LOOH Levels Research Articles

The effect of yeast Yarrowia lipolytica on the antioxidant indices and macro-and microelements in blood plasma of turkey hens.

The aim of the study was to assess the effect of different amounts of Yarrowia lipolytica yeast on the redox response and content of macro- and microelements in the blood plasma of turkey hens. The experiment was carried out on 240 turkey hens aged from 1 to 16 weeks. The birds were randomly assigned to 3 experimental groups of 80 birds each. Group I served as a control (K) and did not receive any experimental compounds. The turkey hens from the experimental groups (YL3 and YL6) were administered dried Yarrowia lipolytica yeast in their feed mixtures in the amount of 3% (YL3) or 6% (YL6). Yarrowia lipolytica yeast in the feed mixtures for the turkey hens did not induce oxidation reactions in the organism of the birds. However, an increase in catalase activity and a reduction in the level of LOOH, MDA and vitamin C were observed in the blood plasma of the turkey hens whose diet was supplemented with YL yeast. In the case of other indices, such as superoxide dismutase activity and total antioxidant potential (FRAP), the additive caused no significant changes. Administering Yarrowia lipolytica yeast to turkey hens may stimulate the enzymatic response of the antioxidant system (e.g. increasing catalase activity), mainly by increasing the concentration of iron in the plasma.

Serum paraoxonase and arylesterase activities in patients with chronic otitis media

Objectives: Paraoxonase-1 (PON1) prevents oxidative stress by inhibiting the oxidation of cell membrane lipids by the reactive oxygen species that form during acute and chronic inflammation. The aim of this study was to investigate serum PON1 activity and oxidative stress in patients with chronic otitis media (COM).Methods: Fifty consecutive patients with COM and 55 controls were enrolled in the present study. The patients were divided into two groups according to the presence of cholesteatoma. The serum PON1 arylesterase activities and lipid hydroperoxide (LOOH) levels were determined.Results: Serum paraoxonase and arylesterase activities were significantly lower in the COM patients than in the controls (P < 0.001 for all comparisons), whereas the LOOH levels were significantly higher (P < 0.001).Discussion: These results indicated that a lower level of PON1 activity was associated with an oxidant–antioxidant imbalance. In addition, decreased PON1 activity may play an important role in the pathophysiology of COM.

OXIDIZED LIPIDS DID NOT REDUCE LIFESPAN IN THE FRUIT FLY, Drosophila melanogaster

Aging is often associated with accumulation of oxidative damage in proteins and lipids. However, some studies do not support this view, raising the question of whether high levels of oxidative damage are associated with lifespan. In the current investigation, Drosophila melanogaster flies were kept on diets with 2 or 10% of either glucose or fructose. The lifespan, fecundity, and feeding as well as amounts of protein carbonyls (PC) and lipid peroxides (LOOH), activities of superoxide dismutase (SOD), catalase, glutathione-S-transferase (GST), and glutathione reductase activity of thioredoxin reductase (TrxR) were measured in "young" (10-day old) and "aged" (50-day old) flies. Flies maintained on diets with 10% carbohydrate lived longer than those on the 2% diets. However, neither lifespan nor fecundity was affected by the type of carbohydrate. The amount of PC was unaffected by diet and age, whereas flies fed on diets with 10% carbohydrate had about fivefold higher amounts of LOOH compared to flies maintained on the 2% carbohydrate diets. Catalase activity was significantly lower in flies fed on diets with 10% carbohydrates compared to flies on 2% carbohydrate diets. The activities of SOD, GST, and TrxR were not affected by the diet or age of the flies. The higher levels of LOOH in flies maintained on 10% carbohydrate did not reduce their lifespan, from which we infer that oxidative damage to only one class of biomolecules, particularly lipids, is not sufficient to influence lifespan.

