Effects of high-fat diets on inflammation and antioxidant status in rats : comparison between palm olein and olive oil.

Palm olein (PO) and olive oil (OO) are widely consumed in the world. PO is considered harmful to health, whereas OO is considered healthy. The aim of the study was to compare the effects of consumption of these oils on antioxidant status and inflammation in rats. This was an experimental study in male wistar rats fed a diet containing 30% of each oil. Rats had free access to food and water. After being fed for 12 weeks, animals were sacrificed and liver and aortic blood were collected. Plasma was used for the determination of interleukin-6 (IL-6) and oxidative stress parameters (Superoxide dismutase -SOD; Gluthation peroxidase - GPx; Thiobarbituric acid reactive substances - TBARS; Thiol groups and isoprostane). The inflammation and oxidative stress status as well as the expression of several genes/proteins were also analyzed in liver homogenate. No significant differences were observed between PO and OO in plasma and liver levels of the studied inflammation and oxidative stress parameters. This study showed that the consumption of PO induces an antioxidant status superimposable to that of OO.   Key words : Palm olein - Olive oil - Oxidative stress - Inflammation - High fat diet.

High dietary intake of palm oils compromises glucose tolerance whereas high dietary intake of olive oil compromises liver lipid metabolism and integrity.

PURPOSE: Palm (PO) and olive oils (OO) are the two most consumed and/or used oils in the world for food elaboration. These oils should not be confused with the solid palm stearin which is widely used in pastry making. Large number of studies was reported dealing with adverse/beneficial cardiovascular effects of PO and OO, whereas few studies were conducted to compare their potential effects on hepatic steatosis and liver lipid metabolism. The aim of this study was to compare the metabolic effects of high intake of POs (both crude and refined) and virgin OO on surrogate parameters of glucose tolerance, hepatic lipid metabolism and liver integrity. METHODS: Thirty-two young male Wistar rats were divided into four equal groups and fed either control diet (11% energy from fat) or three high-fat diets rich in crude or refined POs or in OO (56% energy from fat), during 12 weeks. Systemic blood and liver biochemical parameters linked to glucose and lipid metabolism as well as hepatic steatosis and liver fatty acid composition were explored. The inflammation and oxidative stress status as well as the expression of several genes/proteins were also analyzed. RESULTS: The major effects of POs intake concerned glucose metabolism and liver fatty acid composition, whereas the major effects of OO intake concerned hepatic TG accumulation, inflammation, and cytolysis. CONCLUSIONS: In conclusion, high dietary intake of PO compromises glucose tolerance whereas high dietary intake of OO compromises hepatic lipid composition and liver integrity. However, adverse hepatic effects of OO observed in this study may not be transposed to human since, (a) the rodent model could lead to different effects than those observed in humans and (b) the average normal OO amounts ingested in the population are lower than those corresponding to a high-fat diet. So, further studies are needed to determine a maximum non-invasive dietary intake of OO.

Comparison of Barricor™ vs. lithium heparin tubes for selected routine biochemical analytes and evaluation of post centrifugation stability.

INTRODUCTION: Obtaining suitable results unaffected by pre- or postanalytical phases is pivotal for clinical chemistry service. We aimed comparison and stability of nine biochemical analytes after centrifugation using Barricor™ plasma tubes with mechanical separator vs standard Vacutainer® lithium heparin tubes. MATERIALS AND METHODS: We collected samples on six healthy volunteers and nine patients from intensive care units into 6 mL plastic Vacutainer® lithium heparin tubes and 5.5 mL plastic Barricor™ plasma tubes. All tubes were centrifuged within 30 minutes after venipuncture. First, we compared results of nine biochemical analytes from lithium heparin tubes with Barricor™ tubes for each analyte using Passing-Bablok and Bland-Altman analyses. Second, we calculated the difference of analyte concentrations between baseline and time intervals in tubes stored at + 4 °C. Based on the total change limit we calculated the maximum allowable concentrations percentage change from baseline. RESULTS: The majority of correlation coefficients were close to 0.99 indicating good correlation in the working range. Bland-Altman analyses showed an acceptable concordance for all analytes. In consequence, the Barricor™ tube might be an alternative to regular lithium heparin tube. Stability with this new generation tube is improved for eight analytes (except for aspartate aminotransferase) in comparison with regular lithium heparin tubes. CONCLUSIONS: By using Barricor™ tubes and prompt centrifugation, supplemental analysis or re-analysis for eight analytes including alanine aminotransferase, alkaline phosphatase, C-reactive protein, high sensitivity troponin T, lactate dehydrogenase, NT-pro BNP, potassium and sodium could be performed within 72 h of specimen collection.

