Lower Serum Paraoxonase-1 Activity Is Related to Linoleic and Docosahexanoic Fatty Acids in Type 2 Diabetic Patients

Associations of fatty acids composition and estimated desaturase activities in erythrocyte phospholipids with biochemical and clinical indicators of cardiometabolic risk in non-diabetic Serbian women: the role of level of adiposity

Introduction

Fatty acids (FAs) composition and desaturase activities can be altered in different metabolic conditions, but the adiposity-independent associations with clinical and biochemical indicators of cardiometabolic risk are still unclear. This study aimed to analyze the associations of FAs composition and estimated desaturase activities with anthropometric, clinical, and biochemical cardiometabolic risk indicators in non-diabetic Serbian women, and to investigate if these associations were independent of the level of adiposity and other confounders.

Methods

In 76 non-diabetic, otherwise healthy Serbian women, aged 24-68 years, with or without metabolic syndrome or obesity (BMI=23.6±5.6 kg/m2), FA composition in erythrocyte phospholipids was measured by gas-liquid chromatography. Desaturase activities were estimated from product/precursor FAs ratios (D9D:16:1n-7/16:0; D6D:20:3n-6/18:2n-6; D5D:20:4n-6/20:3n-6). Correlations were made with anthropometric, biochemical (serum glucose, triacylglycerols, LDL-C, HDL-C, ALT, AST, and their ratios) and clinical (blood pressure) indicators of cardiometabolic risk. Linear regression models were performed to test the independence of these associations.

Results

Estimated desaturase activities and certain FAs were associated with anthropometric, clinical and biochemical indicators of cardiometabolic risk: D9D, D6D, 16:1n-7 and 20:3n-6 were directly associated, while D5D and 18:0 were inversely associated. However, the associations with clinical and biochemical indicators were not independent of the associations with the level of adiposity, since they were lost after controlling for anthropometric indices. After controlling for multiple confounders (age, postmenopausal status, education, smoking, physical activity, dietary macronutrient intakes, use of supplements, alcohol consumption), the level of adiposity was the most significant predictor of desaturase activities and aforementioned FAs levels, and mediated their association with biochemical/clinical indicators. Vice versa, desaturase activities predicted the level of adiposity, but not other components of cardiometabolic risk (if the level of adiposity was accounted). While the associations of anthropometric indices with 16:1n-7, 20:3n-6, 18:0 and D9D and D6D activities were linear, the associations with D5D activity were the inverse U-shaped. The only adiposity-independent association of FAs profiles with the indicators of cardiometabolic risk was a positive association of 20:5n-3 with ALT/AST ratio, which requires further exploration.

Discussion

Additional studies are needed to explore the mechanisms of the observed associations.

Oxidative Stress and DNA Damage in Peripheral Blood Mononuclear Cells from Normal, Obese, Prediabetic and Diabetic Persons Exposed to Thyroid Hormone In Vitro

Diabetes, a chronic group of medical disorders characterized byhyperglycemia, has become a global pandemic. Some hormones may influence the course and outcome of diabetes, especially if they potentiate the formation of reactive oxygen species (ROS). There is a close relationship between thyroid disorders and diabetes. The main objective of this investigation was to find out whether peripheral blood mononuclear cells (PBMCs) are more prone to DNA damage by triiodothyronine (T₃) (0.1, 1 and 10 μM) at various stages of progression through diabetes (obese, prediabetics, and type 2 diabetes mellitus—T2DM persons). In addition, some biochemical parameters of oxidative stress (catalase-CAT, thiobarbituric acid reactive substances—TBARS) and lactate dehydrogenase (LDH) were evaluated. PBMCs from prediabetic and diabetic patients exhibited increased sensitivity for T₃ regarding elevated level of DNA damage, inhibition of catalase, and increase of TBARS and LDH. PBMCs from obese patients reacted in the same manner, except for DNA damage. The results of this study should contribute to a better understanding of the role of thyroid hormones in the progression of T2DM.

Is There a Link between Zinc Intake and Status with Plasma Fatty Acid Profile and Desaturase Activities in Dyslipidemic Subjects?