Evidence of gastric ulcer healing activity of Maytenus robusta Reissek: In vitro and in vivo studies

Ethnopharmacological relevanceMaytenus robusta Reissek (Celastraceae) is traditionally used in Brazilian folk medicine to treat gastric ulcer, as a substitute for M. ilicifolia, which is almost extinct. The gastroprotective properties of M. robusta were demonstrated previously using only preventive approaches, such as acute gastric ulcer models. However, the healing effect of M. robusta in gastric ulcers remains unclear. Aim of the studyThe current study was carried out to investigate the healing effectiveness of M. robusta hydroalcoholic extract (HEMR) from aerial parts in the acetic acid-induced chronic ulcer model and to determine its effect on cell proliferation, scavenging free radicals, and inflammatory and oxidative damage. Material and methodsTo evaluate the healing properties of HEMR in vivo, chronic gastric ulcer was induced in rats by 80% acid acetic. Next, different groups of animals (n=6) were treated orally with vehicle (water plus 1% tween, 1ml/kg), omeprazole (20mg/kg), or HEMR (1–10mg/kg), twice daily for 7 days. At the end of the treatment, the total ulcer area (mm2) was measured and a sample of gastric tissue was taken for histological and histochemical analysis. Evaluation of GSH and LOOH levels, GST, SOD, CAT and MPO activity was also performed at the site of the lesion. In parallel, radical scavenging activity, cytoprotective effect, and cell proliferation activity in fibroblasts (L929 cells) were determined by in vitro trials. The antisecretory properties were evaluated using the pylorus ligature model in rats, and the anti-Helicobacter pylori activity was determined in vitro. Acute toxicity was evaluated by relative organ weight and biochemical parameters in serum. The prokinetic properties were also evaluated in mice. ResultsOral administration of HEMR (10mg/kg) reduced the gastric ulcer area by 53%, compared to the vehicle group (120.0±8.3mm2), the regeneration of gastric mucosa was evidenced in histological analysis. Moreover, HEMR treatment increased gastric mucin content and reduced oxidative stress and inflammatory parameters at the site of the ulcer. In vitro, HEMR (1–1000µg/ml) was able to scavenge free radical DPPH and promote cytoprotection against H2O2 in fibroblasts at 0.1–100µg/ml. Moreover, HEMR healing properties also were confirmed by enhancement of proliferation and coverage of scratched wounds in fibroblast monolayer. However, HEMR (10mg/kg) by the intraduodenal route did not promote changes in volume, pH, total acidity or pepsin activity in the pylorus ligature model, and HEMR up to 2000µg/ml also did not present considerable activity against H. pylori. In relation to gastrointestinal motility, HEMR (10mg/kg, p.o) did not provoke alterations. It is also important to mention that oral administration of HEMR did not produce any sign of acute toxicity in animals. ConclusionsThe data here obtained show that M. robusta has evident ulcer healing potential, mainly through the strengthening of protective factors of gastric mucosa, such as mucus layer, antioxidant defenses and cell proliferation. Taking into account the advantages of cultivation and harvesting of M. robusta compared to M. ilicifolia, and the evidence presented here, it is plausible to conclude that hydroalcoholic extract obtained from aerial parts of M. robusta is an interesting source for the development of a phytotherapeutic formulation to treat gastric ulcer.

Antidepressant-like effect of quercetin in bulbectomized mice and involvement of the antioxidant defenses, and the glutamatergic and oxidonitrergic pathways

