Fat-soluble Antioxidants Research Articles

Effects of dicarbonyl trapping agents, antioxidants, and reducing agents on the formation of furan and other volatile components in canned-coffee model systems

The formation of furan and certain volatiles related to furan formation mechanisms was studied using gas chromatography–mass spectrometry combined with solid-phase micro extraction after adding dicarbonyl trapping agents [epicatechin (EC), epigallocatechin gallate (EGCG), and catechin], water-soluble antioxidants (Trolox, caffeic acid, ferulic acid, and chlorogenic acid), fat-soluble antioxidants (α-tocopherol, BHT, and β-carotene), and reducing agents (glutathione and sodium sulfite) to canned-coffee model systems (CMS). The level of furan formation decreased significantly following the addition of EC (by 65.3%), EGCG (by 60.0%), and catechin (by 44.7%). In addition, the formation of Maillard reaction products, including furan derivatives (furfural and 5-methylfurfural), Strecker aldehyde (2-methylbutanal), pyrazines (2,6-dimethylpyrazine), and lipid oxidation products (including hexanal and 2-pentylfuran) was suppressed when any of the dicarbonyl trapping agents was added. Among the water-soluble antioxidants studied, chlorogenic acid most significantly decreased the furan level, by 67.0%, followed by ferulic acid (57.6%), Trolox (50.1%), and caffeic acid (48.2%) in the CMS. Chlorogenic acid also reduced the formation of furfural and lipid oxidation products. However, the addition of caffeic acid, ferulic acid, and chlorogenic acid decreased the generation of key coffee aroma components, such as Strecker aldehydes (2-methylpropanal and 2-methylbutanal), 5-methylfurfural, and pyrazines (2,6-dimethylpyrazine and 2-ethyl-5-methylpyrazine). Among the fat-soluble antioxidants, BHT and α-tocopherol decreased the furan level by 49.3% and 39.3%, respectively, while β-carotene increased the furan level by 34.8%. The addition of sodium sulfite and glutathione to CMS also led to considerable reductions in furan, of 64.1% and 44.9%, respectively.

Cardiovascular calcification and bone: a comparison of the effects of dietary and serum antioxidants

<p>Severe cardiovascular (CV) calcification can manifest as fully formed bone and is regularly found with osteoporosis; both have been shown to be associated with oxidative stress. Studies of the effect of antioxidants on CV calcification are few, but show that deficiency can induce both CV calcification and bone loss, while in conditions of oxidative stress such as renal failure, diabetes and smoking or in osteoporosis and fracture, antioxidants can reduce CV calcification and improve bone. The benefit of antioxidants in healthy adults is less clear and some may be detrimental. Higher intake of <em>α</em>-tocopherol (105.5mg/d vs 76.4mg/d) and β-cryptoxanthin may increase risk of CV calcification while high intake of retinol (≥3000mcg/d) may increase hip fracture risk, although possibly only with vitamin D intake ≤440IU/d; the carotenoids lycopene and β-carotene, however, appear beneficial in bone. Vitamin C shows little effect on CV calcification, although longer term supplementation may improve bone mineral density where calcium intake is >500mg/d. Potential reasons for this include a U-shaped dose/response curve for the fat-soluble antioxidants vitamins A and E (with peak bone mass achieved with retinol intake of 600–840 mcg/d), a failure to measure baseline concentrations so that the response cannot be stratified by requirement, the need to be replete in calcium and vitamin D and supplementation of the wrong isomer of vitamin E. Finally, although little studied, tocotrienols, tocopherols (with the exception of α-tocopherol), resveratrol, epigallocatechin gallate, quercetin, α-lipoic acid and N-acetylcysteine may be effective in both the CV system and bone. </p>

Alfa-Tocopherol supplementation induces morphological changes in the hippocampus of adult offspring

