Age, Homocysteine, and Oxidative Stress: Relation to Hypertension and Type 2 Diabetes Mellitus

Effectiveness of two photosensitizer-mediated photodynamic therapy for treating moderate peri-implant infections in type-II diabetes mellitus patients: A randomized clinical trial

PURPOSE

This study evaluated the impact of Fox Green (FG) against methylthioninium chloride (MTC)-facilitated photodynamic therapy (PDT) as an adjunctive to manual scaling (MS) on the peri‑implant clinical and cytokine parameters in type-2 diabetes mellitus (DM) patients with peri‑implantitis.

METHODS

Patients were divided into group-A comprising 13 patients who received adjunctive FG-PDT using a diode laser (wavelength: 810 nm; irradiation power: 300 mW; irradiation time: 30 s; fluence: 56 Jcm-2), group-B comprising 12 patients who received adjunctive MTC-PDT using a diode laser (wavelength: 660 nm; irradiation power: 100 mW; irradiation time: 120 s/site; fluence: 30 Jcm-2), and group-C comprising 13 patients who received MS alone [control group]). After diagnosing the diabetics with peri‑implantitis (established on eligibility criteria), a structured questionnaire was used to gather the information of the participants. Plaque (PS) and bleeding scores (BS), along with peri‑implant probing scores (PPS) and peri‑implant bone loss (PIBL), together with immunological variables (interleukin [IL]-6, tumor necrosis factor-alpha [TNF-α], and advanced glycation end products [AGEs]) were measured in all study group participants at baseline, 3-month, and 6-month follow-ups.

RESULTS

A significant reduction was observed for PS, BS, and PPS within all tested groups at each follow-up visits compared from their baseline values (p<0.05). However, a substantial decrease in PIBL was observed in all study group patients at 6-month follow-up as compared to 3-month follow-up (p<0.05). Regarding the levels of IL-6 and TNF-α, a substantial reduction was observed in all study groups until 6-month from their baseline scores (p<0.05). However, no changes were observed in the levels of AGEs in any group at either visit (p>0.05).

CONCLUSION

In DM patients with periimplantitis, adjunctive FG-PDT and MTC-PDT exhibited comparable outcomes in terms of peri‑implant clinical as well as pro-inflammatory characteristics than MS alone among peri‑implantitis patients with DM.

Modulation of broiler plasma metabolic spectrum by the addition of lysine residue to the diet

Flavour is an important factor in evaluating meat quality, and amino acids and fats are important components affecting meat flavour. In this study, we evaluated the relationship between the variation of lysine residue addition and the slaughter performance and meat quality of broilers, which decreased with the addition of lysine residues but improved the meat quality of the broilers. 10% lysine residue addition was the most beneficial for reducing feed cost and improving meat quality. Meanwhile, the plasma metabolites of broilers fed increasing concentrations of lysine residue supplemented feeds were analysed using liquid chromatography-mass spectrometry (LC-MS). Principal component analysis (PCA) and partial least square discriminant analysis (OPLS-DA) were used screen, the differential metabolites induced by lysine residue. In the broilers 29, 37, 63, 87, 80 and 111 differential metabolites were detected (p < 0.05). Amongst them, 3-iodotyrosine, N-methyl-L-glutamic acid, coumaraldehyde, 2-dimethylphenol, N-methylnicotinamide and L-erythrone were the common differential metabolites between group A and groups B, C, D, E, F and G. The addition of lysine residue was positively correlated with alanine aminotransferase (p < 0.05, r = 0.942) and high-density lipoprotein cholesterol (p < 0.05, r = 0.798) and negatively correlated with aspartate aminotransferase (p < 0.05, r = 0.822). According to the classification of differential metabolites and their enriched pathway analysis, differential metabolites mainly caused changes in amino acid and lipid metabolism. Our study shows that a certain proportion of lysine residue in diet affects the specific metabolic pathway of broilers, which may affect amino acid and fat metabolism by regulating alanine aminotransferase, aspartate aminotransferase and high-density lipoprotein cholesterol, ultimately affecting the flavour.

