Hepatic Thiobarbituric Acid-reactive Substance Levels Research Articles

PSXI-14 Supplementation with a blend containing Baccharis dracunculifolia and Tamarindus indica improve the oxidative state of steers in finishing phase

Abstract Tissue oxidative stress has been associated with low productivity of beef cattle. Supplementation of animals with natural antioxidants added to the diet may be an alternative to improve the tissue oxidative status and the productivity of steers at finishing phase. The present study evaluated whether the addition to the diet of a blend (Mix) containing Baccharis dracunculifolia (40%), Tamarindus indica seed (40%), cashew nutshell oil (10%) and clove oil (10%) modifies the oxidative state in the plasma and liver of steers (Angus x Zebu) in finishing phase. Forty animals were randomly distributed into four groups (ten animal per group), which received Mix respectively at the daily dose of 0.0, 2.0, 4.0 and 6.0 g per animal during 84 days. Blood and liver were taken at slaughter of the animals. Blood samples were also taken before starting the supplementation and served as control. The ferric reducing ability of plasma (FRAP), thiol groups and protein carbonyl groups were measured as plasma parameters of oxidative stress. The levels of thiobarbituric acid reactive substances (TBARS), protein carbonyl groups, reactive oxygen species (ROS), glutathione and the activity of catalase and superoxide dismutase (SOD) were measured as hepatic parameter of oxidative stress. Plasma levels of protein carbonyl groups were 30% lower in the animals supplemented with 4.0 and 6.0 g Mix and FRAP was 20% higher in the animals supplemented with 6.0 g Mix (P < 0.05; compared to the 0.0 g). Hepatic levels of TBARS were 38% lower in animals supplemented with 6.0 g Mix (P < 0.05). The other parameters were not modified. In conclusion, the supplementation of steers with Mix improved the systemic oxidative status and may be a complementary alternative to the diet of these animals in the termination phase.

Dietary l-cysteine inhibits d-galactosamine-induced acute liver injury in rats

The effects of l-cysteine (1 and 2%) on the antioxidative system were examined in rats with d-galactosamine (d-GalN)-induced injury. These rats showed increases in serum antioxidative enzyme and hepatic thiobarbituric acid reactive substances (TBARS) activities, with decreased hepatic/serum glutathione (GSH) levels and GSH-related enzyme activities. However, l-cysteine supplementation resulted in a decrease of hepatic TBARS levels, and increased catalase and serum GSH levels. The activities of serum enzymes in rats receiving 2% l-cysteine were significantly (p<0.05) lower than in d-GalN-injected group rats, and similar to levels in control group rats without acute liver injury. In addition, 2% l-cysteine increased the glutathione reductase activity and decreased the serum TBARS level in liver injury group rats. Dietary l-cysteine, especially at a 2% level, exerts a hepatoprotective effect by alteration of the GSH level and antioxidative enzyme activities.

Antioxidant effect of myricetin in animal model of type 2 diabetes

Hyperglycemia increases oxidative stress which contributes to the development of diabetic complications. Myricetin has been reported to show antioxidant activity in vitro. The purpose of this study was to investigate the antioxidant effect of myricetin in animal model of type 2 diabetes. Four‐week‐old male db/db mice were fed AIN‐93G diet or diet containing myricetin (150 mg/kg) for 7 weeks after one week of adaptation. The animals were sacrificed after an overnight‐fast. Thiobarbituric acid reactive substances (TBARS) levels of the liver were measured. Activities of hepatic antioxidant enzymes were measured. Hepatic TBARS levels were significantly reduced by consumption of myricetin in db/db mice. Activities of superoxide dismutase (SOD) and catalase of myricetin group were significantly higher than those of the control group (p&lt;0.05). Consumption of myricetin significantly increased glutathione peroxidase (GSH‐Px) activities compared with the control group. These results indicate that myricetin exerts antioxidant effect in db/db mice, suggesting it could be useful in preventing diabetic complications. This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (2012015763).

Chronic dietary intake of quercetin alleviates hepatic fat accumulation associated with consumption of a Western‐style diet in C57/BL6J mice