Antioxidant and oligonutrient status, distribution of amino acids, muscle damage, inflammation, and evaluation of renal function in elite rugby players.

BACKGROUND: Our study investigated the biochemical and anthropometric characteristics in elite athletes of rugby union based in the south of France during the different periods of the competition to identify metabolic and biochemical adaptations to particular lifestyle conditions. METHODS: Participants included 35 players in 2008 and 43 players in 2009. Biochemical variables [creatinine, uric acid, creatine kinase (CK), alanine aminotransferase, aspartate aminotransferase, C-reactive protein] were evaluated. Specific protein levels (albumin, acid α-glycoprotein, prealbumin), vitamins (A, E, C), antioxidant enzymes [glutathione peroxidase (GPx), superoxide dismutase (SOD)], oligoelements (Zn, Se, Cu, erythrocyte magnesium), homocysteine (Hcy), carnitine and the distribution of amino acids were specifically determined for our study during a pre-competition period (September 2008 and 2009). RESULTS: Globally, no deficit was observed for vitamins, oligonutrients and amino acids levels. The high SOD and GPx activities in rugby players suggest a presence of oxidative stress of exercise. The evaluation of renal function should be used with caution because of the interaction between creatinine and lean body mass. In addition, a profound effect of intense exercise on the CK values was reported to establish specific reference values for athletes. The analysis of the biological variation allows optimization of the interpretation of the changes from an increased or decreased baseline value from a season to the other one. CONCLUSIONS: The conclusions of present study were: 1) the necessity of rugby-specific reference intervals for CK and creatinine parameters; 2) the use of enzymatic creatinine for Modification of Diet in Renal Disease (MDRD) and CKD-EPI, or cystatin C to improve glomerular filtration rate estimation; 3) to take into account the oxidative stress testifying of a bad recovery; and 4) better to take care the nutritional status of the players by adapting needs and amino acids supplementations but also to consider a follow-up of oxidative stress and antioxidants according our results.

Immunonutrition before and during radiochemotherapy: improvement of inflammatory parameters in head and neck cancer patients.

PURPOSE: Inflammatory, angiogenic and oxidative stress markers have been explored in head and neck squamous cell carcinoma (HNSCC) patients before and during radiochemotherapy. Furthermore, the effects of an oral supplementation containing amino acids, ω-3 fatty acids, ribonucleic acids, vitamins, and antioxidants on biological markers and acute toxicities were investigated. METHODS: Thirty-one patients with non-metastatic stage III or IV HNSCC treated with concomitant radiochemotherapy were recruited. A nutritional support (Oral Impact) was given during 5 days before each cycle of chemotherapy. Biological samples were collected at baseline, after 5 days of oral supplementation and before the last cycle of chemotherapy. Acute phase proteins levels, proteomic cytokines determination and urinary isoprostanes levels were used as inflammatory and oxidative stress biomarkers. Toxicities were followed up during radiochemotherapy. RESULTS: At baseline, median levels of inflammatory (CRP 9.8 mg/l [0.8-130.1], IL-6 4.2 pg/ml [0.7-126.5]), pro-angiogenic (VEGF 229.5 pg/ml [13.1-595.9]) and pro-oxidative stress (urinary isoprostanes 118 pmol/mmol creatinine [51-299]) markers were increased. Decrease in CRP (p = 0.002) and α-1 acid glycoprotein (p = 0.020) levels were observed after 5 days of oral supplementation. During radiochemotherapy, no significant variation of inflammatory markers was reported, and a low incidence of severe acute mucositis was noted. CONCLUSIONS: Stage III or IV HNSCC patients are characterised by a pro-inflammatory, pro-angiogenic and pro-oxidative status. Nutritional support could improve this inflammatory state and could prevent severe acute mucositis.