Clinical, bacterial, and inflammatory outcomes of indocyanine green-mediated photodynamic therapy for treating periimplantitis among diabetic patients: A randomized controlled clinical trial

Background This 6-months randomized controlled clinical trial aimed to assess the efficacy of indocyanine green mediated photodynamic therapy (ICG-PDT) as an adjunct to peri‑implant manual debridement (PIMD) versus PIMD alone among Diabetes Mellitus (DM) patients in the treatment of peri‑implantitis. Methods A total of 48 DM patients having 64 implants were treated with either ICG-PDT + PIMD (n = 35 implants) or PIMD alone (n = 29 implants). Clinical (probing depth [PD], bleeding on probing [BOP], and plaque index [PI]) and radiographic (peri‑implant crestal bone loss [PCBL]) peri‑implant variables were recorded. Bacterial species including Porphyromonas gingivalis and Treponema denticola were evaluated from peri‑implant plaque biofilms. Levels of interleukin (IL)-1β and IL-6 were assessed after the collection of peri‑implant sulcular fluid. All the evaluations were carried out at baseline, 3- and 6-months. The significance level was set to p < 0.05. Results All clinical parameters significantly reduced within both treatment groups (P<0.05). Intra-group comparison indicates that there was statistically significant reduction in PD and suppuration for ICG-PDT group (P<0.05). There was a statistically significant difference in the BOP between ICG-PDT and PIMD groups at both follow-up periods (P<0.001). However, there was a significant difference for PD (P = 0.001), suppuration (P = 0.01), and PCBL (P = 0.04) on 6 months follow-up between ICG-PDT and PIMD groups, respectively. Only ICG-PDT showed a significant reduction in P. gingivalis and T. denticola on both 3 months and 6 months follow-up compared to baseline. PIMD showed a statistically significant reduction only on 3 months follow-up compared to baseline. This reduction was maintained for both the species when dental implants were treated with ICG-PDT. However, PIMD failed to maintain this reduction until 6 months. Only at 3 months assessment that both treatment groups showed statistically significant reduction in IL-1β and IL-6 with no significant difference between the groups. Both biomarkers failed to maintain the reduction in both groups and significantly increased levels for IL-1β was noted at 6 months follow up Conclusion Multiple application of indocyanine-green mediated photodynamic therapy resulted in improved clinical and microbial parameters among type 2 DM subjects in the treatment of peri‑implantitis. This clinical trial was registered in the ClinicalTrials.gov Protocol Registration and Results System with registration record number: NCT04833569.

Phytosterol Extract Decreases the Oxidative Damage in the Brains of Diabetic db/db Mice

Introduction: Hypercaloric diets induce oxidative stress, and consequently induce hyperglycemia and type 2 diabetes mellitus (T2DM). Thus, oxidative stress is significantly increased in T2DM, leading to oxidative damage to brain, which might contribute to cognitive deficits and neurodegenerative diseases. Therefore, reducing the oxidative stress is important to preserving cognitive functions, and it has been suggested that phytosterols may reduce the oxidative stress. Objective: The objective of the present study was to determine the effects of phytosterols derived from corn on oxidative damage in the cerebellum, frontal cortex, and hippocampus of diabetic db/db mice. Materials and Methods: A phytosterol extract was isolated from yellow corn (Zea mays L.) and 100 mg/kg of the extract was administrated daily to diabetic mice for 8 weeks. At the end of the treatment period, tissues were isolated to determine the levels of oxidized lipid and protein. Results: The phytosterol treatment increased body weight in diabetic db/db mice, but this treatment did not have any effects on body weight in wild-type mice. Moreover, the phytosterol treatment decreased levels of oxidized lipids in the cerebellum, frontal cortex, and hippocampus, and also decreased the levels of oxidized proteins in the cerebellum and frontal cortex in diabetic db/db mice. Conclusion: These important results show that phytosterol treatment can reduce oxidative damage in the brains of diabetic mice.