α-Tocopherol, the main form of vitamin E in mammal organisms, is a potent fat soluble antioxidant and scavenger of hydroperoxyl radicals. It has been considered an important molecule during fetal and early postnatal life, playing fundamental roles in protecting the developing organism against oxidative stress. In fact, free radicals have been indicated as causative agents of pregnancy-related disorders, such as preeclampsia and maternal diabetes, inducing serious complications in both the mother and fetus. On the other hand, it has been demonstrated that maternal supranutritional dietary intake of α-Tocopherol in rats depresses PKC activity and reduces synaptic long-term potentiation in developing hippocampus (1). This effect seems to persist into adulthood, with behavioural alterations in hippocampus-dependent learning. To better understand if α-Tocopherol supplementation through pregnancy and lactation could cause developmental deficit in adult rat offspring, ultrastructural morphometric studies have been carried out to evaluate possible changes in density and morphological features of asymmetric, axo-spinous synapses within hippocampal CA1 stratum radiatum (2). Transmission Electron Microscopy analyses showed that the hippocampus of adult rats born to dams fed with supranutritional doses of α-Tocopherol displayed high density of asymmetric axo-spinous synapses, large astrocytic coverage of presynaptic terminals and high number of axo-spinous synapses contacted by astrocytic endfeet at bouton-spine interface, when compared to the controls. These findings suggest that α-Tocopherol supplementation induced anatomical changes such as a surplus of axo-spinous synapses and an aberrant glia-synapse relationship, thus promoting permanent deficits in hippocampal synaptic plasticity and spatial learning in adult offspring.

The combination of red palm oil and rooibos show anti-inflammatory effects in rats.

BackgroundRed palm oil (RPO) and rooibos have been shown to exhibit cardioprotective properties. RPO is rich in essential fatty acids and fat soluble antioxidants while rooibos contains polyphenolic compounds with a unique composition of flavonoids. They exert their biological effects in different cellular compartments. Therefore the combination of these two natural food compounds has the potential to enhance the spectrum of available dietary antioxidants in different cellular compartments, which could result in an enhanced protection against certain pathological conditions such as inflammation.MethodsMale Wistar rats weighing 150-200 g were supplemented with RPO, rooibos or their combination for 28 days. The Langendorff system and the lipoposaccharide (LPS)-induced inflammatory model were used to establish if RPO and rooibos, when supplemented alone or in combination, will reverse the negative effects of LPS on cardiac function at baseline. The effect of dietary intervention was also investigated on modulation of pro-inflammatory and anti-inflammatory cytokines in plasma and myocardial tissue.Results and discussionThe LPS resulted in induction of systemic inflammation as evidenced by increased levels of IL-1β in plasma of LPS-treated rats compared to their non-treated control counterparts. Dietary supplementation and LPS treatment did not have an effect on baseline cardiac functional parameters. However, the elevation of IL-1β levels in plasma of LPS-induced rats consuming either RPO or rooibos alone were paralleled with increased levels of the anti-inflammatory cytokine, IL-10. The combination of rooibos and RPO was associated with enhanced endogenous production of myocardial IL-10 in LPS-induced rats.ConclusionThe results of this study indicate that RPO and rooibos when supplemented individually showed anti-inflammatory effect at systemic level while their combination exhibited an enhanced anti-inflammatory effect in the myocardial tissue. Therefore, the findings in the current study argue that the combination of these two natural food substances could be beneficial in clinically relevant conditions where inflammation plays a role.

Biomarkers of bone development and oxidative stress in gilthead sea bream larvae fed microdiets with several levels of polar lipids and α-tocopherol

