol prevented mitochondrial oxidative damage and inflammatory tissue injury by attenuating indomethacin-induced depletion of both sirtuin-3 and its transcriptional regulators PGC1α and ERRα. Honokiol also accelerated gastric wound healing but did not alter gastric acid secretion, unlike lansoprazole.

CONCLUSIONS AND IMPLICATIONS

Sirtuin-3 stimulation by honokiol prevented and reversed NSAID-induced gastric injury through maintaining mitochondrial integrity. Honokiol did not affect gastric acid secretion. Sirtuin-3 stimulation by honokiol may be utilized as a mitochondria-based, acid-independent novel gastroprotective strategy against NSAIDs.

Gastroprotective effect methanol extract of Caesalpinia coriaria pods against indomethacin- and ethanol-induced gastric lesions in Wistar rats

ETHNOPHARMACOLOGICAL RELEVANCE

Caesalpinia coriaria (Jacq.) Willd is widely used as a traditional medinal plant in Mexico for protective and healing purposes and the treatment of gastrointestinal diseases.

AIM OF THE STUDY

To investigate the gastroprotective effect of extract of Caesalpinia coriaria pods against ethanol-induced and indomethacin-induced gastric lesion models, its anti-inflammatory and antioxidative activities, and its main compounds through LC-MS analysis.

MATERIALS AND METHODS

Male Wistar rats were orally administered a methanol extract obtained from the pods of C. coriaria at doses of 10, 30, 100, and 300 mg/kg prior to inducing gastric lesions with ethanol or indomethacin. Gastric mucosal lesions were evaluated by macroscopic and histopathological alterations. Determination of prostaglandin E₂ (PGE₂), alpha tumor necrosis factor (TNF-α), leukotriene B₄ (LTB₄), nitrites/nitrates, superoxide dismutase (SOD), and H₂S gastric levels were investigated. Its main compounds of the active extract through LC-MS analysis.

RESULTS

Phenolic compounds were identified as major components of methanol extract. LC-MS analysis identified 15 constituents, and the significant compounds were gallic acid, 3-O-galloylquinic acid, digalloylglucose, tetragalloylglucose, valoneic acid dilactone, pentagalloylglucose, digalloylshikimic acid, and ellagic acid. Pretreatment with the extract at doses of 100 and 300 mg/kg significantly reduced gastric ulcer lesions in both models. Compared with the reference drugs (omeprazole or ranitidine, respectively), no significant difference was found (p < 0.05). The extract's gastroprotective effect was accompanied by significant decreases in leukocyte recruitment, and gastric levels of TNF-α and LTB₄ by two to fourfold (p < 0.05). Also, gastric levels of PGE₂ gastric levels were maintained and the antioxidant enzyme activities of SOD and nitrate/nitrite in the gastric tissue were improved (p < 0.05). The LC-MS analysis indicated the presence of hydrolyzable tannins (mainly gallic acid derivatives).

CONCLUSION

The results suggest that the gastroprotective effect of the methanol extract of C. coriaria pods occurs through anti-inflammatory, antioxidant, and NO modulation properties, and gallic acid derivatives may be the main possible compounds responsible for its actions.

Non-steroidal anti-inflammatory drugs (NSAIDs): A current insight into its molecular mechanism eliciting organ toxicities

Non-steroidal anti-inflammatory drugs (NSAIDs) are a class of medications that are routinely been used across the world. Their analgesic, anti-inflammatory, and antipyretic effects have all been well-documented. Moreover, they are been deliberated to have a protective role against various critical diseases such as cancer and cardiovascular diseases. However, the data presented by numerous studies in past have signified the adverse effects of NSAIDs due to overdosing on various systems such as cardiovascular, gastrointestinal, hepatic, renal, neural, etc. Despite substantial studies representing the mechanism behind the clinical risk of NSAIDs, there are very few reviews that have collated comprehensive records of various toxicities caused by overdosing on NSAIDs. As a result, we have presented a comprehensive overview of existing information on NSAIDs in this review. In addition to that, we have concentrated on presenting our understanding of various organ-based toxicities caused due to NSAID's prolonged use/overdosage.

Osthole Alleviates D-Galactose-Induced Liver Injury In Vivo via the TLR4/MAPK/NF-κB Pathways

Osthole, a coumarin derivative, is found in several medicinal herbs. However, the protective effects of osthole against D-galactose (D-Gal)-induced liver injury still remain unclear. In this study, osthole treatment effectively reversed D-Gal-induced liver injury, according to the results of liver HE staining, and improved ALT and AST activities. Feeding with D-Gal significantly increased MDA content, and reduced the level or activity of SOD, CAT and GSH-Px, which were all alleviated by osthole intervention. Meanwhile, osthole treatment significantly inhibited the D-Gal-induced secretion of pro-inflammatory cytokines, such as TNF-α, IL-1β and IL-6, in both serum and liver tissue. Investigations revealed that osthole ameliorated the D-Gal-induced activation of TLR4, MYD88 and its downstream signaling pathways of MAPK (p38 and JNK) and NF-κB (nucleus p65). Therefore, osthole mediates a protective effect against D-Gal-induced liver injury via the TLR4/MAPK/NF-κB pathways, and this coumarin derivative could be developed as a candidate bioactive component for functional food.

Mitigative effect of caffeine against diclofenac-induced hepato-renal damage and chromosomal aberrations in male albino rats

BACKGROUND

Among the most commonly consumed non-steroidal anti-inflammatory drugs (NSAID) is Diclofenac (Dic), especially in low-income countries due to its high efficiency and affordable price. However, the continuous administration of Diclofenac may induce toxic effects on various body organs including the liver and kidney. Caffeine (Caf) (1,3,7-trimethylxanthine) is a pharmacologically active alkaloid type with antioxidant and anti-inflammatory actions.

AIM

The current study aims to evaluate the ameliorative effect of Caffeine against Dic-induced hepato-renal toxicity and damage.

METHODS

Twenty-four male albino rats type were assigned randomly into four groups (n = 6): (Group 1): Control group, (Group 2): Six male rats were exposed to Dic 10 mg/kg intraperitoneally (I.P) for 28 days, (Group 3): Six male rats were exposed to Caf (15 mg/kg orally) for 28 days; (Groups 4): Six male rats were exposed to Dic (10 mg/kg, i.p) + Caf (15 mg/kg, orally) for 28 days. Histopathological study and various biological parameters were estimated among the four groups including hemoglobin (Hb%) red blood cells (RBCs), Hematocrit (HT%), total leucocyte count (WBCs), lipid peroxidation (LPO), glutathione peroxidase (GPx), alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea, creatinine, tumor necrosis factor-α (TNF-α), and nitric oxide (NO).

RESULTS

The administration of Diclofenac resulted in significant deteriorations in the histopathological findings and estimated biological parameters. Whereas, daily Caffeine administration ameliorated Diclofenac-induced toxicity in the kidney and liver by three mechanisms including antioxidant, anti-inflammatory, and DNA damage inhibition.

CONCLUSION

The current study demonstrated the promising ameliorative and protective effects of Caffeine against Diclofenac-induced hepatic and renal injury.

