Evaluation of oxidative stress and antioxidant status in diabetic and hypertensive women during labor

Dietary Total Antioxidant Capacity and Gestational Diabetes Mellitus: A Case-Control Study

Background

Elevated oxidative stress status has been reported among pregnant women with gestational diabetes mellitus (GDM). In diabetic condition, glucose and lipid peroxidation, and alteration in antioxidant defense lead to increased free radicals. The objective of this study was to investigate the association between dietary total antioxidant capacity (DTAC) and GDM.

Methods

This hospital-based case-control study was conducted in 463 pregnant women (healthy, n = 263; GDM, n = 200). Anthropometric indices, blood pressure, and biochemical analyses were measured. Dietary intake was assessed by the average of three 24-hour dietary intake records. DTAC was calculated by three indices: ferric reducing ability of plasma (FRAP), total radical-trapping antioxidant parameter (TRAP), and Trolox equivalent antioxidant capacity (TEAC). Multivariable logistic regression was performed to examine the relationship between DTAC and GDM risk in crude and adjusted models.

Results

The mean age and BMI were 28.33 ± 6.23 years and 29.67 ± 4.73 kg/m², respectively. Total energy, protein, and selenium intakes were significantly higher in cases than controls (P < 0.05). Moreover, intakes of carbohydrate, vitamins C, B6, and A, manganese, fruits, fruit juices, vegetables, legumes, and FRAP were significantly lower in cases than controls (P < 0.05). The risk of gestational diabetes mellitus was 85% lower among those in the highest tertile of FRAP (OR: 0.15; 95% CI: 0.08-0.29). There was no significant association between the risk of GDM and TRAP (OR: 1.62; 95% CI: 0.94-2.79) as well as TEAC (OR: 1.56; 95% CI: 0.89-2.72).

Conclusion

Pregnant women who were in the highest tertile of FRAP were at lower risk of GDM. However, larger prospective studies are needed to confirm our findings.

Antihypertensive effect of Phragmanthera incana (Schum) Balle on NG-nitro-L-Arginine methyl ester (L-NAME) induced hypertensive rats

ETHNOPHARMACOLOGICAL RELEVANCE

Phragmanthera incana (Schum) Balle is a member of the African mistletoes that has been reported to be used in ethnomedicine for the treatment of hypertension.

AIM

The aim of this study was to investigate the antihypertensive effect of Phragmanthera incana leaf ethanol extract (PILEE) in NG-nitro-L-arginine methyl ester (L-NAME)-induced hypertensive rats.

MATERIALS AND METHODS

Phytochemical analysis of PILEE was determined using the Gas chromatography - Mass spectrophotometry (GC-MS) method. Antihypertensive activity was investigated in rats that received PILEE (50, 100 and 200 mg/kg) or captopril (40 mg/kg) daily for 28 days together with oral administration of L-NAME (40 mg/kg). Blood pressure parameters were measured on day 7, 14, 21 and 28. Blood was obtained for determination of serum nitrite, interleukin-6 (IL-6) and tumor necrosis factor, TNF-α. The heart, liver and kidneys were used to determine oxidative stress indices (malondialdehyde, reduced glutathione and catalase). The cardiac tissue was processed for histopathological changes.

RESULTS

The GC-MS profiling of PILEE identified 20 compounds namely fatty acid esters. Administration of PILEE (50, 100 and 200 mg/kg) dose dependently and significantly reduced systolic blood pressure and mean arterial pressure in hypertensive rats. PILEE administration significantly (p < 0.05) reversed elevated IL-6 and TNF-α in hypertensive rats. PILEE demonstrated antioxidant activity by attenuating L-NAME-induced elevated malondialdehyde and depletion of reduced glutathione and catalase activity in rat tissues. PILEE treatment demonstrated cardioprotective effect in L-NAME-induced cardiac hyperplasia and necrosis in rats.

CONCLUSION

It can be concluded that Phragmanthera incana leaf ethanol extract possess antihypertensive, antioxidant and anti-inflammatory properties, suggesting a protective role in cardiovascular diseases.