Olfactory bulbectomy (OB) is an animal model of depression that can mimic symptoms that are characteristic of depressive patients, such as behavioral, neurochemical and neuromorphological changes. Quercetin decreased the immobility time in the forced swimming test and tail suspension test. With the open field test, quercetin did not alter the locomotor activity of mice and in the splash test, quercetin increased the time spent grooming. The repeated treatment with quercetin (25mg/kg, for 14days) reversed the behavioral hyperactivity induced by OB in the open field test and was able to prevent depressant-like effects in the forced swimming test and tail suspension test. Regarding oxidative stress, OB reduced the levels of glutathione and increase the activity of superoxide dismutase and lipid hydroperoxide content (LOOH) in the hippocampus. Only the increase in LOOH levels was reversed by treatment with quercetin. In a further series of experiments with non-bulbectomized mice, the antidepressant effect of quercetin in the tail suspension test was reversed by the pretreatment of mice with NMDA, l-arginine or sildenafil. The administration of methylene blue and 7-nitroindazole, in combination with an underactive dose of quercetin (5mg/kg, p.o.), decreased the immobility time in the tail suspension test compared with the use of drug alone. There was no significant change in locomotor activity in the open field test. Our results suggest that the antidepressant effect of quercetin is dependent on the inhibition of the NMDA receptors and/or synthesis of nitric oxide. In addition, considering the reduction of LOOH levels on the hippocampus, we verify that the antioxidant effects of quercetin also contribute to its antidepressive potential. These data contribute to the understanding of the mechanisms involved in the antidepressant effect of quercetin and reinforce the involvement of the NMDA receptors and the nitric oxide on the pathophysiology of depression.

Oxidative stress in drug naïve first episode psychosis and antioxidant effects of risperidone

BackgrooundSchizophrenia is accompanied by increased lipid peroxidation and nitric oxide (NO) levels and by lowered antioxidant levels. However, the effect of antipsychotic agents on these processes remains unclear. The objective of this study is to determine the oxidative stress (OS) status in drug naïve first-episode psychotic patients (FEP) compared to healthy controls and to delineate the effects of risperidone on these biomarkers. Methods51 drug naive FEP patients and 61 healthy controls were enrolled; FEP patients were reassessed 11 weeks after risperidone treatment. Three OS biomarkers, i.e. lipid hydroperoxides – LOOH, NO metabolites – NOx, and advanced oxidation protein products – AOPP, and two antioxidant biomarkers, i.e. total radical-trapping antioxidant parameter – TRAP, and paraoxonase 1 – PON1, were measured. The Positive and Negative Syndrome Scale (PANSS) and the Calgary Depression Scale for Schizophrenia (CDSS) were used to measure symptoms severity. ResultsSignificantly lower PON1 activity and increased TRAP values were found in FEP patients. There were no significant associations between any of the OS/antioxidant biomarkers and clinical data. Risperidone treatment significantly increased PON1 activity and decreased LOOH levels. These effects of risperidone were not significantly associated with the clinical response and risperidone dosage. DiscussionChanges in antioxidant profile, but not in lipid or protein oxidation or increased NO production, were found in drug-naive FEP. Risperidone may have antioxidant effects by lowering lipid peroxidation and increasing the antioxidant defenses against lipid peroxidation related to PON1. None of the biomarkers predicted treatment outcome.

Toxicity of environmental Gesagard to goldfish may be connected with induction of low intensity oxidative stress in concentration- and tissue-related manners

Prometryn is a selective herbicide commonly used in agriculture as the commercial preparation, Gesagard. Goldfish (Carassius auratus) exposure for 96h to 0.2, 1, or 5mgL−1 Gesagard 500FW (corresponding to 0.1, 0.5, and 2.5mgL−1 of prometryn) on indices of oxidative stress (lipid peroxides, protein carbonyls, and thiol content) and activities of antioxidant and related enzymes in gills, liver, and kidney was studied. Gills appeared to be the most resistant to Gesagard treatment, reacting to only the highest concentration of herbicide with enhanced levels of low molecular mass thiols and activities of glutathione S-transferase (GST) and glutathione reductase. Goldfish exposure to 0.2–5mgL−1 Gesagard resulted in enhancement of carbonyl protein level and activity of superoxide dismutase (SOD), but reduced the lipid peroxide (LOOH) content and activity of glutathione peroxidase in liver. Kidney appeared to be the main target organ of Gesagard toxicity, showing the greatest number of parameters affected even under low concentrations of herbicide. An increase in the content of L-SH and activity of SOD was accompanied with decreased activities of catalase, GST, and glucose-6-phosphate dehydrogenase and reduced levels of LOOH in kidney of Gesagard treated fish. The treatment also induced various histological changes in goldfish liver and kidney which could be related to their dysfunction. The present study indicates that Gesagard induced oxidative stress of differing intensities in the three goldfish tissues and demonstrated that kidney would be the best target organ to analyze, reveal, and monitor Gesagard effects on fish.