Although dietary marine phospholipids are able to improve culture performance of marine fish larvae in a further extend than soybean lecithin, both types of phospholipids (PL) markedly increase oxidative risk. The inclusion of a fat-soluble antioxidant such as the vitamin E α-tocopherol could allow a better control of oxidative stress. The objective of this study was to determine the combined effect of graded levels of α-tocopherol with different levels and sources of krill phospholipids (KPL) and soybean lecithin (SBL) on growth, survival, resistance to stress, oxidative status, bone metabolism-related genes expression and biochemical composition of sea bream larvae. Sea bream larvae were completely weaned at 16 dph and fed for 30 days seven microdiets with three different levels of PL (0, 40 and 80 g kg−1 diet) and two of α-tocopherol 1500 and 3000 mg kg−1 diet. Sea bream larvae fed diets without PL supplementation showed the lowest survival, growth and stress resistance, whereas increase in PL, particularly KPL, markedly promoted larval survival and growth. However, feeding SBL markedly increased TBARs and GPX gene expression increasing the peroxidation risk in the larvae. Besides, KPL inclusion improved incorporation of n-3 HUFA and, particularly, EPA into larval tissues, these fatty acids being positively correlated with the expression of BMP-4, RUNX 2, ALP, OC and OP genes and to bone mineralization for a given larval size class. The increase in dietary α-tocopherol tends to improve growth in relation to the n-3 HUFA levels in the diet, denoting the protective role of this vitamin against oxidation. Indeed, dietary α-tocopherol decreased the oxidative stress in the larvae as denoted by the reduction in larval TBARs contents and gene expression of SOD and CAT, but not GPX. Thus, increase in dietary α-tocopherol effectively prevented the formation of free radicals from HUFA, particularly EPA, but did not affect the incidence of bone anomalies or the expression of genes related to osteogenetic processes.

Design and straightforward synthesis of novel galloyl phytosterols with excellent antioxidant activity

Novel galloyl phytosterols were rationally designed by incorporation of gallic acid into phytosterols through straightforward esterification. The esterification was successfully achieved by coupling of gallic acid and phytosterols through a mild chemical Steglich esterification reaction that is more straightforward than the enzymatic method. The identity of the newly synthesized galloyl phytosterols was confirmed by NMR, HPLC–MS and IR spectroscopies. Further evaluation of the novel galloyl phytosterols with radical scavenging, ferrous ion chelating, and Rancimat methods revealed its excellent antioxidant activities that are comparable to the most potent fat-soluble antioxidants. This novel antioxidant offers an intriguing solution for naturally derived antioxidants and will have great potential application as antioxidant in food industry. The methods developed in this study will be valuable for development of other phenolic phytosterols.

The relationship of fat soluble antioxidants with gestational diabetes in Iran: a case–control study

Objective: The primary aim of this study was to evaluate the relationship of fat soluble antioxidants (retinol and α-tocopherol) with gestational diabetes (GDM).Methods: This was a case–control study in which 41 pregnant women with GDM and 41 healthy women were recruited. The inclusion criteria were gestational age ≥32 weeks, singleton foetus, nulliparous or parous women up to four pregnancies and normal fasting blood sugar in the early pregnancy. Two groups were matched regarding age, gestational age and body mass index. A 5 ml venous blood sample were drawn and analysed with the chromatograph for measuring retinol and α-tocopherol. Data were analysed through Chi-square and t test.Results: The mean serum retinol of the GDM group was 0.46 µg/dl and in the control group it was 0.59 mg/dl (p = 0.01).The mean α-tocopherol in the women with GDM was 6.21 mg/dl and in the control group it was 6.92 mg/dl (p > 0.05).Conclusion: The level of retinol in the diabetic pregnant women was significantly lower than that in the control group. This reduction may be due to the reduced antioxidant defences in women with GDM.

Anti-inflammatory effects of IKK inhibitor XII, thymulin, and fat-soluble antioxidants in LPS-treated mice.

The present study was designed to compare the anti-inflammatory effects of several agents applied in vivo, namely, a synthetic inhibitor of the NF-κB cascade, fat-soluble antioxidants, and the thymic peptide thymulin. Cytokine response in LPS-treated mice was analysed in tandem with the following parameters: the synthesis of inducible forms of the heat shock proteins HSP72 and HSP90α; activity of the NF-κB and SAPK/JNK signalling pathways; and TLR4 expression. Inflammation-bearing Balb/c male mice were pretreated with an inhibitor of IKK-α/β kinases (IKK Inhibitor XII); with thymulin; with dietary coenzyme Q9, α-tocopherol, and β-carotene; or with combinations of the inhibitor and peptide or antioxidants. Comparable anti-inflammatory effects were observed in inflammation-bearing mice treated separately with thymulin or with dietary antioxidants administered daily for two weeks before LPS treatment. When LPS-injected mice were treated with the inhibitor and antioxidants together, neither plasma cytokines, signal proteins, nor heat shock proteins recovered more efficiently than when mice were treated with these agents separately. In contrast to antioxidant diet, the thymulin was shown to increase the effect of IKK Inhibitor XII in preventing IKK activation in LPS-treated mice.

