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Hsiu-Jen Wang; Yue-Wern Huang; Daniel B. Hier; Shakila Tobwala; Robert Aronstam; Nuran Ercal. N-Acetylcysteine Amide, a Thiol Antioxidant, Protects TBHP-Induced Oxidative Stress in Primary Human Retinal Pigment Epithelial Cells. Free Radical Biology and Medicine 2016, 100, S114 .
AMA StyleHsiu-Jen Wang, Yue-Wern Huang, Daniel B. Hier, Shakila Tobwala, Robert Aronstam, Nuran Ercal. N-Acetylcysteine Amide, a Thiol Antioxidant, Protects TBHP-Induced Oxidative Stress in Primary Human Retinal Pigment Epithelial Cells. Free Radical Biology and Medicine. 2016; 100 ():S114.
Chicago/Turabian StyleHsiu-Jen Wang; Yue-Wern Huang; Daniel B. Hier; Shakila Tobwala; Robert Aronstam; Nuran Ercal. 2016. "N-Acetylcysteine Amide, a Thiol Antioxidant, Protects TBHP-Induced Oxidative Stress in Primary Human Retinal Pigment Epithelial Cells." Free Radical Biology and Medicine 100, no. : S114.
Sri Krishna Yasaswi Maddirala; Shakila Tobwala; Nuran Ercal. Reversing Selenite-Induced Cataractogenesis in Rats by N-Acetylcysteineamide Eye Drops. Free Radical Biology and Medicine 2014, 76, S80 .
AMA StyleSri Krishna Yasaswi Maddirala, Shakila Tobwala, Nuran Ercal. Reversing Selenite-Induced Cataractogenesis in Rats by N-Acetylcysteineamide Eye Drops. Free Radical Biology and Medicine. 2014; 76 ():S80.
Chicago/Turabian StyleSri Krishna Yasaswi Maddirala; Shakila Tobwala; Nuran Ercal. 2014. "Reversing Selenite-Induced Cataractogenesis in Rats by N-Acetylcysteineamide Eye Drops." Free Radical Biology and Medicine 76, no. : S80.
Sutherlandia frutescens (L.) R.Br. (SF) is a South African plant that is widely used to treat stress, infections, cancer, and chronic diseases, many of which involve oxidative stress. The aim of the study was to quantitatively assess the antioxidant potential of SF extracts in cell-free system as well as in cell lines. Dried SF vegetative parts were extracted using six different solvents, and the extracts were assessed for total phenolic and flavonoid contents, total reducing power, iron chelating capacity, and free radical scavenging power, including, scavenging of hydroxyl radicals, superoxide anions, nitric oxide, and hydrogen peroxide. We further investigated the freeze-dried hot water extract of SF (SFE) to assess its effect against oxidative stress induced by tert-butyl hydroperoxide (t-BHP), an organic peroxide. Three different cell lines: Chinese hamster ovary (CHO), human hepatoma (HepaRG), and human pulmonary alveolar carcinoma (A549) cells, were employed to determine cell viability, intracellular reactive oxygen species (ROS) levels, and reduced to oxidized glutathione levels (GSH/GSSG). The results indicated that: (1) SF extracts have significant antioxidant potential that is dependent upon the nature of the extraction solvent and (2) SFE protects against tBHP-induced oxidative stress in cells by scavenging ROS and preserving intracellular GSH/GSSG. Oxidative stress is implicated in a number of disorders, and due to the public’s concerns about synthetic antioxidants, various natural antioxidants are being explored for their therapeutic potential. Our findings support claims for S. frutescens being a promising adjunctive therapeutic for oxidative stress-related health problems.
Shakila Tobwala; Weili Fan; Connor J Hines; William R Folk; Nuran Ercal. Antioxidant potential of Sutherlandia frutescens and its protective effects against oxidative stress in various cell cultures. BMC Complementary and Alternative Medicine 2014, 14, 1 -11.
AMA StyleShakila Tobwala, Weili Fan, Connor J Hines, William R Folk, Nuran Ercal. Antioxidant potential of Sutherlandia frutescens and its protective effects against oxidative stress in various cell cultures. BMC Complementary and Alternative Medicine. 2014; 14 (1):1-11.
Chicago/Turabian StyleShakila Tobwala; Weili Fan; Connor J Hines; William R Folk; Nuran Ercal. 2014. "Antioxidant potential of Sutherlandia frutescens and its protective effects against oxidative stress in various cell cultures." BMC Complementary and Alternative Medicine 14, no. 1: 1-11.
