The peroxisome proliferator‐activated receptor‐γ agonist pioglitazone protects against cisplatin‐induced renal damage in mice

Peroxisome proliferator‐activated receptor‐γ (PPAR‐γ) agonists not only improve metabolic abnormalities of diabetes and consequent diabetic nephropathy, but they also protect against non‐diabetic kidney disease in experimental models. Here, we investigated the effect of PPAR‐γ agonist pioglitazone against acute renal injury on a cisplatin model in mice. Nephrotoxicity was induced by a single intraperitoneal (i.p.) injection of cisplatin (10 mg kg^–1). Pioglitazone was administered for six consecutive days in doses of 15 or 30 mg kg^–1 day^–1, per os (p.o.), starting 3 days before cisplatin injection. Cisplatin treatment to mice induced a marked renal failure, characterized by a significant increase in serum urea and creatinine levels and alterations in renal tissue architecture. Cisplatin exposure induced oxidative stress as indicated by decreased levels of non‐enzymatic antioxidant defenses [glutathione (GSH) and ascorbic acid levels] and components of the enzymatic antioxidant defenses [superoxide dismutase (SOD), catalase (CAT) glutathione peroxidase (GPx), glutathione reductase (GR) and and glutathione S‐transferase(GST) activities)] in renal tissue. Administration of pioglitazone markedly protected against the increase in urea and creatinine levels and histological alterations in kidney induced by cisplatin treatment. Pioglitazone administration ameliorated GSH and ascorbic acid levels decreased by cisplatin exposure in mice. Pioglitazone protected against the inhibition of CAT, SOD, GPx, GR and GST activities induced by cisplatin in the kidneys of mice. These results indicated that pioglitazone has a protective effect against cisplatin‐induced renal damage in mice. The protection is mediated by preventing the decline of antioxidant status. The results have implications in use of PPAR‐γ agonists in human application for protecting against drugs‐induced nephrotoxicity. Copyright © 2012 John Wiley & Sons, Ltd.     

Protective effects of emodin against cisplatin‐induced oxidative stress in cultured human kidney (HEK 293) cells

Emodin (a rhubarb anthraquinone) has strong antioxidant and anticancer actions, and recent studies indicated that it reduces cellular oxidative stress induced by various insults and drugs. Cisplatin is an anticancer drug that is associated with nephrotoxicity and induces oxidative stress in cultured human kidney (HEK 293) cells. This study aimed to assess the in‐vitro antioxidant properties of the emodin against cisplatin‐induced oxidative stress in HEK 293 cells. Our study revealed that emodin acted as a potent free radical scavenger and provided nephroprotection against cisplatin‐induced oxidative stress. Emodin as low as 0.5 µm did not decrease cell viability and restored the cisplatin‐induced glutathione depletion and total antioxidant capacity in a dose‐dependent manner. Emodin augmented the cisplatin‐induced inhibition of antioxidant enzymes (catalase, glutathione peroxidase, glutathione S‐transferase, glutathione reductase and superoxide dismutase). These results suggest that emodin has the potential to be used as an adjunct therapeutic agent in patients receiving cisplatin treatment. Copyright © 2012 John Wiley & Sons, Ltd.     

Selenium modulates β‐cyfluthrin‐induced liver oxidative toxicity in rats

This study was designed to investigate the possibility of β‐cyfluthrin to induce oxidative stress and biochemical perturbations in rat liver and the role of selenium in alleviating its toxic effects. Male Wister rats were randomly divided into four groups of seven each, group I served as control, group II treated with selenium (200 µg/kg BW), group III received β‐cyfluthrin (15 mg/kg BW, 1/25 LD₅₀), and group IV treated with β‐cyfluthrin plus selenium. Rats were orally administered their respective doses daily for 30 days. The administration of β‐cyfluthrin caused elevation in lipid peroxidation (LPO) and reduction in the activities of antioxidant enzymes including catalase (CAT), superoxide dismutase (SOD), glutathione S‐transferase (GST), glutathione peroxidase (GPx), and glutathione reductase (GR). A decrease in reduced glutathione (GSH) content was also observed. Liver aminotransferases (AST and ALT) and alkaline phosphatase (ALP) were decreased, whereas lactate dehydrogenase (LDH) was increased. Selenium in β‐cyfluthrin‐induced liver oxidative injury of the rats modulated LPO, CAT, SOD, GSH, GST, GPx, and GR. Also, liver AST, ALT, ALP, and LDH were maintained near normal level due to selenium treatment. It is concluded that selenium scavenges reactive oxygen species and render a protective effect against β‐cyfluthrin toxicity. © 2013 Wiley Periodicals, Inc. Environ Toxicol 29: 1323–1329, 2014.     