Biomarkers of oxidative stress in the fetus and in the newborn

The dynamic field of perinatology entails ever-increasing search for molecular mechanisms of neonatal diseases, especially in the domain of fetal growth and neurodevelopmental outcome. There is an urgent need for new molecular biomarkers, to early identify newborn at high risk for developing diseases and to provide new treatment targets. The interest in biomarkers of oxidative stress in perinatal period have begun to grow in the last century, when it was evidenced the importance of the free radicals generation underlying the various disease conditions. To date, interesting researches have been carried out, representing milestones for implementation of oxidative stress biomarkers in perinatal medicine. Use of a panel of "oxidative stress biomarkers", particularly non protein bound iron, advanced oxidative protein products and isoprostanes, may provide valuable information regarding functional pathways underlying free radical mediated diseases of newborns and their early identification and prevention. Here, we will review recent advances and the current knowledge on the application of biomarkers of oxidative stress in neonatal/perinatal medicine including novel biomarker discovery, defining yet unrecognized biologic therapeutic targets, and linking of oxidative stress biomarkers to relevant standard indices and long-term outcomes.

Oxidative Stress as Cause, Consequence, or Biomarker of Altered Female Reproduction and Development in the Space Environment

Oxidative stress has been implicated in the pathophysiology of numerous terrestrial disease processes and associated with morbidity following spaceflight. Furthermore, oxidative stress has long been considered a causative agent in adverse reproductive outcomes. The purpose of this review is to summarize the pathogenesis of oxidative stress caused by cosmic radiation and microgravity, review the relationship between oxidative stress and reproductive outcomes in females, and explore what role spaceflight-induced oxidative damage may have on female reproductive and developmental outcomes.

Effect of Antioxidant Supplementation on Total Antioxidant Status in Indian Children with Type 1 Diabetes

Hyperglycemia results in the overproduction of free oxygen radicals that impair the endogenous antioxidant defenses. A randomized controlled trial was conducted to compare the effect of 3 months of antioxidant supplementation in the form of foods rich in micronutrients with pharmacological supplement on total antioxidant status of Indian children with type 1 diabetes. Ninety children with diabetes (mean age 11.5 ± 3.6 yrs, 37 boys) were randomly allocated to three groups: Group 1 (n = 31) = DM controls; Group 2 (n = 30) = multimicronutrient syrup; and Group 3 (n = 29) = dietary supplements (nine snack recipes rich in micronutrients). They received intervention for 3 months. Healthy controls were enrolled from local schools. Fasting blood was tested for total antioxidant status (TAS) and glycosylated hemoglobin (HbA1C). Children with diabetes had lower TAS (0.70 ± 0.2 vs. 1 ± 0.24 mmol/l, p = .0001) compared to healthy controls. Anthropometric and biochemical parameters were similar at baseline for all groups of diabetic children. Group 1 showed significant deterioration in TAS at endline (0.72 ± 0.16 vs. 0.60 ± 0.17 mmol/l, p = .008). Increase in TAS recorded in Group 2 was from 0.66 ± 0.21 to 0.70 ± 0.16 mmol/l and in Group 3 was from 0.68 to 0.73 mmol/l. There was a significant difference between Group 1 and Group 3 for percentage change in TAS (-13% vs. 16%, p = .035). Postsupplementation there was an increase in TAS values in children with diabetes, but they were still lower than in healthy controls. Indian diabetic children have compromised antioxidant status, which may be improved by incorporation of multimicronutrient-rich recipes in their diets.

Comparison of Total Antioxidant Capacity of Saliva in Women with Gestational diabetes mellitus and Non-diabetic Pregnant Women

Background

Pregnancy is considered a stressful event, results in higher levels of oxidative stress and considerable changes in physiological and metabolic functions such as gestational diabetes mellitus (GDM). Due to the cumulative effect of antioxidants and considering the controversies in this area, this study was undertaken to investigate the total antioxidant capacity (TAC) of saliva in pregnant women whit gestational diabetes in comparison to non-diabetic pregnant women.