Emerging role of mitochondrial DAMPs, aberrant mitochondrial dynamics and anomalous mitophagy in gut mucosal pathogenesis

Gastroduodenal inflammation and ulcerative injuries are increasing due to expanding socio-economic stress, unhealthy food habits-lifestyle, smoking, alcoholism and usage of medicines like non-steroidal anti-inflammatory drugs. In fact, gastrointestinal (GI) complications, associated with the prevailing COVID-19 pandemic, further, poses a challenge to global healthcare towards safeguarding the GI tract. Emerging evidences have discretely identified mitochondrial dysfunctions as common etiological denominators in diseases. However, it is worth realizing that mitochondrial dysfunctions are not just consequences of diseases. Rather, damaged mitochondria severely aggravate the pathogenesis thereby qualifying as perpetrable factors worth of prophylactic and therapeutic targeting. Oxidative and nitrosative stress due to endogenous and exogenous stimuli triggers mitochondrial injury causing production of mitochondrial damage associated molecular patterns (mtDAMPs), which, in a feed-forward loop, inflicts inflammatory tissue damage. Mitochondrial structural dynamics and mitophagy are crucial quality control parameters determining the extent of mitopathology and disease outcomes. Interestingly, apart from endogenous factors, mitochondria also crosstalk and in turn get detrimentally affected by gut pathobionts colonized during luminal dysbiosis. Although mitopathology is documented in various pre-clinical/clinical studies, a comprehensive account appreciating the mitochondrial basis of GI mucosal pathologies is largely lacking. Here we critically discuss the molecular events impinging on mitochondria along with the interplay of mitochondria-derived factors in fueling mucosal pathogenesis. We specifically emphasize on the potential role of aberrant mitochondrial dynamics, anomalous mitophagy, mitochondrial lipoxidation and ferroptosis as emerging regulators of GI mucosal pathogenesis. We finally discuss about the prospect of mitochondrial targeting for next-generation drug discovery against GI disorders.

Effect of Ylang-Ylang (Cananga odorata Hook. F. & Thomson) Essential Oil on Acute Inflammatory Response In Vitro and In Vivo

The aim of this study is to evaluate the phytochemical profile, oral acute toxicity, and the effect of ylang-ylang (Cananga odorata Hook. F. & Thomson) essential oil (YEO) on acute inflammation. YEO was analyzed by gas chromatography/mass spectrometry. For in vitro tests, YEO was assessed using cytotoxicity, neutrophil chemotaxis induced by N-formyl methionyl leucyl phenylalanine (fMLP), and phagocytic activity tests. YEO was orally administered in zymosan-induced peritonitis, carrageenan-induced leukocyte rolling, and adhesion events in the in situ microcirculation model and in carrageenan-induced paw edema models. YEO (2000 mg/kg) was also tested using an acute toxicity test in Swiss mice. YEO showed a predominance of benzyl acetate, linalool, benzyl benzoate, and methyl benzoate. YEO did not present in vitro cytotoxicity. YEO reduced the in vitro neutrophil chemotaxis induced by fMLP and reduced the phagocytic activity. The oral treatment with YEO reduced the leukocyte recruitment and nitric oxide production in the zymosan-induced peritonitis model, reduced rolling and adherent leukocyte number induced by carrageenan in the in situ microcirculation model, and reduced carrageenan-induced edema and mechanical hyperalgesia. YEO did not present signs of toxicity in the acute toxicity test. In conclusion, YEO affected the leukocyte activation, and presented antiedematogenic, anti-hyperalgesic, and anti-inflammatory properties.

Indomethacin: an exploratory study of antiviral mechanism and host-pathogen interaction in COVID-19

Introduction

COVID-19, a dreadful pandemic that has impacted human life like no other pathogenic invasion, has claimed the lives of over 100 million people. The need for effective treatment strategies is still a subject of intense research considering the rapidly evolving genome and continental diversity. Indomethacin is administered mostly as co-treatment for affected patients as a non-steroidal anti-inflammatory drug (NSAID). However, the underlying mechanism of action is unresolved. This study explores the basal mechanism of indomethacin and potency in alleviating the damage caused by SARS-CoV-2 and discusses the experimental and clinical efficacy in recent studies.

Areas covered

The literature search and system biology-based network formation were employed to describe the potent effects and risks associated with indomethacin in in-vitro, in-vivo, and clinical studies. This study also highlights the plausible mechanism of antiviral action of indomethacin with its apparent viral protein targets. The SARS-CoV-2 protein, the interacting host proteins, and the effect of indomethacin on this interactome as a standalone treatment or as part of a co-therapy strategy are particularly emphasized using network modeling.

Expert opinion

Indomethacin has demonstrated excellent clinical endpoint characteristics in several studies, and we recommend that it be utilized in the treatment of mild-to-moderate COVID patients.

NF-κB in Gastric Cancer Development and Therapy

Gastric cancer is considered one of the most common causes of cancer-related death worldwide and, thus, a major health problem. A variety of environmental factors including physical and chemical noxae, as well as pathogen infections could contribute to the development of gastric cancer. The transcription factor nuclear factor kappa B (NF-κB) and its dysregulation has a major impact on gastric carcinogenesis due to the regulation of cytokines/chemokines, growth factors, anti-apoptotic factors, cell cycle regulators, and metalloproteinases. Changes in NF-κB signaling are directed by genetic alterations in the transcription factors themselves, but also in NF-κB signaling molecules. NF-κB actively participates in the crosstalk of the cells in the tumor micromilieu with divergent effects on the heterogeneous tumor cell and immune cell populations. Thus, the benefits/consequences of therapeutic targeting of NF-κB have to be carefully evaluated. In this review, we address recent knowledge about the mechanisms and consequences of NF-κB dysregulation in gastric cancer development and therapy.

Protective effect of luteolin on indomethacin-induced gastric ulcer in rats

BACKGROUND

Long-term use of nonsteroidal anti-inflammatory drugs can lead to gastric ulcer. However, there are many side effects associated with the commonly used therapeutic agents for gastric ulcer.

AIM

To investigate the protective effect of luteolin (Lut) on indomethacin (IND)-induced gastric ulcer in rats and the underlying mechanisms.

METHODS

Forty male Wistar rats were randomly divided into a control group, a model group, and low-, medium-, and high-dose Lut groups, with eight rats in each group. A rat gastric ulcer model was established by intragastric administration of IND (40 mg/kg) for 14 d. The low-, medium-, and high-dose Lut groups were given 1 mg/kg, 10 mg/kg, and 100 mg/kg Lut by gavage for 14 d. The control group was given the same volume of carboxymethylcellulose. The macroscopic morphology of the gastric mucosa was observed visually. The pathological changes of the gastric mucosa were examined by HE staining. Apoptosis in the gastric mucosa was detected with the ApopTag Peroxidase In Situ Apoptosis Detection Kit. The levels of superoxide dismutase (SOD), reduced glutathione (GSH), and malondialdehyde (MDA) in the gastric mucosa were determined with commercial kits.

RESULTS

Lut administration could reduce IND-induced gastric ulcer in a dose-dependent manner, improve the pathological morphology of gastric mucosal tissues, reduce the apoptosis of gastric mucosal epithelial cells, increase the levels of SOD and GSH in gastric mucosal tissues, and decrease the level of MDA.

CONCLUSION

Lut can alleviate IND-induced gastric ulcer in rats, and the mechanism may be related to the inhibition of gastric epithelial cell apoptosis and antioxidant stress.