The natural compound 2,3,5,4′‐tetrahydroxystilbene‐2‐O‐β‐d glucoside protects against adriamycin‐induced nephropathy through activating the Nrf2‐Keap1 antioxidant pathway

2,3,5,4′‐Tetrahydroxystilbene‐2‐O‐β‐d ‐glucoside (THSG) is an active compound extracted from Polygonum multiflorum Thunb. This herb and radix Polygoni Multiflori preparata have been used to treat arteriosclerosis, hyperlipidemia, hypercholesterolemia, and diabetes for thousands of years. This study aimed to investigate the protective effects of THSG in an Adriamycin (AD)‐induced focal segmental glomerulosclerosis (FSGS) mouse model and the underlying mechanisms in an in vitro system. Mice were treated with THSG (2.5 and 10 mg/kg, oral gavage) for 24 consecutive days. On the third day, mice were intravenously given a single dose of AD (10 mg/kg). At the end of the experiment, plasma and kidney samples were harvested to evaluate the therapeutic effects of THSG. The potential mechanisms of THSG in protecting against AD‐induced cytotoxicity were examined using a real‐time polymerase chain reaction, immunoblots, lactate dehydrogenase assay, and a cellular oxidized‐thiol detection system in a mouse mesangial cell line. In this study, THSG showed concentration‐dependent protective effects in ameliorating the progression of AD‐induced FSGS. THSG suppressed albuminuria and hypercholesterolemia and reduced the status of lipid peroxidation in urine, plasma, and kidney tissue samples. Furthermore, THSG protected against podocyte damage, reduced renal fibrotic gene expressions, and alleviated the severity of glomerulosclerosis. Treatment of mouse mesangial cells with THSG induced nuclear factor erythroid‐derived 2‐like 2 (Nrf2) nuclear translocation, increased heme oxygenase‐1 and NAD(P)H:quinone oxidoreductase (NQO)‐1 gene expressions, and reduced cellular thiol oxidation and resistance to AD‐induced cytotoxicity. Silencing Nrf2 and its repressor protein, Kelch‐like ECH‐associated protein 1 (Keap1), abolished these protective effects of THSG. In conclusion, THSG can play a protective role in ameliorating the progression of FSGS in a mouse model through activation of the Nrf2‐Keap1 antioxidant pathway. Although a well‐designed therapeutic study is needed, THSG may be applied to manage chronic kidney disease.     

Stevioside protects against rhabdomyolysis‐induced acute kidney injury through PPAR‐γ agonism in rats

We explored the potential role of peroxisome proliferator activated receptor‐γ (PPAR‐γ) in stevioside‐mediated renoprotection using rhabdomyolysis‐induced acute kidney injury (AKI) model in rats. Rhabdomyolysis refers to intense skeletal muscle damage, which further causes AKI. Glycerol (50% w/v, 8 ml/kg) was injected intramuscularly in rats to induce rhabdomyolysis. After 24 hr, AKI was demonstrated by quantifying serum creatinine, urea, creatinine clearance, microproteinuria, and electrolytes in rats. Further, oxidative stress was measured by assaying thiobarbituric acid reactive substances, generation of superoxide anion, and reduced glutathione levels. Additionally, serum creatine kinase (CK) level was assayed to determine glycerol‐induced muscle damage in rats. Pathological changes in rat kidneys were studied using hematoxylin–eosin and periodic acid Schiff staining. Moreover, the expression of apoptotic markers (Bcl‐2, Bax) in rat kidneys was demonstrated by immunohistochemistry. Stevioside (10, 25, and 50 mg/kg) was administered to rats, prior to the induction of AKI. In a separate group, bisphenol A diglycidyl ether (BADGE, 30 mg/kg), a PPAR‐γ receptor antagonist was given prior to stevioside administration, which was followed by rhabdomyolysis‐induced AKI in rats. The significant alteration in biochemical and histological parameters in rats indicated AKI, which was attenuated by stevioside treatment. Pretreatment with BADGE abrogated stevioside‐mediated renoprotection, which is suggestive of the involvement of PPAR‐γ in its renoprotective effect. In conclusion, stevioside protects against rhabdomyolysis‐induced AKI, which may be attributed to modulation of PPAR‐γ expression.     