Material and Methods

In this cross-sectional study (2015-16), a total of 31 women with a diagnosis of GDM and 59 non-diabetic pregnant women were included in the diabetic and control groups, respectively. Salivary samples were collected by spitting method. When all samples were collected, total antioxidant capacity (TAC) was measured with the use of a commercial kit following the manufacturer's instructions. Data were analyzed with descriptive statistics and Mann-Whitney test using SPSS 18.

Results

Average TAC level in the saliva of women with gestational diabetes was 0.10 ± 0.14, with 0.04 ± 0.11 in non-diabetic pregnant women. Nonparametric Mann-Whitney test showed that this difference was statistically significant (P=0.024).

Conclusions

Under the limitations of the present study it can be concluded that there is an increase in oxidative stresses during pregnancy, followed by an increase in the total levels of salivary antioxidants to counteract such stresses. Therefore, it is expected that determining the salivary antioxidant levels during pregnancy can be an alternative technique for the early diagnosis of diabetes. Key words:Gestational diabetes mellitus, pregnancy, saliva, total antioxidant capacity.

Oleuropein improves glucose tolerance and lipid profile in rats with simultaneous renovascular hypertension and type 2 diabetes

Oleuropein mediates most of the beneficial effects of olive products. This study examined the role of oxidative stress in the effects of oleuropein on lipid profile and blood glucose in rats with simultaneous renovascular hypertension and type 2 diabetes. Eight groups (n = 7-9 each) of male Sprague-Dawley rats including a control, a type 2 diabetic, a renovascular hypertensive, a sham, a simultaneously hypertensive diabetic receiving vehicle, and 3 simultaneously hypertensive-diabetic receiving 20, 40, or 60 mg/kg/day oleuropein were used. Four weeks after treatment, blood glucose, lipid profile, and biomarkers of oxidative stress were measured, and glucose tolerance test (GTT) was performed. Simultaneously hypertensive diabetic rats had significantly higher blood pressure, blood glucose, and serum total cholesterol, low-density lipoprotein cholesterol (LDL-C), triglyceride and malondialdehyde. They also had lower serum high-density lipoprotein cholesterol, erythrocyte superoxide dismutase, and impaired glucose tolerance. Oleuropein significantly reduced blood pressure, blood glucose, and serum total cholesterol, LDL-C, triglyceride and malondoaldehyde. It also increased serum high-density lipoprotein cholesterol, erythrocyte superoxide dismutase, and improved glucose tolerance. The findings show that the model is associated with impaired glucose tolerance, and adverse lipid profile. They also show that oleuropein, partly by an antioxidant mechanism, improves glucose tolerance and changed lipid profile favorably.

Oxidative stress and DNA damage in newborns born to mothers with hyperglycemia - a prospective cohort study

BACKGROUND

Hyperglycemic mothers have increased oxidative stress during pregnancy, which can adversely affect the outcome in their neonates.

OBJECTIVES

To measure the oxidative stress and DNA damage in newborns born to mothers with hyperglycemia and correlate their immediate outcome with the amount of oxidative stress and DNA damage.

METHODS

This prospective cohort study conducted in a tertiary care teaching hospital, South India included three groups - newborns born to pregestational diabetic mothers, gestational diabetic mothers, and euglycemic mothers with 24 newborns in each. Oxidative stress parameters - malondialdehyde (MDA), total antioxidant capacity (TAC), and DNA damage (comet assay) were assessed in umbilical cord blood. Association between these parameters and immediate neonatal outcome among three groups were studied.

RESULTS

Newborns born to diabetic mothers had more MDA levels and DNA damage compared to euglycemic mothers. There was a positive correlation between comet parameters and MDA levels. There was an inverse correlation between comet parameters and TAC. Newborns born to diabetic mothers were at high risk to develop respiratory distress syndrome, hypoglycemia, and sepsis.

