Acetaminophen has a reasonable safety profile when consumed in therapeutic doses. However, it could induce hepatotoxicity and even acute liver failure when taken at an overdose. Pioglitazone, PPARγ ligand, is clinically tested and used in treatment of diabetes. PPARγ is a key nuclear hormone receptor of lipid metabolisms and regulates several gene transcriptions associated with differentiation, growth arrest, and apoptosis. The aim of our study was to evaluate the hepatoprotective activity of pioglitazone on acetaminophen-induced hepatotoxicity and to understand the relationship between the PPARγ and acetaminophen-induced hepato injury. For the experiment, Sprague-Dawley rats (160-180 g) were used and divided into four groups. Groups I and II were normal and experimental controls, respectively. Groups III and IV received the pioglitazone 20 mg/kg for 10 days. Hepatotoxicity was induced in Groups II and III on the eighth day with acetaminophen (i.p. 350 mg/kg body weight). The hepatoprotective effect was evaluated by performing an assay of the total protein, total bilirubin, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, and α-fetoprotein as well as glutathione peroxidase, lipid peroxidation, catalase, superoxide dismutase, and glutathione transferase and liver histopathology. The assay results were presented as mean and standard error of mean for each group. The study group was compared with the control group by one-way ANOVA test. A p value of <0.05 was considered significant. Pioglitazone significantly reduced the elevated level of above serum marker enzymes and also inhibits the free radical formation by scavenging hydroxyl ions. It also restored the level of LPO and significantly elevated the levels of endogenous antioxidant enzymes in acetaminophen-challenged hepatotoxicity. Liver histopathological examination showed that pioglitazone administration antagonized acetaminophen -induced liver pathological damage. Various biochemical estimations of different hepatic markers and antioxidant enzymes and histopathological studies of liver tissues glimpse a support to its significant hepatoprotective activity on acetaminophen -induced hepatotoxicity.
Interleukin-6 (IL-6) is the major activator of the acute phase response (APR). One important regulator of IL-6-activated APR is peroxisome proliferator-activated receptor alpha (PPARα). Currently, there is a growing interest in determining the role of PPARα in regulating APR; however, studies on the molecular mechanisms and signaling pathways implicated in mediating the effects of IL-6 on the expression of PPARα are limited. We previously revealed that IL-6 inhibits PPARα gene expression through CAAT/enhancer-binding protein transcription factors in hepatocytes. In this study, we determined that STAT1/3 was the direct downstream molecules that mediated the Janus kinase 2 (JAK2) and phosphatidylinositol-3 kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathways in IL-6-induced repression of PPARα. Treatment of cells with pharmacological inhibitors of JAK2, PI3K, AKT, and mTOR attenuated the inhibitory effect of IL-6 on PPARα protein in a dose-dependent manner. These inhibitors also decreased the IL-6-induced repression of PPARα mRNA expression and promoter activity. Overexpression of STAT1 and STAT3 in HepG2 cells cotransfected with a reporter vector containing this PPARα promoter region revealed that both the expression plasmids inhibited the IL-6-induced repression of PPARα promoter activity. In the presence of inhibitors of JAK2 and mTOR (AG490 and rapamycin, respectively), IL-6-regulated protein expression and DNA binding of STAT1 and STAT3 were either completely or partially inhibited simultaneously, and the IL-6-induced repression of PPARα protein and mRNA was also inhibited. This study has unraveled novel pathways by which IL-6 inhibits PPARα gene transcription, involving the modulation of JAK2/STAT1-3 and PI3K/AKT/mTOR by inducing the binding of STAT1 and STAT3 to STAT-binding sites on the PPARα promoter. Together, these findings represent a new model of IL-6-induced suppression of PPARα expression by inducing STAT1 and STAT3 phosphorylation and subsequent down-regulation of PPARα mRNA expression.