Association between plasma homocysteine and hypertension: Results from a cross-sectional and longitudinal analysis in Beijing's adult population from 2012 to 2017

Plasma homocysteine (Hcy) levels are associated with elevated blood pressure. However, the causal association between Hcy levels and the risk of hypertension remains ambiguous. Taking the study design effect into consideration, this study aimed to investigate this issue through a cross-sectional and longitudinal analysis. Data were obtained from the Beijing Health Management Cohort study, which conducted routine health check-ups from 2012 to 2017. Multivariate logistic regression was used for the cross-sectional analysis, and a quadratic inference function approach was performed for the longitudinal analysis. A total of 30 376 subjects (mean age = 50.0 years) were included in the cross-sectional analysis, and a subgroup of 3913 subjects without hypertension at baseline was included in the longitudinal analysis. After adjusting for potential confounders, the risk of hypertension increased with Hcy levels in the cross-sectional analysis using the traditional definition of hypertension (OR = 1.262, 95% CI: 1.155-1.378, Q2 vs Q1; OR = 1.458, 95% CI: 1.335-1.593, Q3 vs Q1; OR = 1.520, 95% CI: 1.388-1.664, Q4 vs Q1) and the 2017 hypertension definition (OR = 1.159, 95% CI: 1.067-1.259, Q2 vs Q1; OR = 1.328, 95% CI: 1.221-1.445, Q3 vs Q1; OR = 1.328, 95% CI: 1.217-1.449, Q4 vs Q1). The longitudinal analysis showed that hypertension risk increased in the third quartile of Hcy (OR = 1.268, 95% CI: 1.030-1.560, Q3 vs Q1). Elevated total plasma Hcy may be used as a predictive biomarker for hypertension. Attention should be paid to gender-specific mechanisms when issuing precise precautions.

Effect ofBifidobacterium lactisHN019 on inflammatory markers and oxidative stress in subjects with and without the metabolic syndrome

Beneficial effects of probiotics have been reported on body weight, lipid and carbohydrate metabolism, inflammatory state and oxidative stress in healthy subjects and in many metabolic and inflammatory diseases. The aim of this study was to evaluate the effects ofBifidobacterium lactisHN019 on inflammatory state and nitro-oxidative stress in patients with and without the metabolic syndrome (MetS). The usual diets of the thirty-three subjects were supplemented with probiotic milk for 90 d. Inflammatory markers and oxidative measurements were performed. In relation to the baseline values, subjects in both groups showed a decrease in homocysteine (P=0·02 andP=0·03, respectively), hydroperoxides (P=0·02 andP=0·01, respectively) and IL-6 levels (P=0·02). Increases in adiponectin (P=0·04) and nitric oxide metabolites (NOx,P=0·001) levels were only seen in the group with the MetS in relation to the baseline values, whereas only the individuals without the MetS had increases in total radical-trapping antioxidant parameter levels (P=0·002). In conclusion,B. lactisHN019 have several beneficial effects on inflammatory and oxidative biomarkers in healthy subjects and the MetS patients. Patients with the MetS showed a specific improvement in adiponectin and NOx levels, whereas a specific favourable effect was shown in the antioxidant defenses in healthy subjects. If the results obtained in the present study are confirmed, supplementation of fermented milk with probiotics in healthy subjects and patients with the MetS must be further discussed.

