scholarly journals Modulation of cholestan-3β,5α,6β-triol toxicity by butylated hydroxytoluene, α-tocopherol and β-carotene in newborn rat kidney cells in vitro

1997 ◽  
Vol 78 (3) ◽  
pp. 479-492 ◽  
Author(s):  
Alison M. Wilson ◽  
Ruth M. Sisk ◽  
Nora M. O'Brien
Keyword(s):  
Lipid Peroxidation ◽  
Cell Viability ◽  
Rat Kidney ◽  
Oxidation Products ◽  
Butylated Hydroxytoluene ◽  
Cholesterol Oxidation ◽  
Newborn Rat ◽  
Membrane Function ◽  
Β Carotene

Cholesterol oxidation products (COP) have been reported to influence vital cellular processes such as cell growth, cell proliferation, membrane function and de novo sterol biosynthesis. The objectives of the present study were: (1) to develop an in vitro model using newborn rat kidney (NRK) cells to investigate the actions of COP; (2) to investigate the effect of COP on cell viability, endogenous antioxidant enzymes activities, i.e. superoxide dismutase (EC 1.15.1.1; SOD) and catalase (EC 1.11.1.6; CAT), and the extent of lipid peroxidation in this model; (3) to determine whether the addition of 100–1000 nm-α-tocopherol, β-carotene or butylated hydroxytoluene (BHT) could protect against COP-induced cytotoxicity. NRK cells were cultured in the presence of various concentrations (5–50 μM) of cholesterol or cholestan-3β,5α,6β-triol (cholestantriol) for a period of 24 h. Cholesterol over the range 5–50 μM did not induce cytotoxicity as indicated by the neutral-red-uptake assay or the lactate dehydrogenase (EC 1.1.1.27)-release assay. However, cell viability was compromised by the addition of > 10 μM-cholestantriol (P < 0.05). The addition of β-carotene (100–1000 nM) did not increase cell viability significantly in cholestantriol-supplemented cells. However, the addition of α-tocopherol (1000 nM) and BHT (1000 nM) significantly increased percentage cell viability above that of the cholestantriol-supplemented cells but not back to control levels. SOD and CAT activities in NRK cells significantly decreased (P < 0.05) following incubation with cholestantriol. The addition of > 750 nM-α-tocopherol, β-carotene or BHT returned SOD and CAT activities to that of the control. Lipid peroxidation was significantly induced (P < 0.05) in the presence of cholestantriol. Supplementation of the cells with α-tocopherol (250, 500 or 1000 nM) or BHT (750 or 1000 nM) resulted in a reduction in the extent of lipid peroxidation (P < 0.05). The addition of β-carotene over the concentration range of 250–1000 nM did not reduce lipid peroxidation significantly compared with cells exposed to cholestantriol alone. These findings suggest that addition of exogenous antioxidants may be beneficial in the prevention of COP-induced toxicity in vitro.

Glucose Degradation Products and Peritoneal Membrane Function

2001 ◽  
Vol 21 (2) ◽  
pp. 201-207 ◽  
Author(s):  
Janusz Witowski ◽  
Thorsten O. Bender ◽  
Gerhard M. Gahl ◽  
Ulrich Frei ◽  
Achim Jörres
Keyword(s):  
Peritoneal Dialysis ◽  
Cell Viability ◽  
Degradation Products ◽  
Membrane Function ◽  
Peritoneal Mesothelial Cells ◽  
Glucose Degradation Products ◽  
And Function ◽  
The Impact ◽  
Dialysis Fluids