Protective and therapeutic effects of the flavonoid "pinocembrin" in indomethacin-induced acute gastric ulcer in rats: impact of anti-oxidant, anti-inflammatory, and anti-apoptotic mechanisms

Peptic ulcer including gastric and duodenal ulcers is a common gastro-intestinal disorder worldwide, associated with a significant mortality due to bleeding and perforation. Numerous efforts are being exerted to look for natural drugs that lack the potential side effects but still keep beneficial effects for treatment and/or prevention of gastric ulcer. Pinocembrin (PINO) is a natural flavonoid retaining anti-microbial, anti-oxidant, and anti-inflammatory activities. The present study was conducted to investigate the protective and therapeutic effects of PINO against indomethacin (INDO)-induced gastric ulcer in rats and the possible underlying mechanisms. PINO (25 and 50 mg/kg) promoted mucus secretion, decreased ulcer index, and inhibited histopathological changes induced by INDO. Further investigation of possible mechanisms showed that PINO significantly attenuated INDO-induced oxidative and inflammatory responses in both doses when administrated before or after ulcer induction. PINO downregulated mRNA expression level of p38-mitogen-activated protein kinase (p38-MAPK) which subsequently inhibited NF-κB activation and inflammatory cytokine release including tumor necrosis factor-α (TNF-α) and interleukin-1beta (IL-1β). Additionally, PINO inhibited apoptotic activity which was confirmed by downregulation of caspase-3 transcription. The current results demonstrated the promising therapeutic activity of PINO against INDO-induced gastric ulcer due to-at least partly-its anti-oxidant, anti-inflammatory, and anti-apoptotic effects.

Therapeutic effect of various ginsenosides on rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is an autoimmune disease which causes disability and threatens the health of humans. Therefore, it is of great significance to seek novel effective drugs for RA. It has been reported that various ginsenoside monomers are able to treat RA. However, it is still unclear which ginsenoside is the most effective and has the potential to be developed into an anti-RA drug.

Methods

The ginsenosides, including Rg1, Rg3, Rg5, Rb1, Rh2 and CK, were evaluated and compared for their therapeutic effect on RA. In in vitro cell studies, methotrexate (MTX) and 0.05% dimethyl sulfoxide (DMSO) was set as a positive control group and a negative control group, respectively. LPS-induced RAW264.7 cells and TNF-α-induced HUVEC cells were cultured with MTX, DMSO and six ginsenosides, respectively. Cell proliferation was analyzed by MTT assay and cell apoptosis was carried out by flow cytometry. CIA mice model was developed to evaluate the therapeutic efficacy of ginsenosides. The analysis of histology, immunohistochemistry, flow cytometry and cytokine detections of the joint tissues were performed to elucidate the action mechanisms of ginsenosides.

Results

All six ginsenosides showed good therapeutic effect on acute arthritis compared with the negative control group, Ginsenoside CK provided the most effective treatment ability. It could significantly inhibit the proliferation and promote the apoptosis of RAW 264.7 and HUVEC cells, and substantially reduce the swelling, redness, functional impairment of joints and the pathological changes of CIA mice. Meanwhile, CK could increase CD8 + T cell to down-regulate the immune response, decrease the number of activated CD4 + T cell and proinflammatory M1-macrophages, thus resulting in the inhibition of the secretion of proinflammatory cytokine such as TNF-α and IL-6.

Conclusion

Ginsenoside CK was proved to be a most potential candidate among the tested ginsenosides for the treatment of RA, with a strong anti-inflammation and immune modulating capabilities.

The effects and mechanism of Kangfuxin on improving healing quality and preventing recurrence of gastric ulcer

This study investigated the gastroprotective effects and possible mechanism of Kangfuxin (KFX), an ethanol extract of Periplaneta americana L. (Dictyoptera; Blattidae), on improving healing quality and preventing recurrence of gastric ulcer. The effects of KFX were investigated in patients treated with endoscopic submucosal dissection (ESD), gastric ulcer animal model, and rat gastric mucosal cells and fibroblasts. Moreover, the relationship between KFX and p38/NF-κB pathway were explored both in vivo and in vitro. In patients, KFX exhibited protective effects against gastric ulcers and resulted in a decrease in the CD3 expression. In vivo animal experiments confirmed that KFX accelerated ulcer healing by promoting neovascularization (increased CD34 expression), suppressing inflammation (decreased interleukin-1β (IL-1β), myeloperoxidase (MPO), tumor necrosis factor α (TNF-α), intercellular adhesion molecule-1 (ICAM-1), and IL-8 expression), and enhancing growth factor expression, including the epidermal growth factor receptor (EGFR) and hepatocyte growth factor (HGF). In vitro experiments demonstrated that treatment with 10% KFX rat serum decreased IL-1β, IL-1Ra, SIL-1RAP, TNF-α, and ICAM-1 expression in rat gastric mucosal cells or fibroblasts and increased IL-1R expression compared to that in the group treatment with 10% normal rat serum. Furthermore, KFX inhibited the activation of p38/NF-κB pathway both in vivo and in vitro. In conclusion, KFX treatment could effectively improve healing quality and prevent gastric ulcer recurrence, which might be attributed to neovascularization, suppressed inflammation, and enhanced growth factor expression. The p38/NF-κB pathway may be one of important mechanism to mediate the effects of KFX.

Quercetin Oxidation Metabolite Present in Onion Peel Protects Caco-2 Cells against the Oxidative Stress, NF-kB Activation, and Loss of Epithelial Barrier Function Induced by NSAIDs

The potential of 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone (BZF), a quercetin oxidation metabolite, and that of a BZF-rich onion peel aqueous extract (OAE) to protect Caco-2 monolayers against the oxidative stress (OS) and an increased permeability (IP) induced by five nonsteroidal anti-inflammatory drugs (NSAIDs) (indomethacin, diclofenac, piroxicam, ibuprofen, and metamizole) were investigated. Under identical OS conditions, the NSAIDs substantially differed in their ability to induce an IP and/or NF-kB activation. The OAE (100 nM BZF) protected in identical magnitude (84-86%) against OS but in a highly dissimilar manner against the IP (18-73%). While all NSAIDs activated NF-kB, the OAE prevented only that induced by indomethacin. Results reveal that the IP has no direct relationship with the OS and that with the exception of indomethacin, the prevention of NSAIDs-induced OS and/or NF-kB activation plays no fundamental role in the IP-protecting effect of OAE. These results warrant the in vivo evaluation of OAE against indomethacin-induced loss of intestinal barrier function.

Cinnamon Aqueous Extract Attenuates Diclofenac Sodium and Oxytetracycline Mediated Hepato-Renal Toxicity and Modulates Oxidative Stress, Cell Apoptosis, and Inflammation in Male Albino Rats

Among commonly consumed anti-inflammatory and antimicrobial drugs are diclofenac sodium (DFS) and oxytetracycline (OTC), especially in developing countries because they are highly effective and cheap. However, the concomitant administration of anti-inflammatory drugs with antibiotics may exaggerate massive toxic effects on many organs. Cinnamon (Cinnamomum zeylanicum, Cin) is considered one of the most broadly utilized plants with various antioxidant and anti-inflammatory actions. This study aimed to evaluate the possible protective effects of cinnamon aqueous extract (Cin) against DFS and OTC hepato-renal toxicity. Eight groups (8/group) of adult male albino rats were treated orally for 15 days with physiological saline (control), Cin aqueous extract (300 mg/kg b.w.), OTC (200 mg/kg b.w.), single dose of DFS at the 14th day (100 mg/kg b.w.), DFS + OTC, Cin + DFS, Cin + OTC, and Cin + DFS + OTC. The administration of DFS and/or OTC significantly increased (p < 0.05) the serum levels of alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, urea, creatinine, and uric acid. Serum levels of pro-inflammatory cytokines, as well as hepatic and renal malondialdehyde and nitric oxide metabolites, were also raised following DFS and OTC administration. Meanwhile, the activities of reduced glutathione, superoxide dismutase, and catalase in liver and kidney were significantly suppressed in DFS, OTC, and DFS + OTC treated rats. Moreover, hepatic and renal tissue sections from these rats exhibited overexpression of caspase-3 and cyclooxygenase-II on immunohistochemical investigation. The administration of Cin aqueous extract ameliorated the aforementioned deteriorations caused by DFS, OTC, and their combination. Conclusively, Cin is a promising protective plant extract capable of attenuating the oxidative damage, apoptosis, and inflammation induced by DFS and OTC either alone or combined, on hepatic and renal tissues.