To determine the effect of consumption of a quercetin-rich diet on obesity and dysregulated hepatic gene expression. C56BL/6J mice were fed for 20 wk on AIN93G (control) or a Western diet high in fat, cholesterol and sucrose, both with or without 0.05% quercetin. Triglyceride levels in plasma, thiobarbituric acid-reactive substances (oxidative stress marker) and glutathione levels and peroxisome proliferator-activated receptor α expression in livers of mice fed with the Western diet were all improved after 8 wk feeding with quercetin. After 20 wk, further reductions of visceral and liver fat accumulation and improved hyperglycemia, hyperinsulinemia, dyslipidemia and plasma adiponectin and TNFα levels in these mice fed with quercetin were observed. The expression of hepatic genes related to steatosis, such as peroxisome proliferator-activated receptor γ and sterol regulatory element-binding protein-1c was also normalized by quercetin. In mice fed with the control diet, quercetin did not affect body weight but reduces the plasma TNFα and hepatic thiobarbituric acid-reactive substance levels. In mice fed with a Western diet, chronic dietary intake of quercetin reduces liver fat accumulation and improves systemic parameters related to metabolic syndrome, probably mainly through decreasing oxidative stress and reducing PPARα expression, and the subsequent reduced expression in the liver of genes related to steatosis.

Inhibition of hepatic δ-aminolevulinate dehydratase activity induced by mercuric chloride is potentiated by N-acetylcysteine in vitro

Mercuric chloride (HgCl)2 is a toxic metal that causes oxidative damage in several tissues. N-acetylcysteine (NAC) is a sulfhydryl compound with antioxidant activity. In the present study, we investigated the in vitro effects of the association between HgCl2 and NAC in tissues of mice. For this purpose, we evaluated the in vitro effect of HgCl2+NAC association on δ-aminolevulinate dehydratase (δ-ALA-D) activity and on thiobarbituric acid reactive substances (TBARS) levels in liver and kidney of mice. The results demonstrate that HgCl2 inhibited δ-ALA-D activity in both tissues. Hepatic δ-ALA-D activity inhibited by HgCl2 was potentiated by the highest concentration of NAC. The inhibition of hepatic δ-ALA-D activity seems to be related to sulfhydryl groups oxidation of the enzyme. We observed also that HgCl2 increased TBARS levels in kidney and liver. Hepatic TBARS levels were reduced by NAC, at higher concentration. In contrast, NAC, at higher concentration, increased renal TBARS levels. In conclusion, the inhibition of hepatic δ-aminolevulinate dehydratase activity induced by HgCl2 is potentiated by NAC in vitro, and this effect is not related to hepatic lipid peroxidation.

Increased plasma concentrations of soy isoflavones by increased doses of soy isoflavones are irrelevant to lipid peroxidation and aberrant crypt foci formation in colonic cancer model rats

We have investigated whether soy isoflavones supplemented to diets increase plasma concentrations of soy isoflavones and equol, and whether increased plasma concentration of soy isoflavones suppresses tissue levels of lipid peroxides and aberrant crypt foci (ACF) formation in colon cancer model rats. Sprague Dawley male rats were injected with 1,2‐dimethylthydrazine (DMH) and given one of AIN93‐based experimental diets (0, 10, 50, 150, or 500 mg isoflavones per kg diet) for 12 weeks. Thiobarbituric acid reactive substances (TBARS) of plasma and homogenates of liver and kidneys were determined using TBARS assay kit. Plasma concentrations of genistein, daidzein and equol were determined using kits by competitive time‐resolved fluoroimmunoassay technique. Plasma concentrations of genistein (R2=0.521 by genistein intake, p&lt;0.001), daidzein (R2=0.623 by daidzein intake, p&lt;0.001) and equol (R2=0.528 by daidzein intake, p&lt;0.001) were increased dose‐dependently. However, the numbers of ACF decreased significantly (p&lt;0.01) in 10 or 50 mg isoflavones‐fed groups as compared with the control group, and there was no significant correlation between the number of ACF and plasma concentration of genistein, daidzein or equol. Plasma TBARS level was not influenced by either dose or plasma level of soy isoflavones. Hepatic levels of TBARS were significantly lower in 10 and 50 mg isoflavones‐fed groups as compared with the control group. The level of kidney TBARS was significantly lower in only 50 mg isoflavones‐fed group as compared with the control group. Therefore, the results indicate that optimal level of soy isoflavones seemed to be most effective in suppressing ACF formation and lipid peroxidation in DMH‐induced colon cancer model rats.

Cholesterol-Lowering and Antioxidant Status-Improving Efficacy of Germinated Giant Embryonic Rice (Oryza sativa L.) in High Cholesterol-Fed Rats