Resveratrol protects human bronchial epithelial cells against nickel‐induced toxicity via suppressing p38 MAPK,NF‐κB signaling,and NLRP3 inflammasome activation

Nickel is a common environmental pollutant that can impair the lung, but the underlying mechanisms have not yet been fully elucidated. Furthermore, natural products are generally used to inhibit cell damage induced by heavy metal. Resveratrol possesses wide biological activities, including anti‐inflammation and antioxidative stress. This study was conducted to explore the toxicity of nickel on human bronchial epithelial (BEAS‐2B) cells and evaluate the protective effect of resveratrol. The results showed that nickel could induce cell apoptosis, increase oxidative stress, and promote the expression of pro‐inflammatory cytokines, including tumor necrosis factor‐α, interleukin (IL)‐1β, IL‐6, IL‐8, C‐reaction protein. Western blot analysis showed that nickel activated p38 mitogen‐activated protein kinase (MAPK), nuclear factor‐kappa B, and nucleotide‐binding oligomerization domain‐like receptor pyrin‐domain‐containing protein 3 pathways, while resveratrol could reverse these effects. Our results suggested that resveratrol could protect BEAS‐2B cells from nickel‐induced cytotoxicity. Therefore, resveratrol is a potential chemopreventive agent against nickel‐induced lung disease.     

The role of GSH in microcystin‐induced apoptosis in rat liver: Involvement of oxidative stress and NF‐κB

Microcystins (MCs) are potent and specific hepatotoxins produced by cyanobacteria in eutrophic waters, representing a health hazard to animals and humans. The objectives of this study are to determine the relationship between oxidative stress and NF‐κB activity in MC‐induced apoptosis in rat liver and the role of glutathione (GSH). Sprague‐Dawley rats were intraperitoneally (i.p.) injected with microcystin‐LR (MC‐LR) at 0.25 and 0.5 LD₅₀ with or without pretreatment of buthionine‐(S,R)‐sulfoximine (BSO), a specific GSH synthesis inhibitor. MC‐LR induced time‐dependent alterations of GSH levels in rat liver. Increased malondialdehyde (MDA) and significant changes of antioxidant enzymes including GSH peroxidase (GPX) and GSH reductase (GR) were also observed, particularly at 24 h post‐exposure. The results indicated that acute exposure to MC‐LR induced oxidative stress, and GSH depletion (BSO pretreatment) enhanced the level of oxidative stress. Furthermore, the modulation of pro‐apoptotic gene p53 and Bax and anti‐apoptotic gene Bcl‐2 was observed in 0.5 LD₅₀ group at 24 h, and the alteration was more pronounced by BSO injection before MC‐LR treatment, suggesting that GSH played a protective role against MC‐induced toxicity. Additionally, electrophoretic mobility shift assay (EMSA) showed that NF‐κB was induced at 0.25 LD₅₀ but inhibited at 0.5 LD₅₀. The above results indicated that the possible crosstalk of oxidative stress and NF‐κB activity was associated with MC‐LR‐induced hepatocytes apoptosis in vivo. Our data will provide a new perspective for understanding the mechanisms of MC‐induced liver injury. © 2014 Wiley Periodicals, Inc. Environ Toxicol 31: 552–560, 2016.     

Diallyl sulfide alleviates cisplatin‐induced nephrotoxicity in rats via suppressing NF‐κB downstream inflammatory proteins and p53/Puma signalling pathway

