Antioxidative or prooxidative effect of 4-hydroxyquinoline derivatives on free-radical-initiated hemolysis of erythrocytes is due to its distributive status

Chronic exposure to 2,2'-azobis-2-amidinopropane that induces intestinal damage and oxidative stress in larvae of Drosophila melanogaster

Embryonic development is exceptionally susceptible to pathogenic, chemistry and mechanical stressors as they can disrupt homeostasis, causing damage and impacted viability. Oxidative stress has the capacity to induce alterations and reshape the environment. However, the specific impacts of these oxidative stress-induced damages in the gastrointestinal tract of Drosophila melanogaster larvae have been minimally explored. This study used 2,2-azobis (2-amidinopropane) dihydrochloride (AAPH), a free radical generator, to investigate oxidative stress effects on Drosophila embryo development. The results showed that exposing Drosophila eggs to 30 mM AAPH during 1st instar larva, 2nd instar larva and 3rd instar larva stages significantly reduced hatching rates and pupal generation. It increased the activity of antioxidant enzymes and increased oxidative damage to proteins and MDA content, indicating severe oxidative stress. Morphological changes in 3rd individuals included decreased brush borders in enterocytes and reduced lipid vacuoles in trophocytes, essential fat bodies for insect metabolism. Immunostaining revealed elevated cleaved caspase 3, an apoptosis marker. This evidence validates the impact of oxidative stress toxicity and cell apoptosis following exposure, offering insights into comprehending the chemically induced effects of oxidative stress by AAPH on animal development.

In Vitro Biological Activity and Lymphoma Cell Growth Inhibition by Selected Mexican Medicinal Plants

Cancer is a major health problem with significant morbidity and mortality. In addition, plants are a source of metabolites with diverse biological properties, including antitumor potential. In this study, we investigated the in vitro murine lymphoma L5178Y-R cell growth inhibition, human peripheral blood mononuclear cells (PBMC) toxicity and proliferation, and antioxidant, hemolytic, and anti-hemolytic activities of methanol extracts from 15 plants of traditional use in Mexico. Justicia spicigera caused the highest tumor cell growth inhibition with a half maximal inhibitory concentration (IC50) of 29.10 µg/mL and a selectivity index >34.36 compared with those of PBMC, whereas Mimosa tenuiflora showed the highest lymphoproliferative activity from 200 µg/mL compared with that induced by concanavalin A. In addition, M. tenuiflora showed an antioxidant effect (IC50 = 2.86 µg/mL) higher than that of ascorbic acid. Regarding the hemolytic and anti-hemolytic activity, all extracts presented significant anti-hemolytic activity. The extract of J. spicigera is emerging as a possible source of effective antineoplastic compounds.

Protective effect of desloratadine against oxidative stress in human erythrocytes in vitro

Desloratadine (DCL) is a non-sedating antihistamine approved for the treatment of allergic rhinitis or chronic idiopathic urticaria. The objective of this study was to evaluate the potential protective effect of DCL against oxidative stress in human erythrocytes in vitro. Human erythrocytes were oxidized by a water-soluble radical generators-2,2' azobis (2-amidinopropane) hydrochloride (AAPH; 20, 50mM) or tert-butyl hydroperoxide (TBHP; 0.5mM) and the protective effects of DCL (2, 5, 7, 10 and 26μM) on selected oxidative stress markers were investigated. Erythrocytes were divided into aliquots. The first aliquot was incubated for 2h at 37°C with AAPH or TBHP. The other test aliquots were preincubated with selected concentrations of DCL for 30min and followed by AAPH or TBHP incubation for 2h. Malondialdehyde (MDA) content, catalase (CAT) and superoxide dismutase (SOD) activities, as well as hemolysis percentage (H) were measured in all erythrocyte samples. The influence of solvent (0.5% ethanol) on the parameters studied was also checked. Pretreatment with DCL (7, 10, 26μM) could prevent TBHP-induced increase in MDA formation in a concentration-dependent manner. DCL has no influence on CAT activity and it significantly enhanced SOD activity compared to AAPH treatment samples at 7, 10, 26μM. DCL (26μM) also reduced the hemolytic effect on erythrocytes when compared to the erythrocytes exposed to oxidants only. These results suggest a beneficial effect of DCL as an antioxidant, which might be an additional explanation of its therapeutic action.