Background The bioincompatibility of peritoneal dialysis fluids (PDF) in current use has been partially attributed to the presence of glucose degradation products (GDPs), which are generated during heat sterilization of PDF. Several of the GDPs have been identified and we have recently demonstrated that these GDPs per se may impair the viability and function of human peritoneal mesothelial cells (HPMC) in vitro. It is also possible that GDP-related toxicity is further exacerbated by the milieu of PDF. We review the current literature on GDP and present the results of experiments comparing the impact of heat- and filter-sterilized PDF on the viability and function of HPMC. Methods Peritoneal dialysis fluids with low (1.5%) and high (4.25%) glucose concentrations were laboratory prepared according to the standard formula and sterilized either by heat (H-PDF; 121°C, 0.2 MPa, 20 minutes) or filtration (F-PDF; 0.2 μ). The buildup of GDP was confirmed by UV absorbance at 284 nm. Confluent HPMC monolayers were exposed to these solutions mixed 1:1 with standard M199 culture medium. After 24 hours, cell viability was assessed with the MTT assay, and interleukin-1β–stimulated monocyte chemotactic protein-1 (MCP-1) release with specific immunoassay. Results Exposure of HPMC to H-PDF resulted in a significant decrease in cell viability, with solutions containing 4.25% glucose being more toxic than 1.5% glucose-based PDF (27.4% ± 3.4% and 53.4% ± 11.0% of control values, respectively). In contrast, viability of HPMC exposed to F-PDF was not different from that of control cells. Moreover, treatment with H-PDF impaired the release of MCP-1 from HPMC to a significantly greater degree compared to F-PDF (17.4% and 24.9% difference for low and high glucose PDF, respectively). Conclusions Exposure of HPMC to H-PDF significantly impairs cell viability and the capacity for generating MCP-1 compared to F-PDF. This effect is likely to be mediated by GDPs present in H-PDF but not in F-PDF.

scholarly journals Qualitative and quantitative comparison of the cytotoxic and apoptotic potential of phytosterol oxidation products with their corresponding cholesterol oxidation products

2005 ◽  
Vol 94 (3) ◽  
pp. 443-451 ◽  
Author(s):  
Eileen Ryan ◽  
Jay Chopra ◽  
Florence McCarthy ◽  
Anita R. Maguire ◽  
Nora M. O'Brien
Keyword(s):  
Cell Line ◽  
Biological Effects ◽  
Oxidation Products ◽  
Cholesterol Oxidation ◽  
Monocytic Cell ◽  
Monocytic Cell Line ◽  
Cholesterol Oxidation Products ◽  
Phytosterol Oxidation Products ◽  
Induced Apoptosis ◽  
Β Carotene

Phytosterols contain an unsaturated ring structure and therefore are susceptible to oxidation under certain conditions. Whilst the cytotoxicity of the analogous cholesterol oxidation products (COP) has been well documented, the biological effects of phytosterol oxidation products (POP)have not yet been fully ascertained. The objective of the present study was to examine the cytotoxicity of β-sitosterol oxides and their corresponding COP in a human monocytic cell line (U937), a colonic adenocarcinoma cell line (CaCo-2) and a hepatoma liver cell line (HepG2). 7β-Hydroxysitosterol, 7-ketositosterol, sitosterol-3β,5α,6β-triol and a sitosterol-5α,6α-epoxide–sitosterol-5β,6β-epoxide (6:1) mixture were found to be cytotoxic to all three cell lines employed; the mode of cell death was by apoptosis in the U937 cell line and necrosis in the CaCo-2 and HepG2 cells. 7β-Hydroxysitosterol was the only β-sitosterol oxide to cause depletion in glutathione, indicating that POP-induced apoptosis may not be dependent on the generation of an oxidative stress. A further objective of this study was to assess the ability of the antioxidants α-tocopherol, γ-tocopherol and β-carotene to modulate POP-induced cytotoxicity in U937 cells. Whilst α/γ-tocopherol protected against 7β-hydroxycholesterol-induced apoptosis, they did not confer protection against 7β-hydroxysitosterol-or 7-ketositosterol-induced toxicity, indicating that perhaps COP provoke different apoptotic pathways than POP. β-Carotene did not protect against COP- or POP-induced toxicity. In general, results indicate that POP have qualitatively similar toxic effects to COP. However, higher concentrations of POP are required to elicit comparable levels of toxicity.

scholarly journals Aqueous Extracts of Teucrium polium Possess Remarkable Antioxidant Activity In Vitro

2006 ◽  
Vol 3 (3) ◽  
pp. 329-338 ◽  
Author(s):  
Predrag Ljubuncic ◽  
Suha Dakwar ◽  
Irina Portnaya ◽  
Uri Cogan ◽  
Hassan Azaizeh ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Antioxidant Activity ◽  
Rat Liver ◽  
Antioxidant Properties ◽  
Liver Homogenate ◽  
Plasma Oxidation ◽  
Teucrium Polium ◽  
Liver Homogenates ◽  
Β Carotene

