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Selected Functional Foods That Combat the Effects of Hyperglycemia and Chronic Inflammation
Published in Robert Fried, Richard M. Carlton, Type 2 Diabetes, 2018
Robert Fried, Richard M. Carlton
Hyperglycemia resulted in increased lipid peroxidation and protein components in red blood cells and other tissues, and it altered antioxidant enzyme activities. Curcumin reduced oxidative stress in the diabetic rats by inhibiting the increase in TBARS and protein components and reversing altered antioxidant enzyme activities without altering the hyperglycemic state in most of the tissues. Thiobarbituric acid reactive substances (TBARS) are formed as a by-product of lipid peroxidation (i.e., as degradation products of fats), which can be detected by the TBARS assay using thiobarbituric acid as a reagent.
A Brief Review of Receiver Operating Characteristic Curve Analyses
Published in Albert Vexler, Alan D. Hutson, Statistics in the Health Sciences, 2018
In practice, different biomarker levels are usually associated with disease in various magnitudes and in different directions. For example, low levels of high-density lipoprotein (HDL) cholesterol and high levels of thiobarbuturic acid reacting substances (TBARS), biomarkers of oxidative stress and antioxidant status, are indicators of coronary heart disease (Schisterman et al., 2001a). When multiple biomarkers are available, it is of great interest to seek a combination of biomarkers to improve diagnostic accuracy (e.g., Liu et al., 2011). Due to the simplicity in practical applications, we will attend to the best linear combination (BLC) of biomarkers, such that the combined score achieves the maximum AUC or the maximum treatment effect over all possible linear combinations. We refer the reader to Pepe (2003) and Pepe and Thompson (2000) for information regarding general methods related to best combinations of biomarkers that improve diagnostic accuracy.
Statistical Graphics
Published in Albert Vexler, Alan D. Hutson, Xiwei Chen, Statistical Testing Strategies in the Health Sciences, 2017
Albert Vexler, Alan D. Hutson, Xiwei Chen
Summary statistics of all 542 measurements of TBARS in the form of sample mean and sample standard deviation are 1.3808 and 0.4166, respectively. The sample mean and sample standard deviation of all 542 HDL cholesterol measurements (mg/dl) are 49.9384 and 11.7765, respectively. Another clear and useful statistical presentation of the entire body of the data is provided in Figure 3.6, which is the EDF. Figure 3.6 plots the EDF of measurements of TBARS in the left and the EDF of measurements of HDL cholesterol in the right, produced by the following R code: > tbars<-c(tbars.x,tbars.y) > Fn.tbars<-ecdf(tbars) # ECDF of TBARS > hdl<-c(hdl.x,hdl.y) > Fn.hdl<-ecdf(hdl) # ECDF of HDL > par(mfrow=c(1,2)) > plot(Fn.tbars, verticals = TRUE, do.points = FALSE,main="TBARS",lwd=2) > plot(Fn.hdl, verticals = TRUE, do.points = FALSE,main="HDL",lwd=2)
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
Ohkawa et al. (1979) method was used to assess the MDA level (Ohkawa et al., 1979). The estimation was based on the principle that free radical’s reaction causes lipid peroxidation and produces peroxides that further get converted into MDA. Thus, the reaction of thiobarbituric acid along with MDA provides the amount of thiobarbituric acid reactive substances (TBARS); hence, the test is also called the TBARS test. To assess MDA level, 150 mg of tissue was dissolved in 1.5 ml of KCl (0.15 M) and centrifuged at 10000 rpm for 15 min at 4 °C). 0.15 M KCl was prepared by dissolving 2.3 g KCL to the 200 ml distilled water. 1 ml of suspension medium was taken after centrifugation, and TCA (30%) and TBA (0.8%) reagents, 0.5 ml each, were dissolved into it. Aluminum foil was used to cover the tube and shaken for 30 min at 80 °C. After this, the tubes were kept for 30 min in ice-cold water. After 30 min, tubes were centrifuged for 15 min at 3000 rpm, the absorbance was recorded at 540 nm, and the values were expressed as nanomoles of MDA per mg protein (Ohkawa et al., 1979).
The protective effects of capsaicin on oxidative damage-induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin in rats
Published in Drug and Chemical Toxicology, 2022
Muhammed Fatih Doğan, Neşe Başak Türkmen, Aslı Taşlıdere, Yasemin Şahin, Osman Çiftçi
Determination of SOD activity was based on the production of hydrogen peroxide, from xanthine by xanthine oxidase and reduction of nitro blue tetrazolium (Al Olayan et al. 2020). The amount of protein leading to 50% inhibition of NBT reduction rate was defined as one unit of SOD activity. The product was evaluated spectrophotometrically at 560 nm. Results are expressed as U/mg protein. TBARS level was determined spectrophotometrically at 532 nm according to the method of Yagi (Yagi 1998). TBARS level, an important lipid peroxidation indicator, and the results were expressed as nmol/g tissue. The reduced GSH content of the tissue homogenate was measured by the method described by Sedlak and Lindsay (Caglayan et al. 2019) at 412 nm and was expressed as nmol/ml tissue protein. The protein content of tissue homogenates was measured by the method of Lowry with bovine serum albumin as the standard (Pal et al. 2020).
Inhibition of Glutamine Cellular Uptake Contributes to the Cytotoxic Effect of Xanthohumol in Triple-Negative Breast Cancer Cells
Published in Nutrition and Cancer, 2022
The TBARS (thiobarbituric acid reactive substances) assay quantifies oxidative stress by measuring lipid peroxidation damage (malondialdehyde levels) caused by free radicals in the cells. MDA-MB-231cells were treated for 24 h with xanthohumol 10 µM and/or doxorrubicin 10 µM (or the respective solvents). At the end of the treatment, the cells were resuspended in homogenization solution (KH2PO4 62.5 nM, Na2HPO4.2H2O 50 nM, Triton X-100 0.1%, pH = 7) and 200 µl of trichloroacetic acid 50% was added to 300 µl of the resuspension. The samples were vortexed and rested for 5 min at room temperature to be next centrifugated at 10,600 g for 2 min at 4 °C. Then, thiobarbituric acid 1% (w/v) was added and the samples were incubated for 60 min at 95 °C. After that, 300 µl of each sample were transferred to a 96-well culture plate and the absorbance at 535 nm was measured (Thermo Fisher Scientific, Waltham, Massachusetts, USA). The MDA standard curve was performed using MDA bis(dimethyl acetal), subjected to an acid hydrolysis (addition of 0.1 M HCl and incubation at 40 °C for 1 h). The results were normalized to the protein content.