Evaluation of prolidase activity and oxidative status in patients with knee osteoarthritis: relationships with radiographic severity and clinical parameters.

We investigated serum prolidase activity and oxidative/antioxidative status in patients with knee osteoarthritis (OA) and evaluated its relationships with radiographic severity and clinical parameters. The study population consisted of 137 patients with knee OA and 134 healthy volunteers. The severity of knee OA was classified according to the Kellgren-Lawrence criteria. Each patient was also evaluated clinically according to the Western Ontario and McMaster University Osteoarthritis Index (WOMAC). Serum prolidase activity was measured spectrophotometrically. Oxidative status was assessed by measuring serum lipid hydroperoxide (LOOH) and total oxidative status (TOS). Antioxidative status was assessed by measuring serum-free sulfhydryl groups (-SH=total thiol) and total antioxidant capacity (TAC). Oxidative stress index (OSI) was calculated. Serum prolidase activity was significantly lower in the knee OA group than in the control group (p<0.001). The serum prolidase activities decreased with the severity of knee OA. Furthermore, serum LOOH, TOS, and OSI levels of the knee OA group were significantly higher than those of the controls (p<0.001 for all), whereas TAC and -SH levels did not differ between the two groups (p>0.05). In a multiple regression analysis, WOMAC score was independently associated with serum prolidase activity (β=-0.340, p<0.001). Decreased serum prolidase activity and elevated LOOH, TOS, and OSI levels may be associated with knee OA, and serum prolidase activity may be a useful adjunctive indicator of the progression of knee OA in follow-up.

Serum calprotectin: a new potential biomarker for thyroid papillary carcinoma.

The aim of this study was to evaluate serum calprotectin levels and oxidative stress status in patients with papillary thyroid carcinoma (PTC) and the changes in their levels after total thyroidectomy. The study involved 30 patients with PTC and 30 healthy controls. Blood samples were obtained from the PTC patients before and 1 month after the operation. Preoperative and postoperative serum samples from PTC patients and healthy controls were analysed for calprotectin, total antioxidant status (TAS), total oxidant status (TOS) and lipid hydroperokside (LOOH). The preoperative calprotectin, TOS, OSI and LOOH levels of the patients with PTC were significantly higher compared to those of the control group (p < 0.001, for each). The levels of calprotectin decreased significantly in patients with PTC after the operation (p < 0.001), while TAS, TOS and OSI levels remained unchanged (p = 0.313, p = 0.085 and p = 0.163, respectively). Preoperative serum calprotectin levels were positively correlated with TOS, OSI and LOOH levels and negatively correlated with TAS levels in patients with PTC. In conclusion, serum calprotectin levels is increased in patients with PTC, and calprotectin is positively correlated with TOS and LOOH. Serum calprotectin levels is significantly decreased after total thyroidectomy.

Evaluation of Different Oxidative Stress Biomarkers in Endometriosis

Endometriosis is an estrogen‐dependent chronic inflammatory disease in which oxidative stress is one of the key factors for the disease progression. Our aim was to assess oxidative stress parameters secondary to chronic inflammation in women with endometriosis by the determination of tissue thiol groups (GSH), lipid peroxidation (LOOH) and the expression of different genes related to oxidative stress (heme oxygenase‐1 (HO‐1), inducible nitric oxide synthase (iNOS) and inflammation (IL‐6 and IL‐1b). GSH and LOOH were determined by spectrophotometric analysis whereas HO‐1, iNOS, IL‐6 and IL‐1b gene expressions were determined by real time PCR. Our results showed that GSH was significantly reduced in endometriosis group compared to controls; whereas LOOH were surprisingly lower in the endometriosis group. No significant differences were observed in GSH and LOOH levels among the different stages of the disease. In addition, our results showed that HO‐1, iNOS, IL‐6 and IL‐1b genes were more expressed in the endometriosis group. In particular IL‐6 was significantly higher in the moderate groups compared to mild and severe group whereas IL‐1b was significantly higher in the mild group compared to moderate and severe. Furthermore, oxidative stress and inflammatory biomarkers were not dependent on the localization of the disease. Taken all together, our data suggest that oxidative stress is increased in endometriosis and it is not depending on the stadiation or localization of the disease whereas oxidative stress‐related gene expression is depending on the stage of the disease.