Indole and its alkyl-substituted derivatives protect erythrocyte and DNA against radical-induced oxidation

The antioxidant properties of 1,2,3,4-tetra-hydrocarbazole, 6-methoxy-1,2,3,4-tetrahydrocar-bazole (MTC), 2,3-dimethylindole, 5-methoxy-2,3-dimethylindole, and indole were investigated in the case of hemolysis of human erythrocytes and oxidative damage of DNA induced by 2,2'-azobis(2-amidinopropane hydrochloride) (AAPH), respectively. The aim of this work was to explore the influence of methoxy, methyl, and cyclohexyl substituents on the antioxidant activities of indole derivatives. These indole derivatives were able to protect erythrocytes and DNA in a concentration-dependent manner. The alkyl-substituted indole can protect erythrocytes and DNA against AAPH-induced oxidation. Especially, the structural features of cyclohexyl and methoxy substituents made MTC the best antioxidant among the indole derivatives used herein. Finally, the interaction between these indole derivatives and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonate) radical cation and 2,2'-diphenyl-1-picrylhydrazyl, respectively, provided direct evidence for these indole derivatives to scavenge radicals and emphasized the importance of electron-donating groups for the free radical-scavenging activity of indole derivatives.

In vitro models of oxidative stress in rat erythrocytes: Effect of antioxidant supplements

The present study was designed to induce oxidative stress in lipid and aqueous phases through azo bis(2-amidinopropane)dihydrochloride (AAPH), 2,2'-azobis 2,4-dimethylvaleronitrile (ADVN) and hydrogen peroxide (H(2)O(2)) either alone or in combination with vitamin C or vitamin El and to assess the vulnerability of rat erythrocytes to oxidative stress. While AAPH acted equally on cell membrane and cytosol, ADVN increased OS in the membrane. The extent of hemolysis and increased membrane fragility caused was more in the case of azo compounds than of H(2)O(2). While vitamin E (2mM) reduced oxidative stress in the membrane, vitamin C (60mM) was more effective in the lysates. The concentration of malondialdehyde and advanced oxidation protein products was lowered by antioxidants. The level of lipofuscin, a product of lipid peroxidation was also increased by ADVN and H(2)O(2). Antioxidants, did, however, reduce the accumulation of protein carbonyl content in cells exposed to azo compounds although they were ineffective in inhibiting oxidation of membrane band 3 protein and sulphydryl content. Taken together, our study demonstrated the antioxidative property of vitamin E and vitamin C in reducing oxidative stress in aqueous as well as lipid phases of erythrocytes and further suggested the feasibility of in vitro models in evaluating the mechanisms of oxidative injury.

In vitro free radical scavenging activities and effect of synthetic oligosaccharides on antioxidant enzymes and lipid peroxidation in aged mice

In this study we synthesized oligosaccharides using glucose as reactant via a route assisted by microwave irradiation and evaluated their antioxidant activity in vivo and in vitro. The results show that the oligosaccharides exhibited antioxidant activity in vitro as compared to standard antioxidants such as butylated hydroxytoluene (BHT), and alpha-tocopherol. This antioxidant activity depended on concentration and increased with increasing dose of sample. In addition, increased endogenous lipid peroxidation and decreased total antioxidant capacity (TAOC) were observed in aged mice. Thirty-day intraperitoneal administration of the oligosaccharides significantly decreased the lipid peroxidation in a dose-dependent manner. Oligosaccharides treatment increased TAOC and the activity of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in all organs tested in aged mice. The present study suggests that the synthetic oligosaccharides possess promising future for their strong free radical scavenging activity. Therefore they can be employed in compensating the decline in TAOC and the activities of antioxidant enzymes and in reducing the risks of lipid peroxidation.

Sulfation of a polysaccharide produced by a marine filamentous fungus Phoma herbarum YS4108 alters its antioxidant properties in vitro

Free radicals and other reactive oxygen species (ROS) are generated by all aerobic cells and are widely believed to play a significant role in aging as well as a number of degenerative or pathological diseases. This study compared the free radical-scavenging properties and antioxidant activity of YCP, a polysaccharide from the mycelium of a marine filamentous fungus Phoma herbarum YS 4108 and its two chemically sulfated derivatives YCP-S1 and YCP-S2. Sulfation, which masks hydroxyl groups of YCP polysaccharide molecule, could introduce new antioxidant activity, such as superoxide and hydroxyl radicals scavenging activity, metal chelating action, lipid peroxidation and linoleic acid oxidation inhibition capability. Furthermore, sulfated YCP was more potent than YCP at protecting erythrocytes against oxidative damage hemolysis. The current data suggest for the first time that sulfation of polysaccharide significantly increases its antioxidant activity and the chemical modification of polysaccharides may allow the preparation of derivatives with new properties and a variety of applications.