Ferric Reducing Activity Of Plasma Research Articles

Apigetrin-enriched Pulmeria alba extract prevents assault of STZ on pancreatic β-cells and neuronal oxidative stress with concomitant attenuation of tissue damage and suppression of inflammation in the brain of diabetic rats

In the present study, in vitro, in vivo, and in silico models were used to evaluate the therapeutic potential of Pulmeria alba methanolic (PAm) extract, and we identified the major phytocompound, apigetrin. Our in vitro studies revealed dose-dependent increased glucose uptake and inhibition of α-amylase (50% inhibitory concentration (IC50)= 217.19 µg/mL), antioxidant (DPPH, ferric-reducing activity of plasma (FRAP), and lipid peroxidation (LPO) [IC50 = 103.23, 58.72, and 114.16 µg/mL respectively]), and anti-inflammatory potential (stabilizes human red blood cell (HRBC) membranes, and inhibits proteinase and protein denaturation [IC50 = 143.73, 131.63, and 198.57 µg/mL]) by the PAm extract. In an in vivo model, PAm treatment reversed hyperglycemia and attenuated insulin deficiency in rats with streptozotocin (STZ)-induced diabetes. A post-treatment tissue analysis revealed that PAm attenuated neuronal oxidative stress, neuronal inflammation, and neuro-cognitive deficiencies. This was evidenced by increased levels of antioxidants enzymes (superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH)), and decreased malondialdehyde (MDA), proinflammatory markers (cyclooxygenase 2 (COX2), nuclear factor (NF)-κB and nitric oxide (NOx)), and acetylcholinesterase (AChE) activities in the brain of PAm-treated rats compared to the STZ-induced diabetic controls. However, no treatment-related changes were observed in levels of neurotransmitters, including serotonin and dopamine. Furthermore, STZ-induced dyslipidemia and alterations in serum biochemical markers of hepatorenal dysfunction were also reversed by PAm treatment. Extract characterization identified apigetrin (retention time: 21,227 s, 30.48%, m/z: 433.15) as the major bioactive compound in the PAm extract. Consequently, we provide in silico insights into the potential of apigetrin to target AChE/COX-2/NOX/NF-κB Altogether the present study provides preclinical evidence of the therapeutic potential of the apigetrin-enriched PAm extract for treating oxidative stress and neuro-inflammation associated with diabetes.

Antioxidant, Antimicrobial Activities, and Characterization of Phenolic Compounds of Thyme (Thymus vulgaris L.), Sage (Salvia officinalis L.), and Thyme–Sage Mixture Extracts

The antioxidant properties of sage (Salvia officinalis L.) and thyme (Thymus vulgaris L.), and their mixtures were examined using the 2,2-Diphenyl-1-picrylhydrazyl (DPPH•) scavenging activity and ferric-reducing activity of plasma (FRAP) methods. The antimicrobial activity of the plant extracts against four bacterial strains (Escherichia coli, Staphylococcus aureus, Bacillus cereus, and Salmonella typhomorium) was determined using the agar well diffusion method. Results showed the highest overall rate of increase in total phenolic (13.67 mg·GAE/g·DW), and flavonoid (6.75 mg·QUE/g·DW) contents in the thyme–sage mixture extract compared with the thyme and sage extracts. As found by GC-MS analysis of methanolic extracts, thymol, apigenin, rosmarinic acid, and carvacrol were the most abundant phenolic compounds in the thyme–sage extract. The lowest EC50 (DPPH•, 55.51 μg·ml−1) and the highest FRAP value (95.51 mM Fe (II) mg−1 extract) were recorded in the extract of the thyme–sage mixture compared with sage and thyme extracts, and butylated hydroxytoluene solution (BHT). The highest antimicrobial activity against E. coli, S. aureus, B. cereus, and S. typhomorium was observed in the thyme–sage mixture with the inhibition zone diameters of 22.13, 28.67, 31.25, and 23.65 mm, respectively. It is concluded that the extract obtained from the thyme–sage mixture has more potential to be used in the pharmaceutical and food industry as a natural antibacterial and antioxidant agent.