Oxidative stress markers at birth: Analyses of a neonatal population

In order to further understand neonatal stress and, thus, control it efficaciously, there is a need for more information on the manifestations of stress at the molecular level in the newborn, with particular regard to oxidants, and anti-oxidant and anti-stress mechanisms, including mitochondrial heat shock protein-chaperones such as Hsp60. We investigated patterns of anti-oxidants, biomarkers of oxidative stress, and Hsp60 levels in sera from newborns and found significant associations between glutathione (GSH) levels and gestational age, delivery modality, and lipid hydroperoxydes (LOOH) level. LOOH levels and spontaneous (vaginal) delivery were independently associated with increased GSH levels when these were above the median. Hsp60 and LOOH levels were positively correlated whereas Hsp60 and GSH levels were inversely correlated in spontaneously delivered newborns; in contrast, Hsp60 and GSH levels were positively correlated in newborns delivered by cesarea. Our results point to new directions in the search for definite patterns of GSH, LOOH, and Hsp60 in the newborn's serum that might have functional and diagnostic significance and that could help in the monitoring of newborn health during and after delivery. In addition, the data provide a starting basis for investigating the precise roles and interplay of GSH and Hsp60 in the maintenance of an optimal redox balance at birth to cope with the stress inherent to delivery, and also for investigating the predictive value of any given pattern of GSH, LOOH, and Hsp60 at birth with regard to health status and risk of disease in adult life.

Effect of yerba mate (Ilex paraguariensis A. St. Hil.) infusion obtained by freeze concentration technology on antioxidant status of healthy individuals

The present study evaluated whether acute consumption of freeze concentrated yerba mate (Ilex paraguariensis A. St. Hil.) infusion (CM) promotes improvement on the antioxidant and lipid peroxidation parameters in healthy individuals when compared to the traditional mate infusion (TM). In this cross-over study, 31 fasted volunteers ingested 200 mL of TM, CM, or water (control). Blood samples were withdrawn before and 1 h after beverages intake for the measurement of the antioxidant enzyme activities, catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx), reduced glutathione (GSH), lipid peroxidation (LOOH), and antioxidant capacity of serum (FRAP assay). CM intake promoted significant enhancement of the CAT (28.7%), SOD (21.3%), and GPx (9.6%) activities, and increased the levels of GSH (8.8%) and serum antioxidant capacity (7.5%), while TM increased only GSH values (8.3%). Serum levels of LOOH did not change significantly after consumption of both mate infusions. Acute consumption of CM by healthy individuals improved the blood antioxidant defense systems more efficiently than the traditional yerba mate and did not promote pro-oxidant effects.

Paraoxonase and arylesterase activities in patients with papillary thyroid cancer

Objective. The aim of this study was to evaluate paraoxonase-1 (PON1) activities and oxidative stress status, and the changes in their levels after total thyroidectomy in patients with papillary thyroid cancer (PTC). Materials and methods. Twenty-five patients with PTC and 27 healthy controls were enrolled in the study. Blood samples were obtained from the PTC patients before and 3 months after the operation. Preoperative and postoperative serum samples from PTC patients and healthy controls were analyzed for paraoxonase (PON), arylesterase (ARE) activities, and lipid hydroperoxide (LOOH) and –SH (total free sulfhydryl) levels. Results. The preoperative PON, ARE and –SH levels of the patients with PTC were significantly lower compared to those of the control group (p = 0.033, p < 0.001, p = 0.002, respectively), while LOOH levels were significantly higher (p < 0.001). The levels of PON and ARE decreased significantly in patients with PTC after the operation (p = 0.038, p = 0.023, respectively), while LOOH and –SH levels remained unchanged (p = 0.117, p = 0.487, respectively). PON and ARE levels showed a positive correlation with –SH (r = 0.211, p = 0.065; r = 0.471, p < 0.001, respectively) and a negative correlation with LOOH (r = − 0.391, p < 0.001, r = − 0.486, p < 0.001, respectively). Conclusion. Serum PON1 activity is decreased in patients with PTC, and serum PON1 is positively correlated with –SH, a well-known antioxidant, and negatively correlated with LOOH, an oxidant. PON1 activity is significantly decreased after total thyroidectomy.