Multiple sclerosis: evaluation of purine nucleotide metabolism in central nervous system in association with serum levels of selected fat-soluble antioxidants.

In the pathogenesis of demyelinating diseases including multiple sclerosis (MS) an important role is played by oxidative stress. Increased energy requirements during remyelination of axons and mitochondria failure is one of the causes of axonal degeneration and disability in MS. In this context, we analyzed to what extent the increase in purine catabolism is associated with selected blood lipophilic antioxidants and if there is any association with alterations in serum levels of coenzyme Q10. Blood serum and cerebrospinal fluid (CSF) samples from 42 patients with diagnosed MS and 34 noninflammatory neurologic patients (control group) were analyzed. Compared to control group, MS patients had significantly elevated values of all purine nucleotide metabolites, except adenosine. Serum lipophilic antioxidants γ-tocopherol, β-carotene, and coenzyme Q10 for the vast majority of MS patients were deficient or moved within the border of lower physiological values. Serum levels of TBARS, marker of lipid peroxidation, were increased by 81% in the MS patients. The results indicate that the deficit of lipophilic antioxidants in blood of MS patients may have a negative impact on bioenergetics of reparative remyelinating processes and promote neurodegeneration.

158 ASTAXANTHIN EFFECTS ON MATURATION, FERTILIZATION, AND DEVELOPMENT OF PORCINE OOCYTES CULTURED UNDER HEAT STRESS

Heat stress can engender various disorders in reproductive functions such as impairment of oocyte maturation, fertilization, and embryonic development. Astaxanthin, an extremely common carotenoid, is a typical fat-soluble antioxidant that scavenges ROS and blocks lipid peroxidation. Moreover, astaxanthin has been shown to improve the development of embryos exposed to heat stress by a reduction in stress-inducible genes. This study was conducted to investigate the effects of astaxanthin supplementation on the meiotic competence, fertilization, and development of porcine oocytes exposed to high temperature (41°C) during maturation culture. Cumulus–oocyte complexes (COC) collected from ovaries were transferred into maturation medium supplemented with astaxanthin (0, 0.25, 0.5, or 1.0 ppm) and were then cultured for 46 h at 41°C or 38.5°C. After maturation culture, the COC were subjected to IVF and embryo culture to evaluate the fertility and development of oocytes. The total cell number and DNA fragmentation in the blastocysts were assessed using terminal deoxynucleotidyl transferase dUTP nick end labelling and Hoechst 33342 staining. The total numbers of oocytes matured at 41°C and 38.5°C in each treatment group were 432 to 470 and 426 to 444, respectively. Data were analysed using ANOVA, followed by Fisher's protected least significant difference test. Exposure to elevated temperatures during maturation culture significantly reduced the proportions of oocytes that reached metaphase II. When the COC were cultured in the maturation medium supplemented with 0.5 and 1.0 ppm of astaxanthin under heat stress conditions (41°C), the supplementation of astaxanthin significantly improved the proportions of maturation, fertilization, and blastocyst formation compared with the control group (0 ppm) (50–52%, 45–55%, and 11–12% v. 17, 25, and 6%, respectively). The supplementation of the maturation medium with 0.25 ppm of astaxanthin improved only blastocyst formation (9.6%). Similarly, the supplementation of astaxanthin at 1.0 ppm improved the proportions of maturation, fertilization, and blastocyst formation of oocytes matured at 38.5°C s compared with the control group (67, 57, and 18% v. 48, 33, and 12%, respectively). However, no beneficial effect of astaxanthin supplementation was found in the total cell number or DNA fragmentation in the blastocysts, irrespective of culture temperature. Our findings show that the supplementation of astaxanthin to maturation medium improves maturation, fertilization, and embryo development of porcine oocytes exposed to heat stress during maturation culture.

