Chemical and Antioxidant Characterization of the Portuguese Heather Honey from Calluna vulgaris

The Calluna vulgaris honey produced in Portugal, concerning its phenolic compounds and abscisic acids profiles, as well as its antioxidant activity and the protective effect against oxidative damage in human erythrocytes were herein performed for the first time. The phenolic and abscisic acid profiles were tentatively identified by LC-MS/MS (17 compounds). The total content of phenolics and abscisic acids was 15,446.4 µg/g of honey extract, with catechin derivatives and abscisic acids being major constituents. The highest scavenging capacity was found against reactive nitrogen species. Additionally, the honey extract prevented ROO•-induced oxidative damage in erythrocytes collected from human blood, by inhibiting hemolysis, lipid peroxidation and hemoglobin oxidation. In conclusion, C. vulgaris honey contains high content of catechin derivatives and abscisic acids that may be responsible for its biological activity, characterized by a strong antioxidant capacity, which adds up to the nutritional value of this delicacy.

A Probable Mechanism for Recurring Outbreak of Respiratory Syndrome During Autumn Season in Ahvaz City, Iran

Background: Recurring annual asthma or asthma-like outbreak in Ahvaz City, Iran, has become a serious public health problem. A toxic gas, a chemical compound, or an allergen with unknown nature and mechanism leads to severe asthma outbreaks each year. Bronchospasm, cough, dyspnea, chest tightness, and wheezing are the main symptoms of these attacks. Oxygen and anti-asthma therapy are effective treatments in outbreak management. Based on our findings, it is hypothesized that vast amounts of ammonium nitrate used in agriculture underlay high concentrations of nitrate. This substance is transported by PM10 and is the main cause of the respiratory outbreak. Methods: The concentration of nitrate was determined by the ion chromatography method in dust samples during 2015-2016. Using spectroscopic methods, the effect of nitrate ions on hemoglobin oxidation and methemoglobin formation was studied. Results: Our results indicate that the concentration of ammonium nitrate in dust collected from indoor spaces is five times higher than the levels allowed amount in airborne pollutants. Our findings also indicate that this concentration of nitrate in the bloodstream can instantly increase methemoglobin percent to 18% with symptomatic consequences. Conclusion: The exact mechanism proposed by this study is that inhaled nitrate or nitric acid finally increases the nitrate in the circulation of affected individuals. Hemoglobin oxidation and methemoglobin formation are the subsequent events leading to methemoglobinemia with asthma-like reactions seen in Ahvaz respiratory syndrome. Restricting or even prohibiting ammonium nitrate application in agriculture seems to be an urgent measure to stop Ahvaz's recurring respiratory syndrome.

Therapeutic Potential of Carbon Monoxide (CO) and Hydrogen Sulfide (H2S) in Hemolytic and Hemorrhagic Vascular Disorders—Interaction between the Heme Oxygenase and H2S-Producing Systems

Over the past decades, substantial work has established that hemoglobin oxidation and heme release play a pivotal role in hemolytic/hemorrhagic disorders. Recent reports have shown that oxidized hemoglobins, globin-derived peptides, and heme trigger diverse biological responses, such as toll-like receptor 4 activation with inflammatory response, reprogramming of cellular metabolism, differentiation, stress, and even death. Here, we discuss these cellular responses with particular focus on their mechanisms that are linked to the pathological consequences of hemorrhage and hemolysis. In recent years, endogenous gasotransmitters, such as carbon monoxide (CO) and hydrogen sulfide (H2S), have gained a lot of interest in connection with various human pathologies. Thus, many CO and H2S-releasing molecules have been developed and applied in various human disorders, including hemolytic and hemorrhagic diseases. Here, we discuss our current understanding of oxidized hemoglobin and heme-induced cell and tissue damage with particular focus on inflammation, cellular metabolism and differentiation, and endoplasmic reticulum stress in hemolytic/hemorrhagic human diseases, and the potential beneficial role of CO and H2S in these pathologies. More detailed mechanistic insights into the complex pathology of hemolytic/hemorrhagic diseases through heme oxygenase-1/CO as well as H2S pathways would reveal new therapeutic approaches that can be exploited for clinical benefit.