Serum paraoxonase activity, total thiols levels, and oxidative status in patients with acute brucellosis.

It is well known that paraoxonase-1 (PON1) activity may decrease during the course of infection and inflammation. The aim of this study was to investigate serum PON1 activity, oxidative status, and thiols levels in patients with acute brucellosis. In addition, we investigated the PON1 phenotype in patients with acute brucellosis. Thirty patients with acute brucellosis and 35 healthy controls were enrolled. Serum paraoxonase and arylesterase activities, thiols levels, lipid hydroperoxide levels, total antioxidant capacity (TAC), total oxidant status (TOS) and oxidative stress index (OSI) were determined. Serum basal and salt-stimulated paraoxonase-arylesterase activities, TAC levels and thiols levels were significantly lower in patients with acute brucellosis than controls (for all, p < 0.05), while LOOH levels, TOS levels, and OSI values were significantly higher (for all, p < 0.05). We concluded that oxidative stress is increased, while serum PON1 activity is decreased in patients with acute brucellosis. These results indicate that lower PON1 activity is associated with oxidant-antioxidant imbalance.

The effects of fluoxetine on circulating oxidative damage parameters in rats exposed to aortic ischemia–reperfusion

Oxidative stress and reperfusion injury may develop in different ischemia–reperfusion (IR) models. Growing evidence links altered lipid protein redox-homeostasis with IR. The effect of fluoxetine (FLX; N-methyl-3-[4-(trifluoromethyl) phenoxy] benzenepropanamine), on the lipid protein redox-homeostasis mechanisms in the rats exposed to aortic IR is unclear. We aimed to investigate the effects of FLX on circulating protein oxidation and lipid peroxidation parameters, such as ischemia modified albumin (IMA), lipid hydroperoxide (LOOH), prooxidant antioxidant balance (PAB), erythrocyte glutathione (GSH), CuZn-superoxide dismutase (CuZn-SOD), ferric reducing antioxidant power (FRAP), as potential IR biomarkers. Wistar rats were randomized into three groups (n=7/group): 1) Control (sham laparotomy); 2) IR without FLX, (60min ischemia and 120min reperfusion); 3) IR with FLX (FLX+IR) (FLX 20mg/kg/day, i.p. for three days before surgery). All of the aforementioned parameters (IMA, LOOH, PAB, GSH, CuZn-SOD, and FRAP) were measured spectrophotometrically. IMA, LOOH, and PAB levels in IR group were significantly higher than the control (P<0.01 respectively) and fluoxetine groups (P<0.01, P<0.01, and P<0.05 respectively), whereas CuZn-SOD activities, GSH and FRAP were significantly lower in IR groups. Fluoxetine group significantly reduced IMA when compared to IR group (P<0.001) and control group (P<0.01). With respect to IMA, LOOH and PAB, impaired redox homeostasis is substantially more prominent in aortic IR. The antidepressant FLX has profitable effects on circulating redox status in rats exposed to aortic IR. FLX administration before IR might decrease the surgery-enhanced free radical production; taken together, the antioxidant effects of FLX supplementation should be considered in future studies.

Investigation of the role of 8-OHdG and oxidative stress in papillary thyroid carcinoma.