This study was aimed to evaluate the effect of Strobilanthes crispus extract for possible protection against lipid peroxidation and DNA damage induced by iron nitrilotriacetate (Fe-NTA) and hydrogen peroxide (H(2)O(2)). Fe-NTA is a potent nephrotoxic agent and induces acute and subacute renal proximal tubular necrosis by catalyzing the decomposition of H(2)O(2)-derived production of hydroxyl radicals, which are known to cause lipid peroxidation and DNA damage. Incubation of postmitochondrial supernatant and/or calf thymus DNA with H(2)O(2) (40 mM) in the presence of Fe-NTA (0.1 mM) induces lipid peroxidation and DNA damage to about 2.3-fold and 2.9-fold, respectively, as compared to control (P < 0.05). In lipid peroxidation protection studies, S. crispus treatment showed a dose-dependent inhibition (45-53% inhibition, P < 0.05) of Fe-NTA and H(2)O(2) induced lipid peroxidation. Similarly, in DNA damage protection studies, S. crispus treatment also showed a dose-dependent inhibition (18-30% inhibition, P < 0.05) of DNA damage. In addition, the protection was closely related to the content of phenolic compounds as evident by S. crispus extract showing the value of 124.48 mg/g total phenolics expressed as gallic acid equivalent (GAE, mg/g of extract). From these studies, it is concluded that S. crispus inhibits peroxidation of membrane lipids and DNA damage induced by Fe-NTA and H(2)O(2) and possesses the potential to be used to treat or prevent degenerative diseases where oxidative stress is implicated.
Curcumin (diferuloylmethane), a biologically active ingredient derived from rhizome of the plant Curcuma longa, has potent anticancer properties as demonstrated in a plethora of human cancer cell lines/animal carcinogenesis model and also acts as a biological response modifier in various disorders. We have reported previously that dietary supplementation of curcumin suppresses renal ornithine decarboxylase (Okazaki et al. Biochim Biophys Acta 1740:357-366, 2005) and enhances activities of antioxidant and phase II metabolizing enzymes in mice (Iqbal et al. Pharmacol Toxicol 92:33-38, 2003) and also inhibits Fe-NTA-induced oxidative injury of lipids and DNA in vitro (Iqbal et al. Teratog Carcinog Mutagen 1:151-160, 2003). This study was designed to examine whether curcumin possess the potential to suppress the oxidative damage caused by kidney-specific carcinogen, Fe-NTA, in animals. In accord with previous report, at 1 h after Fe-NTA treatment (9.0 mg Fe/kg body weight intraperitoneally), a substantial increased formation of 4-hydroxy-2-nonenal (HNE)-modified protein adducts in renal proximal tubules of animals was observed. Likewise, the levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) and protein reactive carbonyl, an indicator of protein oxidation, were also increased at 1 h after Fe-NTA treatment in the kidneys of animals. The prophylactic feeding of animals with 1.0% curcumin in diet for 4 weeks completely abolished the formation of (i) HNE-modified protein adducts, (ii) 8-OHdG, and (iii) protein reactive carbonyl in the kidneys of Fe-NTA-treated animals. Taken together, our results suggest that curcumin may afford substantial protection against oxidative damage caused by Fe-NTA, and these protective effects may be mediated via its antioxidant properties. These properties of curcumin strongly suggest that it could be used as a cancer chemopreventive agent.