Hemoglobin Oxidation in Stored Blood Accelerates Hemolysis and Oxidative Injury to Red Blood Cells

Introduction Maintaining blood supply is a challenge in blood banks. Red blood cells (RBCs) stored at 4°C experience issues of biochemical changes due to metabolism of cells, leading to changes collectively referred to as “storage lesions.” Oxidation of the red cell membrane, leading to lysis, contributes to these storage lesions. Methods Blood bags with CPD-SAGM stored at 4°C for 28 days were withdrawn aseptically on days 1, 14, and 28. Hematology analyzer was used to investigate RBC indices. Hemoglobin oxidation was studied through spectrophotometric scan of spectral change. RBC lysis was studied with the help of Drabkin's assay, and morphological changes were observed by light and scan electron microscopy. Results RBCs show progressive changes in morphology echinocytes and spherocytes on day 28. There was 0.85% RBC lysis, an approximately 20% decrease in percentage oxyhemoglobin, and a 14% increase in methemoglobin formation, which shows hemoglobin oxidation on day 28. Conclusions Oxidative damage to RBC, with an increase in storage time was observed in the present study. The observed morphological changes to RBC during the course of increased time shows that there is progressive damage to RBC membrane and a decrease in hemoglobin concentration; percentage RBC lysis is probably due to free hemoglobin and iron.

Synthesis and Antioxidative Activity of Piperine Derivatives Containing Phenolic Hydroxyl

Piperine was used in this study in its raw form, and different steps, such as amide hydrolysis and amidation, were used to synthesize piperine derivatives containing a phenolic hydroxyl group. DPPH and ABTS free radical scavenging assays were used to assess piperine derivative antioxidant activities. We constructed an AAPH oxidative stress erythrocyte model to study the effect of piperine derivatives on the hemolysis rate of oxidatively damaged erythrocytes as well as the hemoglobin oxidation rate. This AAPH model was also used to determine piperine derivative effects on antioxidant enzyme activity and malondialdehyde (MDA) content. Results showed that spectroscopic methods could synthesize and identify piperine derivatives containing phenolic hydroxyl groups (H-1∼H-3). Moreover, DPPH and ABTS assay results showed that piperine derivative free radical clearance rates were higher compared with the parent compound. Additionally, piperine derivatives (H-1∼H-3) were found to provide protection to AAPH oxidatively damaged erythrocytes in their ability to inhibit AAPH-induced erythrocyte lysis, while hemoglobin oxidation was higher compared with the parent compound. Piperine derivatives may protect intracellular glutathione peroxidase (GSH-Px) antioxidant enzyme system activities, safeguarding against oxidative damage. This study synthesized novel piperine derivatives for use as potential antioxidant agent candidates.

Isopropyl Nitrite Induced Hemoglobin Oxidation in Diabetics Blood

The effect of isopropyl nitrite on human Type 2 Diabetes blood was undertaken using non diabetics blood as the control group. The differences in patient characteristics such as the mean ages and weights of the two groups were not statistically significant (P>0.05), and the ratios of non-smokers to smokers were similar meaning that the two groups were well matched. These studies revealed that diabetics erythrocytes with a mean HbA1C value ± SEM of 11.4 ± 0.27% were oxidized at a significantly greater rate than that of the control blood (P<0.05). The isopropyl nitrite mean oxidation time ± SEM of diabetics blood was 1.5 ± 0.05 min (n = 20). For the nondiabetics blood a mean HbA1C ± SEM value of 5.5 ± 0.08% was obtained with a mean oxidation time ± SEM of the non-diabetics blood of 4.6 ± 0.13 min (n=20). These studies demonstrate that Diabetes blood has an enhanced susceptibility of oxidation into methemoglobin by isopropyl nitrite compared to its respective control group, i.e., the normal blood. This finding could be attributed to the fact that isopropyl nitrite is a nitrite ester which contains a saturated three hydrocarbon chain similar to other analogous nitrite esters (ethyl nitrite, butyl nitrite, pentyl nitrite and hexyl nitrite) which also contain saturated hydrocarbon chains that previously showed a statistically significant increased oxidation time for diabetics blood (P<0.05) [1-6]. Thus this study confirms that the difference in the number of methylene molecules has no impact on the rate of oxidation on either diabetics blood or nondiabetics blood (P>0.05). These findings also imply that the increased susceptibility to isopropyl nitrite induced oxidation reaction in diabetics blood is a direct function of the amount of HbA1C present in the blood, i.e., a clear inverse relation appears to exist between the amount of HbA1C present and the oxidation time