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Plants from Brazil Used Against Snake Bites
Published in Mahendra Rai, Shandesh Bhattarai, Chistiane M. Feitosa, Wild Plants, 2020
Jocimar de Souza, Bruna Stramandinoli Deamatis, Fernanda Mayumi Ishii, Ingrid Francine Araújo de Oliveira, Gustavo Rodrigues Toledo Piza, Jorge Amaral Filho, Edson Hideaki Yoshida, José Carlos Cogo, Angela Faustino Jozala, Denise Grotto, Rauldenis Almeida Fonseca Santos, Yoko Oshima-Franco
GSH was determined by quantification of total thiols (Ellman 1959). Tyrode solution (with each respective pharmacological protocol) (50 μL) was mixed with 900 μL of phosphate buffer, and it reacted with 50 μL of 5-5-dithio-bis-2-nitrobenzoic acid (DTNB) to form a yellow complex, which was read at 412 nm. GSH levels were expressed in μmol/mL solution.
Pre-Clinical In-Vivo and In-Vitro Methods For Evaluation of Anti-Alzheimer’s Drugs
Published in Atanu Bhattacharjee, Akula Ramakrishna, Magisetty Obulesu, Phytomedicine and Alzheimer’s Disease, 2020
Shilpa A. Deshpande, Niraj S. Vyawahare
Principle: Acetylcholinesterase activity is measured by using an artificial substrate, acetylthiocholine (ATC). It is cleaved by AChE to release thiocholine, which is allowed to react with the -SH reagent, DTNB (5,5’-dithiobis-2-nitrobenzoic acid). DTNB is reduced to thionitrobenzoic acid, a yellow-colored anion which gives an absorption maximum at 412 nm.
The Modification of Cysteine
Published in Roger L. Lundblad, Chemical Reagents for Protein Modification, 2020
More recent studies on the use of DTNB to modify sulfydryl groups in proteins have included the modification of ATP sulfurylase,43 oncomodulin,78 glutathione synthetase,79 fibronectin,80 and streptococcal NADH peroxidase.81 In studies on the modification of ATP sulfurylase,43 it was observed that DTNB was less potent than the more hydrophobic dithionitropyridine derivative (see Figure 32).
Oral delivery of nerolidol alleviates cyclophosphamide-induced renal inflammation, apoptosis, and fibrosis via modulation of NF-κB/cleaved caspase-3/TGF-β signaling molecules
Published in Drug Delivery, 2023
Ashif Iqubal, Abul Kalam Najmi, Shadab Md, Huda Mohammed Alkreathy, Javed Ali, Mansoor Ali Syed, Syed Ehtaishamul Haque
Sedlak & Lindsay (1968) method was used for the GSH estimation (Sedlak & Lindsay, 1968). The estimation was based on the spectrophotometric principle that the –SH group causes a reduction of 5′ –dithiobis-2-nitrobenzoic acid (DNTB), leading to the formation of 2-nitro-5-mercaptobenzoic acid and exhibit yellow color and ultimately absorbance is recorded. For the assessment of GSH level, 150 mg of tissue was dissolved in 1.5 ml of 0.02 M EDTA and centrifuged at 10000 rpm for 20 min at 4 °C. EDTA (0.02 M) was prepared by the dissolving 22.3 g of EDTA in 300 ml of distilled water and 20 ml of the formed solution was further added to 200 ml of distilled water. 1 ml of obtained homogenate was then mixed with the distilled water (4 ml) and trichloroacetic acid (50%) and shaken for 10 min. After 10 min, the solution was centrifuged at 3000 rpm for 15 min, and 2 ml of supernatant was added to 4 ml Tris buffer (0.4 ml, pH 8.9) and 0.1 ml DTNB (0.01 M). Tris buffer was prepared by dissolving 24.2 g of Tris buffer in 100 ml of water, EDTA (0.2 M) was added to this solution, and the volume of 1 liter was adjusted, and the 8.9 pH was adjusted by using 1 N HCl. DTNB was prepared by dissolving (99 mg) to 25 ml Absolut methanol. The absorbance of the resultant mixture was recorded at 412 nm with 5 min of addition of DTNB, and values were expressed as µmole/mg of protein (Sedlak & Lindsay, 1968).
The effects of pomegranate peel extract on the gene expressions of antioxidant enzymes in a rat model of alloxan-induced diabetes
Published in Archives of Physiology and Biochemistry, 2023
Shahrokh Bagheri, Reza Mohammadrezaei Khorramabadi, Vahideh Assadollahi, Peyman Khosravi, Ahmad Cheraghi Venol, Saeed Veiskerami, Hassan Ahmadvand
Glutathione peroxidase (GPx) was measured according to the modified Rotruck et al. method. First, we poured, in order, 200 µL of 0.4 M tris-HCl (pH 7), 100 µL of 1 mM NaN3, 200 µL of the sample, 200 µL of 2 mM glutathione, and 100 µL of 0.2 mM H2O2 into a tube. The tubes were kept at 37 °C for 10 min, after which we added 0.4 ml of 10% TCA to the tubes. The tubes were centrifuged at 2000 rpm for 3 min. A total of 25 µL of the supernatant was poured into an ELISA microplate where it was mixed with 140 µL of 0.2 M tris-EDTA (pH 8) and 30 µL of DTNB. After 30 min incubation at room temperature, an ELISA reader was used to obtain the absorbance of each sample in triplicate at 420 nm versus a blank. The GPx level was reported as U/mg (Ahmadvand et al. 2017). Sodium citrate was used as the solvent for DTNB.
The role of paraoxonase and myeloperoxidase as oxidative stress markers in pregnant women with hypothyroidism
Published in Gynecological Endocrinology, 2022
Suat Cakina, Eren Pek, Onur Ozkavak, Deniz Kocyigit, Fatma Beyazıt
The Relassay Myeloperoxidase Chlorination Activity Assay Kit and The Relassay Myeloperoxidase Peroxidation Activity Assay Kit are quantitative and colorimetric assay kits for measuring the myeloperoxidase activity within a sample. In The Relassay Myeloperoxidase, Taurine chloramine is formed through the reaction of taurine with hypochlorous acid catalyzed by MPO. DTNB is a colorless product developed by the chromophore TNB and taurine chloramine reaction. The amount of enzyme that hydrolyzes the substrate and produces taurine chloramine is considered one unit of MPO activity and consumes 1.0 μmol of TNB per minute. In The Relassay Myeloperoxidase Peroxidation Activity Assay Kit, MPO catalyzes odianisidine to colored o-dianisidyl radical using H2O2. Kinetic activity is measured by examining the increased absorbance at 412 nm wavelength. This kit is easily adapted to automated analyzers and can be used manually.