Repetitions of Strenuous Exercise Consistently Increase Paraoxonase 1 Concentration and Activity in Plasma of Average-Trained Men.

Objectives Oxidative stress, induced by physical activity, may stimulate the expression, release, and activity of certain antioxidant enzymes. We investigated the effect of three repeated bouts of strenuous exercise on paraoxonase 1 concentration (PON1c) and paraoxonase activity (PON). Methods Eleven average-trained healthy men (age 34.0 ± 5.2 years) performed three strenuous exercise tests on a treadmill separated by 72 hours periods of resting. PON1c, PON, ferric-reducing activity of plasma (FRAP), lipid profile, C-reactive protein concentration (CRP), and lactate concentration were determined in plasma. Results Each exercise bout resulted in similar PON1c, PON, FRAP, and high-density lipoprotein concentration (HDL-C) increments, while PON/HDL-C ratio remained stable in all repetitions. Percentage increments at the bout of each exercise were higher for PON1c (by 64.82% at the first, by 92.9% at the second, and by 77.02% at the third exercise) than for PON (by 6.49% at the first, 10.06% at the second, and by 12.32% at the third exercise). Association was found between preexercise PON and PON1c (r = 0.56, p = 0.029), pre- (r = 0.87, p = 0.00003) and postexercise HDL-C (r = 0.6, p = 0.0002), preexercise PON and cardiovascular fitness level of participants measured as VO2max (r = 0.39, p = 0.026), and postexercise PON and lactate concentration (r = 0.44, p = 0.01). Conclusions PON1c and PON increase during strenuous exercise, yet the effect of exercise on PON1 concentration is more pronounced. PON1 does not show tolerance to physical activity. The enzyme may provide short-term protection from oxidative stress in each exercise bout. PON may depend on exercise load. Cardiovascular fitness levels may be associated with PON1 activity.

Examination the antioxidant potentials and antidiabetic properties of phenolic extracts of some Iranian honeys

Introduction: In most ancient cultures, honey has been used for both nutritional and medical purposes. Objectives: In this research, phenolic extracts of four Iranian honeys were evaluated to determine the antioxidant potentials using DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging, nitric oxide (NO) radical scavenging and reducing power by ferric reducing activity of plasma (FRAP) method. Additionally, anti-diabetic properties of honey and phenolic extracts were evaluated by determination of α-amylase and α-glucosidase inhibition. Patients and Methods: Besides, reducing potential was evaluated by ferric-reducing antioxidant power method. Moreover, determination of phenolic and flavonoid contents was performed. Moreover, inhibition of α-amylase and α-glucosidase of honey and phenolic extracts were evaluated. Results: With considering to antioxidant potentials, Gavan (Astragalus) sample showed the greatest phenolic (3817±1.52 mg GAE/100 g), flavonoid contents (3.1±0.005 mg QE/100 g), and DPPH radical scavenging (IC50 = 2±0.003 mg/mL). Bahareh honey had the highest NO radical scavenging (IC50=0.0403±0.0009 mg/mL) and Meymand honey possessed the highest reducing potential by FRAP method (IC50=0.0018±0.000003 mg/mL). The maximum inhibition of α-glucosidase was shown in Meymand honey extract (46±0.1%). After sugar isolation, Zataria honey had the highest inhibition of α-glucosidase (54±0.6%) and the mode of α-amylase inhibition was noncompetitive by this honey. Whole extract (23±0.1%) and phenolic extract of Gavan honey presented the maximum inhibition of α-amylase (31.2±0.1%). Conclusion: Honey samples showed antioxidant potentials and anti-diabetic properties by retardation of α-amylase and α-glucosidase.

Salivary Biomarkers and Their Correlation with Pain and Stress in Patients with Burning Mouth Syndrome.