Teucrium poliumL. (Lamiaceae) (RDC 1117) is a medicinal plant whose species have been used for over 2000 years in traditional medicine due to its diuretic, diaphoretic, tonic, antipyretic, antispasmodic and cholagogic properties. The therapeutic benefit of medicinal plants is often attributed to their antioxidant properties. We previously reported that an aqueous extract of the leaves and stems of this plant could inhibit iron-induced lipid peroxidation in rat liver homogenate at concentrations that were not toxic to cultured hepatic cells. Others have reported that organic extracts of the aerial components of this plant could inhibit oxidative processes. Against this background, we felt further investigation on the antioxidant action of the extract ofT. poliumprepared according to traditional Arab medicine was warranted. Accordingly, we assessed (i) its ability to inhibit (a) oxidation of β-carotene, (b) 2,2′-azobis(2-amidinopropan) dihydrochloride (AAPH)-induced plasma oxidation and (c) iron-induced lipid peroxidation in rat liver homogenates; (ii) to scavenge the superoxide ($${\hbox{ O }}_{2}^{\bullet -}$$) radical and the hydroxyl radical (OH•); (iii) its effects on the enzyme xanthine oxidase activity; (iv) its capacity to bind iron; and (v) its effect on cell glutathione (GSH) homeostasis in cultured Hep G2 cells. We found that the extract (i) inhibited (a) oxidation of β-carotene, (b) AAPH-induced plasma oxidation (c) Fe2+-induced lipid peroxidation in rat liver homogenates (IC50 = 7 ± 2 μg ml−1); (ii) scavenged $${\hbox{ O }}_{2}^{\bullet -}$$(IC50 = 12 ± 3 μg ml−1) and OH• (IC50 = 66 ± 20 μg ml−1); (iii) binds iron (IC50 = 79 ± 17 μg ml−1); and (iv) tended to increase intracellular GSH levels resulting in a decrease in the GSSG/GSH ratio. These results demonstrate that the extract prepared from theT. poliumpossesses antioxidant activityin vitro. Further investigations are needed to verify whether this antioxidant effect occursin vivo.

scholarly journals Lipid Peroxidation: A Signaling Mechanism in Diagnosis of Diseases

2021 ◽  
Author(s):  
Kalpana Sabanna Patil ◽  
Raju Ratan Wadekar
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Clinical Practice ◽  
Oxidation Products ◽  
Signaling Mechanism ◽  
Unsaturated Lipids ◽  
End Products ◽  
Lipid Radicals

Quantification of reactive oxygen species, is perplexing either in vivo or in vitro due to their short half-lives. Consequently, to define the magnitude of oxidative stress, the more stable oxidation products can be measured in biological samples. The oxidative stress leads to the lipid peroxidation that involves the initiation, termination and propagation of lipid radicals, wherein, the process involves the oxygen uptake, rearrangement of the double bonds in unsaturated lipids, that leads to polyunsaturated fatty acid deterioration. Subsequently, the toxic signaling end products are considered as biomarkers of free radicals that act both as signaling molecules and as cytotoxic products cause covalent alteration of lipid peroxidation products. The use of validated signaling mechanism (s) of Lipid peroxidation and products derived thereof exhibits its use clinical practice and basic clinical research as well as in clinical practice has become common place, and their presence as endpoints in clinical trials is now broadly accepted. This knowledge can be used to diagnose disease earlier, or to prevent it before it starts. The signaling markers can be used to excel the effectiveness of the prevailing medicines and to improve the new medicines.

scholarly journals In-vitro and In-vivo Antioxidant Activity of Ethanol Leaf Extract of Justicia carnea

2020 ◽  
pp. 48-60
Author(s):  
Udedi Stanley Chidi ◽  
Ani Onuabuchi Nnenna ◽  
Asogwa Kingsley Kelechi ◽  
Maduji Fitzcharles Chijindu ◽  
Okafor Clinton Nebolisa
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Antioxidant Activity ◽  
Ascorbic Acid ◽  
Superoxide Dismutase ◽  
Leaf Extract ◽  
Dpph Radical ◽  
Β Carotene ◽  
In Vitro Antioxidant Activity

