An Overview of Oxyradicals in Medical Biology

Cylindropuntia cholla aqueous root rich in phytosterols enhanced immune response and antimicrobial activity in tilapia Oreochromis niloticus leukocytes

"Cacti" are rich sources of phytochemicals with antioxidant activity, and their use is mainly focused on infusions in traditional medicine in Mexico. This study characterizes the chemical compounds found in Cylindropuntia cholla root by gas chromatography coupled to mass spectrometry (GC-MS) and determines the total content of polyphenols and flavonoids, as well as their antioxidant capacity. The immunostimulatory effect of aqueous C. cholla root extract (ACcr) was evaluated at concentrations of 50, 250, 500, and 1000 μg/mL in Tilapia peripheral blood leukocytes. The results obtained by the GC-MS analysis revealed the presence of phenolic acids, flavonoid and phytosterol derivatives as β-sitosterol and campesterol. The determination of the total polyphenol and flavonoid contents indicated that ACcr is abundant in polyphenols, showing an anti-radical capacity of scavenging free radicals, such as those of hydroxyl and superoxide, as well as an increase in lipid peroxidation inhibition capacity. Stimulation of tilapia leukocytes resulted in the increase of its phagocytic activity, respiratory burst, nitric oxide production, and superoxide dismutase activity. Finally, the results obtained for the first time allowed establishing the chemical profile of ACcr and its antimicrobial activity against three important pathogenic bacteria. The potential of this root is indicated as an additive in formulating antioxidant and immunostimulant supplements for the aquaculture and pharmaceutical industry.

The necessity of antioxidant inclusion in caprine and ovine semen extenders: A systematic review complemented with computational insight

The inclusion of antioxidants (AOXs) has been proposed in various protocols to conserve the normal physiology of spermatozoa during (cryo) preservation. The main aim of this review was to understand the necessity of AOXs inclusion in semen extenders of caprine and ovine semen samples and to decipher physico-chemical space of AOXs used in semen extenders till now. A total 27 full-text relevant articles were finally discussed here. This systematic review showed that the inclusion of AOXs may improve the success of semen cryopreservation although at least three studies could not support this finding. AOXs have been not added after assaying total antioxidant capacity of the sample of interest, and this is principal measurement bias of all papers. Furthermore, no rational dose-response curve and precise posology have been considered in comparable studies. Furthermore, new methodologies are requested to detect the oxidative status of semen specimens before AXOs fortification and new methodologies like imaging are also needed to detect various injuries of sperms during semen (cryo)preservation. Defining computational chemical and physical spaces of AOXs which used in semen (cryo)preservation would be an interdisciplinary effort to hasten deciphering epoch-making compounds. In conclusion, more in-depth analytical, toxicological and pharmacological methodologies should be pursued in supplementation or addition of AOXs during caprine and ovine semen (cryo)preservation after determining the oxidative status of semen samples.

Unprecedented tetranuclear complexes with “weighing balance shaped” topology: single crystal structures, unusual EPR spectra, magnetic properties and antioxidant activity

Two new copper(ii) complexes have been synthesized and characterized by single crystal X-ray diffraction.

Regulation of both the reactive oxygen species level and antioxidant enzyme activity in drought-stressed rice organs by benzimidazolate-based SOD1 mimics

In the study, three benzimidazolate-based Cu²⁺ complexes were identified as SOD1 mimics to explore their effects on the levels of reactive oxygen species (ROS) and activities of antioxidant enzymes in drought-stressed rice organs. Superoxide dismutase (SOD) activity of the mimics was found to be controlled by unsaturated coordination, auxiliary ligands, and counter-anions. In comparison to the control, SOD1 mimic treatment for rice seeds significantly reduced ROS (O₂•⁻, H₂O₂, and •OH) levels in the rice leaf and root while notably increased activities of antioxidant enzymes, including SOD1 and catalase. It can enhance the tolerance of plant organs to drought stress and, thus, has a practical potency of application in rice production on arid land.

Superoxide dismutase mimics: chemistry, pharmacology, and therapeutic potential

Oxidative stress has become widely viewed as an underlying condition in a number of diseases, such as ischemia-reperfusion disorders, central nervous system disorders, cardiovascular conditions, cancer, and diabetes. Thus, natural and synthetic antioxidants have been actively sought. Superoxide dismutase is a first line of defense against oxidative stress under physiological and pathological conditions. Therefore, the development of therapeutics aimed at mimicking superoxide dismutase was a natural maneuver. Metalloporphyrins, as well as Mn cyclic polyamines, Mn salen derivatives and nitroxides were all originally developed as SOD mimics. The same thermodynamic and electrostatic properties that make them potent SOD mimics may allow them to reduce other reactive species such as peroxynitrite, peroxynitrite-derived CO(3)(*-), peroxyl radical, and less efficiently H(2)O(2). By doing so SOD mimics can decrease both primary and secondary oxidative events, the latter arising from the inhibition of cellular transcriptional activity. To better judge the therapeutic potential and the advantage of one over the other type of compound, comparative studies of different classes of drugs in the same cellular and/or animal models are needed. We here provide a comprehensive overview of the chemical properties and some in vivo effects observed with various classes of compounds with a special emphasis on porphyrin-based compounds.

Fundamental aspects of reactive oxygen species, or what's the matter with oxygen?

A byproduct of normal aerobic metabolism is the generation of dangerously reactive intermediates of the reduction of O2. These include O2-, H2O2, and HO. and arise because of the predisposition of O2 for univalent reductions. These reactive oxygen species (ROS), and others that they can engender, threaten all cellular macromolecules, and defenses are needed. Among those known to date are: superoxide dismutases to convert O2- into O2 + H2O2; catalases to dismute H2O2 into O2 + H2O; and peroxidases to reduce H2O2 into 2H2O) and to reduce ROOH into ROH and H2O. These defenses are aided by enzymes that repair or recycle oxidatively damaged nucleic acids and proteins. A role for such oxidative damage in aging and neurodegenerative diseases is well supported.