Mediators of mitophagy that regulate mitochondrial quality control play crucial role in diverse pathophysiology

Mitochondria are double membrane-bound cellular work-horses constantly functioning to regulate vital aspects of cellular metabolism, bioenergetics, proliferation and death. Biogenesis, homeostasis and regulated turnover of mitochondria are stringently regulated to meet the bioenergetic requirements. Diverse external and internal stimuli including oxidative stress, diseases, xenobiotics and even age profoundly affect mitochondrial integrity. Damaged mitochondria need immediate segregation and selective culling to maintain physiological homeostasis. Mitophagy is a specialised form of macroautophagy that constantly checks mitochondrial quality followed by elimination of rogue mitochondria by lysosomal targeting through multiple pathways tightly regulated and activated in context-specific manners. Mitophagy is implicated in diverse oxidative stress-associated metabolic, proliferating and degenerative disorders owing to the centrality of mitopathology in diseases as well as the common mandate to eliminate damaged mitochondria for restoring physiological homeostasis. With improved health care and growing demand for precision medicine, specifically targeting the keystone factors in pathogenesis, more exploratory studies are focused on mitochondrial quality control as underlying guardian of cellular pathophysiology. In this context, mitophagy emerged as a promising area to focus biomedical research for identifying novel therapeutic targets against diseases linked with physiological redox perturbation. The present review provides a comprehensive account of the recent developments on mitophagy along with precise discussion on its impact on major diseases and possibilities of therapeutic modulation.

Non-steroidal anti-inflammatory drugs (NSAIDs) and organ damage: A current perspective

Owing to the efficacy in reducing pain and inflammation, non-steroidal anti-inflammatory drugs (NSAIDs) are amongst the most popularly used medicines confirming their position in the WHO's Model List of Essential Medicines. With escalating musculoskeletal complications, as evident from 2016 Global Burden of Disease data, NSAID usage is evidently unavoidable. Apart from analgesic, anti-inflammatory and antipyretic efficacies, NSAIDs are further documented to offer protection against diverse critical disorders including cancer and heart attacks. However, data from multiple placebo-controlled trials and meta-analyses studies alarmingly signify the adverse effects of NSAIDs in gastrointestinal, cardiovascular, hepatic, renal, cerebral and pulmonary complications. Although extensive research has elucidated the mechanisms underlying the clinical hazards of NSAIDs, no review has extensively collated the outcomes on various multiorgan toxicities of these drugs together. In this regard, the present review provides a comprehensive insight of the existing knowledge and recent developments on NSAID-induced organ damage. It precisely encompasses the current understanding of structure, classification and mode of action of NSAIDs while reiterating on the emerging instances of NSAID drug repurposing along with pharmacophore modification aimed at safer usage of NSAIDs where toxic effects are tamed without compromising the clinical benefits. The review does not intend to vilify these 'wonder drugs'; rather provides a careful understanding of their side-effects which would be beneficial in evaluating the risk-benefit threshold while rationally using NSAIDs at safer dose and duration.

Tetramethylpyrazine ameliorates indomethacin-induced gastric ulcer in rats: Impact on oxidative, inflammatory, and angiogenic machineries

Available antiulcer medications reveal partial efficacy and numerous adverse reactions. Tetramethylpyrazine (TMP) was known for its potential antioxidant, anti-inflammatory and angiogenic properties. The aim of current study was to investigate the potential gastroprotective effect of TMP against indomethacin-induced gastric ulcer in rats with possible underlying mechanisms. TMP was tested at 3 doses (15, 30 & 60 mg/kg/d po) three days before indomethacin challenge (25 mg/kg ip). Gastric tissue was evaluated morphologically and histopathologically. Oxidative statuses were assessed via glutathione content (GSH), malondialdhyde (MDA) and catalase (CAT) activity, while TNFα and IL-6 were measured as inflammatory mediators. Gastric PGE2 was investigated in addition to vascular endothelial growth factor (VEGF). TMP was effective (at 30 and 60 mg/kg/d) in promoting mucus secretion and preventing histopathologic changes induced by indomethacin. Mechanistically, TMP significantly enhanced GSH content and CAT activity while reducing lipid peroxidation as expressed by MDA concentration. Moreover, TMP effectively reduced TNFα, IL-6 and intracellular adhesion molecule (ICAM-1) concentrations. On the other hand, TMP enhanced both COX-1 and PGE2 and encouraged angiogenesis via increasing VEGF expression. In conclusion, TMP possesses a protective effect against indomethacin-induced gastric ulcer. This could be explained - at least partly - by its antioxidant, anti-inflammatory and angiogenic effects.

Malabaricone C Attenuates Nonsteroidal Anti-Inflammatory Drug-Induced Gastric Ulceration by Decreasing Oxidative/Nitrative Stress and Inflammation and Promoting Angiogenic Autohealing

Aims: Nonsteroidal anti-inflammatory drugs (NSAIDs), among the most commonly used drugs worldwide, are associated with gastrointestinal (GI) complications that severely limit the clinical utility of this essential class of pain medications. Here, we mechanistically dissect the protective impact of a natural product, malabaricone C (Mal C), on NSAID-induced gastropathy. Results: Mal C dose dependently diminished erosion of the stomach lining and inflammation in mice treated with NSAIDs with the protective impact translating to improvement in survival. By decreasing oxidative and nitrative stress, Mal C treatment prevented NSAID-induced mitochondrial dysfunction and cell death; nuclear factor κ-light-chain enhancer of activated B cell induction, release of proinflammatory cytokines and neutrophil infiltration; and disruptions in the vascular endothelial growth factor/endostatin balance that contributes to mucosal autohealing. Importantly, Mal C failed to impact the therapeutic anti-inflammatory properties of multiple NSAIDs in a model of acute inflammation. In all assays tested, Mal C proved as or more efficacious than the current first-line therapy for NSAID-dependent GI complications, the proton pump inhibitor omeprazole. Innovation: Given that omeprazole-mediated prophylaxis is, itself, associated with a shift in NSAID-driven GI complications from the upper GI to the lower GI system, there is a clear and present need for novel therapeutics aimed at ameliorating NSAID-induced gastropathy. Mal C provided significant protection against NSAID-induced gastric ulcerations impacting multiple critical signaling cascades contributing to inflammation, cell loss, extracellular matrix degradation, and angiogenic autohealing. Conclusion: Thus, Mal C represents a viable lead compound for the development of novel gastroprotective agents.

Transcriptomic profiling of Hydra magnipapillata after exposure to naproxen

The extensive use in humans and animals of nonsteroidal anti-inflammatory drugs (NSAIDs) increases their possible impact on aquatic organisms. In the present study, we investigated acute toxicity, morphological responses, and potential physiological and metabolic impacts of naproxen exposure on Hydra magnipapillata. The median lethal concentrations (LC₅₀) of naproxen in H. magnipapillata were 51.999 mg/L, 44.935 mg/L, and 42.500 mg/L after exposure for 24, 48, and 72 h, respectively. Morphological observation of the exposed Hydra showed that 40 mg/L naproxen stimulated the contraction of body column and tentacles after 24 h. A KEGG pathway analysis of the genes differentially expressed in the Hydra after exposure to naproxen for 6, 24, or 48 h demonstrated various cellular and metabolic effects, including protein processing in the endoplasmic reticulum, Wnt signaling, and tryptophan metabolism. These results suggest that exposure to naproxen affects the genetic material, inflammatory processes, and metabolic processes of aquatic organisms.

