Role of oxidative stress in depression.

Catalase is a powerful antioxidant metalloenzyme located in peroxisomes which also plays a central role in signaling processes under physiological and adverse situations. Whereas animals contain a single catalase gene, in plants this enzyme is encoded by a multigene family providing multiple isoenzymes whose number varies depending on the species, and their expression is regulated according to their tissue/organ distribution and the environmental conditions. This enzyme can be modulated by reactive oxygen and nitrogen species (ROS/RNS) as well as by hydrogen sulfide (H2S). Catalase is the major protein undergoing Tyr-nitration [post-translational modification (PTM) promoted by RNS] during fruit ripening, but the enzyme from diverse sources is also susceptible to undergo other activity-modifying PTMs. Data on S-nitrosation and persulfidation of catalase from different plant origins are given and compared here with results from obese children where S-nitrosation of catalase occurs. The cysteine residues prone to be S-nitrosated in catalase from plants and from bovine liver have been identified. These evidences assign to peroxisomes a crucial statement in the signaling crossroads among relevant molecules (NO and H2S), since catalase is allocated in these organelles. This review depicts a scenario where the regulation of catalase through PTMs, especially S-nitrosation and persulfidation, is highlighted.

https://digital.csic.es/bitstream/10261/218290/1/2020_Palma_RB_OA.pdf

Plant catalases as NO and H2S targets

Healthful aging mediated by inhibition of oxidative stress.

Addition of hydrogen peroxide (H2O2) is a method commonly used to trigger cellular oxidative stress. However, the doses used (often hundreds of micromolar) are disproportionally high with regard to physiological oxygen concentration (low micromolar). In this study using polarographic measurement of oxygen concentration in cellular suspensions we show that H2O2 addition results in O2 release as expected from catalase reaction. This reaction is fast enough to, within seconds, decrease drastically H2O2 concentration and to annihilate it within a few minutes. Firstly, this is likely to explain why recording of oxidative damage requires the high concentrations found in the literature. Secondly, it illustrates the potency of intracellular antioxidant (H2O2) defense. Thirdly, it complicates the interpretation of experiments as subsequent observations might result from high/transient H2O2 exposure and/or from the diverse possible consequences of the O2 release.

Use of H2O2 to Cause Oxidative Stress, the Catalase Issue.

Glutathione (GSH) is an important antioxidant found abundantly and synthesized intracellularly in the cytosol in a tightly regulated fashion. It has diverse physiological functions, including protection against reactive oxygen species and nitrogen species, antioxidant defense as well as maintenance of cellular thiol status. The human brain due to the high oxygen consumption is extremely susceptible to the generation of reactive oxygen species. GSH plays a paramount role in brain antioxidant defense, maintaining redox homeostasis. The depletion of brain GSH has also been observed from both autopsies as well as in vivo MRS studies with aging and varied neurological disorders (Alzheimer's disease, Parkinson's disease, etc.). Therefore, GSH enrichment using supplementation is a promising avenue in the therapeutic development for these neurological disorders. This review will enrich the information on the importance of GSH synthesis, metabolism, functions, compartmentation and inter-organ transport, structural conformations and its quantitation via different techniques. The transportation of GSH in the brain via different interventional routes and its potential role in the development of therapeutic strategies for various brain disorders is also addressed. Very recent study found significant improvement of behavioral deficits including cognitive decline, depressive-like behaviors, in APP (NL-G-F/NL-G-FG-) mice due to oral GSH administration. This animal model study put an emergent need to complete GSH supplementation trial in MCI and AD patients for cognitive improvement as proposed earlier.

Glutathione in Brain: Overview of Its Conformations, Functions, Biochemical Characteristics, Quantitation and Potential Therapeutic Role in Brain Disorders

Reactive species produced in the cell during normal cellular metabolism can chemically react with cellular biomolecules such as nucleic acids, proteins, and lipids, thereby causing their oxidative modifications leading to alterations in their compositions and potential damage to their cellular activities. Fortunately, cells have evolved several antioxidant defense mechanisms (as metabolites, vitamins, and enzymes) to neutralize or mitigate the harmful effect of reactive species and/or their byproducts. Any perturbation in the balance in the level of antioxidants and the reactive species results in a physiological condition called "oxidative stress." A catalase is one of the crucial antioxidant enzymes that mitigates oxidative stress to a considerable extent by destroying cellular hydrogen peroxide to produce water and oxygen. Deficiency or malfunction of catalase is postulated to be related to the pathogenesis of many age-associated degenerative diseases like diabetes mellitus, hypertension, anemia, vitiligo, Alzheimer's disease, Parkinson's disease, bipolar disorder, cancer, and schizophrenia. Therefore, efforts are being undertaken in many laboratories to explore its use as a potential drug for the treatment of such diseases. This paper describes the direct and indirect involvement of deficiency and/or modification of catalase in the pathogenesis of some important diseases such as diabetes mellitus, Alzheimer's disease, Parkinson's disease, vitiligo, and acatalasemia. Details on the efforts exploring the potential treatment of these diseases using a catalase as a protein therapeutic agent have also been described.

/pdf/role-of-catalase-in-oxidative-stress-and-age-associated-5dyhdaf0u4.pdf

Role of Catalase in Oxidative Stress- and Age-Associated Degenerative Diseases.

Antioxidant and physicochemical study of Psidium guajava prepared zinc oxide nanoparticles

Fabrication and surface characterisation of c-ZnO loaded TTDMM dendrimer nanocomposites for biological applications

A column-based continuous elution (CCE) method was developed for extracting humic acids (HA) from vermicomposted organic waste. Dissolution of HA by passing extractant (0.2 M NaOH) through vermicompost in a column followed by elution under gravity resulted in yields of 47.5% and 74.7% extractable HA in 24 h by International Humic Substance Society (IHSS) method and CCE method, respectively. These results were 63.3% and 97.9% in 48 h, respectively. The extracted HA showed similar FTIR absorption spectra and chemical compositions. Rate of oxidative degradation of HA during extraction by the CCE method was lower as compared with the IHSS method indicating improvement in extraction without altering the quality.

Nilanjana Das

Papers

Role of Catalase in Oxidative Stress- and Age-Associated Degenerative Diseases.

Antioxidant and physicochemical study of Psidium guajava prepared zinc oxide nanoparticles

Fabrication and surface characterisation of c-ZnO loaded TTDMM dendrimer nanocomposites for biological applications

Improved extraction of humic acids from vermicomposted organic waste by a column-based continuous elution method

Protein extraction from Saccharomyces cerevisiae at different growth phases.