In Vivo Evaluation of Dendropanax morbifera Leaf Extract for Anti-Obesity and Cholesterol-Lowering Activity in Mice.

Metabolic syndrome is a worldwide health problem, and obesity is closely related to type 2 diabetes, cardiovascular disease, hypertension, and cancer. According to WHO in 2018, the prevalence of obesity in 2016 tripled compared to 1975. D. morbifera reduces bad cholesterol and triglycerides levels in the blood and provides various antioxidant nutrients and germicidal sub-stances, as well as selenium, which helps to remove active oxygen. Moreover, D. morbifera is useful for treating cardiovascular diseases, hypertension, hyperlipidemia, and diabetes. Therefore, we study in vivo efficacy of D. morbifera to investigate the prevention effect of obesity and cholesterol. The weight and body fat were effectively reduced by D. morbifera water (DLW) extract administration to high-fat diet-fed C57BL/6 mice compared to those of control mice. The group treated with DLW 500 mg∙kg-1∙d-1 had significantly lower body weights compared to the control group. In addition, High-density lipoprotein (HDL) cholesterol increased in the group treated with DLW 500 mg∙kg-1∙d-1. The effect of DLW on the serum lipid profile could be helpful to prevent obesity. DLW suppresses lipid formation in adipocytes and decreases body fat. In conclusion, DLW can be applied to develop anti-obesity functional foods and other products to reduce body fat.

Protective Effects of Curcumin on Renal Oxidative Stress and Lipid Metabolism in a Rat Model of Type 2 Diabetic Nephropathy.

PURPOSE: Diabetic nephropathy is a serious complication of type 2 diabetes mellitus, and delaying the development of diabetic nephropathy in patients with diabetes mellitus is very important. In this study, we investigated inflammation, oxidative stress, and lipid metabolism to assess whether curcumin ameliorates diabetic nephropathy. MATERIALS AND METHODS: Animals were divided into three groups: Long-Evans-Tokushima-Otsuka rats for normal controls, Otsuka-Long-Evans-Tokushima Fatty (OLETF) rats for the diabetic group, and curcumin-treated (100 mg/kg/day) OLETF rats. We measured body and epididymal fat weights, and examined plasma glucose, adiponectin, and lipid profiles at 45 weeks. To confirm renal damage, we measured albumin-creatinine ratio, superoxide dismutase (SOD), and malondialdehyde (MDA) in urine samples. Glomerular basement membrane thickness and slit pore density were evaluated in the renal cortex tissue of rats. Furthermore, we conducted adenosine monophosphate-activated protein kinase (AMPK) signaling and oxidative stress-related nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling to investigate mechanisms of lipotoxicity in kidneys. RESULTS: Curcumin ameliorated albuminuria, pathophysiologic changes on the glomerulus, urinary MDA, and urinary SOD related with elevated Nrf2 signaling, as well as serum lipid-related index and ectopic lipid accumulation through activation of AMPK signaling. CONCLUSION: Collectively, these findings indicate that curcumin exerts renoprotective effects by inhibiting renal lipid accumulation and oxidative stress through AMPK and Nrf2 signaling pathway.

The modifying effect of vitamin C on the association between perfluorinated compounds and insulin resistance in the Korean elderly: a double-blind, randomized, placebo-controlled crossover trial.

PURPOSE: There is limited evidence whether environmental exposure to perfluorinated compounds (PFCs) affects insulin resistance (IR) and whether vitamin C intake protects against the adverse effect of PFCs. This study was carried out to investigate the effect of PFCs on IR through oxidative stress, and the effects of a 4-week consumption of vitamin C supplement compared placebo on development of IR by PFCs. METHODS: For a double-blind, community-based, randomized, placebo-controlled crossover intervention of vitamin C, we assigned 141 elderly subjects to both vitamin C and placebo treatments for 4 weeks. We measured serum levels of PFCs to estimate PFC exposures and urinary levels of malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) for oxidative stress. We also measured levels of fasting glucose and insulin and derived the homeostatic model assessment (HOMA) index to assess IR. RESULTS: Perfluorooctane sulfonate (PFOS) and perfluorododecanoic acid (PFDoDA) levels were found to be positively associated with HOMA index at the baseline and after placebo treatment. Risks of IR for the top decile of PFOS and PFDoDA exposures were significantly elevated compared with those with lower PFOS and PFDoDA exposures (both, P < 0.0001). However, the effects of PFOS and PFDoDA on HOMA disappeared after vitamin C supplementation (both, P > 0.30). Furthermore, PFOS and PFDoDA levels were also significantly associated with MDA and 8-OHdG levels, and MDA levels were positively associated with HOMA index. CONCLUSION: PFOS and PFDoDA exposures were positively associated with IR and oxidative stress, and vitamin C supplementation protected against the adverse effects of PFOS and PFDoDA on IR.