A fenugreek seed extract selectively reduces spontaneous fat intake in overweight subjects.

PURPOSE: Fenugreek seeds (Trigonella foenum-graecum L.) have long been used as a herbal medicine for treating metabolic and nutritive dysfunctions. They have been shown to modulate feeding behaviour in animals. We have recently observed a selective decrease in fat consumption in healthy normal weight volunteers treated with a hydro-alcoholic seed extract. However, strong clinical data on the effects of fenugreek seeds on energy intake are lacking, especially in overweight individuals. The aim of our study was to investigate the effects of a repeated administration of a fenugreek seed extract on the eating behaviour of overweight subjects. METHODS: Thirty-nine healthy overweight male volunteers completed a 6-week double-blind randomized placebo-controlled parallel trial of a fixed dose of a fenugreek seed extract. Main endpoints were energy intake (dietary records and meal test), weight, fasting and post-absorptive glucose and insulin, appetite/satiety scores and oxidative parameters. RESULTS: Daily fat consumption, expressed as the ratio fat reported energy intake/total energy expenditure (fat-REI/TEE), was significantly decreased in our overweight subjects administered the fenugreek seed extract relative to those receiving the placebo (fat-REI/TEE 0.26 +/- 0.02 vs. 0.30 +/- 0.01, respectively; P = 0.032). We also observed a significant decrease in the insulin/glucose ratio in subjects treated with fenugreek seed extract relative to the placebo group (0.89 +/- 0.09 vs. 1.06 +/- 0.10 mUI mmol(-1), respectively; P = 0.044). No significant effect was observed on weight, appetite/satiety scores or oxidative parameters. CONCLUSION: The repeated administration of a fenugreek seed extract slightly but significantly decreased dietary fat consumption in healthy overweight subjects in this short-term study.

Intradialytic parenteral nutrition: comparison of olive oil versus soybean oil-based lipid emulsions.

Lipid, oxidative and inflammatory parameters are frequently altered in dialysis patients and may be worsened by intravenous lipid emulsions (ILE). We assessed the efficacy and tolerance of olive as compared with standard soybean oil-based ILE during intradialytic parenteral nutrition (IDPN). IDPN mixtures containing amino acids, glucose, and either olive oil (OO group, n 17) or soybean oil-based ILE (SO group, n 18) were administered in a 5-week randomized, double-blind study. On days 0 and 35, patients' nutritional status was assessed by BMI, normalized protein catabolic rate, predialytic creatinine, serum albumin and transthyretin; lipid metabolism by plasma LDL- and HDL-cholesterol, triacylglycerols, phospholipids, apo A-I, A-II, B, C-II, C-III, E and lipoprotein (a); oxidative status by alpha-tocopherol, retinol, selenium, glutathione peroxidase, malondialdehyde and advanced oxidized protein products; inflammatory status by serum C-reactive protein, orosomucoid, IL-2 and IL-6. No serious adverse event was observed. Significant changes were observed from day 0 to day 35 (P<0.05): nutritional criteria improved (albumin in OO; albumin, transthyretin and creatinine in SO); LDL-cholesterol, apo B, C-II, C-III and apo A-I/A-II ratio increased in both groups. HDL-cholesterol decreased in OO; apo E increased and lipoprotein (a) decreased in SO; alpha-tocopherol/cholesterol ratio increased in OO; malondialdehyde decreased in both groups; IL-2 increased in both groups. The between-group comparison only showed the following differences: alpha-tocopherol/cholesterol increased in OO; lipoprotein (a) decreased in SO. From these data, it was concluded that OO- and SO-based IDPNs similarly improved nutritional status and influenced plasma lipid, oxidative, inflammatory and immune parameters.