Heme Oxygenase-1 Polymorphism Is Associated With the Development of Necrotic Acute Pancreatitis Via Vascular Cell Adhesion Molecule-1 and the E-Selectin Expression Regulation Pathway

OBJECTIVES

Severe acute pancreatitis can lead to systemic complications. Here, we explore the mechanisms based on our previous study associated with the deregulation of heme oxygenase-1 (HO-1) and development of severe acute pancreatitis.

METHODS

Acute pancreatitis patients (n = 135) and age- and sex-matched healthy controls (n = 108) were studied. The polymerase chain reaction products were analyzed with an ABI 3130 genetic analyzer and GeneMapper software. A short allele was defined ≤27 dinucleotide (GT) repeats, whereas a long allele was defined >27 GT. Levels of 12 different cytokines in blood serum were measured by enzyme-linked immunosorbent assay. All samples in this study were consistently stored in -80°C.

RESULTS

Patients with the long long genotype expressed E-selectin and vascular cell adhesion molecule-1 at statistically significantly higher levels in serum compared with short short genotype or short long genotypes. Vascular cell adhesion molecule-1 and E-selectin serum levels significantly correlate with the total allele length of the HO-1 promoter region.

CONCLUSION

Polymorphism of the GT repeats in the HO-1 promoter region may be a risk factor for developing acute necrotizing pancreatitis due to deregulation of the immune response.

Rosmarinic Acid Enriched Fraction from Perilla frutescens Leaves Strongly Protects Indomethacin-Induced Gastric Ulcer in Rats

Gastric ulcers are a common problem in upper gastrointestinal tract (GI) disorders. Nonsteroidal anti-inflammatory drugs (NSAIDs) are one of the most aggressive factors leading to inducing gastric ulcers. Natural products with lower toxicity and safety are currently sought as a potential source to minimize the effect of the gastric ulcers. Perilla frutescens or Nga-mon (in Thai) leaves are rich in rosmarinic acid (RA), which has antioxidant, anti-inflammatory, and anticancer effects. This study investigates the protective effect of ethanolic extract (EE) and aqueous fraction (AF) from Perilla frutescens leaves, which are rich in RA, on indomethacin- (IND-) induced gastric ulcer in a rat model. The EE at the doses of 50 and 500 mg/kg body weight, AF at the doses of 50, 250, and 500 mg/kg body weight, or famotidine (a standard drug) were administered for 14 days prior to ulcer induction. The ulceration was performed by intragastric administration of IND. Gross gastric ulcers and biological and histological parameters were examined. The pretreatment with AF had more significant effects than EE, including reduced ulcer index, decreased gastric secretion volume and decreased acidity, but it had an elevated gastric pH relative to the IND-induced gastric ulcer. In a histopathological study, the EE and AF decreased mucosal ulcer, inflammatory infiltration, and degenerative lining cells. The IND-induced expression of inflammatory mediators was significantly attenuated with EE and AF. The experiment also remarkably showed the preservation of mucus and apoptosis protection of EE and AF on a gastric mucosal ulcer. The findings demonstrated that the EE and AF of perilla leaves were capable of protecting the stomach against gastric ulcers induced by IND through anti-inflammatory and antiapoptotic mechanisms that should be further investigated. It is suggested that Perilla frutescens leaf could be a potential alternative source of RA as a therapeutic agent and food supplement for NSAID-induced gastric injuries.

Polyphenols extracted from huangjiu have anti-inflammatory activity in lipopolysaccharide stimulated RAW264.7 cells

In the present study, an extraction method, combining extraction by ethyl acetate + ethanol and purification by HPD400 resin, was established to obtain huangjiu polyphenol extract (HPE). After extraction and purification, the polyphenol yield was 22.57%, and 90.57% protein and 97.99% sugar were removed. HPLC analysis indicated that (+)-catechin (91.33 μg mL-1) was the predominant phenolic compound among the 11 detected polyphenols. In LPS-stimulated RAW264.7 cells, HPE exhibits anti-inflammatory effects by inhibiting the production of NO and pro-inflammatory cytokines (TNF-α, interleukin IL-6 and IL-1β). The anti-inflammatory effect of HPE is associated with the inhibition of iNOS expression, the suppression of NF-κB translocation to the nucleus, and the inhibition of the phosphorylation of IκB and the MAPK family proteins, e.g. p-38, Erk 1/2, and JNK. Moreover, the activation of Nrf2 and HO-1 is also related to the anti-inflammatory effect of HPE.

Gastroprotective effects of oleuropein and thymol on indomethacin-induced gastric ulcer in Sprague-Dawley rats

Ethnopharmacological studies demonstrated that thymol (Thym) and oleuropein (Ole) have therapeutic potential for gastric ulcers. The molecular mechanism underlying the gastroprotective effects of these compounds have not been elucidated yet especially for their individual and combination use at high dose. Therefore, this study was conducted to explore their gastroprotective mechanisms on indomethacin (Indo)-induced gastric ulcer model. Ole (50,100, 250, and 500 mg/kg) and Thym (50,100, 200, and 500 mg/kg) were orally administered to the rats 10 min before the induction of ulcer with Indo. The combination of 500 mg/kg doses of Ole and Thym were applied. The gastric mucosa was evaluated histopathologically. Moreover, TAC/TOS, tumor necrosis factor-alpha (TNF-α), prostaglandin E₂ (PGE₂), endothelial nitric oxide synthase (eNOS), and caspase-3 levels were assessed by ELISA and the caspase-3 and TNF-α expressions were quantified by qRT-PCR. Indo-induced histopathological changes while Ole and Thym pretreatment prevented these effects. Unlike the 500 mg/kg dose of Ole treatment, the 500 mg/kg dose of Thym administration enhanced these damages. The decreased TAC, PGE₂ levels and increased TOS, eNOS, TNF-α, caspase-3 levels were obtained in Indo group. However, these changes were reversed by Ole and Thym groups except the 500 mg/kg dose of Thym and the combination treatment groups. Similar trends were observed in the caspase-3 and TNF-α expression levels. These results demonstrated that enhanced inflammation, oxidant/antioxidant imbalance, and apoptotic activities were occurred in Indo, 500 mg/kg dose of Thym and the combination treatment groups while not in the other groups. The findings demonstrated the gastroprotective ability of Ole and low doses of Thym in gastric ulcer models.