The prevalence of obesity and dyslipidemia has increased worldwide. The role of trace elements in the pathogenesis of these conditions is not well understood. This study examines the relationship between dietary zinc (Zn) intake and plasma concentrations of Zn, copper (Cu) and iron (Fe) with lipid profile indicators, fatty acid composition in plasma phospholipids and desaturase enzyme activities in a dyslipidemic population. The role of the newly proposed biomarker of Zn status, the linoleic:dihomo-gama-linolenic acid (LA:DGLA) ratio, in predicting Zn status of dyslipidemic subjects has been explored. The study included 27 dyslipidemic adults, 39-72 years old. Trace elements were determined using atomic absorption spectrometry and fatty acid composition by a liquid gas chromatography. Desaturase activities were calculated from product-precursor fatty acid ratios. Dietary data were obtained using 24 h recall questionnaires. Insufficient dietary intake of Zn, low plasma Zn concentrations and an altered Cu:Zn ratio is related to modified fatty acid profile in subjects with dyslipidemia. Plasma Zn status was associated with obesity. There was no correlation between dietary Zn intake and plasma Zn status. The LA:DGLA ratio was inversely linked to dietary Zn intake. Cu, in addition to Zn, may directly or indirectly, affect the activity of desaturase enzymes.

Paraoxonase 1 in bovine milk and blood as marker of subclinical mastitis caused by Staphylococcus aureus

The aim of this study was to determine serum lipid values and parameters of oxidative stress in blood and milk of cows with subclinical mastitis (SCM) caused by Staphylococcus aureus and to establish association between these parameters. The study was performed on total of 104 cows assigned into control group of healthy animals (n = 12) and two groups of cows with SCM, either SCM₁ group (n = 37) with ˂ 1000 CFU/mL of S. aureus or SCM₂ group (n = 55) with ≥1000 CFU/mL of causative agent in milk. Significantly lower serum concentrations of high density lipoprotein-cholesterol (HDLC) in SCM₂ group and higher low density lipoprotein-cholesterol (LDL-C) in both SCM groups were recorded. Significantly lower paraoxonase-1 (PON1) activity and higher lipid hydroperoxides (LOOH) concentration in blood and milk were recorded in both groups of SCM cows vs control. In blood serum of cows from SCM₂ group significantly higher concentrations of hydrogen peroxide (H₂O₂) and malondialdehyde (MDA), but significantly lower total antioxidative capacity (TAC) were obtained. In milk serum of SCM cows were detected significantly higher concentrations of H₂O₂ and MDA, but significantly lower TAC vs control. There was a significant positive correlation between PON1 in serum with HDLC, but negative correlation with LDL-C and LOOH. In milk, PON1 negatively correlated with LOOH and somatic cell counts (SCC). Strong positive correlation was obtained between PON1 in blood and milk. Oxidative stress and inflammatory reaction induced by SCM significantly lowered PON1 activity in blood and milk of affected cows.

Synthesis of docosahexaenoic acid–loaded silver nanoparticles for improving endothelial dysfunctions in experimental diabetes

Objective:

To investigate the ability of docosahexaenoic acid (DHA)-loaded silver nanoparticles (AgNPs) in facilitating the incorporation of DHA in the cell membrane, improve cell membrane structure, and attenuate endothelial dysfunction in experimental diabetes.

Methods:

DHA/AgNPs were prepared using a nanoprecipitation technique. Fifty male albino rats were used in this study; 10 of them were served as the control group and 40, as the experimental groups, were injected with streptozotocin. Then, the experimental groups were subdivided into diabetic, diabetic treated with DHA, diabetic treated with AgNPs, and diabetic treated with DHA/AgNPs groups.

Results:

DHA/AgNPs have small spherical size as proved from ultraviolet–visible spectroscopy, transmission electron microscope, dynamic light scattering, and scanning electron microscope techniques. Cell membrane cholesterol and triglycerides showed a significant elevation in the diabetic group compared to the control, but treatment with DHA and DHA/AgNPs caused a significant reduction in both. Treatment with AgNPs and DHA/AgNPs caused a significant improvement in asymmetric dimethylarginine and nitric oxide levels compared to the diabetic group. Cell membrane fatty acids showed that omega-6 polyunsaturated fatty acids (PUFAs) were significantly elevated, while omega-3 PUFA were significantly reduced in the diabetic group compared to the control. There is a significant improvement in the levels of fatty acids in all groups after treatment with DHA, silver, or DHA/AgNPs.

Conclusion:

DHA/AgNPs are potent agents for the improvement of diabetic complication and endothelial dysfunction in experimental diabetes.

