Modulation of carbon tetrachloride-induced oxidative stress by dietary fat in rats(open star)

Polycystic Ovary Syndrome in Insulin-Resistant Adolescents with Obesity: The Role of Nutrition Therapy and Food Supplements as a Strategy to Protect Fertility

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in young reproductive-aged women. PCOS is often associated with obesity and impairs reproductive health. Even though several theories have been proposed to explain the pathogenic mechanism of PCOS, the role of insulin resistance (IR) as a key etiological component, independently of (but amplified by) obesity, is well recognized. The consequent hyperinsulinemia activates excessive ovarian androgen production, leading to PCOS. Additionally, the state of chronic inflammation related to obesity impacts ovarian physiology due to insulin sensitivity impairment. The first-line treatment for adolescents with obesity and PCOS includes lifestyle changes; personalized dietary interventions; and, when needed, weight loss. Medical nutrition therapy (MNT) and the use of specific food supplements in these patients aim at improving symptoms and signs, including insulin resistance and metabolic and reproductive functions. The purpose of this narrative review is to present and discuss PCOS in adolescents with obesity, its relationship with IR and the role of MNT and food supplements in treatment. Appropriate early dietary intervention for the management of adolescents with obesity and PCOS should be considered as the recommended approach to restore ovulation and to protect fertility.

Targeting Metabolic Consequences of Insulin Resistance in Polycystic Ovary Syndrome by D-chiro-inositol and Emerging Nutraceuticals: A Focused Review

Polycystic ovary syndrome (PCOS) is a complex disorder associated with ovarian dysfunction, infertility, menstrual irregularity, and hormonal impairments. Over the last decade, several studies have shown that some PCOS women have insulin resistance (InsR) and hyperinsulinemia, apart from being overweight or obese. Therefore, a crucial clinical aspect is that PCOS patients might develop glucose intolerance and type 2 diabetes. Insulin-sensitizing drugs have been used as first-line treatment to improve hyperinsulinemia in women with PCOS. Although reducing PCOS symptoms and signs, several used insulin-sensitizer drugs may induce side effects, which reduces compliance. D-chiro-inositol (DCI), which is a naturally occurring stereoisomer of inositol, has been classified as an insulin-sensitizer and seems to mitigate multiple InsR-related metabolic alterations in PCOS with a safe profile. However, according to a multi-targeted design, the supplementation with DCI can be synergistically integrated by combining other potential insulin-sensitizing drugs and/or nutraceuticals. The literature provides the initial support for using several unexplored nutraceutical interventions that may target relevant metabolic abnormalities associated with InsR in PCOS. With a need to promote interest in clinical research, this review aims to discuss the efficacy of DCI and the role of emerging nutraceuticals for managing InsR in PCOS.

Effects of consumption of whole grain foods rich in lignans in healthy postmenopausal women with moderate serum cholesterol: a pilot study

This study aims at investigating the effect of an experimental period of intake of whole grain foods rich in lignans as part of an habitual diet on the plasma and urinary excretion of enterolignans, the biomarkers of lipid metabolism and the immunological and antioxidant status in a group of postmenopausal women with moderate serum cholesterol. A randomized double-blind crossover study was completed on 13 subjects in 12-weeks after protocol approval of an ethical committee. The subjects consumed whole grain foods high in lignans (30 g/d of breakfast cereals or biscuits, etc., 80 g/d of whole grain pasta) or refined grain foods for 4 weeks, separated by a 2-weeks wash-out period. A modest hypocholesterolemic effect (p < 0.05) of the whole grain diet was observed and the intake of whole grain products rich in lignans was also associated with an increase in urinary enterodiol excretion (p < 0.05).

Gene expression profiling of flaxseed in mouse lung tissues-modulation of toxicologically relevant genes

BACKGROUND

Flaxseed (FS), a nutritional supplement consisting mainly of omega-3 fatty acids and lignan phenolics has potent anti-inflammatory, anti-fibrotic and antioxidant properties. The usefulness of flaxseed as an alternative and complimentary treatment option has been known since ancient times. We have shown that dietary FS supplementation ameliorates oxidative stress and inflammation in experimental models of acute and chronic lung injury in mice resulting from diverse toxicants. The development of lung tissue damage in response to direct or indirect oxidant stress is a complex process, associated with changes in expression levels of a number of genes. We therefore postulated that flaxseed might modulate gene expression of vital signaling pathways, thus interfering with the development of tissue injury.