CONCLUSIONS

Newborns born to diabetic mothers had increased oxidative stress and DNA damage compared to those born to mothers with euglycemia.

Preventing, treating, and predicting barbering: A fundamental role for biomarkers of oxidative stress in a mouse model of Trichotillomania

Barbering, where a “barber” mouse plucks hair from its cagemates or itself, is both a spontaneously occurring abnormal behavior in mice and a well validated model of Trichotillomania (TTM). N-Acetylcysteine, (NAC) a cysteine derived food additive, is remarkably effective in treating TTM patients, but its mechanism of action is unknown. Reactive Oxygen Species (ROS), also known as free radicals, form as a natural byproduct of the normal metabolism of oxygen. Under normal circumstances, cells are able to defend themselves against ROS damage with antioxidant pathways. NAC is the precursor to the main antioxidant produced to defend the brain. Therefore, we hypothesized that barbering is a disease of oxidative stress, whereby ROS and/or a failure of antioxidant defenses leads to neuronal damage that induces barbering in susceptible animals. We tested this hypothesis in 32 female C57BL/6J mice by treating half with 1g/kg BW/day of NAC in their diet, and testing for protection against developing barbering behavior and curing of barbering behavior, and simultaneously testing for a panel of biomarkers of oxidative stress. NAC reduced the chance that mice would be barbers, and this effect did not differ between healthy (i.e. prevention) and affected animals (i.e. cure). Barbering animals had elevated urinary antioxidant capacity, indicative of oxidative stress, at all timepoints. Additionally, after treatment the risk of barbering increased with decreasing hydroxy-2′-deoxyguanosine (8-OHdG) levels, and with increasing glutathione (GSH) and oxidized glutathione (GSSG) levels, further indicating that barbering mice were under oxidative stress regardless of treatment with NAC. We did not find compelling evidence that urinary total antioxidant capacity, or urinary 8-OHdG, could predict response to NAC treatment. We conclude that NAC is effective in preventing and/or curing barbering at least in part by promoting GSH synthesis, thereby preventing oxidative damage.

Role of Superoxide Dismutase 2 Gene Ala16Val Polymorphism and Total Antioxidant Capacity in Diabetes and its Complications

Diabetes Mellitus (DM) is a chronic heterogeneous disorder and oxidative stress is a key participant in the development and progression of it and its complications. Anti-oxidant status can affect vulnerability to oxidative damage, onset and progression of diabetes and diabetes complications. Superoxide dismutase 2 (SOD2) is one of the major antioxidant defense systems against free radicals. SOD2 is encoded by the nuclear SOD2 gene located on the human chromosome 6q25 and the Ala16Val polymorphism has been identified in exon 2 of the human SOD2 gene. Ala16Val (rs4880) is the most commonly studied SOD2 single nucleotide polymorphism (SNP) in SOD2 gene. This SNP changes the amino acid at position 16 from valine (Val) to alanine (Ala), which has been shown to cause a conformational change in the target sequence of manganese superoxide dismutase (MnSOD) and also affects MnSOD activity in mitochondria. Ala16Val SNP and changes in the activity of the SOD2 antioxidant enzyme have been associated with altered progression and risk of different diseases. Association of this SNP with diabetes and some of its complications have been studied in numerous studies. This review evaluated how rs4880, oxidative stress and antioxidant status are associated with diabetes and its complications although some aspects of this line still remain unclear.