The Cardiovascular Effect of Systemic Homocysteine Is Associated with Oxidative Stress in the Rostral Ventrolateral Medulla

It has been demonstrated that homocysteine (HCY) is a significant risk factor of hypertension, which is characterized by overactivity of sympathetic tone. Excessive oxidative stress in the rostral ventrolateral medulla (RVLM), a key region for control of sympathetic outflow, contributes to sympathetic hyperactivity in hypertension. Therefore, the goal of the present study is to determine the effect of systemic HCY on production of reactive oxygen species (ROS) in the RVLM. In the rat model of the diet-induced hyperhomocysteinemia (L-methionine, 1 g/kg/day, 8 weeks), we found that the HCY resulted in a significant increase (≈3.7-fold, P < 0.05) in ROS production in the RVLM, which was paralleled with enhanced sympathetic tone and blood pressure (BP). Compared to the vehicle group, levels of BP and basal renal sympathetic nerve activity in the HCY group were significantly (P < 0.05, n = 5) increased by an average of 27 mmHg and 31%, respectively. Furthermore, the rats treated with L-methionine (1 g/kg/day, 8 weeks) showed an upregulation of NADPHase (NOX4) protein expression and a downregulation of superoxide dismutase protein expression in the RVLM. The current data suggest that central oxidative stress induced by systemic HCY plays an important role in hypertension-associated sympathetic overactivity.

Clinical Manifestations of Isolated Elevated Homocysteine-Induced Peripheral Neuropathy in Adults

OBJECTIVE

To characterize the clinical features of isolated elevated plasma homocysteine (eHcy)-induced peripheral neuropathy (IHIN) in adults.

METHODS

Charts of subjects with the diagnosis of IHIN who visited neuromuscular clinic from January 01, 2012 to September 30, 2014 were reviewed. Subjects with identifiable etiologies for neuropathy, such as B12/folate deficiency; metabolic, toxic, endocrinologic, infectious/inflammatory renal or liver diseases; or traumatic nerve injury, were excluded. Their clinical presentations were recorded and analyzed.

RESULTS

Thirty subjects (age: 63.2 ± 14.8 years, 13 males) were included. They all had an isolated increased homocysteine level (15.4 ± 5.3 μmol/L) but normal levels of B12, folate, and methylmalonic acid. Of 30, 14 (46.7%) had numb feet, 11 (36.7%) had numb hands, 7 (23.3%) had pain in lower extremities, and 10 (33.3%) had tingling in feet. Distal sensory deficits were present in 18/30 (60%) patients. Distal limb weakness was seen in 4 and decreased tendon reflexes in 12 patients.

CONCLUSIONS

Sensory deficits are predominant components of IHIN. Characterizing clinical features of IHIN would help better understand eHcy-related neuropathy and improve its management.

Daytime sleepiness is associated with hyperhomocysteinemia in rural area of China: A cross-sectional study

OBJECTIVE

To ascertain whether sleep abnormalities including daytime sleepiness, snoring, apnea, sleep disruption and sleep duration abnormity are significantly associated with hyperhomocysteinemia (Hhcy).

METHODS

A total of 5992 participants were involved in the cross-sectional study. Sleep abnormalities were evaluated by a structured questionnaire. Hhcy was defined as plasma levels of homocysteine ≥15μm/L.

RESULTS

After adjustment for age, gender, education, current smoking status and current drinking status, daytime sleepiness (OR, 1.597; 95%CI, 1.210-2.110, P=0.001), sleep duration <6h (OR, 1.273; 95%CI, 1.063-1.524, P=0.009) and sleep duration >8h (OR, 1.205; 95%CI, 1.065-1.364, P=0.003) were significantly associated with Hhcy. While snoring (OR, 1.065; 95%CI, 0.950-1.195, P=0.279), apnea (OR, 1.170; 95%CI, 0.924-1.482, P=0.193), and sleep disruption (OR, 1.065; 95%CI, 0.852-1.331, P=0.580) were not. After further adjustment for body mass index, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride, total cholesterol, physical activity, diabetes, coronary heart disease, stroke, depression, glomerular filtration rate, hypertension and hyperuricemia, still the increased OR could be found in the daytime sleepiness group (OR, 1.569; 95%CI, 1.145-2.150, P=0.005). However, sleep duration <6h (OR, 1.067; 95%CI, 0.788-1.445, P=0.676) and sleep duration >8h groups (OR, 1.080; 95%CI, 0.883-1.320, P=0.453) were no longer significantly associated with Hhcy.