METHODS

We evaluated gene expression in lungs of flaxseed-fed (10%FS) mice under unchallenged, control conditions. We reasoned that array technology would provide a powerful tool for studying the mechanisms behind this response and aid the evaluation of dietary flaxseed intervention with a focus on toxicologically relevant molecular gene targets. Gene expression levels in lung tissues were analyzed using a large-scale array whereby 28,800 genes were evaluated.

RESULTS

3,713 genes (12.8%) were significantly (p < 0.05) differentially expressed, of which 2,088 had a >1.5-fold change. Genes affected by FS include those in protective pathways such as Phase I and Phase II.

CONCLUSIONS

The array studies have provided information on how FS modulates gene expression in lung and how they might be related to protective mechanisms. In addition, our study has confirmed that flaxseed is a nutritional supplement with potentially useful therapeutic applications in complementary and alternative (CAM) medicine especially in relation to treatment of lung disease.

The comparison of in vivo antigenotoxic and antioxidative capacity of two propylene glycol extracts of Calendula officinalis (marigold) and vitamin E in young growing pigs

The objective of the study was to evaluate the protective effect of Calendula officinalis propylene glycol extracts against oxidative DNA damage and lipid peroxidation induced by high polyunsaturated fatty acid (PUFA) intake in young growing pigs. Forty young growing pigs were assigned to five treatment groups: control; oil (linseed oil supplementation); C. officinalis 1 and 2 groups (linseed oil plus 3 ml/day of C. officinalis propylene glycol extracts); and vitamin E group (linseed oil plus 100 mg/kg of vitamin E). Lymphocyte DNA fragmentation and 24-h urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) excretion were measured to determine DNA damage. Lipid peroxidation was studied by analysing plasma and urine malondialdehyde (MDA), and urine isoprostane concentrations (iPF2α-VI), total antioxidant status of plasma and glutathione peroxidase (GPx) assays. C. officinalis 1 (extract from petals) effectively protected DNA from oxidative damage. It indicated a numerical trend towards the reduction of plasma MDA and urinary iPF2α-VI excretion. Its effect was comparable with that of vitamin E. C. officinalis 2 (extract from flower tops) showed less antioxidant potential than the extract from petals. We can conclude that the amount of C. officinalis extracts proposed for internal use by traditional medicine protects the organism against DNA damage induced by high PUFA intake.

Dietary flaxseed enhances antioxidant defenses and is protective in a mouse model of lung ischemia-reperfusion injury

Dietary flaxseed (FS) is a nutritional whole grain with high contents of omega-3 fatty acids and lignans with anti-inflammatory and antioxidant properties. We evaluated FS in a murine model of pulmonary ischemia-reperfusion injury (IRI) by dietary supplementation of 0% (control) or 10% (treatment) FS before IRI. Mice fed 0% FS undergoing IRI had a significant decrease in arterial oxygenation (Pa(O(2))) and a significant increase in bronchoalveolar lavage (BAL) protein compared with sham-operated mice. However, mice fed 10% FS undergoing IRI had a significant improvement in both Pa(O(2)) and BAL protein compared with mice fed 0% FS undergoing IRI. In addition, oxidative lung damage was decreased in 10% FS-supplemented mice undergoing IRI, as assessed by malondialdehyde levels. Immunohistochemical staining of lungs for iPF(2alpha)-III F(2) isoprostane, a measure of lipid oxidation, was diminished. FS-supplemented mice had less reactive oxygen species (ROS) release from the vascular endothelium in lungs in an ex vivo model of IRI, and alveolar macrophages isolated from FS-fed mice had significantly reduced ROS generation in response to oxidative burst. Pulmonary microvascular endothelial cells produced less ROS in a flow cessation model of ischemia when preincubated with purified FS lignan metabolites. Pharmacological inhibition of heme oxygenase-1 (HO-1) resulted in only a partial reduction of FS protection in the same model. We conclude that dietary FS is protective against IRI in an experimental murine model and that FS affects ROS generation and ROS detoxification via pathways not limited to upregulation of antioxidant enzymes such as HO-1.

Serum advanced oxidation protein products, myeloperoxidase and ascorbic acid in pre-eclampsia and eclampsia

BACKGROUND

Activation products from neutrophils and the complement system might cause endothelial dysfunction, which is central to the aetiology of pre-eclampsia. This study aimed to investigate the activity of myeloperoxidase (MPO), and its association with advanced oxidation protein products (AOPP), in women with pre-eclampsia and eclampsia.

