Umberto Mancini

Rhodiola rosea ability to enrich cellular antioxidant defences of cultured human keratinocytes

Keratinocytes are cells strongly exposed to oxidative stress, but normally good equipped for antioxidant responses. However, it has long been suggested that exogenous antioxidants could play a useful role in minimizing the adverse skin responses associated with such oxidant species. In this work it was paid attention to the extract of Rhodiola rosea L. roots by using the phytocomplex as a whole because of the important activity of its composition and mutual distribution of its components. We have measured the protection afforded by the extract to reduced glutathione levels, glyceraldehyde-3-phosphate dehydrogenase activity, and thiobarbituric acid reactive substances levels in cultured human keratinocytes (NCTC 2544) exposed to different oxidative insults: Fe(II)/ascorbate, Fe(II)/H2O2, and tert-butyl-hydroperoxide. We also have investigated the influence of the R. rosea extract on the production of intracellular reactive oxygen species and on the activity of antioxidant enzymes (catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase). Furthermore, we have demonstrated that R. rosea extract was able to increase in a time- and dose-dependent manner the activity of the trans plasma membrane oxido reductase activity as an indirect evaluation of the intracellular redox status and this effect was already evident with small concentration of the extract and in a long time. As a result, NCTC 2544 are able to better counteract to several oxidative insults if incubated with R. rosea extract demonstrating a very good antioxidant activity of this phytocomplex.

Comparison of Uricase-Bound and Uricase-Loaded Erythrocytes as Bioreactors for Uric Acid Degradation

Uric acid is a normal end product of purine catabolism that when it increases in blood over normal values (hyperuricemia) can contribute to a group of diseases characteristic of gout.1 Hyperuricemia can arise by several mechanisms including increased uric acid production or reduced excretion by the kidney. Several approaches have been employed to reduce serum urate levels such as dietary means, promotion of uric acid excretion, administration of uricase and inhibitors of the enzymes responsible for its synthesis.

Red Blood Cells as a Glucocorticoids Delivery System

Macrophages are long-lived phagocytes with both cytocidal and microbicidal activity. These cells exist in a relatively quiescent basal state and also in “stimulated” or “activated” states. Activation of macrophages occurs by different stimuli (cytokines, bacterial lipopolysaccharide, etc.) and results in increased production of reactive oxygen metabolites and nitric oxide, increased phagocytic uptake, and release of many cytokines including IL-1, IL-6, TNF-α and growth factors (M-CSF, G-CSF). Upon activation macrophages also release lipid mediators (prostaglandins and leukotrienes) and numerous enzymes (1).

Effect of surgical stress on nuclear and mitochondrial DNA from healthy sections of colon and rectum of patients with colorectal cancer

Surgical resection at any location in the body leads to stress response with cellular and subcellular change, leading to tissue damage. The intestine is extremely sensitive to surgical stress with consequent postoperative complications. It has been suggested that the increase of reactive oxygen species as subcellular changes plays an important role in this process. This article focuses on the effect of surgical stress on nuclear and mitochondrial DNA from healthy sections of colon and rectum of patients with colorectal cancer. Mitochondrial DNA copy number, mitochondrial common deletion and nuclear and mitochondrial 8-oxo-2′-deoxyguanosine content were measured. Both the colon and rectal tissue were significantly damaged either at the nuclear or mitochondrial level. In particular, mitochondrial DNA was more damaged in rectum than in colon. The present investigation found an association between surgical stress and nuclear and mitochondrial DNA damage, suggesting that surgery may generate an increase in free radicals, which trigger a cascade of molecular changes, including alterations in DNA.

Effect of extremely low frequency electromagnetic fields on antioxidant activity in the human keratinocyte cell line NCTC 2544

Some epidemiological studies have suggested possible associations between exposure to extremely low‐frequency electromagnetic fields (ELF‐EMFs) and various diseases. Recently, ELF‐EMF has been considered as a therapeutic agent. To support ELF‐EMF use in regenerative medicine, in particular in the treatment of skin injuries, we investigated whether significant cell damage occurs after ELF‐EMF exposure. Reactive oxygen species (ROS) production was evaluated in the human keratinocyte exposed for 1 H to 50 Hz ELF‐EMF in a range of field strengths from 0.25 to 2 G. Significant ROS increases resulted at 0.5 and 1 G and under these flux densities ROS production, glutathione content, antioxidant defense activity, and lipid peroxidation markers were assessed for different lengths of time. Analyzed parameters of antioxidant defense and membrane integrity showed a different trend at two selected magnetic fluxes, with a greater sensitivity of the cells exposed to 0.5 G, especially after 1 H. All significant alterations observed in the first 4 H of exposure reverted to controls 24 H after suggesting that under these conditions, ELF‐EMF induces a slight oxidative stress that does not overwhelm the metabolic capacity of the cells or have a cytotoxic effect.