Despite being a potent anticancer drug, nephrotoxicity is an adverse effect which renders the clinical use of cisplatin (Cis) limited. The protective role of diallyl sulfide (DAS); a naturally occurring organo‐sulfide, present in garlic, in cisplatin‐induced nephrotoxicity has been reported earlier. However, the mechanism through which DAS exerts its nephroprotective activity remains elusive. The aim of the current study was to elucidate the possible mechanisms underlying the reno‐protective effect of DAS in cisplatin‐induced nephrotoxicity in rats. DAS was given at 2 dose levels; 50 and 100 mg/kg, orally for 4 consecutive days, starting 1 hour after administration of single dose of cisplatin (3.5 mg/kg, intraperitoneally [i.p.]). The Cis‐induced elevation in serum urea and creatinine, degree of histopathological alterations was significantly ameliorated in cisplatin groups co‐treated with DAS. In addition, DAS significantly restored Cis‐depleted glutathione (GSH) content and superoxide dismutase (SOD) activity and attenuated Cis‐elevated Malondialdehyde (MDA) level. Also, DAS significantly reduced Cis‐increased renal expression of nuclear factor kappa B (NF‐κB) and subsequent pro‐inflammatory mediators; tumour necrosis factor alpha (TNF‐α), interleukin‐1β (IL‐1β), intercellular adhesion molecule‐1 (ICAM‐1) and inducible nitric oxide synthase (iNOS) in kidney tissues. Moreover, co‐treatment with DAS significantly inhibited Cis‐increased caspase‐8 and ‐9 levels. Additionally, DAS significantly mitigated Cis‐induced protein expression of p53, Puma, and Bax while, it significantly restored Cis‐reduced protein expression of Bcl‐xL compared to the Cis group. In conclusion, these results demonstrate that DAS ameliorates cisplatin‐induced nephrotoxicity in rats through enhancement of antioxidant defense, reduction of inflammatory cytokine tissue levels as well as inhibition of apoptosis via p53/Puma signalling pathway.     

PM2.5‐induced oxidative stress increases adhesion molecules expression in human endothelial cells through the ERK/AKT/NF‐κB‐dependent pathway

The aim of this study was to explore the intracellular mechanisms underlying the cardiovascular toxicity of air particulate matter (PM) with an aerodynamic diameter of less than 2.5 µm (PM_2.5) in a human umbilical vein cell line, EA.hy926. We found that PM_2.5 exposure triggered reactive oxygen species (ROS) generation, resulting in a significant decrease in cell viability. Data from Western blots showed that PM_2.5 induced phosphorylation of Jun N‐terminal kinase (JNK), extracellular signal regulatory kinase (ERK), p38 mitogen‐activated protein kinase (MAPK) and protein kinase B (AKT), and activation of nuclear factor kappa B (NF‐κB). We further observed a significant increase in expressions of intercellular adhesion molecule‐1 (ICAM‐1) and vascular adhesion molecule‐1 (VCAM‐1) in a time‐ and dose‐dependent manner. Moreover, the adhesion of monocytic THP‐1 cells to EA.hy926 cells was greatly enhanced in the presence of PM_2.5. However, N‐acetylcysteine (NAC), a scavenger of ROS, prevented the increase of ROS generation, attenuated the phosphorylation of the above kinases, and decreased the NF‐κB activation as well as the expression of ICAM‐1 and VCAM‐1. Furthermore, ERK inhibitor (U0126), AKT inhibitor (LY294002) and NF‐κB inhibitor (BAY11‐7082) significantly down‐regulated PM_2.5‐induced ICAM‐1 and VCAM‐1 expression as well as adhesion of THP‐1 cells, but not JNK inhibitor (SP600125) and p38 MAPK inhibitor (SB203580), indicating that ERK/AKT/NF‐κB is involved in the signaling pathway that leads to PM_2.5‐induced ICAM‐1 and VCAM‐1 expression. These findings suggest PM_2.5‐induced ROS may function as signaling molecules triggering ICAM‐1 and VCAM‐1 expressions through activating the ERK/AKT/NF‐κB‐dependent pathway, and further promoting monocyte adhesion to endothelial cells. Copyright © 2015 John Wiley & Sons, Ltd.     

Knockdown of cathepsin D protects dopaminergic neurons against neuroinflammation‐mediated neurotoxicity through inhibition of NF‐κB signalling pathway in Parkinson's disease model