Reduced Coenzyme Q10 Decreases Urinary 8-Oxo-7,8-Dihydro-2'-Deoxyguanosine Concentrations in Healthy Young Female Subjects.

It remains unclear whether dietary supplementation with coenzyme Q10 (CoQ10) provides beneficial effects for healthy individuals, especially young subjects. This study investigated the effects of dietary supplementation with CoQ10 on oxidative stress in healthy young females. We performed a placebo-controlled trial using a crossover design (n=28) with 100 mg/day CoQ10 in reduced form or placebo, each lasting 2 weeks with a 2-week interval. The urinary levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), a biomarker of oxidative DNA damage, were determined by high-performance liquid chromatography (HPLC) coupled to an electrochemical detector. Levels of malondialdehyde (MDA), a biomarker of lipid peroxidation, and antioxidant vitamin C in urine were also measured using a thiobarbituric acid-reactive substance method with a commercial kit and by the 2,4-dinitrophenylhydrazine method with HPLC, respectively. Urinary 8-oxodG levels during supplementation with reduced form of CoQ10 (median [first and third quartiles]: 1.76 [1.24-2.08] nmol/mmol creatinine) were significantly lower than those with placebo (2.00 [1.34-2.49] nmol/mmol creatinine, P=.031 by Student's paired t-test using the logarithmically transformed values). In contrast, the urinary levels of MDA and vitamin C were not significantly affected (P=.094 and P=.247 by Student's paired t-test, respectively). There was no evidence of any side effects. Supplementation with CoQ10 in the reduced form showed a slightly protective effect against oxidative DNA damage even in healthy young subjects.

Interaction between blood selenium concentration and a levels of oxidative stress and antioxidative capacity in healthy children.

The study aimed at defining the relationship between blood selenium concentration (Se-B) and levels of oxidative stress and antioxidative capacity in healthy children. The studies were conducted on 337 children (mean age: 8.53±1.92 years). The groups of individuals with Se-B <1st quartile (group I, Se-B<70µg/L), with Se-B fitting the range of 1st quartile and median (group II, Se-B: 70-76.9µg/L), with Se-B between the median and 3rd quartile (group III, Se-B: 77-83.9µg/L) and those with Se-B above the 3rd quartile (group IV, Se-B≥84µg/L) were distinguished. Level of oxidative stress was defined using determination of urine malonyldialdehyde concentration (MDA) and urine 8-hydroxy-2-deoxyguanosine concentration (8-OHdg). Urine total antioxidant status (TAS) was determined. In group IV TAS was significantly higher than in groups I-III. A positive correlation was detected between Se-B and TAS. In healthy children an appropriately high Se-B seems to ensure higher total antioxidative status.

Antilithiatic effects of crocin on ethylene glycol-induced lithiasis in rats.