Acute mental stress induces mitochondrial bioenergetic crisis and hyper-fission along with aberrant mitophagy in the gut mucosa in rodent model of stress-related mucosal disease

Psychological stress, depression and anxiety lead to multiple organ dysfunctions wherein stress-related mucosal disease (SRMD) is common to people experiencing stress and also occur as a side effect in patients admitted to intensive care units; however the underlying molecular aetiology is still obscure. We report that in rat-SRMD model, cold restraint-stress severely damaged gut mitochondrial functions to generate superoxide anion (O₂^•-), depleted ATP and shifted mitochondrial fission-fusion dynamics towards enhanced fission to induce mucosal injury. Activation of mitophagy to clear damaged and fragmented mitochondria was evident from mitochondrial translocation of Parkin and PINK1 along with enhanced mitochondrial proteome ubiquitination, depletion of mitochondrial DNA copy number and TOM 20. However, excess and sustained accumulation of O₂^•--generating defective mitochondria overpowered the mitophagic machinery, ultimately triggering Bax-dependent apoptosis and NF-κB-intervened pro-inflammatory mucosal injury. We further observed that stress-induced enhanced serum corticosterone stimulated mitochondrial recruitment of glucocorticoid receptor (GR), which contributed to gut mitochondrial dysfunctions as documented from reduced ETC complex 1 activity, mitochondrial O₂^•- accumulation, depolarization and hyper-fission. GR-antagonism by RU486 or specific scavenging of mitochondrial O₂^•- by a mitochondrially targeted antioxidant mitoTEMPO ameliorated stress-induced mucosal damage. Gut mitopathology and mucosal injury were also averted when the perception of mental stress was blocked by pre-treatment with a sedative or antipsychotic. Altogether, we suggest the role of mitochondrial GR-O₂^•--fission cohort in brain-mitochondria cross-talk during acute mental stress and advocate the utilization of this pathway as a potential target to prevent mitochondrial unrest and gastropathy bypassing central nervous system.

Unfolding the mechanism of cisplatin induced pathophysiology in spleen and its amelioration by carnosine

cis-Diamminedichloroplatinum (cisplatin) is an effective chemotherapeutic and is widely used for the treatment of various types of solid tumors. Bio-distribution of cisplatin to other organs due to poor targeting towards only cancer cells constitutes the backbone of cisplatin-induced toxicity. The adverse effect of this drug on spleen is not well characterized so far. Therefore, we have set our goal to explore the mechanism of the cisplatin-induced pathophysiology of the spleen and would also like to evaluate whether carnosine, an endogenous neurotransmitter and antioxidant, can ameliorate this pathophysiological response. We found a dose and time-dependent increase of the pro-inflammatory cytokine, TNF-α, in the spleen tissue of the experimental mice exposed to 10 and 20 mg/kg body weight of cisplatin. The increase in inflammatory cytokine can be attributed to the activation of the transcription factor, NF-ĸB. This also aids in the transcription of other pro-inflammatory cytokines and cellular adhesion molecules. Exposure of animals to cisplatin at both the doses resulted in ROS and NO production leading to oxidative stress. The MAP Kinase pathway, especially JNK activation, was also triggered by cisplatin. Eventually, the persistence of inflammatory response and oxidative stress lead to apoptosis through extrinsic pathway. Carnosine has been found to restore the expression of inflammatory molecules and catalase to normal levels through inhibition of pro-inflammatory cytokines, oxidative stress, NF-ĸB and JNK. Carnosine also protected the splenic cells from apoptosis. Our study elucidated the detailed mechanism of cisplatin-induced spleen toxicity and use of carnosine as a protective agent against this cytotoxic response.

Modulatory effect of silymarin on nuclear factor-erythroid-2-related factor 2 regulated redox status, nuclear factor-κB mediated inflammation and apoptosis in experimental gastric ulcer

Non-steroidal anti-inflammatory drugs (NSAIDs) consumption has been commonly associated with gastric mucosal lesions including gastric ulcer. Silymarin (SM) is a flavonoid mixture with anti-oxidant and anti-inflammatory activities which explain its protective role against hepatic and renal injuries. However, its impact on gastric ulcer has not yet been elucidated. Thus we went further to investigate the potential protective effects of SM against indomethacin-induced gastric injury in rats. Pretreatment with SM (50 mg/kg orally) attenuated the severity of gastric mucosal damage as evidenced by decreasing ulcer index (UI) and ulcer score, improvement of disturbed histopathologicl features to be insignificant with those induced by the reference anti-ulcer drug. Pretreatment with SM also suppressed gastric inflammation by decreasing myeloperoxidase activity, tumer necrosis factor-α (TNF- α) and interleukin 6 (IL6) levels along with nuclear factor kappa B p65 (NF-κB) expression. Meanwhile, SM prevent gastric oxidative stress via inhibition of lipid peroxides formation, enhancement of glutathione peroxidase, superoxide dismutase activities and up-regulation of nuclear factor-erythroid-2-related factor 2 (Nrf2), the redox-sensitive master regulator of oxidative stress signaling. In conclusion, the results herein revealed that SM has a gastro-protective effect which is mediated via suppression of gastric inflammation, oxidative stress, increased the anti-oxidant and the cyto-protective defense mechanisms.

Redox signaling in the gastrointestinal tract

Redox signaling regulates physiological self-renewal, proliferation, migration and differentiation in gastrointestinal epithelium by modulating Wnt/β-catenin and Notch signaling pathways mainly through NADPH oxidases (NOXs). In the intestine, intracellular and extracellular thiol redox status modulates the proliferative potential of epithelial cells. Furthermore, commensal bacteria contribute to intestine epithelial homeostasis through NOX1- and dual oxidase 2-derived reactive oxygen species (ROS). The loss of redox homeostasis is involved in the pathogenesis and development of a wide diversity of gastrointestinal disorders, such as Barrett's esophagus, esophageal adenocarcinoma, peptic ulcer, gastric cancer, ischemic intestinal injury, celiac disease, inflammatory bowel disease and colorectal cancer. The overproduction of superoxide anion together with inactivation of superoxide dismutase are involved in the pathogenesis of Barrett's esophagus and its transformation to adenocarcinoma. In Helicobacter pylori-induced peptic ulcer, oxidative stress derived from the leukocyte infiltrate and NOX1 aggravates mucosal damage, especially in HspB+ strains that downregulate Nrf2. In celiac disease, oxidative stress mediates most of the cytotoxic effects induced by gluten peptides and increases transglutaminase levels, whereas nitrosative stress contributes to the impairment of tight junctions. Progression of inflammatory bowel disease relies on the balance between pro-inflammatory redox-sensitive pathways, such as NLRP3 inflammasome and NF-κB, and the adaptive up-regulation of Mn superoxide dismutase and glutathione peroxidase 2. In colorectal cancer, redox signaling exhibits two Janus faces: On the one hand, NOX1 up-regulation and derived hydrogen peroxide enhance Wnt/β-catenin and Notch proliferating pathways; on the other hand, ROS may disrupt tumor progression through different pro-apoptotic mechanisms. In conclusion, redox signaling plays a critical role in the physiology and pathophysiology of gastrointestinal tract.

A 35 kDa Phyllanthus niruri protein suppresses indomethacin mediated hepatic impairments: Its role in Hsp70, HO-1, JNKs and Ca2+ dependent inflammatory pathways

The present study has been conducted to explore a novel strategy to modulate the unfavourable effects of indomethacin by Phyllanthus niruri protein (PNP) and the underlying mechanism PNP exploits for the amelioration of that pathophysiology. In hepatocytes, indomethacin enhanced reactive oxygen species (ROS), reduced intracellular antioxidant capacity, up regulated mitogen activated protein kinase (MAPKs), disrupted mitochondrial membrane potential, activated apoptotic pathways and there by reduced the viability of the hepatocytes. Simultaneous treatment with PNP modulated these detrimental actions of the drug and retained cell viability. Similarly, in mice, indomethacin elevated serum marker enzymes (e.g. Alanine Transaminase), decreased antioxidant enzyme activities, elevated oxidations of lipids and proteins, increased intracellular calcium overload mediated endoplasmic reticular stress (ER stress) pathways, up regulated the pro-inflammatory cytokines and there by leading to the mitochondrial dependent caspase-3 activation and poly-ADP ribose polymerase (PARP) cleavage. Moreover investigation of these inherent molecular pathways exhibited that these alterations are associated with up regulation of MAPKs, inducible nitric oxide synthase (iNOS), heme oxygenase-1 and down regulation of survival proteins. However, PNP suppressed those apoptotic indices as evidenced from histopathological studies and DNA fragmentation analysis. Combining, results suggest that PNP could possibly provide a protection against indomethacin-induced hepatic pathophysiology.