CONCLUSIONS

Daytime sleepiness, but not sleep duration abnormity, snoring, apnea and sleep disruption was an independent risk factor for Hhcy.

[Association between metabolic syndrome and hyperhomocysteinemia in an Algerian population]

INTRODUCTION

Metabolic syndrome (MS) is a phenomenon of insulin resistance, a harbinger of serious cardiovascular events. The lifestyle of Algerian becoming increasingly occidental, SM becomes a major problem of public health in our country. Furthermore, hyperhomocysteinemia is also recognized as a cardiovascular risk factor. The objective of this study was to determine the prevalence of hyperhomocysteinemia in patients with SM in our people and to seek a possible relationship between these two risk factors.

PATIENTS AND METHODS

We performed a prospective study that was focused on 62 hospitalized patients with SM, composed of 33 men and 29 women. Clinical data were collected and laboratory tests were also performed.

RESULTS

The average age of our patients was 52±20 years; the average waist circumference was 103.4±10.1cm in men and 91.5±8.42cm in women. In this study, 53.2%, 54.4%, 25.8% and 51.6% of patients had respectively hypertension, hyperglycemia, low HDL-C levels and hypertriglyceridemia. The prevalence of hyperhomocysteinemia was 62.9% in our patients. This prevalence is correlated with age and the number of the SM components. Multivariate linear regression analysis showed no significant association between hyperhomocysteinemia and SM components studied separately.

CONCLUSION

The prevalence of hyperhomocysteinemia in patients with an SM is important in our population. It increases with age and number of SM components, without a relationship between hyperhomocysteinemia and SM components studied separately.

Biomarkers of lipid peroxidation related to hypertension in aging

The aim of this clinical study was to evaluate the influence of aging on the levels of lipid peroxidation (quantified as thiobarbituric acid-reactive substances (TBARS) content), lipid hydroperoxide (LOOH), hexanoyl lysine (HEL), 8-iso-prostaglandin F2α (8-iso-PGF2α) and total antioxidant capacity (TAC), and determine their relationships to the demographic and cardiovascular risk factors in elderly hypertensive (HT) patients. This study consisted of four groups: two elderly groups with 30 HT patients (11 males, 19 females) and 30 normotensive healthy volunteers (15 males, 15 females), and two young groups with 30 HT patients (13 males, 17 females) and 30 normotensive healthy volunteers (12 males, 18 females). In the elderly control group, the TBARS, LOOH, HEL and 8-iso-PGF2α levels, and the carotid intima media thickness (CIMT) were significantly higher than in the young control group. The TBARS, LOOH, HEL and 8-iso-PGF2α levels and the CIMT measurements were significantly higher in the elderly HT group than in the young HT group. In addition, the TAC levels were significantly lower in the elderly and young HT groups than in the elderly and young control groups. The CIMT was significantly positively correlated with TBARS (r=0.40, P<0.001), HEL (r= 0.30, P=0.001), LOOH (r= 0.44, P<0.001) and 8-iso-PGF2α (r= 0.32, P<0.001) in all of the HT groups. It seems that in elderly patients, the LOOH and TBARS are better biomarkers of lipid peroxidation in hypertension in terms of sensitivity. In all of the HT groups, 8-iso-PGF2α had the highest sensitivity. Hypertension is associated with lipid peroxidation due to an impaired oxidant/antioxidant status. Increased lipid peroxidation and decreased antioxidants with aging indicate that peroxidative damage further increases with higher blood pressure and the aging process.

Altered one-carbon metabolism in posttraumatic stress disorder

BACKGROUND

Posttraumatic stress disorder (PTSD) is associated with increased morbidity and mortality through somatic conditions, particularly cardiovascular disease. The one-carbon metabolism in connection with the hypothalamic-pituitary-adrenal (HPA)-axis may be an important mediator of this increased cardiovascular risk.