β-Lactoglobulin improves liposome’s encapsulation properties for vitamin E delivery

Vitamin E (VE) or α-tocopherol is the major fat-soluble antioxidant in the human body. It is a sensitive, easily oxidized in the air, molecule, so it must be protected from pro-oxidant elements which could affect its physiological benefits. Encapsulation constitutes a promising approach to maintain VE native properties over time and increase its concentration in aqueous media. Liposomes have been studied as sustained delivery systems, being biodegradable, non-toxic and non-immunogenic. A new liposome/β-lactoglobulin (β-Lg) formulation has been developed and characterized as a possible stable delivery system for VE. β-Lg has been selected due to its property to bind a variety of hydrophobic molecules. The aim of this study was the preparation of β-Lg-liposome formulation and the determination of VE encapsulation efficiency, in order to develop a new more efficient carrier for VE in aqueous media.

Vitamin E: the enigmatic one!

Vitamin E was first identified more than 90 years ago by Evans and Bishop as an essential dietary factor that is required by rats to maintain normal reproduction (1). Unlike the other three fat-soluble vitamins that have very specific molecular targets and actions, vitamin E lacks specific pathways or specific molecular targets that account for its requirement from the diet. Considerable research had been focused on identifying specific molecular targets and actions for vitamin E (2). For instance, as it became clear that vitamins A and D act through cognate nuclear hormone receptors to regulate vitamin-responsive gene expression, investigators sought, without success, to identify similar activities for vitamin E. These investigations simply led back to the same understanding of vitamin E obtained from studies carried out between the 1930s and the 1980s, that vitamin E acts as a fat-soluble antioxidant. Vitamin E serves as a peroxyl radical scavenger that protects polyunsaturated fatty acids in membranes and lipoproteins from oxidative damage (3). Given that many dietary substances, as well as many substances synthesized within the body, have potent antioxidant properties, what selective pressures drove evolution to require humans and other higher animals to acquire vitamin E from the diet? Is this simply due to the physical properties and/or redox chemistry of vitamin E or is there something about vitamin E that we still do not understand? This issue of the Journal of Lipid Research contains the second installment of the JLR's Thematic Review Series on fat-soluble vitamins. The biology of vitamin E and its role in human cardiovascular disease will be considered in the two reviews that comprise this edition of the Thematic Review Series on fat-soluble vitamins.

Vitamin E in the prevention of cardiovascular disease: the importance of proper patient selection

Vitamin E is a naturally occurring fat-soluble antioxidant which has been proposed as a treatment for both primary and secondary protection against cardiovascular (CV) events. Promising data from observational epidemiological studies associating higher vitamin E dietary intake with lower risk of CV events have not been validated in randomized controlled clinical trials assessing the effect of vitamin E on CV outcomes. While the pendulum of medical opinion has swung to suggest that high dose vitamin E supplements have no place in the treatment and prevention of CV disease, new data is emerging that allows identification of a specific target population for this treatment, namely patients with diabetes mellitus and the haptoglobin genotype 2-2. This review details the scientific basis and clinical evidence related to the effect of vitamin E on CV outcomes, and the importance of proper patient selection in gaining therapeutic benefit from this intervention.

Triglyceride Recrystallized Phytosterols in Fat-Free Milk Improve Lipoprotein Profiles More Than Unmodified Free Phytosterols in Hypercholesterolemic Men and Women

