metallothionein and 1-1-diphenyl-2-picrylhydrazyl

Plantago ovata Forsk is an annual herb with immense medicinal importance, the seed and husk of which is used in the treatment of chronic constipation, irritable bowel syndrome, diarrhea since ancient times. Zinc, an essential metal, is required by plants as they form important components of zinc finger proteins and also aid in synthesis of photosynthetic pigments such as chlorophyll. However, in excess amount Zn causes chlorosis of leaf and shoot tissues and generate reactive oxygen species. The present study is aimed at investigating the changes in expression levels of MT2 gene in Plantago ovata under zinc stress. Data show up to 1.66 fold increase in expression of PoMT2 in 1000 µM ZnSO

Topics: Biphenyl Compounds; Chlorophyll; Chlorophyll A; Dose-Response Relationship, Drug; Gene Expression Regulation, Plant; Metallothionein; Oxidation-Reduction; Oxidative Stress; Picrates; Plant Extracts; Plant Proteins; Plant Roots; Plant Shoots; Plantago; Seedlings; Seeds; Zinc Sulfate

The present study aimed to explore the ability of vanillin to ameliorate the adverse effects induced by potassium bromate (KBrO3) in the renal tissue. Our results showed a significant increase in hydrogen peroxide, superoxide anion, malondialdehyde, advanced oxidation protein product and protein carbonyl levels in the kidney of KBrO3 treated mice, compared with the control group. Nephrotoxicity was evidenced by a decrease in plasma uric acid and kidney glutathione levels, Na(+)-K(+)-ATPase, lactate dehydrogenase and catalase activities. Additionally, creatinine and urea levels significantly increased in the plasma and declined in the urine. Also, Kidney glutathione peroxidase, superoxide dismutase, metallothionein (MT1 and MT2) mRNA expression remarkably increased. These modifications in biochemical and molecular values were substantiated by histopathological data. Co-treatment with vanillin restored these parameters to near control values. Interestingly, vanillin proved to possess, in vitro, a stronger scavenging radical activity than vitamin C and Trolox. Thus, vanillin inhibited KBrO3-induced damage via its antioxidant and antiradical activities as well as its capacity to protect genes expression and histopathological changes.

Topics: Adenosine Triphosphatases; Animals; Antioxidants; Benzaldehydes; Benzothiazoles; Biphenyl Compounds; Bromates; Environmental Pollutants; Hair Preparations; Kidney; Lipid Peroxidation; Metallothionein; Mice; Oxidative Stress; Picrates; Sulfonic Acids; Up-Regulation

Mammalian metallothioneins (MT) have been reported to scavenge free radicals. There is no experimental evidence to show that fish MT has a similar property. In the present study cadmium-induced MT (Cd-MT) from the liver of an Indian freshwater fish Channa punctata Bloch was investigated for its free radical scavenging activity using three different in vitro assays. Exposure to cadmium chloride (0.2 mg/kg body weight; three doses on alternate days) resulted in a marked induction of Cd-MT in liver. Only a single isoform of Cd-MT was found to be induced. Molecular weight of Cd-MT was found to be 14 kDa as deduced by SDS-PAGE analysis. The purified Cd-MT effectively scavenged the following free radicals: superoxide radical (O2*-), 2,2'-azinobis 3-ethylbenzothiazoline-6-sulfonic acid (ABTS*+) and 1,1-diphenyl-picrylhydrazyl radical (DPPH*). The radical scavenging effect was found to be concentration-dependent. Also, the purified MT exhibited an inhibitory effect on ferric nitrilotriacetate (Fe-NTA) induced oxidative DNA damage in vitro. The cysteine residues of MT are proposed to be the main candidate for its radical scavenging activity. Findings of the present study strongly suggest a free radical scavenging role for fish MT. Present study adds to the little existing knowledge about fish MT and its possible biological functions.

