TBARS substance

The products formed during lipid peroxidation include unsaturated aldehydes, such as 4-hydroxynonenal. Their quantification is of great interest because of their extremely reactive and cytotoxic properties. This extreme reactivity and metabolic conversion, however, may make them unsuitable as test analytes for in vivo antioxidant activity studies except at high levels of oxidative stress. Furthermore, simple chemical tests such as the TBARS (thiobarbituric acid reactive substances) and LPO-586 (colorimetric... 

This test is used for both in vitro and in vivo determinations. It involves reacting thiobarbituric acid (TBA) with malondialdehyde (MDA), produced by lipid hydroperoxide decomposition, to form a red chromophore with peak absorbance at 532 nm (Fig. 10.1). The TBARS reaction is not specific. Many other substances, including other alkanals, proteins, sucrose, or urea, may react with TBA to form colored species that can interfere with this assay. 

Overproduction of free radicals by erythrocytes and leukocytes and iron overload result in a sharp increase in free radical damage in T1 patients. Thus, Livrea et al. [385] found a twofold increase in the levels of conjugated dienes, MDA, and protein carbonyls with respect to control in serum from 42 (3-thalassemic patients. Simultaneously, there was a decrease in the content of antioxidant vitamins C (44%) and E (42%). It was suggested that the iron-induced liver damage in thalassemia may play a major role in the depletion of antioxidant vitamins. Plasma thiobarbituric acid-reactive substances (TBARS) and conjugated dienes were elevated in (3-thalassemic children compared to controls together with compensatory increase in SOD activity [386]. The development of lipid peroxidation in thalassemic erythrocytes probably depends on a decrease in reduced glutathione level and decreased catalase activity [387]. 

Hassoun et al. (1993) examined the effects of various pesticides on lipid peroxidation and DNA single strand breakage in the hepatic cells of female Sprague-Dawley rats. Animals were dosed orally once with endrin at 4.5 mg/kg, lindane at 30 mg/kg, chlordane at 120 mg/kg, or DDT (dichlorodiphenyl trichloro-ethane) at 40 mg/kg, or vehicle only (com oil, control). At 6, 12, and 24 hours post-dosing, 4 animals from each group were sacrificed, their livers removed, and prepared for lipid peroxidation assay. Lipid peroxidation was measured calorimetrically by determining the amount of thiobarbituric acid reactive substances (TBARS) formed. Exposure to endrin resulted in a 14.5% increase in hepatic mitochondrial... 

TBARS, thiobarbituric acid reactive substances 22 6(o3, docosahexaenoic add 20 4to6, arachidonic acid 18 lfi)9, oleic acid 20 5fl)3, eicosapentaenoic add. 

Figure 5. Inhibitory effect of NO on Fe -induced lipid peroxidation. Shown is the decreased generation of an oxidative marker (thiobarbituric acid reactive substances, TBARS) as a result of 0.9 iM NO. HL-60 cells (5 x loVral) were placed in an O2 monitor and at the designated time points, butylated hydroxytoluene was added and samples were quick frozen for determination of TBARS. The values represent the mean and standard error of 3-5 independent determinations. Also shown for comparison is the residual concentration of O2 after exposure to the the same conditions. This shows a decrease in utilization of O2 in the presence of NO. We conclude that NO reduces TBARS, and the percent inhibition is similar to the poeent inhibition of O2 consumption. (Modified from our data in Kelley, E.E., Wagner, B.A., Buettner, G.R., and Bums, C.P., 1999, Arch. Biochem. Biophys. 370 97-104).

Other indices measure a secondary stage of oxidation, such as the anisidine value (ANV), pointing to formation of carbonyl compounds, capable of undergoing condensation reactions with p-anisidine, and the thiobarbituric acid reactive substance (TBARS) pointing to the presence of malondialdehyde (MDA) in particular. In biological systems, TBARS is of widespread use as a measure for the extent of oxidation damage. Another test for stability of oils to oxidation is based on the development of acidity as secondary product, for example, standards using the Rancimat equipment or a similar setup. 