Effects of lifestyle factors on urinary oxidative stress and serum antioxidant markers in pregnant Japanese women: A cohort study

Oxidative stress plays a major pathological role in pregnancy-related complications. Although oxidative stress is induced by exogenous toxins in association with a poor lifestyle in normal subjects, there is little information on the factors altering oxidative stress and antioxidant levels during pregnancy. The purpose of this study was to determine the relationship between lifestyle factors and oxidative stress/antioxidant levels during each trimester and 1-month postpartum. This prospective cohort study followed 54 healthy women through pregnancy; first, second, and third trimester and 1-month postpartum. Participants were administered a questionnaire on characteristics and lifestyle factors. Morning blood and urine samples were obtained to measure urinary biopyrrins and serum coenzyme Q10 (CoQ10) levels. The levels of urinary biopyrrins and serum CoQ10 increased significantly throughout pregnancy, with peak values registered during the third trimester. Higher biopyrrin levels were significantly associated with non-consumption of morning meal during the first trimester, smoking during the third trimester and 1-month postpartum, alcohol consumption during the third trimester, high food-based polyunsaturated fatty acid intake during the third trimester, and poor mental health scores during the first and third trimesters. Higher CoQ10 levels were significantly associated with no smoking during pregnancy and at 1-month postpartum, and with a high frequency of exercise during the third trimester and 1-month postpartum. Thus, pregnancy represents a state of oxidative stress, which can be counterbalanced by increased levels of antioxidants, such as CoQ10. We speculate that certain lifestyle choices such as avoiding smoking can reduce oxidative stress and increase antioxidant levels during pregnancy.

Evaluation of general toxicity, anti-oxidant activity and effects of ficus carica leaves extract on ischemia/reperfusion injuries in isolated heart of rat

PURPOSE

This study was aimed to evaluate general toxicity, anti-oxidant activity and effects of Ficus carica leaves extract on ischemia/reperfusion injuries.

METHODS

Antioxidant activity, total phenolic and flavonoid compounds of 70% methanolic extract of Ficus carica leaves were measured. The general toxicity test was carried out by brine shrimp lethality assay. Isolated hearts of male rats were mounted on a Langendorff apparatus and perfused with modified Krebs-Henseleit solution. In control group, the hearts were perfused with normal Krebs solution, however, treatment groups received enriched solution with the extract (0.04, 0.2 and 1 mg/ml) during stabilization and reperfusion (after 30 min global ischemia), respectively. Cardiac arrhythmias were analyzed and TTC method was used for infarct size determination.

RESULTS

The extract displayed antioxidant activity in the DPPH assay (RC50=0.06666 mg/ml). Total phenolic content was 12.29 mg GAE/100 g dry sample and the amount of flavonoids was calculated 40.729 mg/g. LD50 value by brine shrimp test was 0.158 mg/ml. The extract decreased number of VEBs, incidence and duration of Rev VF with clear reduction in infarct size and infarct volume (P<0.001).

CONCLUSION

Ficus carica decreased ischemia/reperfusion-induced injuries. These protections are probably due to antioxidant capacity and the existence of flavonoid and phenolic compounds in the extract.

Effects of uncomplicated vaginal delivery and epidural analgesia on fetal arterial acid-base parameters at birth in gestational diabetes

AIM

To investigate the effects of uncomplicated vaginal delivery and epidural analgesia on fetal acid-base parameters in women with gestational diabetes (GDM) compared with controls.

METHODS

A retrospective case-control study of 142 women with gestational diabetes and 284 controls. To evaluate the effect of diabetes and analgesia on acid-base status correcting for potential confounders we used ordered logistic equations including quartiles of fetal arterial acid-base parameters collected at birth as outcomes and categories of diabetes and epidural analgesia as explanatory variables.

RESULTS

In the GDM group cord base deficit (-2.63 mmol/l, interquartile range [IQR]=4.2 to -0.65 mmol/l vs. -1.9 mmol/l, IQR=-3.3 to -0.2 mmol/l, p=0.009, odds ratio (OR)=1.51, 95% confidence interval (CI)=1.04-2.18) was lower and concentration of calcium higher (1.49 mmol/l, IQR=1.42-1.56 mmol/l vs. 1.47 mmol/l, IQR=1.41-1.51 mmol/l, p=0.009, OR=1.69, 95% CI=1.12-2.56) compared with controls. Epidural analgesia in the GDM group was associated with reduced cord concentration of glucose (84.0mg/dl [4.7 mmol/l], IQR=70-103.3mg/dl vs. 92.5mg/dl [5.1 mmol/l], IQR=76.5-121.8 mg/dl, p=0.004), lactate (2.65 mmol/l (IQR=1.80-4.20) vs. 3.70 mmol/l (IQR=2.90-5.55 mmol/l), p=0.002) and less pronounced base deficit (-2.05 mmol/l, IQR=-3.90 to -0.17 mmol/l vs. -2.8, IQR=-5.57 to -1.05 mmol/l, p=0.01, OR=0.7, 95% CI=0.49-0.99).