This study investigated the in-vitro antioxidant activity of ethanol leaf extract of Justicia carnea and its effect on antioxidant status of alloxan-induced diabetic albino rats. The in-vitro antioxidant activity was assayed by determining the total phenol, flavonoids, ascorbic acid, β-carotene and lycopene contents and by using 2,2 diphenyl-1-picrylhydrazyl (DPPH) radical, reducing antioxidant power and inhibition of lipid peroxidation antioxidant systems. Oxidative stress was produced in rats by single intraperitoneal injection of 150 mg/kg alloxan and serum concentration of malonaldehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) were determined. Five experimental groups of rats (n=6) were used for the study. Two groups of diabetic rats received oral daily doses of 100 and 200 mg/kg Justicia carnea leaf extract respectively while gilbenclamide (5 mg/ml); a standard diabetic drug was also given to a specific group for 14 days. From the result, the leaf extract contained a higher concentration of flavonoids followed byphenols, ascorbic acid, lycopene and β-carotene. The extract displayed more potent reducing power ability with EC50 of 40 µg/ml compared to BHA (EC50 of 400µg/ml). The percentage DPPH radical scavenging activity of the extract was also higher with EC50 of 200µg/ml and increased with increase in concentration while BHA had EC50of 320µg/ml. The inhibition of lipid peroxidation also increased with increase in concentration with EC50 of 58µg/ml and comparable with BHA (EC50=60µg/ml). The effect of the plant extract on antioxidant enzyme activities was concentration-dependent. Administration of 100mg/kg of the plant extract resulted in a significant decrease (p<0.05) in serum MDA concentration, while 200 mg/kg of the extract caused a significant (p˂0.05) increase in superoxide dismutase (SOD) and catalase activities with a non-significant increase (p>0.05) in the serum level of MDA when compared with the diabetic untreated group. These findings suggest that ethanol leaf extract of Justicia carnea have antioxidant properties and could handle diabetes-induced oxidative stress.

scholarly journals Overexpression of MnSOD Protects against Cold Storage-Induced Mitochondrial Injury but Not against OMA1-Dependent OPA1 Proteolytic Processing in Rat Renal Proximal Tubular Cells

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1272
Author(s):  
Julia Tobacyk ◽  
Grishma KC ◽  
Lee Ann MacMillan-Crow
Keyword(s):  
Cell Viability ◽  
Cold Storage ◽  
Renal Injury ◽  
Rat Kidney ◽  
Proteolytic Processing ◽  
Independent Manner ◽  
Western Blots ◽  
Proximal Tubular ◽  
Dependent Cell

Kidneys from deceased donors undergo cold storage (CS) preservation before transplantation. Although CS is a clinical necessity for extending organ quality preservation, CS causes mitochondrial and renal injury. Specifically, many studies, including our own, have shown that the triggering event of CS-induced renal injury is mitochondrial reactive oxygen species (mROS). Here, we explored the role of OMA1-depedent OPA1 proteolytic processing in rat kidney proximal tubular epithelial (NRK) cells in an in vitro model of renal CS (18 h), followed by rewarming (6 h) (CS + RW). The involvement of mROS was evaluated by stably overexpressing manganese superoxide dismutase (MnSOD), an essential mitochondrial antioxidant enzyme, in NRK cells. Western blots detected rapid OPA1 proteolytic processing and a decrease in ATP-dependent cell viability in NRK cells subjected to CS + RW compared to control cells. Small interfering RNA (siRNA) knockdown of OMA1 reduced proteolytic processing of OPA1, suggesting that OMA1 is responsible for OPA1 proteolytic processing during CS + RW-induced renal injury. Overexpression of MnSOD during CS + RW reduced cell death, mitochondrial respiratory dysfunction, and ATP-dependent cell viability, but it did not prevent OMA1-dependent OPA1 processing. These data show for the first time that OMA1 is responsible for proteolytically cleaving OPA1 in a redox-independent manner during renal cell CS.