Antioxidant activity was also tested in a liver microsome system. In this study, mice were treated by oral intubation (2 times/wk) with 0.2 ml olive oil alone or containing CLA (0.1 ml), linoleic acid (0.1 ml), or dl-a-tocopherol (lOmg). Four weeks after the first treatment, liver microsomes were prepared and subsequently subjected to oxidative stress using a non-enzymatic iron-dependent lipid peroxidation system. Microsomal lipid peroxidation was measured as thiobarbituric acid-reactive substance (TBARS) production using malondialdehyde as the standard. It was found that pretreatment of mice with CLA or dl-a-tocopherol significantly decreased TBARS formation in mouse liver microsomes (p < 0.05) (Sword, J. T. and M. W. Pariza, University of Wisconsin, unpublished data). 

Commonly, 1,1,3,3-tetramethoxypropane (TMP) or its tetraethoxy analog is used as a standard. Under acidic conditions these acetals are hydrolyzed to 1,3-propanedial (i.e., malonaldehyde) and therefore can be used in the construction of a TBA reactive substances (TBARS) standard curve one mole of malonaldehyde is released for each mole of TMP. 

Ke, P.J., Cervantes, E., and Robles-Martinez, C. 1984. Determination of thiobarbituric acid reactive substances (TBARS) in fish tissue by an improved distillation-spectrophotometric method. J. Sci. FoodAgric. 35 1248-1254. 

Tangerine oil. see Citrus Orange Tannins, structure of. see also Polyphenolics Taste, see Flavor analysis TBA. see 2-Thiobarbituric acid TBARS. see 2-Thiobarbituric acid reactive substances... 

Thiobarbituric acid reactive substances (TBARS), determination in lipids, 547-564... 

SPME solid-phase microextraction SV saponification value TA titratable acidity TBA thiobarbituric acid TBARS thiobarbituric acid-reactive substances... 

FIG. 9 Serum PSA, thiobarbituric acid substances (TBARS), and thiols in prostate cancer cases and controls ( p < 0.05). (Lycopene, tomatoes and health New Perspectives 2000. Reprinted from Lycopene and the prevention of chronic diseases. Major findings from five international conferences. 2002. A.V. Rao, D. Heber, eds., p. 23. By permission of Caledonian Science Press.)... 

Figure 8.2 Pomegranate juice polyphenols and antioxidant potency in comparison to other fruit juices. Total polyphenol concentration in the different juices was determined using quercetin as a standard. LDL (100 pg of protein/milliliter) was preincubated with increasing volume concentration (0-25 pL) of the juices. Then, 5 pmol/L of CuS04 was added, and the LDL was further incubated for 2 hours at 37°C. The extent of LDL oxidation was measured by the thiobar-bituric acid reactive substance (TBAR) assay, and the ICh, values (the concentration needed to get 50% inhibition) are given. Results are given as mean S.D. of three different experiments.

The effect of PJ consumption by patients with CAS on their serum oxidative state was measured also as serum concentration of antibodies against Ox-LDL.31 A significant (p < 0.01) reduction in the concentration of antibodies against Ox-LDL by 24 and 19% was observed after 1 and 3 months of PJ consumption, respectively (from 2070 61 EU/mL before treatment to 1563 69 and 1670 52 F.lI/mL after 1 and 3 months of PJ consumption, respectively). Total antioxidant status (TAS) in serum from these patients was substantially increased by 2.3-fold (from 0.95 0.12 nmol/L at baseline up to 2.20 0.25 nmol/L after 12 months of PJ consumption). These results indicate that PJ administration to patients with CAS substantially reduced their serum oxidative status and could thus inhibit plasma lipid peroxidation. The susceptibility of the patient s plasma to free radical-induced oxidation decreased after 12 months of PJ consumption by 62% (from 209 18 at baseline to 79 6 nmol of peroxides/milliliter). The effect of PJ consumption on serum oxidative state was recently measured also in patients with non-insulin-dependent diabetes mellitus (NIDDM). Consumption of 50 mL of PJ per day for a period of 3 months resulted in a significant reduction in serum lipid peroxides and thiobarbituric acid reactive substance (TBAR) levels by 56 and 28%, respectively.32... 

Schimke I, Kahl PE, Romaniuk R Papies B. Concentration of thiobarbituric acid reactive substances (TBARS) in serum following myocardial infarction. Klin Wochenschr 1986 64 1237-1239. 

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