The aim of this study was to determine levels of serum 8-hydroxy-2'-deoxyguanosine (8-OHdG) as an indicator of oxidant-induced DNA damage and oxidant status in patients with papillary thyroid carcinoma before and after surgery. This study included 25 patients with papillary thyroid carcinoma and age-matched 27 healthy controls. Total antioxidant status (TAS), total oxidant status (TOS), lipid hydroperoxide (LOOH), and 8-OHdG levels were measured. 8-OHdG levels were significantly higher in the preoperative papillary thyroid carcinoma (PTC) group compared with the healthy control group (p < 0.001) and were significantly lower after operation in patients with papillary thyroid carcinoma (p = 0.004). Oxidative stress index (OSI) levels were significantly higher in both preoperative and postoperative PTC patients compared with the healthy control group (p < 0.001 and p < 0.001, respectively). TOS levels were higher in the preoperative and postoperative PTC groups compared to the healthy control group (p < 0.001 and p < 0.001, respectively). TAS levels was lower in the preoperative PTC groups compared to the healthy control group (p = 0.011). Serum LOOH levels were higher in both preoperative and postoperative PTC groups compared to the healthy control group (p < 0.001 and p < 0.001, respectively). Correlation analysis yielded that serum 8-OHdG levels were positively correlated with OSİ and LOOH levels in patients with PTC before surgery (r = 0.668, p < 0.001; r = 0.446, p = 0.025, respectively) and had a negative correlation with TAS levels (r = -0.616, p = 0.001). We have shown severe oxidative DNA damage and impaired antioxidant status in papillary thyroid carcinoma.

Eicosapentaenoic acid inhibits glucose-induced membrane cholesterol crystalline domain formation through a potent antioxidant mechanism

Lipid oxidation leads to endothelial dysfunction, inflammation, and foam cell formation during atherogenesis. Glucose also contributes to lipid oxidation and promotes pathologic changes in membrane structural organization, including the development of cholesterol crystalline domains. In this study, we tested the comparative effects of eicosapentaenoic acid (EPA), an omega-3 fatty acid indicated for the treatment of very high triglyceride (TG) levels, and other TG-lowering agents (fenofibrate, niacin, and gemfibrozil) on lipid oxidation in human low-density lipoprotein (LDL) as well as membrane lipid vesicles prepared in the presence of glucose (200mg/dL). We also examined the antioxidant effects of EPA in combination with atorvastatin o-hydroxy (active) metabolite (ATM). Glucose-induced changes in membrane structural organization were measured using small angle x-ray scattering approaches and correlated with changes in lipid hydroperoxide (LOOH) levels. EPA was found to inhibit LDL oxidation in a dose-dependent manner (1.0–10.0µM) and was distinguished from the other TG-lowering agents, which had no significant effect as compared to vehicle treatment alone. Similar effects were observed in membrane lipid vesicles exposed to hyperglycemic conditions. The antioxidant activity of EPA, as observed in glucose-treated vesicles, was significantly enhanced in combination with ATM. Glucose treatment produced highly-ordered, membrane-restricted, cholesterol crystalline domains, which correlated with increased LOOH levels. Of the agents tested in this study, only EPA inhibited glucose-induced cholesterol domain formation. These data demonstrate that EPA, at pharmacologic levels, inhibits hyperglycemia-induced changes in membrane lipid structural organization through a potent antioxidant mechanism associated with its distinct, physicochemical interactions with the membrane bilayer.

Decreased serum paraoxonase and arylesterase activities in patients with rosacea.