Betaine modulates oxidative stress, inflammation, apoptosis, autophagy, and Akt/mTOR signaling in methionine-choline deficiency-induced fatty liver disease

We examined the effects of betaine, an endogenous and dietary methyl donor essential for the methionine-homocysteine cycle, on oxidative stress, inflammation, apoptosis, and autophagy in methionine-choline deficient diet (MCD)-induced non-alcoholic fatty liver disease (NAFLD). Male C57BL/6 mice received standard chow (control), standard chow and betaine (1.5% w/v in drinking water), MCD, or MCD and betaine. After six weeks, serum and liver samples were collected for analysis. Betaine reduced MCD-induced increase in liver transaminases and inflammatory infiltration, as well as hepatosteatosis and serum levels of low-density lipoprotein, while it increased that of high-density lipoprotein. MCD-induced hepatic production of reactive oxygen and nitrogen species was significantly reduced by betaine, which also improved liver antioxidative defense by increasing glutathione content and superoxide-dismutase, catalase, glutathione peroxidase, and paraoxonase activity. Betaine reduced the liver expression of proinflammatory cytokines tumor necrosis factor and interleukin-6, as well as that of proapoptotic mediator Bax, while increasing the levels of anti-inflammatory cytokine interleukin-10 and antiapoptotic Bcl-2 in MCD-fed mice. In addition, betaine increased the expression of autophagy activators beclin 1, autophagy-related (Atg)4 and Atg5, as well as the presence of autophagic vesicles and degradation of autophagic target sequestosome 1/p62 in the liver of NAFLD mice. The observed effects of betaine coincided with the increase in the hepatic phosphorylation of mammalian target of rapamycin (mTOR) and its activator Akt. In conclusion, the beneficial effect of betaine in MCD-induced NAFLD is associated with the reduction of liver oxidative stress, inflammation, and apoptosis, and the increase in cytoprotective Akt/mTOR signaling and autophagy.

Effect of Eicosapentaenoic Acid Supplementation on Paraoxonase 2 Gene Expression in Patients with Type 2 Diabetes Mellitus: a Randomized Double-blind Clinical Trial

Type 2 diabetes mellitus (T2DM) is recognized as one of the most prevalent metabolic diseases, and it is mostly associated with oxidative stress, atherosclerosis and dyslipidemia. Paraoxonase 2 (PON2) due to its antioxidant properties may play a role in the atherosclerosis development. Although long-chain omega-3 polyunsaturated fatty acids, such as eicosapentaenoic acid (EPA) have been shown to reduce the risk of cardiovascular disease, the exact mechanism of action is still unknown. Our goal in this study was to determine the effect of EPA administration on gene expression of PON2 in patients with T2DM. Present study was a randomized, controlled double-blind trial. Thirty-six patients with T2DM were randomly allocated to receive 2 g/day EPA (n = 18) or placebo (n = 18) for 8 weeks. There were no significant differences between 2 groups concerning demographic or biochemical variables, and dietary intakes as well (p > 0.05). However, patients received EPA showed a significant increase in the gene expression of PON2 compared with placebo group (p = 0.027). In addition, high-density lipoprotein cholesterol increased and fasting blood sugar decreased significantly after EPA supplementation compared with control group. Taken together, supplementation with 2 g/day EPA could be atheroprotective via the upregulation of PON2 in patients with T2DM.

Oxidative stress and DNA damage in peripheral blood mononuclear cells from normal, obese, prediabetic and diabetic persons exposed to adrenaline in vitro

Diabetes represents one of the major health concerns, especially in developed countries. Some hormones such as the stress hormone adrenaline can induce reactive oxygen species (ROS) and may worsen the diabetes. Therefore, the main aim of the investigation was to find out whether peripheral blood mononuclear cells (PBMCs) from normal persons have less DNA damage induced by adrenaline (0.1, 1 and 10 μM) in comparison to PBMCs from obese, prediabetic and diabetic patients. Also, the biochemical parameters of oxidative stress (TBARS, catalase) and lactate dehydrogenase were monitored. It was observed that higher concentrations of adrenaline (1 and 10 μM) induced DNA damage in the obese, prediabetic and diabetic groups. In healthy individuals only the highest concentration of adrenaline caused significant increase in the DNA damage. In summary, total comet score (TCS) comparison has shown significant differences between groups, and DNA damaging effects of adrenaline were most evident in diabetic patients. The results of the biochemical analysis also demonstrate that adrenaline exerts most obvious effects in diabetic individuals which is manifested as significant change of parameters of oxidative stress. In summary, the obtained results demonstrated that diabetics are more sensitive to genotoxic effects of adrenaline and this effect probably resulted from decreased antioxidative defence mechanisms in various stages of progression through diabetes. Therefore, these results could contribute to a better understanding of a role of endocrine factors to damage of cellular biomolecules which could be useful in finding novel therapeutic approaches and lifestyle changes with an aim to lower the possibility of diabetes complications.

