Search results for "VITRO"

Mechanism of interaction of betanin and indicaxanthin with human myeloperoxidase and hypochlorous acid.

2005

Hypochlorous acid (HOCl) is the most powerful oxidant produced by human neutrophils and contributes to the damage caused by these inflammatory cells. It is produced from H2O2 and chloride by the heme enzyme myeloperoxidase (MPO). Based on findings that betalains provide antioxidant and anti-inflammatory effects, we performed the present kinetic study on the interaction between the betalains, betanin and indicaxanthin, with the redox intermediates, compound I and compound II of MPO, and its major cytotoxic product HOCl. It is shown that both betalains are good peroxidase substrates for MPO and function as one-electron reductants of its redox intermediates, compound I and compound II. Compoun…

Melatonin protects human red blood cells from oxidative hemolysis: new insights into the radical-scavenging activity.

1999

Antioxidant activity of melatonin in human erythrocytes, exposed to oxidative stress by cumene hydroperoxide (cumOOH), was investigated. CumOOH at 300 microM progressively oxidized a 1% suspension of red blood cells (RBCs), leading to 100% hemolysis in 180 min. Malondialdehyde and protein carbonyls in the membrane showed a progressive increase, as a result of the oxidative damage to membrane lipids and proteins, reaching peak values after 30 and 40 min, respectively. The membrane antioxidant vitamin E and the cytosolic reduced glutathione (GSH) were totally depleted in 20 min. As a consequence of the irreversible oxidative damage to hemoglobin (Hb), hemin accumulated into the RBC membrane d…

Evaluation of whole antioxidant defenses of human mononuclear cells by a new in vitro biological test: lack of correlation between erythrocyte and mo…

2009

1873-2933 (Electronic) Journal Article; OBJECTIVES: This work aims to evaluate the resistance of mononuclear cells to oxidative stress using a "KRL" test, formerly utilized to evaluate the resistance of erythrocyte to free radicals. METHODS: The "KRL" test evaluates the resistance to lysis of cells treated by free radicals generated under standardized conditions. RESULTS: We defined new analytical parameters (level of radical production, time course, number of cells) to obtain an accurate assay determining the resistance to oxidative stress of mononuclear cells, in comparison to that of erythrocytes. This test allows the evaluation of change in the redox state of mononuclear cells (improved…

Synthesis and evaluation of diverse thio avarol derivatives as potential UVB photoprotective candidates.

2007

Semisynthesis of 13 new thio avarol derivatives (4-16) and in vitro evaluation on the photodamage response induced by UVB irradiation are described. Their ability to inhibit NF-kappaB activation and TNF-alpha generation in HaCaT cells as well as their antioxidant capacity in human neutrophils has also been studied. Among them we have identified two monophenyl thio avarol derivatives (4-5) lacking cytotoxicity which can be considered promising UVB photoprotective agents through the potent inhibition of NF-kappaB activation with a mild antioxidant pharmacological profile.

Potential therapeutic effects of natural heme oxygenase-1 inducers in cardiovascular diseases.

2013

Significance: Many physiological effects of natural antioxidants, their extracts or their major active components, have been reported in recent decades. Most of these compounds are characterized by a phenolic structure, similar to that of α-tocopherol, and present antioxidant properties that have been demonstrated both in vitro and in vivo. Polyphenols may increase the capacity of endogenous antioxidant defenses and modulate the cellular redox state. Such effects may have wide-ranging consequences for cellular growth and differentiation. Critical Issues: The majority of in vitro and in vivo studies conducted so far have attributed the protective effect of bioactive polyphenols to their chem…

Anti-inflammatory activity of erycristagallin, a pterocarpene from Erythrina mildbraedii.

2003

Erycristagallin, a pterocarpene isolated from Erythrina mildbraedii, was tested in vitro for its antioxidant properties on the stable 2,2-diphenyl-1-pycryl-hydrazyl (DPPH) free radical and on the arachidonic acid metabolism. In addition, erycristagallin was tested on different experimental models of inflammation, such as the acute and chronic inflammation induced by the application of 12-O-tetradecanoylphorbol 13-acetate (TPA) on mice and the phospholipase A(2)-induced mouse paw oedema test. In the carrageenan-induced mouse paw oedema test, the ethyl acetate extract obtained from E. mildbraedii showed anti-inflammatory activity, and erycristagallin was isolated as the active principle. In v…

Assessment of the anti-inflammatory activity and free radical scavenger activity of tiliroside

2003

Three flavonoids, gnaphaliin, pinocembrin and tiliroside, isolated from Helichrysum italicum, were studied in vitro for their antioxidant and/or scavenger properties and in vivo in different models of inflammation. In vitro tests included lipid peroxidation in rat liver microsomes, superoxide radical generation in the xanthine/xanthine oxidase system and the reduction of the stable radical 1,1-diphenyl-2-pycryl-hydrazyl (DPPH). Acute inflammation was induced by application of 12-O-tetradecanoylphorbol 13-acetate (TPA) to the mouse ear or by subcutaneous injection of phospholipase A(2) or serotonin in the mouse paw. Eczema provoked on the mouse ear by repeated administration of TPA was selec…

In vitro digestion of betalainic foods. Stability and bioaccessibility of betaxanthins and betacyanins and antioxidative potential of food digesta.

2008

Betalains are considered to be bioactive dietary phytochemicals. The stability of betacyanins and betaxanthins from either fresh foods or manufactured products of cactus pear fruit ( Opuntia ficus indica L. Mill. cv. Gialla and Rossa) and red beet ( Beta vulgaris L. ssp. vulgaris) was assessed in a simulated oral, gastric, and small intestinal digestion and compared with the digestive stability of purified pigments. A minor loss of indicaxanthin, at the gastric-like environment only, and a decrease of vulgaxanthin I through all digestion steps were observed, which was not affected by food matrix. In contrast, food matrix prevented decay of betanin and isobetanin at the gastric-like environm…

Gamma interferon administration differently affects sensitive or doxorubicin resistant P388 leukemia cells; a relationship with antioxidant defenses?

1989

2021

Drosera rotundifolia L. is a carnivorous plant used in traditional medicine for its therapeutic properties. Because of its small size, its collection in nature is laborious and different cultivation methods have been studied to ensure availability. However, only a few studies exist where the lab-grown sundew tissue and field-grown sundew would have been compared in their functionality or metabolic profiles. In this study, the antioxidant and antiviral activities of lab-grown and field-grown sundew extracts and their metabolic profiles are examined. The effect of drying methods on the chromatographic profile of the extracts is also shown. Antioxidant activity was significantly higher (5–6 ti…