Objective: To evaluate a panel of salivary analytes involving biomarkers of inflammation, stress, immune system and antioxidant status in patients with burning mouth syndrome (BMS) and to study their relationship with clinical variables. Materials and Methods: A total of 51 patients with BMS and 31 controls were consecutively enrolled in the study, with the recording of oral habits, the severity of pain using a visual analogue scale (VAS), the Hospital Anxiety and Depression (HAD) score and the Oral Health Impact Profile-14 (OHIP14) score. Resting whole saliva was collected with the drainage technique, followed by the measurement of 11 biomarkers. Results: The salivary flow was higher in patients with BMS. Among all the biomarkers studied, significantly higher levels of alpha-amylase, immunoglobulin A (IgA), and macrophage inflammatory protein-4 (MIP4) and lower levels of uric acid and ferric reducing activity of plasma (FRAP) were observed in the saliva of patients with BMS as compared to the controls (p < 0.05 in all cases). Positive correlations were found between pain, oral quality of life and anxiety scores and salivary biomarkers. Conclusions: BMS is associated with changes in salivary biomarkers of inflammation, oxidative stress and stress, being related to the degree of pain and anxiety.

Cladribine Treatment Improved Homocysteine Metabolism and Increased Total Serum Antioxidant Activity in Secondary Progressive Multiple Sclerosis Patients.

Hyperhomocysteinemia plays a crucial role in the pathogenesis of many diseases of the central nervous system (CNS). The nervous system is particularly sensitive to high homocysteine (Hcy) level mainly due to its prooxidative and cytotoxic effects. Cladribine, a drug recently registered for the treatment of multiple sclerosis (MS), possesses additionally neuroprotective effects which are independent of its peripheral immunosuppressant action. Accumulating evidence suggests that oxidative stress and homocysteine thiolactone-mediated protein homocysteinylation play a causal role in MS. Both of these processes may be attenuated by paraoxonase 1 (PON1). Therefore, in the present study, we aimed to examine whether the beneficial effects of the drug in MS patients with a secondary progressive (SP) clinical course, treated with cladribine subcutaneously (s.c.), may be related to its ability to modify serum PON1 activity, Hcy concentration, and protein homocysteinylation, as well as to correct total antioxidant status. A total of 118 subjects were enrolled into the study: (1) patients with a SP type of MS, SP-MS (n = 40); (2) patients with a relapsing-remitting (RR) type of MS, RR-MS (n = 30); and (3) healthy people (n = 48). Patients with SP-MS were treated with cladribine. The drug was given in SP-SM patients s.c. six times every 6 weeks up to a total mean cumulative dose of 1.8 mg/kg. PON1 activity was assessed spectrophotometrically. The level of Hcy, homocysteine thiolactone (HTL) attached to plasma proteins (N-Hcy-protein), and antibodies against homocysteinylated proteins was assessed with an enzyme immunoassay. The total antioxidant activity of the serum was assessed with the ferric-reducing activity of plasma (FRAP) method. Basically, there was no difference in PON1 activity between untreated SP-MS, RR-MS, and control subjects. Serum Hcy was significantly higher in RR-MS patients (p < 0.001) and in SP-MS patients (p < 0.01) compared to the control group. The N-Hcy protein level was higher in RR-MS patients (p < 0.05) in comparison to the control group. Moreover, the elevated level of antibodies against homocysteinylated proteins was observed in the serum of patients with SP-MS. The total antioxidant capacity of serum was lower in MS patients vs. the control group (p < 0.001). After cladribine treatment, the activity of PON1 did not change in SP-MS patients, whereas cladribine treatment decreased the level of total Hcy (p < 0.05). Treatment with cladribine increased the total serum antioxidant activity in SP-MS patients (p < 0.01). The Expanded Disability Status Scale (EDSS) score did not change in SP-MS patients. Cladribine treatment in the SP-MS group attenuates hyperhomocysteinemia-induced protein homocysteinylation (n.s.). It also stabilises the neurological condition of SP-MS patients. The stabilisation of a neurological condition observed in SP-MS patients after cladribine treatment may be partially related to its ability to reduce elevated Hcy level and to improve serum antioxidant potential.