MATERIALS AND METHOD

Twenty-one pregnant women with pre-eclampsia, 11 pregnant women with eclampsia and 19 healthy pregnant women were studied. Serum levels of malondialdehyde (MDA), AOPP, ascorbic acid (AA) and activities of MPO and catalase (CAT) were measured using a colorimetric method.

RESULTS

The MDA level was significantly higher in the pre-eclampsia (3.15+/-0.28 nmol/mL) and eclampsia (4.01+/-0.66 nmol/mL) groups than in controls (1.85+/-0.18 nmol/mL); the difference between MDA levels in the pre-eclampsia and eclampsia groups was not statistically significant. MPO activity was significantly higher in the eclampsia (347.59+/-88.06 U/L) group than in the pre-eclampsia (196.17+/-30.8) and control (93.22+/-9.52) groups, and there was also no significant difference in these levels between the pre-eclampsia and control groups. CAT activity was significantly higher in the pre-eclampsia (166.35+/-31.75 U/L) and eclampsia (166.98+/-40.31 U/L) groups than in controls (81.28+/-7.41 U/L), and AA level was significantly higher in the pre-eclampsia (0.54+/-0.15 mg/dL) group than in controls (0.18+/-0.01 mg/dL); the differences in AA and CAT activity between the pre-eclampsia and eclampsia groups were not statistically significant. AOPP levels did not change significantly among the control, pre-eclampsia and eclampsia groups (106.88+/-5.62, 98.89+/-6.47, 111.89+/-6.8 micromol/L, respectively).

CONCLUSIONS

We suggest that increased oxidative stress might contribute to the pathophysiological mechanisms of pre-eclampsia and eclampsia, and that AA and CAT might have a protective role via free radical-scavenging properties. However, further study is needed.

Effect of fish or soybean oil-rich diets on bradykinin, kallikrein, nitric oxide, leptin, corticosterone and macrophages in carrageenan stimulated rats

We have previously demonstrated that both n-3 and n-6 polyunsaturated fatty acids (PUFA)-rich diets decrease the acute inflammatory response partially explained by the high corticosterone basal levels. The present study aimed to determine the effect of hyperlipidic diets (PUFA n-3 or n-6) on phagocytosis, hydrogen peroxide (H(2)O(2)) and nitric oxide (NO) release by macrophages, bradykinin (BK) and NO release in the paw inflammatory perfusate and Kallikrein (KK), corticosterone and leptin blood levels. Hyperlipidic diets decreased H(2)O(2) release from macrophages stimulated by carrageenan or phorbol-miristate-acetate (PMA), NO release from macrophage stimulated by carrageenan, BK and NO release in the edema perfusate, KK plasma levels and the increase of serum leptin after carrageenan stimulus. These data show that both fish and soybean oil-rich diets promote similar alterations on inflammatory mediators of carrageenan edema and a causal association with the anti-inflammatory effect of these diets.

Dietary flaxseed supplementation ameliorates inflammation and oxidative tissue damage in experimental models of acute lung injury in mice

Flaxseed (FS) is a nutritional supplement with high concentrations of (n-3) fatty acids and lignans that have anti-inflammatory and antioxidant properties. The use of FS in the prevention or treatment of acute lung disease is unknown. In this study, we evaluated diets with high FS content in experimental murine models of acute lung injury and inflammation. The kinetics of lignan accumulation in blood, following 10% FS supplementation, was determined using liquid chromatography tandem mass spectrometry. Mice were fed isocaloric control and 10% FS-supplemented diets for at least 3 wk and challenged by hyperoxia (80% oxygen), intratracheal instillation of lipopolysaccharide, or acid aspiration. Bronchoalveolar lavage was evaluated for white blood cells, neutrophils, and proteins after a 24 h postintratracheal challenge of hydrochloric acid or lipopolysaccharide, or after 6 d of hyperoxia. Lung lipid peroxidation was assessed by tissue malondialdehyde concentrations. The plasma concentrations of the FS lignans, enterodiol and enterolactone, were stable after mice had eaten the diets for 2 wk. Following hyperoxia and acid aspiration, bronchoalveolar lavage neutrophils decreased in FS-supplemented mice (P = 0.012 and P = 0.027, respectively), whereas overall alveolar white blood cell influx tended to be lower (P = 0.11). In contrast, neither lung injury nor inflammation was ameliorated by FS following lipopolysaccharide instillation. Lung malondialdehyde levels were lower in hyperoxic mice than in unchallenged mice (P = 0.0001), and decreased with FS treatment following acid aspiration (P = 0.011). Dietary FS decreased lung inflammation and lipid peroxidation, suggesting a protective role against pro-oxidant-induced tissue damage in vivo.