CONCLUSIONS

In uncomplicated pregnancies and deliveries, well-controlled gestational diabetes mellitus has potentially significant detrimental effects on fetal acid-base status at birth. Epidural analgesia reduces cord arterial glucose and lactates.

Reactive oxygen species, vascular Noxs, and hypertension: focus on translational and clinical research

SIGNIFICANCE

Reactive oxygen species (ROS) are signaling molecules that are important in physiological processes, including host defense, aging, and cellular homeostasis. Increased ROS bioavailability and altered redox signaling (oxidative stress) have been implicated in the onset and/or progression of chronic diseases, including hypertension.

RECENT ADVANCES

Although oxidative stress may not be the only cause of hypertension, it amplifies blood pressure elevation in the presence of other pro-hypertensive factors, such as salt loading, activation of the renin-angiotensin-aldosterone system, and sympathetic hyperactivity, at least in experimental models. A major source for ROS in the cardiovascular-renal system is a family of nicotinamide adenine dinucleotide phosphate oxidases (Noxs), including the prototypic Nox2-based Nox, and Nox family members: Nox1, Nox4, and Nox5.

CRITICAL ISSUES

Although extensive experimental data support a role for increased ROS levels and altered redox signaling in the pathogenesis of hypertension, the role in clinical hypertension is unclear, as a direct causative role of ROS in blood pressure elevation has yet to be demonstrated in humans. Nevertheless, what is becoming increasingly evident is that abnormal ROS regulation and aberrant signaling through redox-sensitive pathways are important in the pathophysiological processes which is associated with vascular injury and target-organ damage in hypertension.

FUTURE DIRECTIONS

There is a paucity of clinical information related to the mechanisms of oxidative stress and blood pressure elevation, and a few assays accurately measure ROS directly in patients. Such further ROS research is needed in humans and in the development of adequately validated analytical methods to accurately assess oxidative stress in the clinic.

Effect of oxidative stress on heme oxygenase-1 expression in patients with gestational diabetes mellitus

The anti-oxidative stress effect of heme oxygenase-1 (HO-1) expression is being increasingly studied. However, few studies regarding HO-1 have been conducted in patients with gestational diabetes mellitus (GDM). In the present study, HO-1 expression was compared in peripheral blood mononuclear cells at 24-28 weeks of pregnancy in patients with GDM and healthy females, to investigate the correlation between HO-1 and oxidative stress by calculation of MDA content in the peripheral blood serum (thiobarbituric acid method), tested ROS (flow cytometry method), HO-1mRNA (RT-PCR method), and HO-1 protein (western blotting method) of Mononuclear cells. The results show that the levels of serum malonaldehyde (MDA), reactive oxygen species (ROS), HO-1 mRNA and HO-1 protein expression in peripheral blood mononuclear cells were higher in the GDM group than in the control group. Correlation analysis showed that the expression levels of HO-1 protein were positively correlated with the HO-1 mRNA expression levels (r=0.680; P=0.000), and the levels of ROS (r=0.572; P=0.000) and MDA (r=0.614; P=0.000). HO-1 mRNA expression levels were found to positively correlate with the levels of MDA (r=0.451; P=0.010) and fasting plasma glucose (FPG; r=0.337; P=0.039). Partial correlation analysis demonstrated that, after removing the effects of body mass index, FPG and 2-h plasma glucose, HO-1 protein expression levels were positively correlated with the levels of HO-1 mRNA expression (r=0.611; P=0.005), ROS (r=0.526; P=0.021) and MDA (r=0.519; P=0.015). These findings indicate that pregnant females with GDM may be protected against oxidative injury due to the induction of adaptive and compensatory expression of HO-1 to guard against oxidative stress induced by high glucose levels.