Parkinson's disease (PD) is a progressive neurodegenerative disorder pathologically characterized by the loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc). Chronic neuroinflammation is one of the hallmarks of PD pathophysiology. Cathepsin D (CathD), a soluble aspartic protease, has been reported to play an important role in neurodegenerative diseases such as PD. This research focuses on the role of CathD and the molecular mechanisms involved in the process of neuroinflammation and neurotoxicity. We use 1‐methyl‐4phenyl‐1, 2, 3, 6‐tetrahydropyridine (MPTP)‐challenged mice and lipopolysaccharide (LPS)‐induced murine microglia BV2 cells as the in vivo and in vitro models, respectively. The effect of CathD on the neuroinflammation, cytotoxicity and the underlying mechanisms associated with NF‐κB signalling pathway are investigated. Data showed that MPTP induces motor deficit, inflammation and depletion of dopaminergic neurons in PD model mice. Notably, cathD was overexpressed in the SNpc of MPTP‐induced PD mice and was highly expressing in LPS‐stimulated primary microglial cells and BV‐2 cells. Furthermore, knockdown of CathD with lentiviral transduction inhibited LPS‐induced neuroinflammation through inhibition of NF‐κB signalling pathway primarily by regulating the NF‐κB p65 nuclear translocation both in BV‐2 and primary microglial cells. Additionally, knockdown of CathD protected the activated‐microglia induced dopaminergic neurons MN9D cells from neurotoxicity as well as apoptosis. Our findings bring a new insight into understanding the complex mechanisms underlying the pathogenesis of PD and provide a novel target to attenuate the excessive neuroinflammatory responses in the treatment of PD.     

Resveratrol protects Leydig cells from nicotine‐induced oxidative damage through enhanced autophagy

Some studies have revealed that nicotine can damage the male reproductive system through various means including oxidative stress, which is a primary factor in the pathogenesis of male infertility. The strong anti‐oxidative capacity of resveratrol has been demonstrated previously, but its role in the context of male reproduction remains inconclusive. To explore the biological role of resveratrol in protecting male reproductive function and the potential underlying mechanism, nicotine‐induced Leydig cells were used as a cell model of oxidative damage. The data showed that resveratrol treatment increased cell viability, SOD activity and anti‐apoptotic activity in nicotine‐stressed Leydig cells. This effect was accompanied by the upregulation of autophagy, which was illustrated by MDC‐LysoTracker red staining. Moreover, pretreating with 3‐methyladenine (3‐MA), an autophagy inhibitor, attenuated resveratrol‐induced Leydig cells autophagy and promoted apoptosis. Apart from this, resveratrol enhanced AMPK phosphorylation but reduced mTOR phosphorylation. Subsequently, upon inhibiting AMPK phosphorylation by AMPK inhibitors, Leydig cell autophagy induced by resveratrol was obviously abolished. In conclusion, resveratrol may exert its cytoprotective role against oxidative injury by the activation of autophagy via AMPK/mTOR pathway.     

Naringenin attenuates CCl4‐induced hepatic inflammation by the activation of an Nrf2‐mediated pathway in rats

The possible protective effects of naringenin, a naturally occurring citrus flavonone, on carbon tetrachloride (CCl₄)‐induced liver injury in rats and the mechanism underlying its effects were investigated. Forty rats were divided into five groups. Rats in Groups I and II served as the normal and injured liver groups, respectively; Group III rats were treated with the standard drug silymarin as a positive control; and rats in Groups IV and V (naringenin‐treated groups) were administrated 50 mg/kg, p.o., naringenin for 7 days. Liver samples were collected to evaluate mRNA and protein expression, histological changes and oxidative stress. Naringenin inhibited lipid peroxidation and reduced serum levels of hepatic enzymes induced by CCl₄. In addition, naringenin increased the liver content of reduced glutathione and the activity of anti‐oxidant enzymes in rats treated with CCl₄. Naringenin attenuated liver inflammation by downregulating CCl₄‐induced activation of tumour necrosis factor (TNF)‐α, inducible nitric oxide synthase (iNOS) and cyclo‐oxygenase (COX‐2) at both the protein and mRNA levels. Naringenin treatment significantly increased NF‐E2‐related factor 2 (Nrf2) and heme oxygenase (HO‐1) expression in injured livers. In rats treated with CCl₄ alone, decreases were seen in nuclear Nrf2 expression and in the mRNA levels of its target genes (e.g. HO‐1, NQO1 and glutathione S‐transferase alpha 3 (GST‐a3)). Together, the results suggest that naringenin can protect the liver against oxidative stress, presumably by activating the nuclear translocation of Nrf2 as well as attenuating the TNF‐α pathway to elicit an anti‐inflammatory response in liver tissue.     