In this study, the antilithiatic potential of crocin, a pharmacologically active constituent of Crocus sativus L. (saffron), was evaluated against ethylene glycol (EG)-induced nephrolithiasis in rats. Negative control rats were provided with EG (1 %) in drinking water for 30 days. crocin (10, 20 and 40 mg/kg, i.p.) was administered simultaneously once daily for 30 days (prophylactic regimen) or 14 days after stone induction (therapeutic study). For biochemical analysis, 24-h urine was collected from all experimental animals at the beginning (day 0) and end of the experiment (day 30). The urine output was evaluated during the first 24 h (day 1). Ethylene glycol feeding resulted in decreased hyperoxaluria (P < 0.01) and total protein loss (P < 0.001), along with decreased excretion of citrate and magnesium (P < 0.01) compared with the intact animals. Treatment with prophylactic regimen of crocin (20 and 40 mg/kg) significantly reduced the elevated oxalate, and increased the citrate and magnesium levels of urine. The attenuation of protein loss was only seen with a high dose of crocin in a prophylactic study. Urine volume was not significantly altered after EG or crocin administration. The increased number of calcium deposits in the kidney tissue of lithiatic rats was decreased after prophylactic treatment with 20 and 40 mg/kg of crocin. The urinary ionic parameters and crystal count were not significantly altered after the therapeutic study. A marked increase in malondialdehyde (MDA, a lipid peroxidation product) level was observed in the EG-given group. Treatment with crocin (20 and 40 mg/kg) reduced the elevated levels of MDA. Results indicate that crocin can be effective in preventing urine calculi formation and recurrence of the disease. The mechanism underlying this effect is mediated possibly through balancing promoter and inhibitor factors and an antioxidant effect.

Positive Effects of hydrogen water on 2,4-dinitrochlorobenzene-induced atopic dermatitis in NC/Nga mice.

Atopic dermatitis (AD) is a chronically relapsing, pruritic, eczematous skin disorder accompanying allergic inflammation. AD is triggered by oxidative stress and immune imbalance. In the present study, we investigated the effect of drinking hydrogen water (HW) on 2,4-dinitrochlorobenzene (DNCB)-induced atopic dermatitis in NC/Nga mice and found that HW ameliorated DNCB-induced AD-like clinical symptoms. In line with this, the level of reactive oxygen species in the HW group was significantly inhibited compared with that in the purified water (PW) group. In parallel, HW enhanced glutathione peroxidase activity in DNCB-induced AD as compared with the PW group. Accordingly, the levels of thymus and activation-regulated chemokine and cytokines were significantly decreased in the HW group compared with the PW group. Notably, the levels of Th2 cytokine, interleukin-5 (IL-5), and proinflammatory cytokines such as tumor necrosis factor-α and IL-6 in HW-fed mice were significantly lower than in control and PW-fed mice. The total serum immunoglobulin E level was also markedly reduced in the HW group. The collective results indicate that HW suppresses DNCB-induced AD in NC/Nga mice via redox balance and immune modulation and could be a safe clinical fluid treatment for AD.

Pre-stimulation of the kallikrein system in cisplatin-induced acute renal injury: an approach to renoprotection.

Antineoplastic treatment with cisplatin is frequently complicated by nephrotoxicity. Although oxidative stress may be involved, the pathogenic mechanisms responsible for renal damage have not been completely clarified. In order to investigate the role of the renal kinin system in this condition, a group of rats was submitted to high potassium diet to stimulate the synthesis and excretion of tissue kallikrein 1 (rKLK1) previous to an intraperitoneal injection of 7 mg/kg cisplatin. A significant reduction in lipoperoxidation, evidenced by urinary excretion of malondialdehyde and renal immunostaining of hidroxy-nonenal, was accompanied by a decline in apoptosis. Coincident with these findings we observed a reduction in the expression of renal KIM-1 suggesting that renoprotection may be occurring. Stimulation or indemnity of the renal kinin system deserves to be evaluated as a complementary pharmacological measure to diminish cisplatin nephrotoxicity.

Effects of Korean red ginseng (Panax Ginseng Meyer) on bisphenol A exposure and gynecologic complaints: single blind, randomized clinical trial of efficacy and safety.

