Search results for "Assay"

Caseinophosphopeptides exert partial and site-specific cytoprotection against H2O2-induced oxidative stress in Caco-2 cells

2011

Abstract Caseinophosphopeptides can sequester prooxidant metals and scavenge free radicals, and may thus be used as functional food ingredients. The total antioxidant capacity (TEAC and ORAC) of two pools of caseinophosphopeptides (1–3 mg/ml), obtained from casein subjected to simulated gastrointestinal digestion (at two different pH values) and selective precipitation, was evaluated to determine dose–response activity. Pool B (which showed the highest antioxidant capacity due to the presence of more antioxidant amino acids) was used to test its cytoprotective effect against H2O2-induced oxidative stress in Caco-2 cells. Caseinophosphopeptides protected the cells against oxidative damage by…

Alternariol-induced cytotoxicity in Caco-2 cells. Protective effect of the phenolic fraction from virgin olive oil.

2014

The extra virgin olive oil (EVOO) has been associated to antioxidant effects. The mycotoxin alternariol (AOH) can contaminate olives. The aims of this work were to determine the cytotoxic effects and reactive oxygen species (ROS) produced by AOH, tyrosol and oleuropein (two polyphenols of olive oil) and a real EVOO extract in Caco-2 cells. The MTT assay and the ROS production by the H2-DCFDA probe were used. Results demonstrated that AOH reduces cellular proliferation depending on concentration, whereas tyrosol and oleuropein did not (12.5-100 μM). The combination of AOH + oleuropein (50 μM) increased cell proliferation (24%) whereas, AOH + tyrosol decreased (47%) it. Besides, AOH increased…

Melatonin protects against ischemia-reperfusion injury and inhibits apoptosis in isolated working rat heart.

2003

INTRODUCTION: Melatonin (MEL), a pineal hormone, is well known as a potent antioxidant in a variety of ischemia-reperfusion models. Recent studies have assumed a pivotal role of reactive oxygen species (ROS) in the development of apoptosis. There are few pieces of information concerning a possible protective role of MEL against apoptosis in ischemia-reperfusion injury of myocardium. METHODS: We conducted an in vitro experiment: (1) to study the effect of MEL in the model of isolated and perfused working rat heart; (2) to evaluate the antioxidant capacity of MEL by a simple fluorescence test; and (3) to analyze the extent of apoptosis inhibition by MEL. Four groups of male Wistar rat were us…

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…

Cytoprotective effect of resveratrol diastereomers in CHO-K1 cells exposed to beauvericin

2015

Beauvericin (BEA) causes cytotoxicity, lipid peroxidation and reactive oxygen species in CHO-K1 cells. Resveratrol (RSV) is a polyphenol with multiple biological properties, including antioxidant effects. RSV has two forms: trans and cis. The aims of this study were to determine the cytoprotective effect of trans-RSV and diastereomers mixtures (50:50 trans/cis-RSV and 70:30 trans/cis-RSV) incubated alone and in combination with BEA in ovarian (CHO-K1) cells. The results demonstrated that cell viability increases (from 9% to 77%) when they were exposed to low concentration of RSV. Moreover, when the cells were pre-treated with RSV and then exposed to BEA, a cytoprotective effect (from 25% to…

Flavonoids from Erythrina schliebenii

2017

Prenylated and O-methylflavonoids including one new pterocarpan (1), three new isoflavones (2–4), and nineteen known natural products (5–23) were isolated and identified from the root, stem bark, and leaf extracts of Erythrina schliebenii. The crude extracts and their constituents were evaluated for antitubercular activity against Mycobacterium tuberculosis (H37Rv strain), showing MICs of 32–64 μg mL–1 and 36.9–101.8 μM, respectively. Evaluation of their toxicity against the aggressive human breast cancer cell line MDA-MB-231 indicated EC50 values of 13.0–290.6 μM (pure compounds) and 38.3 to >100 μg mL–1 (crude extracts).

Revisiting the thiosemicarbazonecopper(II) reaction with glutathione. Activity against colorectal carcinoma cell lines.

2018

Thiosemicarbazones (TSCs), and their copper derivatives, have been extensively studied mainly due to the potential applications as antitumor compounds. A part of the biological activity of the TSC-CuII complexes rests on their reactivity against cell reductants, as glutathione (GSH). The present paper describes the structure of the [Cu(PTSC)(ONO2)]n compound (1) (HPTSC =pyridine-2-carbaldehyde thiosemicarbazone) and its spectroscopic and magnetic properties. ESI studies performed on the reaction of GSH with 1 and the analogous [{Cu (PTSC*)(ONO2)}2] derivative (2, HPTSC* =pyridine-2-carbaldehyde 4N-methylthiosemicarbazone) show the absence of peaks related with TSC-Cu-GSH species. However GS…

Haptoglobin interacts with apolipoprotein E and beta-amyloid and influences their crosstalk.

2014

Beta-amyloid accumulation in brain is a driving force for Alzheimer's disease pathogenesis. Apolipoprotein E (ApoE) represents a critical player in beta-amyloid homeostasis, but its role in disease progression is controversial. We previously reported that the acute-phase protein haptoglobin binds ApoE and impairs its function in cholesterol homeostasis. The major aims of this study were to characterize the binding of haptoglobin to beta-amyloid, and to evaluate whether haptoglobin affects ApoE binding to beta-amyloid. Haptoglobin is here reported to form a complex with beta-amyloid as shown by immunoblotting experiments with purified proteins, or by its immunoprecipitation in brain tissues …

Opposite vascular activity of (R)-apomorphine and its oxidised derivatives. Endothelium-dependent vasoconstriction induced by the auto-oxidation meta…

2003

We have synthetised a series of oxidised apomorphine derivatives (orto and para quinones 2-5), in order to analyse their vascular activity. We have performed radioligand binding assays on rat cortical membranes and functional studies on rat aortic rings. Instead the relaxant activity exhibited by (R)-apomorphine, o-quinones 2, 4, show contractile activity dependent on endothelium in rat aortic rings. Compound 2, the main metabolite of (R)-apomorphine auto-oxidation, was the product which showed enhanced contractile activity by a complex mechanism related to activation of Ca(2+) channels through release and/or inhibition of endothelial factors. Moreover, this compound disrupts the endothelia…

Oxygenated Cembrene Diterpenes from Sarcophyton convolutum: Cytotoxic Sarcoconvolutum A–E

2021

The soft coral genus Sarcophyton contains the enzymatic machinery to synthesize a multitude of cembrene-type diterpenes. Herein, highly oxygenated cembrenoids, sarcoconvolutum A–E (1–5) were purified and characterized from an ethyl acetate extract of the red sea soft coral, Sarcophyton convolutum. Compounds were assemblies according to spectroscopic methods including FTIR, 1D- and 2D-NMR as well as HRMS. Metabolite cytotoxicity was tested against lung adenocarcinoma, cervical cancer, and oral-cavity carcinoma (A549, HeLa and HSC-2, respectively). The most cytotoxic compound, (4) was observed to be active against cell lines A549 and HSC-2 with IC50 values of 49.70 and 53.17 μM, respectively.