복숭아 품종별 핵과 종자의 항염증 및 항산화 효과간의 상관관계

Peach seeds contain a large amount of phenolic components and exhibit excellent physiological effects in various diseases. We examined the antioxidant effects of stone and seed of three peach cultivars (Miwhang, MH; Kanoiwa hakuto, KH; and Cheonhong, CH) by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, ferric reducing activity of plasma (FRAP) assay, and cupric ion reducing antioxidant capacity (CUPRAC) reduction. The results showed that the stone extracts of CH had higher levels of total phenols and flavonoids than those of the other cultivars do, and the stone extracts of KH and CH have the potential to reduce DPPH, FRAP, and CUPRAC activities. In addition, we found that KH, MH, and CH stone extracts decreased nitric oxide generation in RAW 264.7 and BV2 cells. The total phenol and flavonoid contents had no significant correlation with anti-oxidant activities. On the other hand, the anti-inflammatory activity had a low linear correlation with anti-oxidant activities and total phenol and flavonoid contents. The present results suggest that the correlation between antioxidant and anti-inflammatory effects of stone and seed, and the appropriate combination of the stone and seed extracts could be used as an anti-inflammatory treatment and prevention material, respectively.

Xanthine oxidase activity in patients with age-related cataract associated with hypertension.

Reactive oxygen species and lipid peroxidation are important factors that contribute to the development of age-related cataract. The study included 130 patients with age-related cataract, 69 of whom were diagnosed with hypertension (HT), 20 with hypertension and type 2 diabetes mellitus (DM), and 41 had no accompanying condition. The following parameters were measured in the serum of the examinees: products of lipid peroxidation malondialdehyde (MDA) and lipofuscin-like fluorophores (LLF), activity of prooxidative enzymes xanthine oxidase (XO) and myeloperoxidase (MPO), antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx), the concentration of thiol groups, and the ferric reducing activity of plasma. The activity of prooxidative enzymes XO and MPO was higher in the plasma of patients with HT (XO=9.0±1.2 U/L; MPO=77.3±8.4 U/L) and with HT and DM (XO=11.9±0.9 U/L; MPO=89.5±5.0 U/L) compared to patients with age-related cataract (XO=6.2±0.9 U/L; MPO=52.4±6.3 U/L; P<0.01). Our research has shown that patients with age-related cataract and hypertension were exposed to increased oxidative damage of biomolecules, based on the increased plasma LLF and MDA content and decreased levels of thiol groups. Oxidative changes of biomolecules in these patients were associated with increased activity of the XO, MPO, and GPx enzymes and a lower extracellular SOD activity and total ferric reductive ability of plasma.

Influence of varied metabolizable energy levels on antioxidant status and performance of transition Murrah buffaloes

Present experiment was conducted to study the effect of varied levels of metabolizable energy (ME) on performance and antioxidant status of Murrah buffaloes. Advance pregnant Murrah buffaloes (n=16) were randomly divided into three experimental groups i.e., 5, 5 and 6 animals in LME, MME and HME, respectively on the basis of most probable production ability (MPPA) and lactation number. They were fed graded levels of ME, namely low metabolizable energy (LME), medium metabolizable energy (MME), high metabolizable energy (HME) which is 85, 100 and 115 percent of ICAR, 2013 requirements for 130 days, duration i.e., 40 day prepartum to 90 days postpartum. Animals in group LME, MME and HME were offered concentrate with metabolizable energy content (MJ/kg DM) 11.80, 12.18, and 13.85, respectively. Green fodder (maize) and dry roughage (wheat straw) were fed as per the experimental protocol. No significant effect on dry matter intake (DMI), crude protein (CPI) and metabolizable protein (MPI) (% BW) were observed due to dietary variation in ME. ME intake (MJ/100 kg BW) before and after calving was statistical (P&gt;0.05) higher in HME (15.01, 24.66) followed by MME (14.07, 22.11) and LME (12.33, 19.16) groups, respectively. Significant (P&gt;0.05) higher milk yield efficiency (kg/kg DMI) and 6% FCM (kg/kg DMI) were observed in MME in comparison to HME group. The antioxidant profile revealed no significant influence of dietary treatment on superoxide dismutase (SOD) and ferric reducing activity of plasma (FRAP) whereas significant (P&gt;0.05) lower level of antioxidant status i.e., glutathione peroxidase (GPx) (µmol/L) in HME (1834.60) than LME (2240.23) was observed. Considering optimum production performance and similar antioxidant activity among treatment groups, it can be concluded that ICAR, 2013 recommendations are suitable for feeding transition Murrah buffaloes.