Oxidative stress, which is the loss of balance between antioxidant defense and oxidant production in the cells, is implicated in the molecular mechanism of heavy metal-induced neurotoxicity. Given the key role of lead (Pb) and cadmium (Cd) in inducing oxidative stress, we investigated their role in disrupting the integrity and function of immortalized human brain microvascular endothelial cells (hCMEC/D3). To study this, hCMEC/D3 cells were exposed to control media or to media containing different concentrations of Pb or Cd. Those exposed to Pb or Cd showed significantly higher oxidative stress than the untreated group, as indicated by cell viability, reactive oxygen species (ROS), glutathione (GSH) levels, and catalase enzyme activity. Pb also induced oxidative stress-related disruption of the hCMEC/D3 cell monolayer, as measured by trans-endothelial electrical resistance (TEER), the dextran permeability assay, and the level of tight junction protein, zona occluden protein (ZO-2). However, no significant disruption in the integrity of the endothelial monolayer was seen with cadmium at the concentrations used. Taken together, these results show that Pb and Cd induce cell death and dysfunction in hCMEC/D3 cells and, in the case of Pb, barrier disruption. This suggests blood brain barrier (BBB) dysfunction as a contributing mechanism in Pb and Cd neurotoxicities.
Shakila Tobwala; Hsiu-Jen Wang; Joshua Warren Carey; William A. Banks; Nuran Ercal. Effects of Lead and Cadmium on Brain Endothelial Cell Survival, Monolayer Permeability, and Crucial Oxidative Stress Markers in an in Vitro Model of the Blood-Brain Barrier. Toxics 2014, 2, 258 -275.
AMA StyleShakila Tobwala, Hsiu-Jen Wang, Joshua Warren Carey, William A. Banks, Nuran Ercal. Effects of Lead and Cadmium on Brain Endothelial Cell Survival, Monolayer Permeability, and Crucial Oxidative Stress Markers in an in Vitro Model of the Blood-Brain Barrier. Toxics. 2014; 2 (2):258-275.
Chicago/Turabian StyleShakila Tobwala; Hsiu-Jen Wang; Joshua Warren Carey; William A. Banks; Nuran Ercal. 2014. "Effects of Lead and Cadmium on Brain Endothelial Cell Survival, Monolayer Permeability, and Crucial Oxidative Stress Markers in an in Vitro Model of the Blood-Brain Barrier." Toxics 2, no. 2: 258-275.
Shakila Tobwala; Eylem Y. Pinarci; Yasaswi Maddirala; Nuran Ercal. N-acetylcysteine amide protects against dexamethasone-induced cataract related changes in cultured rat lenses. Advances in Biological Chemistry 2014, 04, 26 -34.
AMA StyleShakila Tobwala, Eylem Y. Pinarci, Yasaswi Maddirala, Nuran Ercal. N-acetylcysteine amide protects against dexamethasone-induced cataract related changes in cultured rat lenses. Advances in Biological Chemistry. 2014; 04 (01):26-34.
Chicago/Turabian StyleShakila Tobwala; Eylem Y. Pinarci; Yasaswi Maddirala; Nuran Ercal. 2014. "N-acetylcysteine amide protects against dexamethasone-induced cataract related changes in cultured rat lenses." Advances in Biological Chemistry 04, no. 01: 26-34.
To ascertain the molecular basis of Ca2+-mediated activation of matrix metalloproteinase-9 (MMP-9), we determined the accessibility of tryptophan residues to externally added acrylamide as quencher in the absence and presence of the metal ion. The steady-state and time resolved fluorescence data revealed that MMP-9 possesses two classes of tryptophan residues, “exposed” and “buried” which are quenched by the collisional rate constants (kq) of 3.2′ 109M-1.s-1 and 7.5′ 108M-1.s-1, respectively. These values are impaired by approximately two and three-fold, respectively, in the presence of 10 mM Ca2+. The Stern-Volmer constants (Ksv values) predicted from the time resolved fluorescence data (in the absence of Ca2+ ) satisfied the dynamic quenching model of the enzyme’s tryptophan residues. This was not the case in the presence of Ca2+ ; the steady-state acrylamide quenching data could only be explained by a combination of “dynamic” and “static” quenching models. A cumulative account of these data led to the suggestion that the binding of Ca2+ modulated the tertiary structure of the protein by decreasing the dynamic flexibility of the enzyme, which is manifested in further structuring of the enzyme’s active site pocket toward facilitating catalysis. Arguments are presented that the binding of Ca2+ at distal sites “dynamically” communicates with the active site residues of MMP-9 during catalysis.
Shakila Tobwala; D. K. Srivastava. Cooperative binding of calcium ions modulates the tertiary structure and catalytic activity of Matrix-Metalloproteinase-9. Advances in Enzyme Research 2013, 01, 17 -29.
AMA StyleShakila Tobwala, D. K. Srivastava. Cooperative binding of calcium ions modulates the tertiary structure and catalytic activity of Matrix-Metalloproteinase-9. Advances in Enzyme Research. 2013; 01 (02):17-29.
Chicago/Turabian StyleShakila Tobwala; D. K. Srivastava. 2013. "Cooperative binding of calcium ions modulates the tertiary structure and catalytic activity of Matrix-Metalloproteinase-9." Advances in Enzyme Research 01, no. 02: 17-29.