Topics: Animals; Benzothiazoles; Biphenyl Compounds; Cadmium; DNA; DNA Damage; Ferric Compounds; Free Radical Scavengers; Free Radicals; Hydrazines; Kidney; Liver; Metallothionein; Molecular Weight; Muscle, Skeletal; Nitrilotriacetic Acid; Nitrites; Perciformes; Picrates; Sulfonic Acids; Superoxides

The high concentration of zinc in the hippocampal mossy fiber axon boutons is localized in the vesicles and is mobilized by exocytosis of the zinc-laden vesicles. Furthermore, the mammalian hippocampi contain metallothionein (MT) isoforms which regulate the steady state concentration of zinc, an important antioxidant. Indeed, zinc deprivation leads to an increased lipid peroxidation, reduces the activity of Cu++-Zn++ superoxide dismutase, and protect against oxidative stress such as exposure to ultraviolet A irradiation. By employing electron spin resonance (ESR) spectroscopy, we have demonstrated that rat hippocampal MT isoforms 1 and 2 were able to scavenge 1,1-diphenyl-2-picrylhydrazyl radicals (DPPH), hydroxyl radicals (*OH) generated in a Fenton reaction, and superoxide anions (O2*-) generated by the hypoxanthine and xanthine oxidase system. In addition, MT-1 isoform protected the isolated hepatocytes from lipid peroxidation as determined by thiobarbituric acid bound malondialdehyde. MT antibodies scavenged DPPH radicals, hydroxyl radicals and reactive oxygen species but not superoxide anions. The results of these studies suggest that although both isoforms of MT are able to scavenge free radicals, the MT-1 appears to be a superior scavenger of superoxide anions and 1,1-diphenyl-2-picrylhydrazyl radicals. Moreover, antibodies formed against MT isoform retain some, but not all, free radical scavenging actions exhibited by MT-1 and MT-2.

Topics: Animals; Bepridil; Biphenyl Compounds; Cells, Cultured; Electron Spin Resonance Spectroscopy; Free Radical Scavengers; Hippocampus; Hydroxyl Radical; Male; Metallothionein; Picrates; Piperidones; Protein Isoforms; Rats; Rats, Sprague-Dawley; Superoxides; tert-Butylhydroperoxide; Triacetoneamine-N-Oxyl

By employing electron spin resonance spectroscopy, we examined the free radicals scavenging effects of hepatic metallothionein (MT) isoforms I and II (MTs-I and II) on four types of free radicals. Solutions of 0.15 mM of MT-I and 0.3 mM of MT-II were found to scavenge the 1,1-diphenyl-2-picrylhydrazyl radicals (1.30 x 10(15) spins/ml) completely. In addition, both isoforms exhibited total scavenging action against the hydroxyl radicals (1.75 x 10(15) spins/ml) generated in a Fenton reaction. Similarly, 0.3 mM of MT-I scavenged almost 90% of the superoxide (2.22 x 10(15) spins/ml) generated by the hypoxanthine and xanthine oxidase system, while a 0.3 mM MT-II solution could only scavenge 40% of it. By using 2,2,6,6-tetramethyl-4-piperidone as a "spin-trap" for the reactive oxygen species (containing singlet oxygen, superoxide and hydroxyl radicals) generated by photosensitized oxidation of riboflavin and measuring the relative signal intensities of the resulting stable nitroxide adduct, 2,2,6,6-tetramethyl-4-piperidine-1-oxyl, we observed that MT-II (0.3 mM) could scavenge 92%, while MT-I at 0.15 mM microl/ml concentrations could completely scavenge all the reactive species (2.15 x 10(15) spins/ml) generated. The results of these studies suggest that although both isoforms of MT are able to scavenge free radicals, the MT-I appears to be a superior scavenger of superoxide and 1,1 diphenyl-2-picrylhydrazyl radicals.

Topics: Animals; Bepridil; Biphenyl Compounds; Chromatography, High Pressure Liquid; Electron Spin Resonance Spectroscopy; Free Radical Scavengers; Free Radicals; Hydroxyl Radical; Liver; Male; Metallothionein; Oxygen; Picrates; Rats; Rats, Sprague-Dawley; Singlet Oxygen; Superoxides; Zinc