Probucol is a clinically used cholesterol-lowering drug, with pronounced antioxidant properties. We have reported previously, that dietary supplementation of probucol enhances NAD(P)H:quinone reductase (Iqbal M, Okada S (2003) Pharmacol Toxicol 93:259-263) and inhibits Fe-NTA induced lipid peroxidation and DNA damage in vitro (Iqbal M, Sharma SD, Oakada (2004) Redox Rep 9:167-172). Further to this, in the present study, we evaluated the modulatory effect of probucol on iron nitrilotriacetae (Fe-NTA) dependent renal carcinogenesis, hyperproliferative response and oxidative stress. In Fe-NTA alone treated group, a 20% renal cell tumor incidence was recorded whereas, in N-diethylnitrosamine (DEN)-initiated and Fe-NTA promoted animals, the percentage tumor incidence was increased to 70% as compared with untreated controls. No tumor incidence was recorded in DEN-initiated, nonpromoted group. Diet supplemented with 1.0% probucol fed prior to, during and after Fe-NTA treatment in DEN-initiated animals afforded >65% protection in renal cell tumor incidence. Probucol fed diet pretreatment also resulted a significant and dose dependent inhibition of Fe-NTA induced renal ornithine decarboxylase (ODC) activity. In oxidative stress studies, Fe-NTA alone treatment enhanced lipid peroxidation, accompanied by a decrease in the level of GSH, activities of antioxidants and phase II metabolizing enzymes in kidney concomitant with histolopathological changes. These changes were significantly and dose-dependently alleviated by probucol fed diet. From this data, it can be concluded that probucol can modulates toxic and tumor promoting effects of Fe-NTA and can serve as a potent chemopreventive agent to suppress oxidant induced tissue injury and carcinogenesis, in addition to being a cholesterol lowering and anti-atherogenic drug.
Tissue engineering approaches often require expansion of cell numbers in vitro to accelerate tissue regenerative processes. Although several studies have used this technique for therapeutic purposes, a major concern involving the use of isolated chondrocyte culture is the reduction of extracellular matrix (ECM) protein expressed due to the transfer of cells from the normal physiological milieu to the artificial 2D environment provided by the cell culture flasks. To overcome this issue, the use of alginate hydrogel beads as a substrate in chondrocyte cultures has been suggested. However, the resultant characteristics of cells embedded in this bead is elusive. To elucidate this, a study using chondrocytes isolated from rabbit knee articular cartilage expanded in vitro as monolayer and chondrocyte-alginate constructs was conducted. Immunohistochemical evaluation and ECM distribution was examined with or without transforming growth factor (TGF-β1) supplement to determine the ability of cells to express major chondrogenic proteins in these environments. Histological examination followed by transmission electron microscopy and scanning electron microscopy was performed to determine the morphology and the ultrastructural characteristics of these cells. Results demonstrated a significant increase in glycosaminoglycan/mg protein levels in chondrocyte cultures grown in alginate construct than in monolayer cultures. In addition, an abundance of ECM protein distribution surrounding chondrocytes cultured in alginate hydrogel was observed. In conclusion, the current study demonstrates that the use of alginate hydrogel beads in chondrocyte cultures with or without TGF-β1 supplement provided superior ECM expression than monolayer cultures.
Conventional therapies for severe ischemic heart disease are limited in applicability. While several angiogenesis researches have shown novel efficacy, safety and feasibility for clinical use, recently we have started the clinical trial of a sole cell therapy using autologous bone marrow mononuclear cells transplantation targeted into ischemic hibernating myocardium. Here, we review the background of bone marrow cell research and introduce therapeutic angiogenesis for severe ischemic heart disease by autologous bone marrow cells transplantation.
Metastasized lung and liver cancers cause over 2 million deaths annually, and are amongst the top killer cancers worldwide. Morinda citrifolia (Noni) leaves are traditionally consumed as vegetables in the tropics. The macro and micro effects of M. citrifolia (Noni) leaves on metastasized lung cancer development in vitro and in vivo were compared with the FDA-approved anti-cancer drug Erlotinib. The extract inhibited the proliferation and induced apoptosis in A549 cells (IC50 = 23.47 μg/mL) and mouse Lewis (LL2) lung carcinoma cells (IC50 = 5.50 μg/mL) in vitro, arrested cancer cell cycle at G0/G1 phases and significantly increased caspase-3/-8 without changing caspase-9 levels. The extract showed no toxicity on normal MRC5 lung cells. Non-small-cell lung cancer (NSCLC) A549-induced BALB/c mice were fed with 150 and 300 mg/kg M. citrifolia leaf extract and compared with Erlotinib (50 mg/kg body weight) for 21 days. It significantly increased the pro-apoptotic TRP53 genes, downregulated the pro-tumourigenesis genes (BIRC5, JAK2/STAT3/STAT5A) in the mice tumours, significantly increased the anti-inflammatory IL4, IL10 and NR3C1 expression in the metastasized lung and hepatic cancer tissues and enhanced the NFE2L2-dependent antioxidant responses against oxidative injuries. The extract elevated serum neutrophils and reduced the red blood cells, haemoglobin, corpuscular volume and cell haemoglobin concentration in the lung cancer-induced mammal. It suppressed inflammation and oedema, and upregulated the endogenous antioxidant responses and apoptotic genes to suppress the cancer. The 300 mg/kg extract was more effective than the 50 mg/kg Erlotinib for most of the parameters measured.