Objective: Foods incorporating plant sterols (PS) consistently decrease serum low-density lipoprotein cholesterol (LDL-C), although results vary depending on the PS form and food matrix. The objective was to study the effect of a novel triglyceride-recrystallized phystosterol (TRP) incorporated into fat-free milk on markers of cardiovascular risk compared to unmodified free sterols alone in the same fat-free milk. Methods: Hypercholesterolemic men and women (n = 13 males/7 females; 56 ±10 years; body mass index 27.3 ±5.9 kg/m2) participated in 3 sequential 4-week phases of 480 mL milk consumption. During phase 1 (control) all subjects consumed 2% milk containing no PS, followed by phase 2 with fat-free milk containing free PS (2 g/d fPS) and phase 3 with fat-free milk with TRP (2 g/d). After each phase, determinations of lipoprotein cholesterol distribution, particle concentration via nuclear magnetic resonance (NMR), apolipoproteins, inflammatory markers, and fat-soluble dietary antioxidants were made. Results: Body mass, body composition, dietary energy and macronutrients, and physical activity were unaffected throughout the study. Compared to the control 2% milk, LDL-C was significantly (p < 0.05) decreased by fPS (−9.1%) and was further decreased by TRP (−15.4%); reductions with TRP were significantly greater. Total LDL particle concentration was decreased to a greater extent after TRP (−8.8%) than fPS (−4.8%; p < 0.05). Only TRP significantly decreased serum levels of apolipoprotein B (apoB; −6%), interleukin-8 (IL-8; −11%) and monocyte chemotactic protein-1 (MCP-1; −19%). Plasma α- and γ-tocopherols and carotenoids, normalized to cholesterol, remained unchanged throughout the study with the exception that β-carotene was lowered by 18%. Conclusion: In summary, TRP in fat-free milk may provide cardiovascular benefits beyond that of fPS by inducing more substantial decreases in LDL cholesterol and particle concentration, associated with declines in markers of vascular inflammation.

Milk production, fatty acid composition and vitamin E content of Payoya goats according to grazing level in summer on Mediterranean shrublands

Dietary intake of certain unsaturated fatty acids (FA), in particular conjugated linoleic acid (CLA) and omega-3 FA (n-3 FA), and fat-soluble antioxidants (e.g. α-tocopherol) has been linked to potential health benefits. Nevertheless, there is little information about how Mediterranean shrublands affect the fat composition and fat-soluble antioxidants of milk of dairy goats. The aim of this study was to evaluate the effect during the summer of different grazing levels on Mediterranean scrublands on milk production, milk FA profile and vitamin E content from Payoya goats. Eight farms were selected and data were collected monthly from June to October of 2010. Indicators for feeding management and productivity were obtained. The Percentage of the milking goat's net energy requirements obtained from grazing (NERG) was calculated. Farms were segregated in two groups according to the grazing level: high (HG, n=3) and medium grazing (MG, n=5). Whole milk was collected monthly from bulk tanks of the farms and analyzed for chemical composition, FA profile, α-tocopherol content and total antioxidant capacity (TAC). NERG differed between treatment groups and months (P<0.001 and P<0.05, respectively). No differences between groups were observed for the most studied chemical parameters. The percentages of C16:1 (P<0.01), C18:1 n-9 trans (P<0.05), C18:1 n-9 cis (P<0.05) and MUFA (P<0.01) were significantly higher and the total SFA significantly lower (P<0.01) in milk from MG farms compared with HG farms. In contrast, percentages of the nutritionally desirable FA (α-linolenic acid, C22:5 n-3, total n-3 PUFA) were significantly higher, while levels of total n-6 PUFA and n6:n3 ratio were significantly lower in milk from HG group. In addition, the percentages of NERG were correlated positively with the contents of several n-3 FA and negatively with the n-6 FA and n-6:n-3 ratio. CLA cis-9, trans-11 and CLA trans-10, cis-12 were not affected by grazing level. The short and long-chain FA showed significant variations during the period of study. HG farms showed significant higher α-tocopherol content in September (P=0.030) and October (P=0.025). The TAC levels did not significantly vary according to the grazing level and the month. In conclusions, the high grazing farms showed significantly higher levels of n-3 FA and α-tocopherol compared with the medium grazing farms, which are widely recognized as having beneficial effects on human health.

