scholarly journals Role of superoxide dismutase in survival of Leishmania within the macrophage

2003 ◽  
Vol 369 (3) ◽  
pp. 447-452 ◽  
Author(s):  
Sanjay GHOSH ◽  
Srikanta GOSWAMI ◽  
Samit ADHYA
Keyword(s):  
Superoxide Dismutase ◽  
Antisense Rna ◽  
Axenic Culture ◽  
Free Radical Damage ◽  
Enhanced Sensitivity ◽  
Mouse Macrophages ◽  
Parasite Survival ◽  
Radical Damage ◽  
Genus Leishmania

Intracellular parasitic protozoans of the genus Leishmania depend for their survival on the elaboration of enzymic and other mechanisms for evading toxic free-radical damage inflicted by their phagocytic macrophage host. One such mechanism may involve superoxide dismutase (SOD), which detoxifies reactive superoxide radicals produced by activated macrophages, but the role of this enzyme in parasite survival has not yet been demonstrated. We have cloned a SOD gene from L. tropica and generated SOD-deficient parasites by expressing the corresponding antisense RNA from an episomal vector. Such parasites have enhanced sensitivity to menadione and hydrogen peroxide in axenic culture, and a markedly reduced survival in mouse macrophages. These results indicate that SOD is a major determinant of intracellular survival of Leishmania.

Study of antioxidant potential in leaves, stems, nuts of Juglans regia L.

2012 ◽  
Vol 1 (10) ◽  
pp. 79 ◽  
Author(s):  
G. Raja* ◽  
Ivvala Anand Shaker ◽  
Inampudi Sailaja ◽  
R. Swaminathan ◽  
S. Saleem Basha ◽  
...  
Keyword(s):  
Free Radicals ◽  
Free Radical ◽  
Antioxidant Activities ◽  
Radical Scavenging Activity ◽  
Juglans Regia ◽  
Radical Scavenging ◽  
Antioxidant Compounds ◽  
Free Radical Damage ◽  
Radical Damage

Natural antioxidants can protect the human body from free radicals and retard the progress of many chronic diseases as well as lipid oxidative rancidity in foods. The role of antioxidants has protected effect against free radical damage that may cause many diseases including cancer. Primary sources of naturally occurring antioxidants are known as whole grains, fruits, and vegetables. Several studies suggest that regular consumption of nuts, mostly walnuts, may have beneficial effects against oxidative stress mediated diseases such as cardiovascular disease and cancer. The role of antioxidants has attracted much interest with respect to their protective effect against free radical damage that may cause many diseases including cancer. Juglans regia L. (walnut) contains antioxidant compounds, which are thought to contribute to their biological properties. Polyphenols, flavonoids and flavonols concentrations and antioxidant activity of Leaves, Stems and Nuts extract of Juglans regia L. as evaluated using DPPH, ABTS, Nitric acid, hydroxyl and superoxide radical scavenging activity, lipid peroxidation and total oxidation activity were determined. The antioxidant activities of Leaves, Stems and Nuts extract of Juglans regia L. were concentration dependent in different experimental models and it was observed that free radicals were scavenged by the test compounds in all the models.

scholarly journals Lens Lipid Peroxides and Glutathione Concentrations in Diabetic Cataract

1997 ◽  
Vol 34 (2) ◽  
pp. 190-192 ◽  
Author(s):  
D Özmen ◽  
I Mutaf ◽  
B Özmen ◽  
J Mentes ◽  
O Bayindir
Keyword(s):  
G Protein ◽  
Lipid Peroxide ◽  
Lipid Peroxides ◽  
Thiobarbituric Acid ◽  
Thiobarbituric Acid Reactive Substances ◽  
Diabetic Cataract ◽  
Free Radical Damage ◽  
Significant Difference ◽  
Radical Damage

This study aims to explore the role of reactive oxygen radicals in the genesis of diabetic cataract. Lipid peroxide (LPO) concentrations in senile ( n = 30) and diabetic ( n = 14) cataractous lenses, were determined as thiobarbituric acid-reactive substances (TBARS) by a method modified from Satoh and Yagi, and reduced glutathione (GSH) concentrations were measured according to Beutler. Lens LPO levels (mean, SD; nmol TBARS/g protein) were significantly higher in diabetics (107·54, 18·12) than senile cataractous subjects (53·54, 15·48) ( P < 0·0001). Lens GSH levels (mean, SD; nmol/g protein) showed no significant difference between diabetics (4·29, 2·05) and senile cataractous subjects (4·68, 3·12). These results suggest that free radical damage is more effective in the genesis of diabetic cataract than in senile cataract.

scholarly journals Role of prokaryotic Cu,Zn superoxide dismutase in pathogenesis

2003 ◽  
Vol 31 (6) ◽  
pp. 1326-1329 ◽  
Author(s):  
A. Battistoni
Keyword(s):  
Superoxide Dismutase ◽  
Bacterial Pathogens ◽  
Superoxide Dismutases ◽  
Bacterial Survival ◽  
Bacterial Killing ◽  
Multiple Copies ◽  
Micro Organisms ◽  
Radical Damage ◽  
Type Strains