The protective activity of N-(2-hydroxyphenyl)acetamide (NA-2) and NA-2-coated gold nanoparticles (NA-2-AuNPs) in glycerol-treated model of acute kidney injury (AKI) in mice was investigated. NA-2 (50 mg/kg) and NA-2-AuNPs (30 mg/kg) were given to the animals for four days followed by 24-h water deprivation and injection of 50% glycerol (10 ml/kg im). The animals were sacrificed on the next day. Blood and kidneys were collected for biochemical investigations (urea and creatinine), histological studies (hematoxylin and eosin; and periodic acid-Schiff staining), immunohistochemistry (actin and cyclooxygenase-2, Cox-2), and real-time RT-PCR (inducible nitric oxide synthase, iNOS; nuclear factor-κB p50, NFκB; hemeoxygenase-1, HO-1; and kidney injury molecule-1, Kim-1). NA-2 protected renal tubular necrosis and inflammation, though the result of NA-2-AuNPs was better than compound alone and it also exhibited the activity at far less dose. The test compound and its gold nano-formulation decreased the levels of serum urea and creatinine level in the treated animals. Both NA-2 and NA-2-AuNPs also conserved actin cytoskeleton, and lowered COX-2 protein expression. Moreover, the mRNA expressions of iNOS and NFkB p50 were down-regulated, and HO-1 and Kim-1 genes were up-regulated. We conclude that NA-2 and NA-2-AuNPs ameliorates kidney inflammation and injury in glycerol-induced AKI animal model via anti-oxidant and anti-inflammatory mechanisms which make it a suitable candidate for further studies. We believe that these findings will contribute in the understanding of the mechanism of action of paracetamol-like drugs and can be considered for clinical research for the prevention of AKI.
Cytokines play a key role in the pathogenesis of coronary artery disease (CAD). The aim of current study was to investigate the relationship between the serum concentrations of 12 cytokines with mortality and extent of CAD in individuals undergoing angiography and healthy controls. 342 CAD patients were recruited and divided into 2 groups: those with ≥50% occlusion in at least one coronary artery [Angiography (+)] or <50% obstruction in coronary arteries [Angiography (-)]. Also 120 healthy subjects were enrolled as control group. Lipid profile, fasting blood glucose, body mass index, and blood pressure were evaluated in all the subjects. An Evidence Investigator® was used for measuring 12 cytokines (IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, TNF-α, MCP-1, IFN-γ, EGF, VEGF) using sandwich chemiluminescent assays. Univariate analysis, multivariate regression models, ROC, and Kaplan-Meier survival curves were used for exploring the candidate markers in CAD patients. Serum level of IFN-γ, IL-4, MCP-1, EGF, IL-6, and IL-8 were markedly higher in angiogram-positive patients, while VEGF concentrations were significantly (P 2.16 pg/mL IL-6 had a > 94% sensitivity and 70% specificity in predicting 2 years mortality in the subjects with a serum MCP-1 > 61.95 pg/ mL, and patients having IL-6/MCP-1 combination had a shorter survival.Our findings demonstrate that CAD patients with serum MCP-1 and IL-6 levels of >61.95 and >2.16 pg/mL had a higher mortality with 94.1% sensitivity and 70.5% specificity for predicting mortality in CAD patients.