Comparison of the effects of melatonin and pentoxifylline on carbon tetrachloride-induced liver toxicity in mice

The purpose of the study was to determine whether along and in combination melatonin (MLT) and pentoxifylline (PTX) exerted beneficial effects on histopathological changes and changes in oxidant and antioxidant systems in liver caused by CCl4-induced liver toxicity in mice. Mice were randomly divided into six groups: control, olive oil, toxicity, MLT, PTX, PTX+MLT. MLT 10 mg/kg/day, PTX 50 mg/kg/day, and the same individual doses in MLT+PTX combination were given intraperitoneally to mice for 7 day. CCl4 0.8 mg/kg/day was administered on the 4th, 5th, and 6th days of therapy in all groups except the control and olive oil groups. In the toxicity group, increased concentrations of malondialdehyde (MDA) and lipid hydroperoxides (LOOH) and decreased glutathione peroxidase (GSH-Px) and catalase (CAT) activities were found compared to the control and olive oil groups (p < 0.05). Compared to the toxicity group, both the PTX group and the PTX+MLT group had decreased MDA and LOOH levels, whereas MLT reduced only LOOH levels (p < 0.01). MLT, PTX and MLT+PTX increased the GSH-Px and CAT activities compared to the toxicity group (p < 0.05). MLT increased CAT activity compared to PTX and MLT+PTX (p < 0.05). Superoxide dismutase enzyme activity did not change in any group (p < 0.05). Histopathologically, ballooning, degeneration, apoptosis, and bridging necrosis were seen in the toxicity group. MLT, PTX and MLT+PTX decreased the apoptosis and bridging necrosis (p < 0.01), and PTX and MLT+PTX decreased balloon degeneration compared to the toxicity group (p < 0.01). These results indicate that administration of PTX and MLT alone and in combination before onset of liver toxicity might prevent the oxidative damage by reducing oxidative stress and increasing antioxidant enzyme levels.

Flaxseed and cardiovascular risk

Flaxseed has recently gained attention in the area of cardiovascular disease primarily because it is the richest known source of both alpha-linolenic acid (ALA) and the phytoestrogen, lignans, as well as being a good source of soluble fiber. Human studies have shown that flaxseed can modestly reduce serum total and low-density lipoprotein cholesterol concentrations, reduce postprandial glucose absorption, decrease some markers of inflammation, and raise serum levels of the omega-3 fatty acids, ALA and eicosapentaenoic acid. Data on the antiplatelet, antioxidant, and hypotensive effects of flaxseed, however, are inconclusive. More research is needed to define the role of this functional food in reducing cardiovascular risk.

Dietary flavonoids fail to suppress F2-isoprostane formation in vivo

Dietary antioxidants, including alpha-tocopherol (alpha-TOH) and polyphenolic flavonoid compounds, have been the subject of much research interest, but few studies have investigated interactions between these two antioxidants in vivo. We have conducted a feeding study to determine if supplementation with dietary flavonoids or polyphenol-containing compounds will provide antioxidant protection in tocopherol-deficient animals or exceed the antioxidant protection provided by alpha-TOH alone, using the sensitive and specific measure of lipid peroxidation, F2-isoprostanes. Seventy-two male Sprague Dawley rats were divided into 12 treatment groups to receive either alpha-TOH-sufficient or -deficient AIN93-G diet supplemented with one of five compounds: 0.5% quercetin, catechin, or epicatechin; or 1% cocoa powder or lignin. The fat source was polyunsaturated oil, increased from 7 to 11.05% (w/w with diet) to maximize lipid peroxidation while staying within a physiological range. After 7 weeks of treatment, animals were sacrificed with plasma and hearts analyzed to determine differences in F2-isoprostane levels. None of the treatment compounds significantly decreased plasma or heart F2-isoprostanes compared to the control beyond the significant protection displayed by alpha-tocopherol. We conclude that under these experimental conditions, quercetin, catechin, and epicatechin do not suppress lipid peroxidation in vivo.