The ameliorative effect of Cetraria islandica against diabetes-induced genetic and oxidative damage in human blood

CONTEXT

The aqueous extracts of Cetraria islandica (L.) Ach. (Parmeliaceae) is traditionally used in many countries against a number of conditions, including inflammatory conditions.

OBJECTIVE

The present study aimed to assess, for the first time, the effectiveness of C. islandica in cultured primary blood cells of Type 1 diabetes subjects.

MATERIALS AND METHODS

Diabetic and control blood samples were treated with or without aqueous lichen extract (5 and 10 μg mL(-1)) for 48 h. The activity of antioxidant enzymes in erythrocytes and also malondialdehyde levels in plasma were determined to evaluate the oxidative status. DNA damages were analyzed by SCE, MN and comet assays in cultured human lymphocytes. Additionally, proliferation index (PI) was evaluated in peripheral blood lymphocytes.

RESULTS

There were significant increases in observed total DNA damage (comet assay) (240.2%) and SCE (168.8%), but not in MN frequencies of cultures with diabetes as compared (p > 0.05) to controls. Whereas, the significant reductions of total DNA damage (69.2 and 65.3%) and SCE frequencies (17.7 and 12.3%) were determined when the 5 and 10 mg mL(-1) lichen extract was added to the cell culture medium, respectively. However, lichen extract did not completely inhibit the induction of SCEs in lymphocytes of patients with diabetes. C. islandica extract was also useful on PI rates.

DISCUSSION

In conclusion, the antioxidant role of C. islandica in alleviating diabetes-induced genomic instability and for increasing cell viability was firstly indicated in the present study.

A parallel increase in placental oxidative stress and antioxidant defenses occurs in pre-gestational type 1 but not gestational diabetes

We aimed to determine the oxidative stress status in placentas obtained from gestational (GDM) and type 1 (T1D) diabetic pregnancies. Malonaldehyde and protein carbonyls, two biomarkers of oxidative damage, were higher in T1D but not in GDM placentas. Also, higher reduced glutathione and lower oxidized glutathione levels and higher glutathione peroxidase activity were found in T1D but not in GDM placentas. These results suggest that T1D placentas may develop a protective antioxidant mechanism to overcome higher oxidative stress levels.

Rosmarinic acid administration attenuates diabetes-induced vascular dysfunction of the rat aorta

OBJECTIVES

Oxidative stress as well as inflammation processes are engaged in diabetic vascular complications. Rosmarinic acid, a natural phenol antioxidant carboxylic acid, was found to have multiple biological activity, including anti-inflammatory and antitumour effects, which are a consequence of its inhibition of the inflammatory processes and of reactive oxygen species scavenging. The aim of this work was to study effects of rosmarinic acid administration on vascular impairment induced by experimental diabetes in rats.

METHODS

Diabetes was induced by streptozocin (3 × 30 mg/kg daily, i.p.) in Wistar rats. Rosmarinic acid was administered orally (50 mg/kg daily). Ten weeks after streptozocin administration, the aorta was excised for functional studies, evaluation by electron microscopy and real time PCR analysis.

KEY FINDINGS

In the aorta of diabetic rats, decreased endothelium-dependent relaxation was accompanied by overexpression of interleukin-1β, tumour necrosis factor-α, preproendothelin-1 and endothelin converting enzyme-1. Structural alterations in the endothelium, detected by electron microscopy, indicated aortic dysfunction caused by diabetes. The diabetes-induced aortic disorders were prevented by rosmarinic acid administration.

CONCLUSIONS

Rosmarinic acid protected aortic endothelial function and ultrastructure against diabetes-induced damage. Both antioxidant and anti-inflammatory effects of rosmarinic acid seemed to participate in the mechanism of this protection.