Secretory phospholipase A2 (sPLA2) group of enzymes have been shown to hydrolyze phospholipids, among which sPLA2 Group V (GV) and Group X (GX) exhibit high selectivity towards phosphatidylcholine-rich cellular plasma membranes. The enzymes have recently emerged as key regulators in lipid droplets formation and it is hypothesized that sPLA2-GV and GX enhanced cell proliferation and lipid droplet accumulation in colon cancer cells (HT29). In this study, cell viability and lipid droplet accumulation were assessed by Resazurin assay and Oil-Red-O staining. Interestingly, both sPLA2-GV and GX enzymes reduced intracellular lipid droplet accumulation and did not significantly affect cell proliferation in HT29 cells. Incubation with varespladib, a pan-inhibitor of sPLA2-Group IIA/V/X, further suppressed lipid droplets accumulation in sPLA2-GV but have no effects in sPLA2-GX-treated cells. Further studies using catalytically inactive sPLA2 enzymes showed that the enzymes intrinsic catalytic activity is required for the net reduction of lipid accumulation. Meanwhile, inhibition of intracellular phospholipases (iPLA2-γ and cPLA2-α) unexpectedly enhanced lipid droplet accumulation in both sPLA2-GV and GX-treated cells. The findings suggested an interconnected relationship between extracellular and intracellular phospholipases in lipid cycling. Previous studies indicated that sPLA2 enzymes are linked to cancer development due to their ability to induce release of arachidonic acid and eicosanoids as well as the stimulation of lipid droplet formation. This study showed that the two enzymes work in a distinct manner and they neither confer proliferative advantage nor enhanced the net lipid droplet accumulation in HT29 cells.
The crystallins are a family of monomeric proteins present in the mammalian lens and mutations in these proteins cause various forms of cataracts. The aim of our current study is to emphasize the structural characterization of aggregation propensity of mutation R58H on γD crystallin using molecular dynamics (MD) approach. MD result revealed that difference in the sequence level display a wide variation in the backbone atomic position, and thus exhibits rigid conformational dynamics. Changes in the flexibility of residues favoured to increase the number of intra-molecular hydrogen bonds in mutant R58H. Moreover, notable changes in the hydrogen bonding interaction resulted to cause the misfolding of mutant R58H by introducing α-helix. Principal component analysis (PCA) result suggested that mutant R58H showed unusual conformational dynamics along the two principal components when compared to the wild-type (WT)-γD crystallin. In a nutshell, the increased surface hydrophobicity could be the cause of self-aggregation of mutant R58H leading to aculeiform cataract.
Infertility is a subject of worldwide concern as it affects approximately 15% of couples. Among the prime contributors of infertility, urogenital bacterial infections have lately gained much clinical importance. Staphylococcal species are commensal bacteria and major human pathogens mediating an array of reproductive tract infections. Emerging evidences are 'bit by bit' revealing the mechanisms by which Staphylococci strategically disrupt normal reproductive functions. Staphylococcal species can directly or through hematogenous routes can invade the reproductive tissues. In the testicular cells, epididymis as well as in various compartments of female reproductive tracts, the pathogen recognition receptors, toll-like receptors (TLRs), can recognize the pathogen-associated molecular patterns on the Staphylococci and thereby activate inflammatory signalling pathways. These elicit pro-inflammatory mediators trigger other immune cells to infiltrate and release further inflammatory agents and reactive oxygen species (ROS). Adaptive immune responses may intensify the inflammation-induced reproductive tissue damage, particularly via activation of T-helper (Th) cells, Th1 and Th17 by the innate components or by staphylococcal exotoxins. Staphylococcal surface factors binding with sperm membrane proteins can directly impair sperm functions. Although Staphylococci, being one of the most virulent bacterial species, are major contributors in infection-induced infertility in both males and females, the mechanisms of their operations remain under-discussed. The present review aims to provide a comprehensive perception of the possible mechanisms of staphylococcal infection-induced male and female infertility and aid potential interventions to address the lack of competent therapeutic measures for staphylococcal infection-induced infertility.