Background/Aims: The purpose of the current study is to investigate the influence of germinated giant embryonic rice consumption on the lipid metabolism and antioxidant system in rats fed a high-cholesterol diet. Methods: Four groups of rats were given a diet containing 1 g cholesterol/kg for 5 weeks. The control group only received a high-cholesterol diet, while the other 3 experimental groups received each of the diets made of germinated giant embryonic rice, giant embryonic rice, or conventional brown rice (hereafter referred to as GGE-D, GE-D, and BR-D, respectively). Plasma and hepatic lipid profiles were measured, and the antioxidant status of liver was examined. Results: The plasma HDL-cholesterol concentration was significantly higher in rats fed GGE-D compared with the source material (GE-D) or BR-D, while there were no differences in the plasma total cholesterol and triglyceride concentrations between the groups. Consequently, the atherogenic indices of the GGE-D and GE-D groups were significantly lower than for the other groups. The plasma and hepatic thiobarbituric acid-reactive substance levels were higher in rats in the order of those fed BR-D > GE-D > GGE-D. While superoxide dismutase and catalase were significantly activated in rats fed both GGE-D and GE-D, glutathione peroxidase was significantly and most effectively activated in those fed GGE-D. Conclusions: The current results indicate that consumption of germinated giant embryonic rice is effective in lowering atherosclerosis cardiovascular disease risk.

Effect of different vitamin E levels on lipid peroxidation in streptozotocin-diabetic rats.

Administration of streptozotocin is used to induce diabetes in experimental models, causing a selective destruction of pancreatic beta islet cells associated with generation of free radicals. Supplementation with antioxidant vitamins such as vitamin E is a protective factor against free radicals. The objective of this study was to determine the effect of administration of a diet supplemented with, or deficient in vitamin E to streptozotocin diabetic rats, controlled or not with insulin, on plasma glucose, hepatic vitamin E and hepatic thiobarbituric acid reactive substance (TBARS) levels before streptozotocin and 24 hours and one and two weeks after drug administration. Deficiency of vitamin E alone increased TBARS levels, and streptozotocin elevated TBARS two times in deficient groups, regardless of insulin control. In rats supplemented with vitamin E, a reduction of plasma glucose and liver vitamin E was observed two weeks after streptozotocin administration (p < 0.05). In conclusion, vitamin E supplementation probably protected against lipoperoxidation and contributed to the absence of elevation of plasma glucose levels, and vitamin E deficiency produced an increase in hepatic TBARS levels in streptozotocin diabetic rats.

Effect of d-amphetamine repeated administration on rat antioxidant defences.

The purpose of this study was to evaluate rat tissue antioxidant status after repeated administration of d-amphetamine. Three groups of four rats each were used: control, d-amphetamine sulphate dosed (s.c., 20 mg/kg per day), and pair-fed. After 14 days of d-amphetamine daily administration, superoxide dismutase (CuZnSOD and MnSOD), catalase, glutathione peroxidase (GPx), glutathione reductase (GRed), glutathione-S-transferase (GST), glutathione (GSH), cysteine and thiobarbituric acid reactive substances (TBARS) were measured in liver, kidney, and heart. Various serum and urine parameters were also analysed. d-Amphetamine treatment induced an increase of liver GSH, as well as a decrease of cysteine and MnSOD levels in this organ. A small increase in serum transaminases was also observed in comparison to the pair-fed group. Hepatic levels of TBARS, GPx, GRed and CuZnSOD were found to be similar among the three groups of rats. d-Amphetamine treatment induced an increase of kidney GST, GRed and catalase levels, and an elevation of N-acetyl-beta-D-glucosaminidase efflux to the urine, accompanied by a decrease in urinary creatinine, compared to the pair-fed group. In d-amphetamine treated animals, heart cysteine levels were significantly depleted when compared to the pair-fed group, but all three groups of rats were found to have similar heart antioxidant enzyme levels. These results indicate that repeated administration of d-amphetamine caused a certain degree of stress in liver and kidney, which was followed by adaptations of antioxidant defences. The mechanisms involved in d-amphetamine-induced toxicity may explain the different adaptations observed for the studied organs.

Age and exercise-related changes in lipid peroxidation and superoxide dismutase activity in liver and soleus muscle tissues of rats

Thiobarbituric acid-reactive substances (TBARS) level, as marker of lipid peroxidation, and superoxide dismutase (SOD) activity, as endogenous antioxidant enzyme, were examined in liver and soleus muscle tissue of young and old male Wistar rats. We established different types of exercise running on a treadmill both for young and old rats, investigated the effect of aging, exhaustion and training on these groups. The hepatic TBARS levels were raised in the short-training young group and in the long-training old group. On the other hand, the TBARS content decreased in soleus muscle in the short-training young group, and long-training exercise enhanced lipid peroxidation in old rats. SOD activity increased in liver in short-training group, while this activity showed the lowest values in long-training old rats. With respect to soleus muscle tissue, SOD activity was elevated after exhaustive exercise in young rats and old rats had the highest activity in the long-training old group. These findings suggest that free radicals play a role in aging and that the different type, intensity and duration of exercise modify the lipid peroxidation level and antioxidant enzyme activity.