Effects of the Dietary Addition of Amaranth (Amaranthus mantegazzianus) Protein Isolate on Antioxidant Status, Lipid Profiles and Blood Pressure of Rats.

The effects of the dietary addition of 2.5% (w/w) Amaranthus mantegazzianus protein isolate (AI) on blood pressure, lipid profiles and antioxidative status of Wistar rats were evaluated. Six diets were used to feed animals during 28 days: (base (AIN93G), Chol (cholesterol 1%, w/w), CE (α-tocopherol 0.005%, w/w), CholE (cholesterol 1% (w/w) + α-tocopherol 0.005%, w/w), CAI (AI 2.5% w/w), CholAI (cholesterol 1% (w/w) + AI 2.5%, w/w). Lipid profiles of plasma and liver and faecal cholesterol content were analyzed. Antioxidant status was evaluated by the ferric reducing activity of plasma (FRAP), the 2-thiobarbituric acid (TBA) assay and superoxide dismutase (SOD) activity in plasma and liver. Blood pressure was measured in the tail artery of rats. CholA group presented a significant (α < 0.05) reduction (16%) in the plasma total cholesterol. In liver, the intake of cholesterol (Chol group) induced a significant increment in cholesterol and triglycerides (2.5 and 2.3 times, respectively), which could be decreased (18% and 47%, respectively) by the addition of AI (CholA group). This last group also showed an increased faecal cholesterol excretion (20%). Increment (50%) in FRAP values, diminution of TBA value in plasma and liver (70% and 38%, respectively) and diminution of SOD activity (20%) in plasma of CholA group suggest an antioxidant effect because of the intake of AI. In addition, CA and CholA groups presented a diminution (18%) of blood pressure after 28 days.

Effect of exercise on plasma paraoxonase1 activity in rugby players: Dependance on training experience

ObjectivesThere are conflicting data on the influence of physical activity on paraoxonase1 (PON1) activity. The purpose of this study is to investigate the effect of maximal exercise (ME) on plasma paraoxonase (PON) and arylesterase (ARE) activity in elite rugby players. In addition, the influence of training experience and PON1 Q192R polymorphism on PON1 activity changes at ME was evaluated.MethodsTwenty-five elite rugby players ages 22.0 ± 3.71 years, consisting of 11 juniors – J (2–7 years of training) and 14 seniors – S (8–15 years of training), completed ME on a cycle ergometer. PON and ARE activity, ferric reducing activity of plasma (FRAP), uric acid (UA), and total bilirubin concentration, as well as thiobarbituric acid reactive substances and lipid profile were investigated in the plasma before, at the bout, and 30 minutes after ME.ResultsAt the bout of ME we found an increase in PON1 activities, ARE/high-density lipoprotein C ratio, TBil, and TChol. However, ARE activity changes were not observed in the group of rugby players training for ≤7 years. FRAP and UA increased later – 30 minutes after ME.ConclusionWe conclude that in rugby players PON1 changes during ME depend on age, body composition, and training experience. The influence of PON1 Q192R polymorphism on PON1 changes at ME remains debatable.

Antioxidant and antiapoptotic properties of chlorogenic acid on human umbilical vein endothelial cells

Chlorogenic acid (CGA) is one of the phenols isolated from Lonicera japonica Thumb. This study was designed to investigate whether CGA prevents human umbilical vein endothelial cells (HUVECs) from hydrogen peroxide (H2O2)–induced damage. The cell viability was examined by methylthiazolyl tetrazolium (MTT) assay. Malondialdehyde (MDA) level was measured using the thiobarbituric acid method. Reactive oxygen species (ROS) levels were determined using the 2',7'-dichlorofluorescin-diacetate (DCFH-DA) assay. The antioxidant enzymes activities, including glutathione peroxidase (GPx) and superoxide dismutase (SOD) were examined photometrically. Total antioxidant capacity (T-AOC) was measured using the ferric reducing activity of plasma (FRAP) assay. Apoptotic cells were detected by terminal deoxyribonucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL), annexin-V binding and by assessment of caspase-3. Protein and mRNA expression of Bax and Bcl-2 were determined by western blot and reverse transcription-polymerase chain reaction (RT-PCR). In the process of H2O2-induced damage, the expression of Bcl-2 was decreased and the expression of Bax was increased. The antioxidant enzymes activities and T-AOC levels were decreased. The content of MDA and the level of ROS were increased. Pretreatment with CGA significantly reduced oxidative stress by increased T-AOC levels and antioxidant enzymes activities, decreased ROS levels and lipid peroxidation. CGA significantly reduced apoptosis by up-regulation the expression of Bcl-2 and down-regulation the expression of Bax. Taken together, these results suggest that CGA exhibits antioxidant and antiapoptotic properties to prevent H2O2-induced cytotoxicity in HUVECs. Key words: Chlorogenic acid, human umbilical vein endothelial cells (HUVECs), hydrogen peroxide, oxidative stress, apoptosis.

