redox status evaluation in dogs affected by mast cell tumour

Spectrophotometric assays for evaluation of Reactive Oxygen Species (ROS) in serum: general concepts and applications in dogs and humans

Reactive oxygen species (ROS) are reactive compounds derived from oxygen. In biological systems, an excessive amount of ROS can cause oxidative damage to biological macromolecules being involved in different diseases. Several assays have been developed in the last 30 years for ROS evaluation. The objective of this article will be to provide an update about the spectrophotometric methods currently used in the assessment of ROS in serum. The chemical basis of four different techniques will be reviewed, and examples of their possible applications will be provided. A particular emphasis about the practical applications of these assays in the dog will be made, but selected information about their use in humans will also be presented for comparative purposes, following a One-Health approach. The information about the spectrophotometric assays presented in this paper should be interpreted with caution once limited information about them is available yet, and further studies should be performed to clarify what they measure and their clinical application. Ideally, when applied to evaluate a sample's oxidative status, they should be incorporated in a panel of analytes where other oxidants, antioxidants, and biomarkers of inflammation were also included.

Oxidant–Antioxidant Status in Canine Multicentric Lymphoma and Primary Cutaneous Mastocytoma

Oxidative stress is a prominent event in several acute and chronic diseases including neoplasia. Although its direct involvement in carcinogenesis still remains to be clearly defined, a deeper knowledge of oxidative stress in oncologic patients could help to monitor their clinical outcome and to develop new therapeutic approaches. Therefore, the present study was undertaken to explore redox status in blood of neoplastic dogs affected either by multicentric lymphoma or by primary cutaneous mastocytoma. Superoxide anion (O2 •−), nitric oxide (NO) and hydroperoxides (ROOH) were measured. Detoxifying enzyme superoxide dismutase (SOD) and total non-enzymatic antioxidant capacity (ferric reducing-antioxidant power (FRAP)) were assessed. The oxidative stress index (OSi) both for enzymatic (OSiE) and non-enzymatic (OSiNE) scavengers were evaluated. Both pathologies, showed a reduced NO generation, while O2 •− levels were decreased only in mastocytoma. The oxidative stress indexes showed a significant decrease in mastocytoma patients, only for OSiE.

Prognostic relevance of oxidative stress measurement in chronic lymphocytic leukaemia

OBJECTIVE

To evaluate the prognostic significance of oxidative stress (OS) and antioxidant defence status measurement in patients with chronic lymphocytic leukaemia (CLL).

METHODS

d-ROMs test and BAP test were evaluated at diagnosis of 165 patients with CLL and correlated with clinical-biological features and prognosis.

RESULTS

An increased oxidative damage (d-ROMs test) and a reduced antioxidant potential (BAP test) were found in CLL patients than normal controls (P<.0001). CLL patients with higher d-ROMs values had higher number of circulating white blood cells and lymphocytes, and higher values of β₂ -microglobulin. Higher d-ROMs values were found in female (P=.0003), in patients with unmutated IgVH (P=.04), unfavourable cytogenetics (P=.002) and more advanced clinical stage (P=.002). Higher BAP test values were found in patients expressing CD49d (P=.01) and with more advanced clinical stage (P=.004). At a median follow-up of 48 months, CLL patients with d-ROMs ≥418 CARR U were found to have a shorter time to first treatment (TFT) (P=.0002), and a reduced survival (P=.006) than others. CLL patients with BAP test values ≥2155 μmol/L had a shorter TFT (P=.008) and a shorter survival (P=.003).

CONCLUSIONS

OS can affect CLL patients by concomitantly increasing reactive oxygen metabolites production and decreasing antioxidant defences.

Pathological effect of arterial ischaemia and venous congestion on rat testes

Many studies on various organs have concluded that venous congestion (VC) causes severe organ dysfunction with elevation of oxidative stress relative to that of arterial ischaemia (AI). However, a comparison of the pathological effects of AI and VC on the testes has not been conducted. In this study, models of AI and VC and their reperfusion in rat testes, respectively, were developed and analysed. Testicular arteries or veins were interrupted for 6 h, re-perfused and kept for 4 weeks; the effects on the testes were then evaluated. Severe spermatogenic disturbances were observed at 4 weeks after reperfusion in AI but not in VC. At 6 h after blood flow interruption, oxidative stress was significantly increased and germ cells were severely damaged in AI compared with those in VC. RT-PCR analyses revealed that haem oxygenase-1, which exhibits anti-oxidative effects, and vascular endothelial growth factor-A, which exhibits vasculogenic effects, were significantly increased in VC but not in AI. Surprisingly, the results of our experiment in rat testes differed from those of experiments in previous studies performed in other organs. Oxidative stress in testes was more easily elevated by AI than it was by VC, explainable by the different experimental conditions.