Vitamin E prevents high-fat high-carbohydrates diet-induced memory impairment: The role of oxidative stress

Memory and learning are impaired by imbalanced diet consumption. High-fat high-carbohydrate diet (HFCD) induces oxidative stress, which results in neuronal damage and interference with synaptic transmission; hence, a decline in cognitive function. Vitamin E is a fat soluble antioxidant that is believed to have positive effects on learning and memory. In this study, we tested the hypothesis that chronic administration of vitamin E prevents learning and memory impairment induced by HFCD. In addition, possible molecular targets for HFCD, and vitamin E that lead to cognitive effects were examined. Vitamin E and/or HFCD were concurrently administered to animals for 6weeks. Thereafter, behavioral studies were conducted to test the spatial learning and memory using radial arm water maze (RAWM). Additionally, brain derived neurotrophic factor (BDNF) level and antioxidant markers were assessed in the hippocampus. The results of this project revealed that HFCD impairs both short-term and long-term memories (p<0.05). The administration of vitamin E prevented the memory impairment induced by HFCD consumption (p<0.05). The consumption of HFCD reduced activities of hippocampal superoxide dismutase (SOD) and catalase (p<0.05); whereas the levels of thiobarbituric acid reactive substances (TBARS) and oxidized glutathione (GSSG) were elevated (p<0.05). The administration of vitamin E normalized the effect of HFCD on the oxidative stress markers. None of the treatments induced changes in the levels of BDNF or glutathione peroxidase (GPx). In conclusion, HFCD induces memory impairment, and the administration of vitamin E prevented this impairment probably through normalizing antioxidant mechanisms in the hippocampus.

Antioxidative, and Inhibitory Activities on Melanogenesis of Vitex negundo L. Leaf Extract

The aim of this study was to evaluate various aspects of Vitex negundo L. leaf extract, such as the antioxidative activity, tyrosinase inhibitory effects, and inhibitory activities on -MSH induced melanogenesis, and active component analysis. The DPPH (1, 1-diphenyl-2-picrylhydrazyl) scavenging activities () of the ethyl acetate fraction and aglycone fraction of V. negundo L. leaf extract were and , respectively. A luminol-dependent chemiluminescence assay revealed that the reactive oxygen species (ROS) scavenging activity () of the aglycone fraction of V. negundo L. leaf extract on ROS generated in an - system was the most prominent at . The protective effects of the extracts fractions of V. negundo L. leaf against the rose-bengal sensitized photohemolysis of human erythrocytes were increased in a concentration dependent manner (). In particular, there were greater protective effects of the aglycone fraction on the cellular membrane than that of the fat-soluble antioxidant (+)--tocopherol. The inhibitory effects () on mushroom tyrosinase were the highest for the ethyl acetate fraction ( = ). The inhibitory effect on -MSH induced melanogenesis in B16 melanoma cells was 41.80% at of ethyl acetate fraction. Active component analyses by TLC, HPLC and LC/ESI-MS revealed luteolin and isoorientin. These results indicate that V. negundo L. leaf extract can be used as an antioxidant for ROS scavenging. Particularly, the luteolin and isoorientin of the ethyl acetate fraction may be applicable to new whitening cosmetics because of its inhibitory effect on mushroom tyrosinase and -MSH induced melanogenesis in B16 melanoma cells.

АSSOCIATION BETWEEN OXIDATIVE-ANTIOXIDANT MODIFICATIONS OF LOW-DENSITY LIPOPROTEINS AND CORONARY HEART DISEASE IN A MALE POPULATION OF NOVOSIBIRSK