Effects of Reactive Oxygen Species on Mitochondrial Content and Integrity of Human Anastomotic Colorectal Dehiscence: A Preliminary DNA Study

BACKGROUND: Anastomotic dehiscence is one of the most severe complications of colorectal surgery. Gaining insight into the molecular mechanisms responsible for the development of anastomotic dehiscence following colorectal surgery is important for the reduction of postoperative complications.

Protective Effect of Juglans regia L. Walnut Extract Against Oxidative DNA Damage

Walnuts (Juglans regia L.) are relevant components of the Mediterranean diet providing important macronutrients, micronutrients and other bioactive constituents including unsaturated fatty acids, proteins, fiber, vitamins, minerals, phytosterols and polyphenols. Although the walnut beneficial effects in human health are widely recognized by a lot of epidemiologic studies very little is known regarding its effect on damaged DNA. The aim of the present study was to investigate the effect of Juglans regia L. ethanolic extract from kernel on the induction of DNA strand breaks by thiol/Fe3+/O2 mixed function oxidase, tert-butyl hydroperoxide or UVC radiations in acellular and cellular models. Plasmid DNA cleavage and fast Halo assay were used to monitor oxidative damage to DNA. Both approaches showed protection of oxidatively injured DNA. These results agree with a lot of scientific proofs which recommend walnut as dietary adjunct in health promotion and prevention as well as in treatment of lifestyle-related oxidative diseases.

Xenobiotic Detoxification by GSH-Loaded Erythrocytes

It is well known that the cells of higher organisms are able to excrete unwanted foreign chemicals (pesticides, herbicides, aromatic amines used in the dye industries, etc.) after metabolic conversion. An important role in this process is performed by reduced glutathione (GSH) which is present at high concentrations (2mM) in all living cells. In human cells, such as erythrocytes, GSH can be conjugate to a number of electrophilic compounds by the catalytic reaction of glutathione S-transferase (GST).1–3 The intracellular glutathione S-conjugate is excreted from the erythrocytes by an ATP requiring transport system.4,5 This process plays an important role as a detoxification mechanism that protects the red blood cells (RBCs) as well as other tissue cells from injuries by xenobiotics.

Protective Role of Italian Juglans regia L. nut Ethanolic Extract in Human Keratinocytes under Oxidative and Inflammatory Stress

OBJECTIVE In this research, fatty acid profile and polyphenolic content of an ethanolic extract of walnut from Juglans regia L. collected in Central Italy, were characterized. The potential antioxidant and anti-inflammatory effects of the extract were investigated in the human keratinocytes cell line. METHODS Fatty acid profile was determined by gas chromatography/mass spectrometry analysis, total phenolic content by Folin-Ciocalteu method and aluminum chloride colorimetric method was used for determination of total flavonoids. Kertatinocytes were exposed to t-butyl hydroperoxide or Tumor Necrosis Factor alfa in the absence or presence of extract. Reduced glutathione was determined by Sedlak method; lipid peroxidation was assessed by measuring thiobarbituric acid reactive substances. t-butyl hydroperoxide and Tumor Necrosis Factor alfa-induced intracellular reactive oxygen species were monitored by fluorescent probes. The expression of some genes related to the inflammatory process (IL-6, IL-8, ikB, and ICAM) were analysed by Real-time PCR. RESULTS JRE contains a favourable fatty acid profile with low saturated fats (19%) and high-unsaturated fats (81%) with a prevalence of the omega-6 linoleic acid (48%). Also a significant amount of polyphenols was found (5,0052 mg gallic acid equivalent/gdw). Antioxidant and anti-inflammatory properties of JRE were observed on analysed cellular model. JRE antioxidants counteracted ROS production, GSH depletion and lipid peroxidation as well downregulated the expression of some genes related to the inflammatory process. Moreover, polyunsaturated fatty acids exhibited anti-inflammatory properties. CONCLUSION The obtained results uphold walnut as dietary adjunct in health promotion and drive towards its development in drug therapy against chronic inflammatory disorders, including inflammatory skin diseases.