Taurine protects cisplatin induced cardiotoxicity by modulating inflammatory and endoplasmic reticulum stress responses

Oxidative stress, ER stress, inflammation, and apoptosis results in the pathogenesis of cisplatin-induced cardiotoxicity. The present study was designed to investigate the signaling mechanisms involved in the ameliorating effect of taurine, a conditionally essential amino acid, against cisplatin-mediated cardiac ER stress dependent apoptotic death and inflammation. Mice were simultaneously treated with taurine (150 mg kg^-1 body wt, i.p.) and cisplatin (10 mg kg^-1 body wt, i.p.) for a week. Cisplatin exposure significantly altered serum creatine kinase and troponin T levels. In addition, histological studies revealed disintegration in the normal radiation pattern of cardiac muscle fibers. However, taurine administration could abate such adverse effects of cisplatin. Taurine administration significantly mitigated the reactive oxygen species production, alleviated the overexpression of nuclear factor-κB (NF-κB), and inhibited the elevation of proinflammatoy cytokines, adhesion molecules, and chemokines. Cisplatin exposure resulted in the unfolded protein response (UPR)-regulated CCAAT/enhancer binding protein (CHOP) up-regulation, induction of GRP78: a marker of ER stress and eIF2α signaling. Increase in calpain-1 expression level, activation of caspase-12 and caspase-3, cleavage of the PARP protein as well as the inhibition of antiapoptotic protein Bcl-2 were reflected on cisplatin-triggered apoptosis. Taurine could, however, combat against such cisplatin induced cardiac-abnormalities. The above mentioned findings suggest that taurine plays a beneficial role in providing protection against cisplatin-induced cardiac damage by modulating inflammatory responses and ER stress. © 2016 BioFactors, 42(6):647-664, 2016.

Selective scavenging of intra-mitochondrial superoxide corrects diclofenac-induced mitochondrial dysfunction and gastric injury: A novel gastroprotective mechanism independent of gastric acid suppression

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used to treat multiple inflammatory diseases and pain but severe gastric mucosal damage is the worst outcome of NSAID-therapy. Here we report that mitoTEMPO, a mitochondrially targeted superoxide (O₂^-) scavenger protected as well as healed gastric injury induced by diclofenac (DCF), the most commonly used NSAID. Common existing therapy against gastric injury involves suppression of gastric acid secretion by proton pump inhibitors and histamine H₂ receptor antagonists; however, dyspepsia, vitamin B12 deficiency and gastric microfloral dysbalance are the major drawbacks of acid suppression. Interestingly, mitoTEMPO did not inhibit gastric acid secretion but offered gastroprotection by preventing DCF-induced generation of O₂^- due to mitochondrial respiratory chain failure and by preventing mitochondrial oxidative stress (MOS)-mediated mitopathology. MitoTEMPO even restored DCF-stimulated reduced fatty acid oxidation, mitochondrial depolarization and bioenergetic crisis in gastric mucosa. MitoTEMPO also prevented the activation of mitochondrial pathway of apoptosis and MOS-mediated proinflammatory signaling through NF-κB by DCF. Furthermore, mitoTEMPO when administered in rats with preformed gastric lesions expedited the healing of gastric injury and the healed stomach exhibited its normal physiology as evident from gastric acid and pepsin secretions under basal or stimulated conditions. Thus, in contrast to the existing antiulcer drugs, mitochondrially targeted O₂^- scavengers like mitoTEMPO may represent a novel class of gastroprotective molecules that does not affect gastric acid secretion and may be used in combination with DCF, keeping its anti-inflammatory action intact, while reducing its gastrodamaging effects.

Pharmacological effects of Vitamin C & E on Diclofenac Sodium intoxicated Rats

OBJECTIVE

The aim of this study was to evaluate the probable protective effect of vitamin C and vitamin E on diclofenac-induced acute nephrotoxicity using biochemical, molecular and histopathological examination in rats following administration of diclofenac sodium (50mg/kg, I.M).

METHODS

Ninety male Wister rats were allotted in six equal groups. Rats in the 1st group (control group) were injected with physiological saline, while rats in the 2nd group (C-group) were given vitamin C (100mg/kg orally via stomach tube) for 5 successive days. The 3rd group (E-group) was given vitamin E (250mg/kg orally in diet) for 5 successive days. Rats in the 4th group (D-group) were injected by diclofenac sodium (50mg/kg, I.M) for 5 successive days. The 5th group (DvC-group) was given diclofenac sodium (50mg/kg, I.M) and vitamin C (100mg/kg orally via stomach tube) for 5 successive days. Rats in the 6th group (DvE-group) were given diclofenac sodium (50mg/kg, I.M) and vitamin E (250mg/kg orally in diet) for 5 successive days. Blood samples were collected two days post treatment (1st week of experiment), 2nd and 4th week of the experiment for assessment of urea, creatinine, malondialdehyde, nitric oxide and superoxide dismutase activities. At the end of 4th week, rats were sacrificed and kidneys were excised for biochemical analyses, histopathological evaluation and determination of kidney interleukin-1β, interleukin-18, demsin and nepherin expressions in by reverse transcriptase-polymerase chain reaction (RT-PCR).

RESULTS

The results showed that, diclofenac induced severe kidney damage as indicated by histopathological changes and increased serum oxidative stress parameters. Behavioral changes were monitored; a significant increase in uremia in intoxicated animals was also noted indicating that diclofenac sodium provoked kidney damage in rats. Application of vitamin C (DvC-group) and vitamin E (DvE-group) were found to improve the abovementioned abnormalities.

CONCLUSION

The present data suggest that, vitamin C and vitamin E might play an important role in reducing oxidative stress and kidney damage induced by diclofenac sodium.

Nuclear factor-like factor 2-antioxidant response element signaling activation by tert-butylhydroquinone attenuates acute heat stress in bovine mammary epithelial cells

Nuclear factor (erythroid-derived 2)-like factor 2 (Nrf2) is a transcription factor that binds to the antioxidant response element (ARE) in the upstream promoter region of many antioxidative genes. The Nrf2-ARE signaling plays a key role in the cellular antioxidant-defense system, but whether Nrf2 activation has protective effects against heat shock (HS) stress in mammary epithelial cells (MEC) remains unclear. The objective of this study was to determine whether tert-butylhydroquinone (tBHQ), a well-known Nrf2 activator, could attenuate heat stress-induced cell damage in MAC-T cells of the bovine MEC line. The MAC-T cells were exposed to HS (42.5°C for 1h) followed by recovery at 37°C to mimic HS. Compared with cells that were consistently cultured at normothermia (37°C), the cell viability levels significantly decreased after HS stress. In parallel, heat stress increased the reactive oxygen species levels and induced cellular apoptosis and endoplasmic reticulum stress. The MAC-T cells that were pretreated with tBHQ (10μM) for 2h followed by HS had a reduction in the loss of cell viability. The tBHQ pretreatment significantly decreased cellular reactive oxygen species levels and stress-related marker gene expression. The tBHQ-treated MAC-T cells showed strong Nrf2-ARE signaling activation and a nuclear accumulation of Nrf2 and upregulated expression of Nrf2-ARE downstream genes. Small interfering RNA silencing of Nrf2 in HS-treated MAC-T cells almost completely abolished the cytoprotective effects by tBHQ. Overall, our results demonstrated that HS could cause cell damage in cultured bovine MEC, and that activation of Nrf2 by tBHQ could attenuate HS-induced cell damage.