Lipid peroxidation of the brush-border membrane: membrane physical properties and glucose transport

1993 ◽  
Vol 264 (6) ◽  
pp. G1009-G1015 ◽  
Author(s):  
D. Jourd'Heuil ◽  
P. Vaananen ◽  
J. B. Meddings
Keyword(s):  
Lipid Peroxidation ◽  
Physical Properties ◽  
Glucose Transport ◽  
Brush Border ◽  
Brush Border Membrane ◽  
Membrane Vesicles ◽  
Membrane Lipid ◽  
Membrane Function ◽  
Membrane Lipid Bilayer

During inflammatory conditions, peroxidation of biological membranes often takes place. Deleterious physiological consequences, in terms of membrane function, could theoretically be mediated by either direct oxidative attack upon integral membrane proteins or by indirectly altering the lipid environment surrounding these proteins. To address this issue, in vitro peroxidation of guinea pig brush-border membrane vesicles was induced by incubation of the vesicles with ferrous sulfate and ascorbic acid. We found that ongoing peroxidative attack initiates lipid peroxidation and radically alters the physical properties of the membrane lipid bilayer in a well-defined and regional manner. Peroxidation of microvillous membrane produced an increasingly rigid membrane. Coupled with these alterations was a fivefold reduction in maximal rates of sodium-dependent glucose transport that appeared to have a multifactorial origin. Approximately one-third of this reduction was secondary to altered membrane physical properties and was reversible by fluidizing the vesicles and returning membrane physical properties to normal. The remaining reduction in glucose transport activity was not responsive to membrane fluidization and was presumably related to direct damage of the transport protein.

scholarly journals GC-MS Analysis of the Antioxidant Active Fractions of Micromeria juliana with Anticholinesterase Activity

2009 ◽  
Vol 4 (9) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Mehmet Öztürk ◽  
Ufuk Kolak ◽  
Mehmet Emin Duru ◽  
Mansur Harmandar
Keyword(s):  
Lipid Peroxidation ◽  
Antioxidant Activity ◽  
Radical Scavenging ◽  
Reducing Power ◽  
Light Petroleum ◽  
Inhibition Activity ◽  
Total Antioxidant ◽  
Lipid Peroxidation Inhibition ◽  
Β Carotene

The aerial parts of Micromeria juliana (L.) Bentham ex Reichb. were extracted with light petroleum, acetone and methanol, successively. The antioxidant activity of different concentrations of the extracts was evaluated using different antioxidant tests, namely total antioxidant (lipid peroxidation inhibition activity), DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging, ferric reducing power, and metal chelating. Total antioxidant activity was determined using the β-carotene-linoleic acid assay. Unexpectedly, the light petroleum extract exhibited strong lipid peroxidation inhibition activity. The extract was fractionated on a silica gel column and the antioxidant activity of the fractions was determined by the β-carotene-linoleic assay at 25 μg/mL concentration. The fractions that exhibited more than 50% inhibition activity were analysed by GC and GC/MS; thus, the structure of fourteen compounds were elucidated. In addition, acetyl- and butyrylcholinesterase inhibitory activities of the extracts were also determined in vitro. The light petroleum and acetone extracts were found to have mild butyrylcholinesterase inhibitory activity.

scholarly journals Artifactual Oxidation of Cholesterol During the Analysis of Cholesterol Oxidation Products: Protective Effect of Antioxidants

2004 ◽  
Vol 87 (2) ◽  
pp. 493-498 ◽  
Author(s):  
Francesc Guardiola ◽  
Sandra Garcia-Cruset ◽  
Ricard Bou ◽  
Rafael Codony
Keyword(s):  
Protective Effect ◽  
Ascorbyl Palmitate ◽  
Nitrogen Atmosphere ◽  
Disodium Salt ◽  
Oxidation Products ◽  
Butylated Hydroxytoluene ◽  
Cholesterol Oxidation ◽  
Dim Light ◽  
Cold Saponification ◽  
Ethylene Diaminetetraacetic Acid

Abstract To study the influence of the addition of various antioxidants and their combinations on the artifactual oxidation of cholesterol during analysis, 2 factorial experiments were performed in duplicate. In the first experiment, 2 amounts of the following antioxidants were assayed: ethylene-diaminetetraacetic acid (EDTA) disodium salt (0 and 1 mg), pyrogallol (0 and 600 μg), and butylated hydroxytoluene (BHT; 0 and 600 μg); in the second, EDTA disodium salt (0 and 1 mg), ascorbyl palmitate (0 and 600 μg), and BHT (0 and 600 μg). Under low oxidative conditions of dim light, evaporation of solvents at low temperatures, and cold saponification in darkness under nitrogen atmosphere, the addition of antioxidants showed no further protective effect. Furthermore, the presence of ascorbyl palmitate significantly increased the formation of cholesterol- 5β,6β-epoxide, and 7β-hydroxycholesterol.

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