BACKGROUND: Korean red ginseng (KRG) is a processed ginseng from raw ginseng to enhance safety, preservation and efficacy, known having beneficial effects on women's health due to its estrogen like function. While estrogen supplementation showed some modulation of endocrine disrupting chemicals, bisphenol A (BPA) has been focused as a potential endocrine disrupting chemical. In this study, we examined the efficacy and safety outcomes of KRG against BPA, focusing on female quality of life (QOL). Individual variations in susceptibility to KRG were also investigated with the Sasang Typology, the personalized medicine used for hundred years in Korea. METHODS: We performed a single-blind randomized clinical trial. Study subjects were young women (N = 22), consumed 2.7 g of KRG or placebo per day for 2 weeks and filled up questionnaires regarding gynecologic complaints at the 4 time spots. We analyzed urinary total BPA and malondialdehyde (MDA), an oxidative stress biomarker, with GC/MS and HPLC/UVD respectively, and diagnosed their Sasang Typology with the questionnaire for the Sasang constitution Classification (QSCC II). RESULTS: KRG consumption decreased urinary BPA and MDA levels (ps < 0.05) and alleviated 'menstrual irregularity', 'menstrual pain', and 'constipation' (ps < 0.05). SoEum type (Lesser Yin person) among the Sasang types showed significant alleviation in insomnia, flushing, perspiration and appetite by KRG consumption, rather than other Sasang types. During the intervention, no one experienced any aggravated side effects. CONCLUSION: We suggest KRG is efficient for protection for female QOL and BPA- exposure and - related oxidative stress. However, individual variation in susceptibility to KRG should be further considered for identifying ideal therapy. TRIAL REGISTRATION: KCT0000920.

Plasma selenium levels and oxidative stress biomarkers: a gene-environment interaction population-based study.

The role of selenium exposure in preventing chronic disease is controversial, especially in selenium-repleted populations. At high concentrations, selenium exposure may increase oxidative stress. Studies evaluating the interaction of genetic variation in genes involved in oxidative stress pathways and selenium are scarce. We evaluated the cross-sectional association of plasma selenium concentrations with oxidative stress levels, measured as oxidized to reduced glutathione ratio (GSSG/GSH), malondialdehyde (MDA), and 8-oxo-7,8-dihydroguanine (8-oxo-dG) in urine, and the interacting role of genetic variation in oxidative stress candidate genes, in a representative sample of 1445 men and women aged 18-85 years from Spain. The geometric mean of plasma selenium levels in the study sample was 84.76 µg/L. In fully adjusted models the geometric mean ratios for oxidative stress biomarker levels comparing the highest to the lowest quintiles of plasma selenium levels were 0.61 (0.50-0.76) for GSSG/GSH, 0.89 (0.79-1.00) for MDA, and 1.06 (0.96-1.18) for 8-oxo-dG. We observed nonlinear dose-responses of selenium exposure and oxidative stress biomarkers, with plasma selenium concentrations above ~110 µg/L being positively associated with 8-oxo-dG, but inversely associated with GSSG/GSH and MDA. In addition, we identified potential risk genotypes associated with increased levels of oxidative stress markers with high selenium levels. Our findings support that high selenium levels increase oxidative stress in some biological processes. More studies are needed to disentangle the complexity of selenium biology and the relevance of potential gene-selenium interactions in relation to health outcomes in human populations.

Response of urinary biomarkers of systemic oxidation to oral iron supplementation in healthy men.

BACKGROUND: Urinary biomarkers are used in assessment of severe, clinical oxidative stress. Little is known, however, about their diagnostic value within the normative range. OBJECTIVE: To evaluate the response of urinary thiobarbituric acid reactive substances (TBARS) and 8-hydroxy-2-deoxyguanosine (8-OHdG) as indicators of systemic oxidation in response to short-term oral iron and antioxidant supplementation. METHODS: Five healthy adult men participated in the pilot study phase and 12 in the definitive intervention trial. For 7 days each, separated by 12-day washouts, the subjects received different treatment regimens, consisting of 120 mg of iron, 120 mg of iron in refined palm oil, and 120 mg of iron in palm oil combined with one of the two doses of Carotino Tocotrienol Carotene Mixed Concentrate (CTCMC). Creatinine-normalized urinary TBARS and 8-OHdG concentrations were quantified in samples taken from subjects with and without active supplementation. Temporal and correlative associations between TBARS and 8-OHdG were explored. RESULTS: Daily intake of supplemental iron failed to produce any increment in urinary excretion of TBARS or 8-OHdG. However, a significant within-individual correlation between the urinary biomarkers was observed (Spearman r = 0.697, p < .0001, n = 466). Both doses of CTCMC significantly lowered urinary excretion of both oxidation indicators. CONCLUSIONS: Despite the lack of effect of oral iron on the biomarkers of systemic oxidation, they show a strong and significant mutual association within the nonpathological range of oxidative stress in healthy male adults.