Comparison of oxidative stress among migraineurs, tension-type headache subjects, and a control group.

Background:A primary headache, particularly migraine, is associated with oxidative stress during the attack. However, data regarding the interictal state in migraineurs and in those with tension-type headache (TTH) is limited.Objectives:(1) To assess the oxidative stress in migraineurs and TTH subjects in between the episodes and (2) to see if there is a difference in the degree of oxidative stress in the different subtypes of migraine and TTH.Materials and Methods:Fifty migraineurs, 50 patients with TTH, and 50 control subjects were included in this study after screening for the exclusion criteria. Diagnosis of headache was made according to the International Classification of Headache Disorders (ICHD)-2 criteria. A venous blood sample was collected from the antecubital vein at least 3 days after the last attack of headache. The sample was centrifuged immediately and the plasma was stored at –70°C. The ferric reducing activity of plasma (FRAP) and the malondialdehyde (MDA) levels were assessed using colorimetric methods. Statistical analysis was done with the help of SPSS for Windows, v 11.0. One way ANOVA with post hoc Tukey test, independent sample t test, univariate regression, and multivariate regression analysis were done as indicated.Results:Migraineurs had higher values of MDA and FRAP than the subjects in the other two groups (P<0.001). No difference was observed between the TTH group and the control group. FRAP levels were significantly higher in subjects who had mixed migraine (migraine with aura and without aura) as compared to those with only migraine without aura (mean difference 196.1; 95% CI = 27.3 to 364.9; P = 0.01). Similarly, oxidative stress was significantly higher in patients with episodic TTH as compared to those with chronic TTH (FRAP t = 3.16; P = 0.003 and MDA t = 2.75; P = 0.008).Conclusions:This study suggests that oxidative stress continues even between headache episodes in migraineurs but not in those with TTH. This could probably be consequent to the different pathophysiological mechanisms of TTH and migraine.

Occupational exposure to mineral fibres. Biomarkers of oxidative damage and antioxidant defence and associations with DNA damage and repair

In order to study the effect of mineral wool exposure on oxidative DNA damage and lipid peroxidation, an epidemiological study was conducted in a mineral wool factory in Slovakia. Altogether 141 subjects were investigated (21-58 years old), 43 controls (20 men and 23 women: 27 non-smokers, 16 smokers) and 98 exposed (75 men and 23 women: 61 non-smokers, 37 smokers). We found higher malondialdehyde (MDA) levels in the group of all exposed workers (P = 0.025) and in exposed non-smokers (P = 0.003) and a significantly suppressed activity of ceruloplasmin oxidase (P = 0.02, P < 0.02, respectively) and catalase (CAT) (P = 0.04, P = 0.01, respectively) in these groups. The activity of glutathione S-transferase (GST) was affected by exposure to mineral wool; levels were significantly lower in all exposed subjects (P = 0.04), in the exposed non-smokers (P = 0.03) and in exposed men (P < 0.01). Concentrations of vitamin C in plasma and the ferric-reducing activity of plasma (FRAP) were not affected by the mineral wool exposure. There was a significant negative correlation between the activity of glutathione peroxidase (GPX) and MDA in the whole group (P < 0.01) and in the exposed group and between CAT activity and MDA in all subjects (P < 0.01). GST activity correlated inversely with oxidized pyrimidines in lymphocyte DNA, in almost all subgroups. We found significant negative correlations between DNA repair and GPX in all subjects (P = 0.03) as well as in control men (P < 0.03) and between DNA repair and CAT in all control subjects (P < 0.02) and in control men (P < 0.01). Interestingly, we found a positive correlation between DNA repair and MDA in all subjects (P < 0.01) and in all exposed subjects (P < 0.03). The presented results indicate that mineral wool exposure induces an increase in oxidative damage to biomolecules especially in the group of male non-smokers. However, optimal levels of antioxidants could have a protective effect. Biomarkers such as MDA, antioxidant enzymes and antioxidant vitamins measured in blood may be useful biomarkers of oxidative stress and antioxidant protection. We do not recommend FRAP as a marker of antioxidant status as interference from other constituents can provide false or confusing results. Our study supports the idea that there might also be other mechanisms by which antioxidant enzymes (especially GST) protect cells against oxidative DNA damage.