METHODS

In a mixed-gender sample of 49 PTSD patients and 45 healthy controls we therefore investigated: (1) alterations in the one-carbon metabolism as reflected in fasting plasma concentrations of homocysteine, folate, vitamins B6 and B12, and (2) associations of these one-carbon metabolites with the HPA-axis hormones cortisol, dehydroepiandrosterone (DHEA) and its sulfate (DHEA-S).

RESULTS

After correction for confounders, PTSD patients had significantly elevated homocysteine (z = 2.963, p = .003) compared to controls, but normal levels of folate, vitamin B6 and B12. Comorbid depression did not explain the observed higher homocysteine levels. Patients showed increased risk for moderate hyperhomocysteinemia (OR = 7.0, χ(2) = 7.436, p = .006). Additionally, homocysteine was associated with PTSD severity (z = 2.281, p = .005). Moreover, all HPA-axis hormones were associated with folate in both patients and controls (all p's ≤ .011), while DHEA-S influenced folate in patients (z = 2.089, p = .037).

LIMITATIONS

Our clinical sample is relatively small and therefore small-sized effects may have remained undetected.

CONCLUSIONS

Our study indicates that: (1) the one-carbon metabolism is altered in PTSD patients, (2) earlier findings of higher homocysteine in male PTSD patients are generalized to female patients, (3) homocysteine is negatively associated with PTSD severity, and (4) HPA-axis alterations are associated with the one-carbon metabolism. Longitudinal studies are needed to determine whether elevated homocysteine levels reflect preexisting risk factors and/or consequences of psychological trauma.

Factors that characterize bone health with aging in healthy postmenopausal women

The exponential increase in the incidence of fragility fractures in older people is attributed to attenuation of both bone strength and neuromuscular function. Decrease in bone mineral density (BMD) does not entirely explain this increase. The objective of this study is to investigate the effect of age on various parameters related to bone health with aging, and to identify combinations of factors that collectively express the bone metabolic state in healthy postmenopausal women. Height, weight, and grip strength were measured in 135 healthy postmenopausal volunteer women. Hip BMD, biomechanical indices derived from quantitative computed tomography (QCT), cross-sectional areas of muscle and fat of the proximal thigh, and various biochemical markers of bone metabolism were measured. A smaller group of factors explanatory for bone health was identified using factor analysis and each was newly named. As a result, the factors bone mass, bone turnover, bone structure, and muscle strength had the greatest explanatory power for assessing the bone health of healthy postmenopausal women. Whereas dual X-ray absorptiometry parameters only loaded on the factor bone mass, QCT parameters loaded on both the factors bone mass and bone structure. Most bone turnover markers loaded on the factor bone turnover, but deoxypyridinoline loaded on both bone turnover and muscle strength. Age was negatively correlated with bone mass (r = -0.49, p < 0.001) and muscle strength (r = -0.67, p < 0.001). We conclude that aging is associated as much with muscle weakening as with low BMD. More attention should be paid to the effects of muscle weakening during aging in assessments of bone health.

Association of glutathione S-transferase T1 and M1 gene polymorphisms with ischemic stroke risk in the Chinese Han population

Atherosclerosis plays an important role in ischemic stroke, and oxidative stress participates in the entire process of atherosclerosis. Glutathione S-transferase (GST) acting with other antioxidant enzymes can eliminate reactive oxygen species and protect cells against oxidative damage. To assess the association of glutathione S-transferase (GSTT1 and GSTM1) gene polymorphisms with ischemic stroke in the Chinese Han population, the present study selected 315 patients with ischemic stroke and 210 healthy controls for comparison. GSTT1 and GSTM1 genotypes were determined using polymerase chain reactions, electrophoresis and imaging analysis. No obvious evidence of GSTT1-null, GSTM1-null and GSTT1/GSTM1-double null genotype distribution differences was found between case and control groups or between genders. Subgroup analysis showed that the risk of stroke was increased when hypertension was accompanied by GSTT1-null (odds ratio (OR) = 2.996, P < 0.001) and GSTM1-null (OR = 3.680, P < 0.001) genotypes; diabetes mellitus was accompanied by GSTT1-null (OR = 1.860, P = 0.031) and GSTM1-null (OR = 2.444, P = 0.002) genotypes, and smokers showed a GSTT1-null genotype (OR = 2.276, P = 0.003). GSTT1- and GSTM1-null genotypes may interact synergistically with hypertension, diabetes mellitus and smoking to increase the incidence risk of ischemic stroke.