Antioxidant and Anti-inflammatory Activities of a Commercial Noni Juice revealed by Carrageenan-induced Paw Edema

This study aimed to investigate antioxidant and anti-inflammatory activities of a commercial product of noni (Morinda citrifolia) juice. Carrageenan-induced rat paw edema was employed as inflammatory model. One control and three experimental groups were formed. Experimental groups were administered noni juice alone, noni juice+carrageenan, and carrageenan alone. Oxidant and antioxidant capacity were determined by d-ROMs test and BAP test, respectively. Plasma concentrations of endothelin-1 and leptin were measured by ELISA. Measurements were performed at zero time and 2nd hour of inflammation. Oxidant capacity decreased in noni-received groups at 2nd hour (p=0.019). Antioxidant capacity of the group which received noni alone was found to be higher at 2nd hour (p=0.036). Plasma concentrations of endothelin-1 and leptin were notably lower in noni-received groups (p=0.001 and p=0.021, respectively). The results show that the commercial noni juice investigated has pronounced antioxidant and anti-inflammatory activities.

Oxidative stress predicts long-term resight probability and reproductive success in Scopoli's shearwater (Calonectris diomedea)

A major challenge in conservation physiology is to find out biomarkers that reliably reflect individual variation in wear and tear. Recent work has suggested that biomarkers of oxidative stress may provide an additional tool to assess the health state of individuals and to predict fitness perspectives. In this study, we assessed whether three biomarkers of plasma oxidative status predicted the following factors: (i) the resight probability as breeder in the next seasons; and (ii) the cumulative reproductive output over multiple years in Scopoli's shearwaters (Calonectris diomedea) using a 7 year individual-based data set. Our results show that shearwaters having higher levels of a marker of oxidative damage (reactive oxygen metabolites) in 2008 had a lower resight probability in the next years and a lower number of chicks raised from 2008 to 2014. In contrast, two biomarkers of antioxidant defences (non-enzymatic antioxidant capacity of plasma and thiols) did not have any predictive value. Increased concentrations of plasma reactive oxygen metabolites, together with the significant individual repeatability over time in this metric of oxidative stress found in numerous studies, suggest that this metric might serve as a blood-derived biomarker for health and fitness perspectives in birds and, possibly, also in other taxa.

Oxidative stress markers are increased in patients with mastocytosis

BACKGROUND

Mastocytosis is characterized by clonal proliferation of mast cells limited to the skin (cutaneous mastocytosis: CM and mastocytosis in the skin: MIS) and/or involving internal organs (systemic mastocytosis: SM). Oxidative stress occurring in various inflammatory and neoplastic disorders causes molecular damage with the production of advanced oxidation protein products (AOPPs) and advanced glycation end products (AGEs). We evaluated these markers of oxidative stress in patients with CM/MIS and SM and correlated their levels with the presence of symptoms related to mast cell activation.

METHODS

Serum levels of AOPPs and AGEs in 34 patients with mastocytosis (23 CM/MIS and 11 SM) and 27 healthy controls were measured by spectrofluorimetric and spectrophotometric methods. Serum tryptase levels were measured by immunofluorescence.

RESULTS

Serum AOPPs, but not AGEs, were significantly higher in patients with mastocytosis as compared to healthy controls. While serum tryptase levels were higher in patients with SM as compared to those with CM/MIS, there was no difference in AOPP and AGE concentrations between these two groups of patients. Patients with recurrent mediator-related symptoms had lower AOPPs and AGEs as compared to patients without symptoms. AOPPs and AGEs were inversely correlated with the severity of symptoms, and in patients with symptoms, AOPPs correlated with tryptase levels.

DISCUSSION

Our data show that mastocytosis is associated with a state of increased oxidative stress that, in patients with mediator-related symptoms, correlates with mast cell burden as assessed by tryptase. Patients with symptoms presumably have an adaptive response resulting in lower blood levels of AOPPs and AGEs.