Several bacterial pathogens possess sodC genes that encode periplasmic or membrane-associated Cu,Zn superoxide dismutases. Since professional phagocytes generate large amounts of reactive oxygen species to control the growth of invading micro-organisms, Cu,Zn superoxide dismutase might protect infectious bacteria from oxy-radical damage and facilitate their survival within the host. This idea has gained support from studies showing that sodC-null mutants of different bacteria are less virulent than their parental wild-type strains, and from the discovery that, despite apparent dispensability for growth under laboratory conditions, various pathogens (including several highly virulent Salmonella strains) possess multiple copies of sodC. Our studies indicate that Cu,Zn superoxide dismutase effectively protects bacteria from phagocytic killing, and that the role in infection of the redundant sodC genes may vary in distinct Salmonella enterica serovars. More unexpectedly, we have found that Cu,Zn superoxide dismutase also modulates bacterial survival within epithelial cells, where bacterial killing appears to be mediated by an NAD(P)H oxidase resembling the enzyme complex typical of phagocytes. Finally, a striking feature of Cu,Zn superoxide dismutases from bacterial pathogens is their apparent ability to exploit the structural versatility of the enzyme to modulate its function. In fact, several enzyme variants exhibit unique properties that may lead to the acquisition of novel specialized functions distinct from superoxide dismutation.

The role of iron in oxygen-free radical damage during kidney storage at hypothermia

Cryobiology ◽  
1985 ◽  
Vol 22 (6) ◽  
pp. 614 ◽  
Author(s):  
B. Fuller ◽  
C. Green ◽  
G. Healing ◽  
S. Marley ◽  
S. Simpkin ◽  
...  
Keyword(s):  
Free Radical ◽  
Oxygen Free Radical ◽  
Free Radical Damage ◽  
Radical Damage

scholarly journals The 29-Kilodalton Thiol-Dependent Peroxidase of Entamoeba histolytica Is a Factor Involved in Pathogenesis and Survival of the Parasite during Oxidative Stress

2007 ◽  
Vol 6 (4) ◽  
pp. 664-673 ◽  
Author(s):  
Abhik Sen ◽  
Nabendu Sekhar Chatterjee ◽  
M. Ali Akbar ◽  
Nilay Nandi ◽  
Pradeep Das
Keyword(s):  
Oxidative Stress ◽  
Entamoeba Histolytica ◽  
Antisense Rna ◽  
Antioxidant Activities ◽  
Cytotoxic Activities ◽  
Oxygen Species ◽  
Tissue Invasion ◽  
Ros Accumulation ◽  
Parasite Survival

ABSTRACT The 29-kDa surface antigen (thiol-dependent peroxidase; Eh29) of Entamoeba histolytica exhibits peroxidative and protective antioxidant activities. During tissue invasion, the trophozoites are exposed to oxidative stress and need to deal with highly toxic reactive oxygen species (ROS). In this investigation, attempts have been made to understand the role of the 29-kDa peroxidase gene in parasite survival and pathogenesis. Inhibition of eh29 gene expression by antisense RNA technology has shown approximately 55% inhibition in eh29 expression, maximum ROS accumulation, and significantly lower viability in 29-kDa downregulated trophozoites during oxidative stress. The cytopathic and cytotoxic activities were also found to decrease effectively in the 29-kDa downregulated trophozoites. Size of liver abscesses was substantially lower in hamsters inoculated with 29-kDa downregulated trophozoites compared to the normal HM1:IMSS. These findings clearly suggest that the 29-kDa protein of E. histolytica has a role in both survival of trophozoites in the presence of ROS and pathogenesis of amoebiasis.

scholarly journals Regulation of photosynthetic electron flow on dark to light transition by ferredoxin:NADP(H) oxidoreductase interactions

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Manuela Kramer ◽  
Melvin Rodriguez-Heredia ◽  
Francesco Saccon ◽  
Laura Mosebach ◽  
Manuel Twachtmann ◽  
...  
Keyword(s):  
Electron Transport ◽  
Electron Flow ◽  
Carbon Assimilation ◽  
Photosynthetic Electron Transport ◽  
Immunogold Labelling ◽  
Free Radical Damage ◽  
Transport Pathways ◽  
Photosynthetic Electron Flow ◽  
Radical Damage

During photosynthesis, electron transport is necessary for carbon assimilation and must be regulated to minimize free radical damage. There is a longstanding controversy over the role of a critical enzyme in this process (ferredoxin:NADP(H) oxidoreductase, or FNR), and in particular its location within chloroplasts. Here we use immunogold labelling to prove that FNR previously assigned as soluble is in fact membrane associated. We combined this technique with a genetic approach in the model plant Arabidopsis to show that the distribution of this enzyme between different membrane regions depends on its interaction with specific tether proteins. We further demonstrate a correlation between the interaction of FNR with different proteins and the activity of alternative photosynthetic electron transport pathways. This supports a role for FNR location in regulating photosynthetic electron flow during the transition from dark to light.

Clinical Role of Antioxidants in the Treatment of Diseases

2019 ◽  
pp. 392-401 ◽  
Author(s):  
Kirti Rani
Keyword(s):  
Oxidative Stress ◽  
Coronary Heart Disease ◽  
Heart Disease ◽  
Clinical Role ◽  
Free Radical Damage ◽  
Potential Benefits ◽  
Risk Of Cancer ◽  
Radical Damage ◽  
Wide Assortment

Antioxidants are our first line of defense against free radical damage and are critical for maintaining optimum healthcare. Although most of the present day research is focused on the potential benefits of antioxidant nutrients or supplements, it has become clear that the best protection against oxidative stress involves a wide assortment of interrelated antioxidants and antioxidant cofactors. Additionally, the combination of several suboptimal concentrations of these kinds of detoxifying supplements may have an additive or even synergistic role to decrease the risk of some of diseases which are caused by aging. Adequate intake of fruit and vegetables have essential antioxidants like B-carotene and vitamin C, which are reported for decreasing the risk of cancer and coronary heart disease (CHD).

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