Aim. To investigate the association between potentially atherogenic oxidativeantioxidant modifications of low-density lipoproteins (LDL) and coronary heart disease (CHD) in a male population. Material and methods. A population-based survey included 1024 male residents ofNovosibirskCity, aged 47–73 years. The participants underwent a questionnaire survey, a standard cardiologic survey, anthropometry, blood pressure measurement, and electrocardiography. “Definite CHD” (Functional Class II–IV stable effort angina) was registered in 223 men (21,8%), according to validated epidemiologic, clinical, and functional criteria. Blood biochemistry analyses focused on the levels of total cholesterol (TCH), triglycerides (TG), high-density lipoprotein cholesterol (HDL–CH), high-sensitivity C-reactive protein (hsCRP), glucose, baseline levels of lipid peroxidation (LPO) products and fat-soluble antioxidants (alpha-tocopherol, retinol, beta-carotene, and xanthines) in LDL, LDL oxidation resistance in vitro, and an concentration of autoantibodies to oxidised LDL (oxLDL). Results. There were positive correlations and independent associations between the oxidative LDL modifications, in particular between reduced LDL oxidation resistance and CHD. On the other hand, there were negative correlations between the antioxidant LDL modifications (such as reduced alpha-tocopherol levels in LDL) and CHD. The prevalence of CHD was higher in participants with baseline levels of LPO products in LDL &gt;0,8 nM MDA/mg LDL protein and with reduced LDL oxidation resistance (baseline levels &gt;5,4 nM MDA/mg LDL protein vs. levels &gt;13,2 nM MDA/mg LDL protein at later stages of LDL oxidation). However, the prevalence of CHD was lower in individuals with LDL levels of alpha-tocopherol &gt;1,06 mg/mg LDL protein. Conclusion. These findings agree with the previously obtained data on the key role of oxidative LDL modifications in the pathogenesis of atherosclerosis and CHD.

^|^alpha;-Tocopherol Status and Expression of ^|^alpha;-Tocopherol Transfer Protein in Type 2 Diabetic Goto-Kakizaki Rats

Vitamin E, a critical fat-soluble vitamin antioxidant, is expressed on cell membranes and prevents propagation of lipid peroxidation. α-Tocopherol transfer protein (α-TTP) is a cytosolic protein located in the hepatocytes that acts as the principal regulator of the circulating α-tocopherol levels. Type 2 diabetes is a metabolic disorder characterized by hyperglycemia, caused by insulin resistance. Lipid peroxidation promotes the clinical progression and development of complications in type 2 diabetes. Results of animal and human experiments on the vitamin E status in diabetes are conflicting. The present study was conducted with the objective of investigating the vitamin E status and α-TTP expression in Goto-Kakizaki (GK) rats, a model of type 2 diabetes. In diabetic GK rats, increases of the α-tocopherol levels in the plasma and liver were observed as compared with the levels in the controls. No alternation in the CuZn-superoxide dismutase (SOD) or Mn-SOD gene expression was found in the liver of GK rats as compared with that in the controls. The GK rats showed an increase of the hepatic expression of the α-TTP gene as compared with the level in the controls. It can be suggested that the increased hepatic α-TTP gene expression levels may influence plasma α-tocopherol levels in the diabetic animals. Hence, investigation of the regulatory factors of α-TTP expression may provide important clues to highlighting the antioxidant mechanisms of vitamin E.

Relationships between a Thiol-Disulfide System and Liposoluble Antioxidants with Cytogenetic Indices in Humans Exposed to Low Doses Radiation

This work presents the results of biochemical examination of people exposed to irradiation as a result of the Chernobyl catastrophe. In remote period ( in 4, 5, 6 and 7 years) after Chernobyl accident we studied the state of the redox system of glutathione(GSH, GSSG) and the response of the system of essential lipid antioxidants (vitamin E, A) in blood plasma of people of various ages. An analysis of correlations between cytogenetic indices in lymphocytes and levels of reduced glutathione and liposoluble antioxidants in the plasma of peripheral blood in children born after the Chernobyl accident and liquidators is presented. The cumulative doses for the examined group of children received by their mothers from 0.8 to 70 cSv and liquidators received, on average, the highest irradiation doses from 0.1 to 150 cSv. A complex relationship between lipo-and water-soluble antioxidants level in plasma in human population (children living in radionuclide-contaminated regions and the Chernobyl liquidators) exposed to chronic low-level radiation after the Chernobyl accident was demonstrated. The obtained experimental data indicate different responses of the human population water-and fat-soluble antioxidants system to low (from 0.1 to 20 cSv) and high (from 20 to 150 cSv) doses of ionizing radiation.