An initial evaluation of newly proposed biomarker of zinc status in humans - linoleic acid: dihomo-γ-linolenic acid (LA:DGLA) ratio

BACKGROUND

Zinc is an essential micronutrient for humans with important physiological functions. A sensitive and specific biomarker for assessing Zn status is still needed.

OBJECTIVE

The major aim of this study was to examine if the changes in the content of plasma phospholipid LA, DGLA and LA: DGLA ratio can be used to efficiently predict the dietary Zn intake and plasma Zn status of humans.

METHODS

The study was performed on healthy human volunteers, 25-55 years of age. The dietary Zn intake was assessed using 24 h recall questionnaires. Plasma phospholipid fatty acid analysis was done by gas chromatography, and plasma analysis of minerals by atomic absorption spectrometry. Biochemical, anthropometrical and hematological parameters were assessed.

RESULTS

No significant relationship was found between the dietary and plasma zinc status (r = 0.07; p = 0.6). There was a statistically significant correlation between DGLA and plasma Zn (r = 0.39, p = 0.00). No relationship was observed between the linoleic acid and plasma Zn, while there was a significant negative correlation between LA: DGLA ratio and plasma Zn status (r = -0.35, p = 0.01). Similarly, there were statistically significant difference in DGLA status (p = 0.004) and LA: DGLA ratio (p = 0.042) between the Zn formed groups.

CONCLUSIONS

This study is an initial step in evaluating LA: DGLA ratio as a biomarker of Zn status in humans. The results are encouraging as they show that concentration of DGLA is decreased and LA: DGLA ratio increased in people with lower dietary Zn intake. However, additional studies are needed to fully examine the sensitivity of this biomarker.

Polymorphisms of rs174616 in the FADS1-FADS2 gene cluster is associated with a reduced risk of type 2 diabetes mellitus in northern Han Chinese people

AIMS

Several studies have shown associations between the composition of polyunsaturated fatty acids (PUFAs) in various tissues and type 2 diabetes mellitus (T2DM) development in European populations. Genetic variants of fatty acid desaturase (FADS) contribute to the variations of PUFA composition. Here we have explored whether similar correlations are also true among Chinese Han people.

METHODS

A case-control study was employed to examine this correlation in Han Chinese people. The study included 421 healthy adults and 331 T2DM patients.

RESULTS

The ratio of arachidonic acid/linoleic acid (AA/LA), which reflects Δ6 desaturase activity, was significantly increased in T2DM patients. Furthermore, the ratio of eicosapentaenoic acid/α-linolenic acid (EPA/ALA), which reflects Δ5 desaturase activity, was markedly decreased in T2DM patients. Importantly, among four single nucleotide polymorphisms (rs174545, rs2072114, rs174602 and rs174616) in the FADS1-FADS2 gene cluster, only minor allele (T) of rs174616 was associated with decreased risk of T2DM in both codominant and dominant models after adjustment for age, gender and BMI. Furthermore, the ratio of AA/LA in both controls and T2DM was reduced in T carriers while an increased proportion of LA was seen in T2DM patients compared with control patients.

CONCLUSION

These data suggest that in northern Han Chinese people, the minor allele (T) of rs174616 in the FADS1-FADS2 gene cluster is associated with a decreased conversion rate of LA to AA, which may contribute to decreased reduced risk of developing T2DM.

Comprehensive profiling of plasma fatty acid concentrations in young healthy Canadian adults