Consumption of Hibiscus sabdariffa L. aqueous extract and its impact on systemic antioxidant potential in healthy subjects.

BACKGROUND: To evaluate health benefits attributed to Hibiscus sabdariffa L. a randomized, open-label, two-way crossover study was undertaken to compare the impact of an aqueous H. sabdariffa L. extract (HSE) on the systemic antioxidant potential (AOP; assayed by ferric reducing antioxidant power (FRAP)) with a reference treatment (water) in eight healthy volunteers. The biokinetic variables were the areas under the curve (AUC) of plasma FRAP, ascorbic acid and urate that are above the pre-dose concentration, and the amounts excreted into urine within 24 h (Ae(0-24) ) of antioxidants as assayed by FRAP, ascorbic acid, uric acid, malondialdehyde (biomarker for oxidative stress), and hippuric acid (metabolite and potential biomarker for total polyphenol intake). RESULTS: HSE caused significantly higher plasma AUC of FRAP, an increase in Ae(0-24) of FRAP, ascorbic acid and hippuric acid, whereas malondialdehyde excretion was reduced. Furthermore, the main hibiscus anthocyanins as well as one glucuronide conjugate could be quantified in the volunteers' urine (0.02% of the administered dose). CONCLUSION: The aqueous HSE investigated in this study enhanced the systemic AOP and reduced the oxidative stress in humans. Furthermore, the increased urinary hippuric acid excretion after HSE consumption indicates a high biotransformation of the ingested HSE polyphenols, most likely caused by the colonic microbiota.

In vivo antioxidant potential of Sweet chestnut (Castanea sativa Mill.) wood extract in young growing pigs exposed to n-3 PUFA-induced oxidative stress.

BACKGROUND: Farm animals in intensive farming systems are frequently exposed to oxidative stress, which demands adequate antioxidant protection. The aim of this study was to evaluate the antioxidant potential of different concentrations of Sweet chestnut wood extract (SCW; 0.75, 1.5 and 3 g kg⁻¹) in case of n-3 PUFA-induced oxidative stress in young pigs. RESULTS: The highest concentration (3 g kg⁻¹) of SCW decreased malondialdehyde excretion in urine by 31.7%, but had no effect on plasma malondialdehyde. A linear trend towards decrease of urine isoprostanes iPF(2α)-VI was observed with the addition of SCW. All three concentrations of SCW efficiently protected blood lymphocytes from DNA damage and lowered plasma alanine aminotransferase levels. The antioxidative and antigenotoxic effect of 3 g SCW kg⁻¹ feed was comparable to the effect of 90.4 mg kg⁻¹ of added vitamin E. CONCLUSION: The results from this study show that, besides being known as antihelmintic, antimicrobial and antiviral agent, Sweet chestnut wood extract could also be considered as a promising natural antioxidant in animal nutrition.

The comparison of black currant juice and vitamin E for the prevention of oxidative stress.

Black currant is known as a fruit with a very strong in vitro antioxidative capacity, but its in vivo antioxidant efficacy has not yet been characterized. The aim of the experiment was to determine the potency of black currant juice in comparison to vitamin E, for decreasing oxidative stress. Oxidative stress was induced by high intake of polyunsaturated fatty acids (PUFAs) in pigs as a model for humans. Twenty-four growing pigs were divided into four groups. All groups received isocaloric daily rations composed of an equal amount of basal diet that was supplemented with starch (CONT), linseed oil (OIL), linseed oil and black currant juice (OIL+BCJ), or linseed oil and vitamin E (OIL+VIT E). The experiment confirmed that the high proportion of PUFAs in the OIL group increased oxidative stress. In comparison with the OIL group, vitamin E supplementation significantly lowered plasma malondiadehyde (MDA) and the 24-hour urine MDA excretion rate, and reduced the degree of DNA damage in leukocytes to the level of the CONT group. The black currant juice intake failed to significantly decrease plasma MDA and 24-hour urine MDA excretion rate, but did reduce the degree of DNA damage in leukocytes to the level of the CONT group, as well as increase plasma beta+gamma-tocopherol concentrations. Although black currant juice did not reduce the formation of MDA, it efficiently prevented DNA damage induced by the high intake of PUFAs. It could be concluded that under these experimental conditions vitamin E was more efficient as an antioxidant that black currant juice.