Functional Vitamin E deficiency in ApoE4 patients with Alzheimer's disease.

Oxidative stress has been implicated in the development of Alzheimer's disease (AD). Consequently, antioxidant therapies including Vitamin E (VitE) supplementation for both prevention and treatment of neurodegenerative diseases currently appears to be a promising avenue of research. The aim of the present study was to examine the relationship between AD and the ApoE phenotype, lipid parameters and VitE levels in a large cohort of elderly subjects. No absolute deficit was observed in plasma VitE levels. However in AD, ApoE4 is not associated with an increase in total cholesterol (TC) and VitE levels. Moreover, our results suggest that oxidative stress-induced injury and protection by VitE in AD are related to the ApoE phenotype. Our study strongly supports the hypothesis of an impairment of lipophilic antioxidant delivery to neuronal cells in AD leading to a tissular antioxidant deficiency which could facilitate oxidative stress.

Fenofibrate improves the atherogenic lipid profile and enhances LDL resistance to oxidation in HIV-positive adults.

BACKGROUND: Low HDL-cholesterol, hypertriglyceridemia (HTG) and occurrence of small dense LDL could be involved in increased cardiovascular risk in HIV-infected patients. This study evaluates the effects of fenofibrate and/or Vitamin E on lipoprotein profile. DESIGN: Thirty-six HIV-positive adults with fasting triglycerides (TGs) > or =2 mmol/l and stable antiretroviral therapy (ART) were randomly assigned to receive either micronised fenofibrate (200 mg/day) or Vitamin E (500 mg/day) for a first period of 3 months and the association of both for an additional 3-month period. METHODS AND RESULTS: Total cholesterol, HDL-C, LDL-C, triglycerides, apoA1, apoB, apoCIII, lipoprotein composition, LDL size and LDL resistance to copper-induced oxidation were determined before initiation of fenofibrate or Vitamin E, and 3 and 6 months thereafter. Three months of fenofibrate treatment results in a significant decrease in triglycerides (-40%), apoCIII (-21%), total cholesterol (-14%), apoB (-17%) levels, non-HDL-C (-17%), TG/apoA1 ratio in HDL (-27%) associated with an increase in HDL-C (+15%) and apoA1 (+11%) levels. Moreover, fenofibrate increases LDL size and enhances LDL resistance to oxidation. Three months of Vitamin E supplementation only improves LDL resistance to oxidation and addition to fenofibrate results in a slightly greater effect. CONCLUSION: Fenofibrate therapy improves the atherogenic lipid profile in HIV-positive adults with hypertriglyceridemia.

Vitamin E supplementation increases LDL resistance to ex vivo oxidation in hemodialysis patients.

BACKGROUND: Oxidative stress and alterations in lipid metabolism observed in hemodialysis patients potentiate the low-density lipoprotein (LDL) oxidability, recognized as a key event during early atherogenesis. OBJECTIVE: To explore the effects of an oral vitamin E supplementation on oxidative stress markers and LDL oxidability in hemodialysis patients. METHODS: Fourteen hemodialysis patients and six healthy volunteers were given oral vitamin E (500 mg/day) for six months. Oxidative stress was assessed using: plasma and lipoprotein vitamin E levels [high-performance liquid chromatography (HPLC) procedure]; thiobarbituric acid reactive substances (TBARS, Yaggi method); and copper-induced LDL oxidation. All parameters were evaluated before initiation of vitamin E supplementation, and at three and six months thereafter. RESULTS: At baseline, a significantly higher TBARS concentration and a higher LDL oxidability were observed in hemodialysis patients when compared to controls. After six months of vitamin E supplementation, TBARS and LDL oxidability were normalized in hemodialysis patients. CONCLUSION: Our data confirm that hemodialysis patients are exposed to oxidative stress and increased susceptibility to ex vivo LDL oxidation. Since oral vitamin E supplementation prevents oxidative stress and significantly increases LDL resistance to ex vivo oxidation, supplementation by natural antioxidants such as vitamin E may be beneficial in hemodialysis patients.