Nuclear factor erythroid 2-related factor 2 antibody attenuates thermal hyperalgesia in the dorsal root ganglion: Neurochemical changes and behavioral studies after sciatic nerve-pinch injury

Oxidative stress is generated in several peripheral nerve injury models.Nuclear factor erythroid 2-related factor 2 (Nrf2) is activated to have a role in antioxidant effect. After nerve injury, the severely painful behavior is also performed. However, little has been explored regarding the function of Nrf2 in this painful process. Therefore, in this study, we compared the effects of Nrf2 antibody administration following sciatic nerve-pinch injury on painful behavior induced in young mice and neurochemical changes in dorsal root ganglion neurons. After pinch nerve injury, we found that the magnitude of the thermal allodynia was significantly decreased after application of Nrf2 antibody (5ul, 1mg/ml) in such injured animals and phosphorylated ERK(p-ERK) as well as the apoptotic protein (i.e., Bcl-6) in DRG neurons were also down-regulated in the anti-Nrf2-treated injured groups compared to the saline-treated groups. Taken collectively, these data suggested that the Nrf2 antibody reduced thermal hyperalgesia via ERK pathway and the down regulation of Bcl-6 protein from the apoptosis pathway might be protecting against the protein deletions caused by anti-Nrf2 effect and suggested the new therapeutic strategy with Nrf2 inhibitor following nerve injury.

Expression, purification and characterization of Plasmodium falciparum vacuolar protein sorting 29

Translocation of various proteins to the subcellular organelles is an essential mechanism to regulate the metabolic pathways and often vacuolar protein sorting (VPS) proteins are involved in this transportation. Plasmodium falciparum VPS29 (PfVPS29) is predicted to be a functional component in the assembly of the retromer complex; however, so far detailed characterization of PfVPS29 in its native form is not yet done. We report the successful expression and purification of tag-free recombinant PfVPS29 with a yield of 5.6 mg from 1 L of Escherichia coli culture. PfVPS29 was purified by combined anion-exchange and size exclusion chromatography. The protein showed a single band in SDS-PAGE and it exhibited molecular mass of 21.7 kDa as measured by MALDI-TOF mass spectrometry. Secondary structure was elucidated by circular dichroism spectroscopy. It was found to be a monomeric protein in solution as evident from dynamic light scattering studies, chemical cross-linking experiments and size exclusion chromatography. Subsequently, polyclonal anti-PfVPS29 antibody was generated and used for evaluating protein expression by western blot and following subcellular localization in P. falciparum by confocal immunofluoroscence microscopy. PfVPS29 was found to be located in cytoplasm and expressed from early trophozoite to schizont stages with maximum expression in trophozoite stage. This study provides purification, biophysical characterization and subcellular localization of PfVPS29 in different asexual stages of P. falciparum.

Cobalt Protoporphyrin Upregulates Cyclooxygenase-2 Expression Through a Heme Oxygenase-Independent Mechanism

Cobalt protoporphyrin (CoPP) is a potent HO-1 inducer and generally known to be an antioxidant in various cell types. Little is known about the CoPP-induced cyclooxygenase-2 (COX-2) expression and its downstream signaling in microglial cells. In current study, CoPP caused concentration- and time-dependent increases in COX-2 expression in microglial cells. Furthermore, activation of apoptosis signal-regulating kinase (ASK) 1/MAP kinase involved in CoPP-induced COX-2 expression in microglia. CoPP also induced P2X7 receptor activation, and treatment of P2X7 inhibitors effectively reduced CoPP-induced COX-2 expression. Protein inhibitor of activated STAT (PIAS) 1 is reported to be involved in modulating anti-inflammatory response through negative regulation of transcription factors. Interestingly, treatment with CoPP markedly induced PIAS1 degradation which is regulated by PI3K, Akt, and glycogen synthase kinase 3α/β (GSK3α/β) signaling pathways. These results suggest that CoPP induces COX-2 expression through activating P2X7 receptors and ASK1/MAP kinases as well as PIAS1 degradation signaling pathways. Our study provides a new insight into the regulatory effect of CoPP on neuroinflammation in microglial cells.

Ellagic Acid, a Dietary Polyphenol, Inhibits Tautomerase Activity of Human Macrophage Migration Inhibitory Factor and Its Pro-inflammatory Responses in Human Peripheral Blood Mononuclear Cells

Ellagic acid (EA), a phenolic lactone, inhibited tautomerase activity of human macrophage migration inhibitory factor (MIF) noncompetitively (Ki = 1.97 ± 0.7 μM). The binding of EA to MIF was determined by following the quenching of tryptophan fluorescence. We synthesized several EA derivatives, and their structure-activity relationship studies indicated that the planar conjugated lactone moiety of EA was essential for MIF inhibition. MIF induces nuclear translocation of NF-κB and chemotaxis of peripheral blood mononuclear cells (PBMCs) to promote inflammation. We were interested in evaluating the effect of EA on nuclear translocation of NF-κB and chemotactic activity in human PBMCs in the presence of MIF. The results showed that EA inhibited MIF-induced NF-κB nuclear translocation in PBMCs, as evident from confocal immunofluorescence microscopic data. EA also inhibited MIF-mediated chemotaxis of PBMCs. Thus, we report MIF-inhibitory activity of EA and inhibition of MIF-mediated proinflammatory responses in PBMCs by EA.

Morin protects gastric mucosa from nonsteroidal anti-inflammatory drug, indomethacin induced inflammatory damage and apoptosis by modulating NF-κB pathway

BACKGROUND

Deregulation in prostaglandin (PG) biosynthesis, severe oxidative stress, inflammation and apoptosis contribute to the pathogenesis of nonsteroidal anti-inflammatory drug (NSAID)-induced gastropathy. Unfortunately, most of the prescribed anti-ulcer drugs generate various side effects. In this scenario, we could consider morin as a safe herbal potential agent against IND-gastropathy and rationalize its action systematically.

METHODS

Rats were pretreated with morin for 30 min followed by IND (48 mgkg(-1)) administration for 4 h. The anti-ulcerogenic nature of morin was assessed by morphological and histological analysis. Its effects on the inflammatory (MPO, cytokines, adhesion molecules), ulcer-healing (COXs, PGE(2)), and signaling parameters (NF-κB and apoptotic signaling) were assessed by biochemical, RP-HPLC, immunoblots, IHC, RT-PCR, and ELISA at the time points of their maximal changes due to IND administration.

RESULTS

IND induced NF-κB and apoptotic signaling in rat's gastric mucosa. These increased proinflammatory responses, but reduced the antioxidant enzymes and other protective factors. Morin reversed all the adverse effects to prevent IND-induced gastric ulceration in a PGE2 independent manner. Also, it did not affect the absorption and/or primary pharmacological activity of IND.

CONCLUSIONS

The gastroprotective action of morin is primarily attributed to its potent antioxidant nature that also helps in controlling several IND-induced inflammatory responses.

GENERAL SIGNIFICANCE

For the first time, the study reveals a mechanistic basis of morin mediated protective action against IND-induced gastropathy. As morin is a naturally abundant safe antioxidant, future detailed pharmacokinetic and pharmacodynamic studies are expected to establish it as a gastroprotective agent.