Antioxidant effect on urinary excretion of malondialdehyde in non-athletes during aerobic training.

Conditions in the body during aerobic exercise increase the level of lipid peroxidation (LP). LP is associated with elevated concentration of modified low-density lipoproteins that are implicated in development of cardiovascular disease. Supplementation with antioxidant vitamin E to athletes at 267 mg (400 IUs) or greater has been reported to reduce levels of LP associated with exercise. Little is currently known about the effects of modest supplementation of vitamin E on previously sedentary adults who initiate an aerobic fitness program. In the present study, sedentary subjects (n = 14) kept 24-hour diet records to establish antioxidant intake of vitamins E and C and collected 24-hour urine samples that were used to determine baseline urinary malondialdehyde (MDA) concentrations, one measure of in vivo LP. No significant differences were noted in the parameters between groups. Seven subjects were randomly selected and supplemented daily with 133 mg (200 IUs) of vitamin E. All subjects participated in moderate-intensity aerobic training for 8 weeks. Post-training, non-supplemented subjects excreted significantly more MDA (p<0.05) and consumed significantly fewer antioxidants than the supplemented group. Vitamin E supplementation appears to suppress elevated LP associated with beginning an aerobic exercise regimen in previously sedentary subjects.

The role of ribose on oxidative stress during hypoxic exercise: a pilot study.

Oxygen free radicals are produced during stress, are unstable, and potentially interact with other cellular components or molecules. This reactivity can influence cellular function, including a prolongation in tissue recovery following exercise. We tested the effect of ribose (d-ribose), a pentose carbohydrate, in a double-blinded, crossover study on markers of free radical production during hypoxic exercise. Seven healthy volunteers cycled at their lactate threshold for 25 minutes while inhaling 16% O(2) with a subsequent 60-minute resting period at room air. Subjects ingested either placebo or 7 g of ribose in 250 mL of water before and after the exercise session. Urinary malondialdehyde (MDA) and plasma reduced glutathione levels increased significantly during placebo ingestion (0.2 +/- 0.03 nM/mg and 0.26 +/- 0.29 microM, respectively) but were lower with ribose supplementation (0.04 +/- 0.03 nM/mg and 0.38 +/- 0.29 microM, respectively; P < .05). Uric acid levels were similar between groups (ribose vs. placebo, 4.55 +/- 0.06 mg/dL vs. 4.67 +/- 0.06 mg/dL). Ribose demonstrated a beneficial trend in lower MDA and reduced glutathione levels during hypoxic stress.

Effects of NADPH oxidase inhibitor on diabetic nephropathy in OLETF rats: the role of reducing oxidative stress in its protective property.

Diabetic nephropathy is the most serious complication in diabetes mellitus. Oxidative stress via nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and vascular endothelial growth factor (VEGF) pathway play critical roles in the development of diabetic nephropathy. We evaluated the effects of apocynin, NADPH oxidase inhibitor on diabetic nephropathy in a type 2 diabetic rat model. Sixteen Otsuka Long Evans Tokushima Fatty (OLETF) rats and 9 Long Evans Tokushima Otsuka (LETO) were divided into the following three groups: LETO rats (n=9), control OLETF rats (n=7) and apocynin-treated OLETF rats (n=9). We examined body weights, plasma glucose levels, urinary albumin-creatinine ratio (ACR) and protein-creatinine ratio (PCR). At 50 weeks, experimental rats were sacrificed and their kidneys were extracted for hematoxylin eosin stain, immunohistochemical VEGF stain and VEGF mRNA real-time RT-PCR. To examine oxidative stress, we checked 24h urinary 8-OHdG (8-hydroxy-2'-deoxyguanosine) and MDA (malondialdehyde). Urinary protein and albumin excretions were reduced after apocynin treatment, though apocynin could not significantly decrease serum glucose levels. There were improvements of glomerular and mesangial expansion in the apocynin-treated OLETF rats. Apocynin significantly decreased optical density of glomerular VEGF expression in immunohistochemical stain and reduced the concentration of 24h urinary 8-OHdG and MDA. From these results, it was suggested that apocynin may have the potential to protect against diabetic nephropathy via amelioration of oxidative stress.