Circulating fatty acids (FA) are associated with a multitude of chronic diseases. However, a major gap in establishing such relationships is the lack of accepted fatty acid reference ranges representing healthy individuals. Data on validated FA reference ranges would provide a better understanding of study baseline measures and aid in the evaluation and interpretation of pharmaceutical or dietary interventions. Reference ranges for plasma FA levels have been reported in a few small studies and on a limited number of FA. Therefore, we determined the average and percentiles of a broad set of 61 FA (C14 - C24:1) from plasma total lipids from an ethnically diverse population of healthy young Canadian males and females (Total n = 826). Plasma concentrations of some of the major FA ranged from 0.3 to 4.1 mmol/L for palmitic acid, 0.1 to 1.0 mmol/L for stearic acid, 0.03 to 3.2 mmol/L for oleic acid, 0.2 to 5.0 mmol/L for linoleic acid (LA), 12.0 to 186.9 μmol/L for α-linolenic acid, and 7.2 to 237.5 μmol/L for docosahexaenoic acid (DHA). Males had significantly higher plasma concentrations of γ-linolenic acid (GLA) and n-3 docosapentaenoic acid and lower concentrations of palmitoleic acid, LA and DHA than females. Comparison of FA concentrations between Caucasians, East Asians and South Asians revealed that South Asians had significantly lower levels of palmitoleic acid (p < 0.01) and oleic acid (p = 0.01) while East Asians had lower levels of GLA (p = 0.02) and dihomo-γ-linolenic acid (p = 0.03). Overall, these data provide a comprehensive set of quantitative values that profiles a small cohort of Canadians which highlights the utility of establishing validated FA reference ranges that may be used to understand how deficient, suboptimal, or excess amounts of a given FA may be associated with chronic disease.

Effect of PUFA-rich plant oil on risk factors of STZ-induced diabetes in Wistar rats

OBJECTIVE

This study has been focused on the effect of an n-6 polyunsaturated fatty acid (PUFA) rich plant oil on oxidation and glycooxidation stress markers as well as on antioxidant enzyme activities in male Wistar rats with streptozotocin-induced diabetes.

METHODS

The non-diabetic and diabetic groups of Wistar rats were administered plant oil at concentrations of 100 and 500 mg/kg body weight and controls without plant oil. The parameters of glycaemic control, lipid profile, total antioxidant status, antioxidant enzyme activities, together with oxidative and glycooxidative stress markers were measured in the blood.

RESULTS

The intake of the plant oil did not significantly influence the parameters of glycaemic control and significantly increased the levels of all lipid profile parameters in the diabetic rats. Plant oil administration significantly decreased the total antioxidant status and glutathione peroxidase activity and the activity of Cu/Zn superoxide dismutase was significantly increased. The plant oil also increased the levels of lipoperoxides and advanced the glycation end products.

DISCUSSION

These results suggest that the plant oil with high concentrations of n-6 PUFA - linoleic acid, acts prooxidatively when administered to the rats.

Ethnic- and sex-specific associations between plasma fatty acids and markers of insulin resistance in healthy young adults

BACKGROUND

Although evidence indicates that fatty acids (FA) can affect insulin resistance (IR), not all FA contribute equally to the process. Indeed, monounsaturated FA (MUFA) and polyunsaturated FA (PUFA) are reported to reduce IR, whereas saturated FA (SFA) and trans FA appear to increase IR. However, it is not yet clear how individual FA are associated with markers of IR, and whether these relationships are influenced by ethnicity and/or sex. Therefore, the goal of this study was to examine the ethnic- and sex-specific relationships between plasma FA and markers of IR in a cohort of healthy young Caucasian, East Asian, and South Asian adults.

METHODS

Gas chromatography was used to quantify fasting plasma FA from young Canadian adults (22.6 ± 0.1 yrs) of Caucasian (n = 461), East Asian (n = 362), or South Asian (n = 104) descent. Linear regression models were used to investigate associations between plasma FA and markers of IR (i.e. fasting insulin, glucose, and HOMA-IR) according to ethnicity and sex.

RESULTS

Numerous significant associations (P < 0.05, adjusted for multiple testing) were identified between individual FA and markers of IR, with the majority identified in Caucasians. For SFA, positive associations were found between 14:0 and fasting insulin and HOMA-IR in Caucasian and East Asian populations, and 18:0 and fasting glucose in Caucasians only. Several positive associations were also found for specific MUFA (18:1t11 and 18:1t6-8 with HOMA-IR, and 18:1c9 with fasting glucose) and PUFA (18:2n6 with fasting glucose and 18:2c9t11 with HOMA-IR) in Caucasian adults only. Most of the aforementioned associations were stronger in males compared to females. Interestingly, no significant associations were found between FA and markers of IR in South Asian adults.

CONCLUSIONS

We report numerous associations between plasma FA and markers of IR in Caucasian and East Asian populations, but not in South Asian individuals. Furthermore, these associations appeared to be more robust in men. This demonstrates the importance of investigating associations between FA and markers of IR in an ethnic- and sex-specific manner in order to better understand the contribution of plasma FA to the development of IR and type-2 diabetes.

