scholarly journals Modulatory effect of Persea Americana oil against diethylnitrosamine-induced hepatotoxicity in rats: a proposed mechanism

2021 ◽  
Vol 45 (1) ◽  
Author(s):  
Omayma A. R. Abozaid ◽  
Lobna M. Anees ◽  
Gehan R. Abdel-Hamed
Keyword(s):  
Nadph Oxidase ◽  
Caspase 3 ◽  
Persea Americana ◽  
Gene Expressions ◽  
Apoptosis Pathway ◽  
Mitochondrial Apoptosis Pathway ◽  
Apoptotic Effect ◽  
Oxide Synthase ◽  
Parp 1 ◽  
Inducible Nitric Oxide

Abstract Background The purpose of this study was to investigate the effectiveness of Persea Americana (avocado) oil against diethylnitrosamine (DEN)-induced hepatotoxicity in rats. Methods For the induction of hepatotoxicity, DEN was administrated orally in a dose of 20 mg/kg B.wt for 6 successive weeks, and then the animals were gavaged with Persea Americana oil in a dose of 4 mL/kg b.wt. daily for another 6 weeks. Serum caspase-3 activity and poly (ADP-ribose) polymerase-1 (PARP-1) levels were estimated; in addition to gene expressions for NADPH oxidase, inducible nitric oxide synthase (iNOS), Bcl-2, and Bax were detected. Results The DEN-intoxicated group exhibited a remarkable increase in NADPH oxidase and iNOS expression combined with over-activation of PARP-1 and increased antiapoptotic Bcl-2 gene expression, whereas the expression of apoptotic biomarkers significantly decreased. On the other hand, treatment with Persea Americana oil significantly suppressed the elevated levels of hepatic enzymes and improved histopathological alterations in the liver. Furthermore, these groups displayed marked downregulation in NADPH oxidase and iNOS expressions. Persea Americana oil suppressed the expression of the antiapoptotic Bcl-2, activated the intrinsic mitochondrial apoptosis pathway through upregulation of pro-apoptotic Bax, and induced an obvious increase in caspase-3 activity. Moreover, Persea Americana oil administration markedly inhibited the activity of PARP-1. Conclusions This study indicated the promising potential of Persea Americana oil against DEN-induced hepatic injury through its anti-oxidative activity and pro-apoptotic effect via caspase activation and PARP-1 inhibition.

Geldanamycin inhibits hemorrhage-induced increases in caspase-3 activity: role of inducible nitric oxide synthase

2007 ◽  
Vol 103 (3) ◽  
pp. 1045-1055 ◽  
Author(s):  
Juliann G. Kiang ◽  
Phillip D. Bowman ◽  
Xinyue Lu ◽  
Yansong Li ◽  
Brian W. Wu ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Inducible Nitric Oxide Synthase ◽  
Caspase 3 ◽  
Gene Transfection ◽  
Organ Injury ◽  
Molecular Events ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

Hemorrhage has been shown to increase inducible nitric oxide synthase (iNOS) and deplete ATP levels in tissues and geldanamycin limits both processes. Moreover, it is evident that inhibition of iNOS reduces caspase-3 and increases survival. Thus we sought to identify the molecular events responsible for the beneficial effect of geldanamycin. Hemorrhage in mice significantly increased caspase-3 activity and protein while treatment with geldanamycin significantly limited these increases. Similarly, geldanamycin inhibited increases in proteins forming the apoptosome (a complex of caspase-9, cytochrome c, and Apaf-1). Modulation of the expression of iNOS by iNOS gene transfection or siRNA treatment demonstrated that the level of iNOS correlates with caspase-3 activity. Our data indicate that geldanamycin limits caspase-3 expression and protects from organ injury by suppressing iNOS expression and apoptosome formation. Geldanamycin, therefore, may prove useful as an adjuvant in fluids used to treat patients suffering blood loss.

scholarly journals virB-Mediated Survival of Brucella abortus in Mice and Macrophages Is Independent of a Functional Inducible Nitric Oxide Synthase or NADPH Oxidase in Macrophages

2002 ◽  
Vol 70 (9) ◽  
pp. 4826-4832 ◽  
Author(s):  
Yao-Hui Sun ◽  
Andreas B. den Hartigh ◽  
Renato de Lima Santos ◽  
L. Garry Adams ◽  
Renée M. Tsolis
Keyword(s):  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Nadph Oxidase ◽  
Inducible Nitric Oxide Synthase ◽  
Brucella Abortus ◽  
In Vivo Models ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

ABSTRACT The Brucella abortus virB locus is required for establishing chronic infection in the mouse. Using in vitro and in vivo models, we investigated whether virB is involved in evasion of the bactericidal activity of NADPH oxidase and the inducible nitric oxide synthase (iNOS) in macrophages. Elimination of NADPH oxidase or iNOS activity in macrophages in vitro increased recovery of wild-type B. abortus but not recovery of a virB mutant. In mice lacking either NADPH oxidase or iNOS, however, B. abortus infected and persisted to the same extent as it did in congenic C57BL/6 mice up until 60 days postinfection, suggesting that these host defense mechanisms are not critical for limiting bacterial growth in the mouse. A virB mutant did not exhibit increased survival in either of the knockout mouse strains, indicating that this locus does not contribute to evasion of nitrosative or oxidative killing mechanisms in vivo.

scholarly journals Lycium barbarumPolysaccharides Protect Rat Corneal Epithelial Cells against Ultraviolet B-Induced Apoptosis by Attenuating the Mitochondrial Pathway and Inhibiting JNK Phosphorylation