Wheat germ supplementation of a low vitamin E diet in rats affords effective antioxidant protection in tissues.

BACKGROUND: Oxidative stress is implicated in the etiology of many diseases, but most of clinical trials failed to demonstrate beneficial effects of antioxidant supplementation. METHODS: In the present experiment, we assessed the mean-term effect of wheat germ supplementation, as a dietary source of vitamin E, on antioxidant protection in rat. RESULTS: Feeding rats a 20% wheat germ diet significantly increased plasma and liver vitamin E levels, compared to the low vitamin E basal diet. Concurrently, wheat germ diet consumption strongly decreased the susceptibility of heart and liver lipids to oxidation, as well as the plasma. Wheat germ feeding did not change triglycerides (TG) nor total cholesterol concentrations in plasma or liver, resulting in higher vitamin E/TG ratio compared to controls. Similar results were found with a diet in which wheat germ oil provided the same amount of vitamin E. CONCLUSIONS: Wheat germ appears thus very effective to improve antioxidant defense status, especially in tissues, irrespective of modifications of lipids status.

A liquid chromatography-quadrupole time-of-flight (LC-QTOF)-based metabolomic approach reveals new metabolic effects of catechin in rats fed high-fat diets.

Unbalanced diets generate oxidative stress commonly associated with the development of diabetes, atherosclerosis, obesity and cancer. Dietary flavonoids have antioxidant properties and may limit this stress and reduce the risk of these diseases. We used a metabolomic approach to study the influence of catechin, a common flavonoid naturally occurring in various fruits, wine or chocolate, on the metabolic changes induced by hyperlipidemic diets. Male Wistar rats ( n = 8/group) were fed during 6 weeks normolipidemic (5% w/w) or hyperlipidemic (15 and 25%) diets with or without catechin supplementation (0.2% w/w). Urines were collected at days 17 and 38 and analyzed by reverse-phase liquid chromatography-mass spectrometry (LC-QTOF). Hyperlipidic diets led to a significant increase of oxidative stress in liver and aorta, upon which catechin had no effect. Multivariate analyses (PCA and PLS-DA) of the urine fingerprints allowed discrimination of the different diets. Variables were then classified according to their dependence on lipid and catechin intake (ANOVA). Nine variables were identified as catechin metabolites of tissular or microbial origin. Around 1000 variables were significantly affected by the lipid content of the diet, and 76 were fully reversed by catechin supplementation. Four variables showing an increase in urinary excretion in rats fed the high-fat diets were identified as deoxycytidine, nicotinic acid, dihydroxyquinoline and pipecolinic acid. After catechin supplementation, the excretion of nicotinic acid was fully restored to the level found in the rats fed the low-fat diet. The physiological significance of these metabolic changes is discussed.

Effect of docosahexaenoic acid and eicosapentaenoic acid supplementation on oxidative stress levels during pregnancy.

Docosahexaenoic acid (DHA) is an indispensable component of cell membranes with high requirements during pregnancy. DHA supplementation is thought to enhance oxidative stress because of increased likelihood of lipid peroxidation. We estimated the oxidative stress levels in two groups of pregnant women who received daily supply of required vitamins with (n = 23) or without (n = 23) 500 mg of DHA and 150 mg of eicosapentaenoic acid (EPA) from 20 weeks of gestation to the time of delivery. Urinary excretions of 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker of oxidative DNA damage and of malondialdehyde (MDA), a marker of lipid peroxidation, were measured at 20, 30 weeks and at the time of delivery. Urinary MDA excretion remained unchanged throughout the study period in both groups. Urinary 8-OHdG excretion at delivery was significantly higher than at 20 and 30 weeks (p < 0.05), but there were no group differences at the three time points. There were no differences between the two groups in plasma a-tocopherol levels. We conclude that under the conditions studied, a daily supplementation of 500 mg DHA and 150 mg EPA with vitamins to pregnant women did not enhance lipid peroxidation or oxidative DNA damage.