Recent evidence suggests that oxidative stress may be an important phenomenon in the pathophysiology of rosacea. Paraoxonase-1 (PON1) is an antioxidant enzyme with three activities: paraoxonase, arylesterase and dyazoxonase. In this study, we evaluated serum paraoxonase and arylesterase activities, and serum lipid hydroperoxide (LOOH) levels in patients with rosacea in comparison to healthy controls. The study included 39 rosacea patients and healthy controls, consisting of 40 age- and sex-matched healthy volunteers. Serum paraoxonase and arylesterase activities were measured using paraoxon and phenylacetate substrates. Serum LOOH levels were measured with the ferrous ion oxidation-xylenol orange assay. In rosacea group mean serum paraoxonase and arylesterase activities were 74.54 ± 38.30 U L(-1) and 141.29 ± 22.27 kU L(-1) respectively, which were significantly lower than controls (P = 0.010, 0.005; respectively). Mean serum LOOH level of rosacea group was 8.17 ± 1.91 μmol L(-1) which was significantly higher than controls (P = 0.009). There were no statistically significant differences between the clinical subtypes of the disease, menopause situation or ocular involvement with the respect to the serum paraoxonase and arylesterase activities and LOOH levels (all; P > 0.05). Serum PON1 enzyme activities have decreased significantly in rosacea. These findings support that decreased PON1 activity and increased oxidative stress may play a role in the pathogenesis of rosacea. Further studies are needed to elucidate the role of PON1 activity in the pathophysiology of rosacea.

Acute coronary syndrome remodels the protein cargo and functions of high-density lipoprotein subfractions.

ObjectivesThis study examined alterations in the functions and proteome of high-density lipoprotein (HDL) subfractions (HDL2 and HDL3) isolated from patients with acute coronary syndrome (ACS) compared with control subjects.MethodsWe measured HDL subfraction cholesterol efflux capacity, inflammatory index (HII), paraoxonase-1 (PON1) activity, and lipid hydroperoxide (LOOH) levels in both male age-matched controls and the ACS group (n = 40/group). Additionally, proteomic analysis was used to monitor changes in the HDL subfraction proteome between controls and ACS subjects.ResultsBoth HDL2 and HDL3 from ACS patients had greater HII and LOOH levels compared with controls (P<0.001); PON1 activity and cholesterol efflux capacity in both HDL2 and HDL3 from the ACS group were significantly less than those of controls (P<0.001). Using proteomic analysis, we demonstrated that, compared with the control group, nine proteins were selectively enriched in HDL3 from subjects with ACS, and ras-related protein Rab-7b was decreased in HDL3. Additionally, in the ACS subjects, 12 proteins were decreased in HDL2 and 4 proteins were increased in HDL2.ConclusionsFunctional HDL subfractions shifted to dysfunctional HDL subfractions during ACS, and the functional impairment was linked to remodeled protein cargo in HDL subfractions from ACS patients.

Paraoxonase-1 activity and oxidative stress in patients with anterior ST elevation myocardial infarction undergoing primary percutaneous coronary intervention with and without no-reflow

BackgroundReperfusion and ischemic injuries are pathogenetic mechanisms of no-reflow. Oxidative stress plays a critical role during ischemia as well as during the reperfusion phase following ST elevation myocardial infarction (STEMI). We sought to investigate the relationship between no-reflow with paraoxonase-1 (PON-1) activity and oxidative stress markers (total antioxidant capacity (TAC), total oxidant status (TOS), oxidative stress index (OSI), lipid hydro-peroxide (LOOH)) in patients with anterior STEMI undergoing primary percutaneous coronary intervention (PCI). MethodsIn this study, 319 consecutive anterior STEMI patients undergoing primary PCI were prospectively included (mean age 56.5 ± 12.5 years). The patients were divided into two groups as normal flow (n = 231) and no-reflow (n = 88) groups. Serum PON-1 activity was measured spectrophotometrically. TAC and TOS levels were determined by using an automated measurement method. LOOH levels were measured by ferrous oxidation with xylenol orange assay. ResultsPON-1 activity and TAC levels were significantly lower and TOS, OSI and LOOH levels were significantly higher in patients with no-reflow compared to normal flow group (p < 0.05, for all). On multivariate logistic regression analysis, PON-1 activity (β = 0.976, 95% CI = 0.962–0.990, p = 0.001) and OSI (β = 1.094, 95% CI = 1.042–1.148, p < 0.001) as well as diabetes, infarction time, thrombus score and initial SYNTAX score were independently associated with no-reflow. ConclusionIn patients with no-reflow compared with normal flow, oxidants are increased, while serum PON-1 activity and antioxidants are decreased. This result shows that increased oxidative stress has a role in the pathogenesis of no-reflow.