Diphenyl diselenide protects against glycerol‐induced renal damage in rats

In this study we evaluated the effect of diphenyl diselenide (PhSe)₂ on glycerol‐induced acute renal failure in rats. Rats were pre‐treated by gavage every day with (PhSe)₂ (7.14 mg kg^?1) for 7 days. On the eighth day, rats received an intramuscular injection of glycerol (8 mL kg^?1). Twenty‐four hours afterwards, rats were euthanized and the levels of urea and creatinine were measured in plasma. Catalase (CAT), glutathione peroxidase (GPx), glutathione S‐transferase (GST), δ‐aminolevulinate dehydratase (δ‐ALA‐D) and Na⁺, K⁺‐ATPase activities and ascorbic acid levels were evaluated in renal homogenates. Histopathological evaluations were also performed. The results demonstrated that (PhSe)₂ was able to protect against the increase in urea and creatinine levels and histological alterations in kidney induced by glycerol. (PhSe)₂ protected against the inhibition in δ‐ALA‐D, CAT and GPx activities and the reduction in ascorbic acid levels induced by glycerol in kidneys of rats. In conclusion, the present results indicate that (PhSe)₂ was effective in protecting against acute renal failure induced by glycerol. Copyright © 2009 John Wiley & Sons, Ltd.     

The protective effects of sciadopitysin against methylglyoxal‐induced cytotoxicity in cultured pancreatic β‐cells

Increased glycation of macromolecules via the reactive dicarbonyl and α‐oxoaldehyde methylglyoxal (MG) has shown an association with diabetes and its complications. In the present study, the protective effects of sciadopitysin against MG‐induced oxidative cell damage were investigated in the insulin‐producing pancreatic β‐cell line, RIN‐m5F cells. When exposed to MG for 48 hours, RIN‐m5F cells experienced significant loss of viability and impaired insulin secretion; however, treatment with sciadopitysin protected RIN‐m5F cells against MG‐induced cell death and decreased insulin secretion. Treatment of RIN‐m5F cells with sciadopitysin prevented MG‐induced production of interleukin‐1β, intracellular reactive oxygen species and cardiolipin peroxidation. Furthermore, sciadopitysin increased adenosine monophosphate‐activated protein kinase phosphorylation of RIN‐m5F cells. Treatment of cells with sciadopitysin increased the activity of glyoxalase I and decreased the levels of MG‐protein adducts, indicating that sciadopitysin protects against MG‐induced protein glycation by increasing MG detoxification. Taken together, the results indicated the potential utility of sciadopitysin as an intervention against MG‐induced cell damage in pancreatic β ‐ cells.     

Daphnetin inhibits TNF‐α and VEGF‐induced angiogenesis through inhibition of the IKKs/IκBα/NF‐κB,Src/FAK/ERK1/2 and Akt signalling pathways

Coumarins, identified as plant secondary metabolites possess diverse biological activities including anti‐angiogenic properties. Daphnetin (DAP), a plant derived dihydroxylated derivative of coumarin has shown significant pharmacological properties such as anticancer, anti‐arthritic and anti‐inflammatory. The present study was performed to investigate the anti‐angiogenic potential of DAP, focusing on the mechanism of action. The in vivo anti‐angiogenic potential of DAP was evaluated by vascular endothelial growth factor (VEGF)‐induced rat aortic ring (RAR) assay and chick chorioallantoic membrane (CAM) assay. For in vitro evaluation, wounding migration, transwell invasion, tube formation and apoptosis assays were performed on VEGF (8 ng/mL)‐induced human umbilical vein endothelial cells (HUVECs). The cellular mechanism of DAP was examined on TNFα (10 ng/mL) and VEGF‐induced HUVECs by extracting the mRNA and protein levels using RT‐qPCR and western blotting. Our data demonstrated that DAP inhibited the in vivo angiogenesis in the RAR and CAM assay. DAP also inhibited the different steps of angiogenesis, such as migration, invasion, and tube formation in HUVECs. DAP inhibited nuclear factor‐κB signalling together including TNF‐α induced IκBα degradation; phosphorylation of IκB kinase (IKKα/β) and translocation of the NF‐κB‐p65 protein. Furthermore, western blotting revealed that DAP significantly down‐regulated the VEGF‐induced signalling such as c‐Src, FAK, ERK1/2 and the related phosphorylation of protein kinase B (Akt) and VEGFR2 expressions. DAP reduced the elevated mRNA expression of iNOS, MMP2 and also, induced apoptosis in VEGF‐stimulated HUVECs by the caspase‐3 dependent pathway. Taken together, this study reveals that DAP may have novel prospective as a new multi‐targeted medication for the anti‐angiogenesis and cancer therapy.     