Extra-virgin olive oil consumption reduces the age-related decrease in HDL and paraoxonase 1 anti-inflammatory activities

Paraoxonase 1 (PON1) is associated with HDL and modulates the antioxidant and anti-inflammatory role of HDL. The goals of the present study were to investigate the effect of ageing and the role of PON1 on the anti-inflammatory activity of HDL, and to determine whether extra-virgin olive oil (EVOO) consumption could improve the atheroprotective activity of HDL. HDL and PON1 were isolated from the plasma of ten young (Y-HDL and Y-PON1) and ten elderly (E-HDL and E-PON1) healthy volunteers before and after 12 weeks of EVOO consumption. Inflammation was assessed by measuring intracellular adhesion molecule 1 (ICAM-1) expression. THP-1 (human acute monocytic leukaemia cell line) monocyte chemotaxis was measured using a Boyden chamber. Oxidative damage to HDL was assessed by measuring conjugated diene formation and changes in electrophoretic migration. Y-HDL had more anti-inflammatory activity than E-HDL. The conjugated diene content and the electrophoretic mobility of E-HDL were higher than those of Y-HDL. Y-PON1 had significant anti-inflammatory activity, reducing ICAM-1 expression by 32·64 (SD 2·63)%, while E-PON1 had no significant effect. THP-1 chemotaxis measurements confirmed the ICAM-1 expression results. The 12 weeks of EVOO consumption significantly increased the anti-inflammatory activities of both HDL and PON1. The anti-inflammatory activity of HDL was modulated by PON1 and was lower in the elderly volunteers. EVOO consumption increased the anti-inflammatory effect of HDL and reduced the age-related decrease in anti-atherogenic activity.

Positive correlation of paraoxonase 1 (PON1) activity with serum insulin level and HOMA-IR in dementia. A possible advantageous role of PON1 in dementia development

Paraoxonase 1 (PON1) activity and metabolic syndrome traits were evaluated in 169 demented patients (81 recognized as AD, 32 as VaD, 56 as MD) and in 64 control individuals. Paraoxonase activity was determined spectrophotometrically using phenyloacetate as substrate. Metabolic syndrome was recognized according to AHA/NHLBI criteria. In the whole group with dementia significant positive correlation between PON1 activity/HDL cholesterol ratio (i.e. HDL corrected PON1 activity) and insulin level as well as HOMA IR index, was observed. The multivariate analysis showed that the PON1/HDL-C ratio was also significantly positively associated with the presence of metabolic syndrome (with insulin resistance as a major underlying trait) both in dementia and in control group. High insulin level and HOMA-IR are considered to be the traits of insulin resistance. It has however to be taken into account that they both could also depend on insulin production and release which, as was recently stated in cell experiments, are enhanced by PON1. The observed positive correlation suggests an advantageous role of the enzyme in metabolic syndrome influence on dementia development.

Effects of orange juice and hesperetin on serum paraoxonase activity and lipid profile in hyperuricemic rats

INTRODUCTION

Hypouricemic, antioxidant and xanthine oxidase inhibitory effects of orange juice and hesperetin have been already indicated. The objective of this study was to investigate the effects of orange juice and hesperetin on paraoxonase and arylesterase activity and lipid profile of hyperuricemic rats.

METHODS

Forty eight male Wistar rats were divided into 8 equal groups of healthy control, healthy+orange juice, healthy+hesperetin, healthy+allopurinol, hyperuricemic control, hyperuricemic+orange juice, hyperurice-mic+hesperetin and hyperuricemic+allopurinol. Hyperuricemia was induced using potassi-um oxonate (250 mg/kg ip). The treatments were carried out by daily gavage of 5 ml/kg orange juice, 5 mg/kg hesperetin and 5 mg/kg allopurinol for 2 weeks. Paraoxonase activi-ty in serum was measured spectrophotometrically using paraoxon and phenylacetate as substrates. Serum lipids levels were determined using enzymatic colorimetric methods.

RESULTS

Hyperuricemia-induced reduction of paraoxonase and arylesterase activity was restored after treatment with orange juice and hesperetin (p<0.05). The effect of both treatments on lipid profile was marginal and only orange juice could significantly increase the levels of HDL-C.

CONCLUSION

Supplementation of orange juice and hesperetin could restore paraoxonase and arylesterase activity in hyperuricemic rats. Orange juice could also partially improve the lipid profile. These effects could have major implications with respect to the prevention of cardiovascular disease in hyperuricemic patients. However, more studies are needed in future investigations.