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Shaobo Du ◽  
Biao Han ◽  
Kang Li ◽  
Xuan Zhang ◽  
Xueli Sha ◽  
...  
Keyword(s):  
Caspase 3 ◽  
Underlying Mechanism ◽  
Mitochondrial Pathway ◽  
Ultraviolet B ◽  
Lycium Barbarum ◽  
Apoptosis Pathway ◽  
Corneal Epithelial ◽  
Mitochondrial Apoptosis Pathway ◽  
Induced Apoptosis

Lycium barbarumpolysaccharides (LBPs) have been shown to play a key role in protecting the eyes by reducing the apoptosis induced by certain types of damage. However, it is not known whether LBPs can protect damaged corneal cells from apoptosis. Moreover, no reports have focused on the role of LBPs in guarding against ultraviolet B- (UVB-) induced apoptosis. The present study aimed to investigate the protective effect and underlying mechanism of LBPs against UVB-induced apoptosis in rat corneal epithelial (RCE) cells. The results showed that LBPs significantly prevented the loss of cell viability and inhibited cell apoptosis induced by UVB in RCE cells. LBPs also inhibited UVB-induced loss of mitochondrial membrane potential, downregulation ofBcl-2, and upregulation ofBaxand caspase-3. Finally, LBPs attenuated the phosphorylation of c-Jun NH2-terminal kinase (JNK) triggered by UVB. In summary, LBPs protect RCE cells against UVB-induced damage and apoptosis, and the underlying mechanism involves the attenuation of the mitochondrial apoptosis pathway and the inhibition of JNK phosphorylation.

scholarly journals Gan-Qing-Ning Formula Inhibits the Growth of Hepatocellular Carcinoma by Promoting Apoptosis and Inhibiting Angiogenesis in H22 Tumor-Bearing Mice

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Fan-Yan Zeng ◽  
Kai-Li Zhao ◽  
Le-Zhen Lin ◽  
Ying Deng ◽  
Si Qin ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Antitumor Effect ◽  
Caspase 3 ◽  
Tumor Tissue ◽  
Mitochondrial Apoptosis ◽  
Apoptosis Pathway ◽  
Expression Levels ◽  
Mitochondrial Apoptosis Pathway ◽  
Tumor Bearing ◽  
Mrna Expression Levels

Objective. Gang-Qing-Ning (GQN) is a traditional Chinese medicine formula that has been used in the treatment of hepatocellular carcinoma (HCC) in the folk population for decades. However, scientific validation is still necessary to lend credibility to the traditional use of GQN against HCC. This study investigates the antitumor effect of GQN on H22 tumor-bearing mice and its possible mechanism. Methods. Fifty H22 tumor-bearing mice were randomly assigned to five groups. Three groups were treated with high, medium, and low dosages of GQN (27.68, 13.84, and 6.92 g/kg, respectively); the positive control group was treated with cytoxan (CTX) (20 mg/kg) and the model group was treated with normal saline. After 10 days’ treatment, the tumor inhibitory rates were calculated. Pathological changes in tumor tissue were observed, and the key proteins and genes of the mitochondrial apoptosis pathway were measured, as well as the mRNA expression levels of VEGF in tumor tissue. Results. The tumor inhibitory rates of high, medium, and low dosages of GQN groups were 47.39%, 38.26%, and 22.17%, respectively. The high dosage of the GQN group significantly increased the protein and mRNA expression levels of Bax, Cyt-C, and cleaved Caspase 3 (or Caspase 3) (P<0.01) but decreased the expression levels of Bcl-2, VEGF, and microvessel density (MVD) (P<0.01). Conclusions. The high dosage of GQN can significantly inhibit the tumor growth in H22 tumor-bearing mice. It exerts the antitumor effect by enhancing proapoptotic factors and inhibiting the antiapoptotic factor of the mitochondrial apoptosis pathway and inhibiting tumor angiogenesis.

Mechanisms of inflammatory neurodegeneration: iNOS and NADPH oxidase

2007 ◽  
Vol 35 (5) ◽  
pp. 1119-1121 ◽  
Author(s):  
G.C. Brown
Keyword(s):  
Nitric Oxide ◽  
Nadph Oxidase ◽  
Neuronal Death ◽  
Glutamate Release ◽  
Inos Expression ◽  
Calcium Dependent ◽  
Vesicular Release ◽  
Oxide Synthase ◽  
Oxide Inhibition ◽  
Inducible Nitric Oxide

Inflammation contributes to a wide variety of brain pathologies, apparently via glia killing neurons. A number of mechanisms by which inflammatory-activated microglia and astrocytes kill neurons have been identified in culture. These include iNOS (inducible nitric oxide synthase), which is expressed in glia only during inflammation, and PHOX (phagocytic NADPH oxidase) found in microglia and acutely activated by inflammation. High levels of iNOS expression in glia cause (i) NO (nitric oxide) inhibition of neuronal respiration, resulting in neuronal depolarization and glutamate release, followed by excitotoxicity, and (ii) glutamate release from astrocytes via calcium-dependent vesicular release. Hypoxia strongly synergizes with iNOS expression to induce neuronal death via mechanism (i), because NO inhibits cytochrome oxidase in competition with oxygen. Activation of PHOX (by cytokines, β-amyloid, prion protein, ATP or arachidonate) causes microglial proliferation and inflammatory activation; thus PHOX is a key regulator of inflammation. Activation of PHOX alone causes no death, but when combined with expressed iNOS results in extensive neuronal death via peroxynitrite production.

Sign in / Sign up

Export Citation Format

Share Document