MiR‐146a regulates PM1‐induced inflammation via NF‐κB signaling pathway in BEAS‐2B cells

Exposure to particulate matter (PM) leads to kinds of cardiopulmonary diseases, such as asthma, COPD, arrhythmias, lung cancer, etc., which are related to PM‐induced inflammation. We have found that PM_2.5 (aerodynamics diameter <2.5 µm) exposure induces inflammatory response both in vivo and in vitro. Since the toxicity of PM is tightly associated with its size and components, PM₁ (aerodynamics diameter <1.0 µm) is supposed to be more toxic than PM_2.5. However, the mechanism of PM₁‐induced inflammation is not clear. Recently, emerging evidences prove that microRNAs play a vital role in regulating inflammation. Therefore, we studied the regulation of miR‐146a in PM₁‐induced inflammation in human lung bronchial epithelial BEAS‐2B cells. The results show that PM₁ induces the increase of IL‐6 and IL‐8 in BEAS‐2B cells and up‐regulates the miR‐146a expression by activating NF‐κB signaling pathway. Overexpressed miR‐146a prevents the nuclear translocation of p65 through inhibiting the IRAK1/TRAF6 expression, and downregulates the expression of IL‐6 and IL‐8. Taken together, these results demonstrate that miR‐146a can negatively feedback regulate PM₁‐induced inflammation via NF‐κB signaling pathway in BEAS‐2B cells.     

C‐phycocyanin protects against ethanol‐induced gastric ulcers in rats: Role of HMGB1/NLRP3/NF‐κB pathway

Gastric ulcer is a widespread inflammatory disease with high socio‐economic burden. C‐phycocyanin is one of the active constituents of Spirulina microalgae, and although it is well known for its antioxidant and anti‐inflammatory properties, its protective effects against gastric ulcer have not yet been identified. High‐mobility group box 1 (HMGB1) is a nuclear protein that, once secreted extracellularly, initiates several inflammatory reactions, and it is involved in the pathogenesis of gastric ulcer. The aim of the present study was to investigate the anti‐inflammatory and anti‐ulcerogenic effects of C‐phycocyanin against ethanol‐induced gastric ulcer targeting HMGB1/NLRP3/NF‐κB pathway. Ulcer induction showed increase in HMGB1 expression through activation of nucleotide‐binding domain and leucine‐rich repeat‐containing protein 3 (NLRP3) inflammasome and nuclear factor kappa p65 (NF‐κB p65). Moreover, oxidative stress and inflammatory markers were elevated in the ulcer‐treated group compared to the normal control group. However, pre‐treatment with C‐phycocyanin significantly reduced HMGB1 expression via suppression of NLRP3/NF‐κB, oxidative markers, IL‐1β, tumour necrosis factor‐α (TNF‐α) and ulcer index value. These results were consistent with histopathological and immunohistochemistry examination. Thus, C‐phycocyanin is a potential therapeutic strategy with anti‐inflammatory and anti‐ulcerogenic effects against ethanol‐induced gastric ulcer.     

Anti‐oxidative effect of the β‐blocker carvedilol on diabetic nephropathy in non‐obese type 2 diabetic rats

Oxidative stress plays an important role in the pathogenesis of diabetic nephropathy. The β‐blocker carvedilol has been proven to have an anti‐oxidant property. The aim of the present study was to elucidate the effects of carvedilol on diabetic nephropathy. At 20 weeks of age, male Spontaneously Diabetic Torii (SDT) rats were divided into three groups based on treatment: (i) an INS group (administered insulin); (ii) a CAR group (administered 10 mg/kg per day, p.o., carvedilol); and (iii) a diabetic (DM) group (administered vehicle). Rats were treated for a period of 10 weeks and were killed at 30 weeks of age. Urinary albumin excretion, renal histomorphology, and oxidative stress were evaluated. Urinary albumin excretion was significantly lower in the CAR than DM group (42.82 ± 3.94 vs 76.62 ± 13.74 mg/day respectively; P < 0.05). The mesangial index was lower in the CAR group than in the DM group. Urinary excretion of 8‐hydroxydeoxyguanosine (8‐OHdG), the number of 8‐OHdG‐positive cells in glomeruli, and the mRNA expression of NADPH oxidase p22^phox and p47^phox were also lower in the CAR than DM group. However, haemoglobin A1c (HbA1c) and blood pressure levels were comparable between the two groups. The results suggest that carvedilol could prevent the progression of diabetic nephropathy by suppressing oxidative stress.