ENVIRONMENTAL EFFECT ON ANTIOXIDANT CONTENT OF TEN RASPBERRY CULTIVARS

ENVIRONMENTAL EFFECT ON ANTIOXIDANT CONTENT OF TEN RASPBERRY CULTIVARS

Estimate of antioxidant capacity and lipid peroxidation in plasma of healthy subjects

Abstract Serum contains various antioxidant molecules that may provide important protection against free radical attack. The aim of this work was to assess the total antioxidant capacity of plasma and a marker of lipid per oxidation [(thiobarbituric acid-reactive substances (TBARS)] in plasma of healthy smoking and non-smoking young and elderly subjects. In addition, we investigated plasma concentrations of α-tocopherol, β-carotene, and ascorbic acid. In in vitro experiments, the effects of exogenous compounds (ascorbic acid, uric acid, Trolox) on total ferric-reducing activity of plasma (FRAP) were also tested. We demonstrated that total antioxidant capacity of plasma obtained from healthy non-smoking young subjects was significantly higher than plasma antioxidant capacity of smoking elderly subjects. The concentration of TBARS in young non-smoking volunteers was lower than that in young smokers. The concentration of TBARS in elderly non-smoking volunteers was lower than in elderly smokers. Plasma concentrations of alpha-tocopherol, beta-carotene and ascorbic acid were significantly lower in elderly smoker than in elderly non-smokers of the same age. No difference in the plasma levels of alpha-tocopherol, beta-carotene and ascorbic acid were found in 22-year-old smoking and non-smoking subjects. In vitro addition of ascorbic acid, uric acid, or Trolox to plasma samples significantly increased their total antioxidant capacity. Decrease of FRAP values and increase of TBARS concentrations is a significant physiologic condition of the aging process. Supplementation of antioxidants could be useful for the enhancement of antioxidant screen in plasma.

Different antioxidants status, total antioxidant power and free radicals in essential hypertension

Hypertension is a multi-factorial process, prevalent in developed as well as in developing countries. Different antioxidants and free radicals play an important role in cardiovascular system. In present study, total antioxidant power in terms of FRAP (ferric reducing activity of plasma), free radicals and different antioxidants have been studied in essential hypertensives (n = 50) and normal subjects (n = 50). Levels of total cholesterol, low-density lipids-cholesterol, malonialdehyde, very low-density lipids (VLDL), uric acid, plasma homocysteine and low-density lipids (LDL), were significantly higher in hypertensives as compared to normotensive. HDL-cholesterol, SOD, GPx, reduced glutahione, total glutathione, oxidized glutathione, total thiols, protein thiols, non protein thiols, RNI, total antioxidant power, vitamin A, ascorbic acid and glutahione-S-transferase (GST) were decreased significantly in normotensive. We observed significantly low nitric oxide levels in hypertensive patients. No correlation was observed between severity of disease and plasma nitric oxide levels. There was a significant decrease in plasma FRAP value in essential hypertensives as compared to normotensive controls, which showed a negative correlation with diastolic blood pressure. In conclusion, our study revealed that there was a consistent significant difference between essential hypertensives versus controls with respect to most of the parameters. These complex changes are consistent in the view that essential hypertension is associated with an abnormal level of antioxidant status compared to normal response to oxidative stress or both.