Oxidative stress in patients with Alzheimer's disease: effect of extracts of fermented papaya powder

Brain tissue is particularly susceptible to oxidative stress (OS). Increased production of reactive oxygen species (ROS), reduced antioxidant systems, and decreased efficiency in repairing mechanisms have been linked to Alzheimer's disease (AD). Postmortem studies in AD patients' brains have shown oxidative damage markers (i.e., lipid peroxidation, protein oxidative damage, and glycoxidation). Fermented papaya (FPP, a product of Carica papaya Linn fermentation with yeast) is a nutraceutical supplement with favorable effects on immunological, hematological, inflammatory, and OS parameters in chronic/degenerative diseases. We studied 40 patients (age 78.2 ± 1.1 years), 28 AD patients, and 12 controls. Urinary 8-OHdG was measured to assess OS. Twenty AD patients were supplemented with FPP (Immunage, 4.5 grams/day) for 6 months, while controls did not receive any treatment. At baseline, 8-OHdG was significantly higher in patients with AD versus controls (13.7 ± 1.61 ng/mL versus 1.6 ± 0.12 ng/mL, P < 0.01). In AD patients FPP significantly decreased 8-OHdG (14.1 ± 1.7 ng/mL to 8.45 ± 1.1 ng/mL, P < 0.01), with no significant changes in controls. AD is associated with increased OS, and FPP may be helpful to counteract excessive ROS in AD patients.

Curcumin restores mitochondrial functions and decreases lipid peroxidation in liver and kidneys of diabetic db/db mice

Background

Nitrosative and oxidative stress play a key role in obesity and diabetes-related mitochondrial dysfunction. The objective was to investigate the effect of curcumin treatment on state 3 and 4 oxygen consumption, nitric oxide (NO) synthesis, ATPase activity and lipid oxidation in mitochondria isolated from liver and kidneys of diabetic db/db mice.

Results

Hyperglycaemia increased oxygen consumption and decreased NO synthesis in liver mitochondria isolated from diabetic mice relative to the control mice. In kidney mitochondria, hyperglycaemia increased state 3 oxygen consumption and thiobarbituric acid-reactive substances (TBARS) levels in diabetic mice relative to control mice. Interestingly, treating db/db mice with curcumin improved or restored these parameters to normal levels; also curcumin increased liver mitochondrial ATPase activity in db/db mice relative to untreated db/db mice.

Conclusions

These findings suggest that hyperglycaemia modifies oxygen consumption rate, NO synthesis and increases TBARS levels in mitochondria from the liver and kidneys of diabetic mice, whereas curcumin may have a protective role against these alterations.

Effect of curcumin on hepatic heme oxygenase 1 expression in high fat diet fed rats: is there a triangular relationship?

High fat diet (HFD) is associated with oxidative stress induced fatty liver. Curcumin, an extract of Curcuma longa, has been shown to possess potent antioxidant and hypolipidemic properties. In this study, we investigated the effect of curcumin treatment on hepatic heme oxygenase-1 (HO-1) expression along with pro-oxidant-antioxidant status and lipid accumulation in rats fed an HFD. Male Sprague-Dawley rats were distributed among 4 groups: Group 1, which was fed the control diet (10% of total calories from fat); Group 2, which was fed the HFD (60% of total calories from fat); and groups 3 and 4, which received the HFD supplemented with curcumin and the control diet supplemented with curcumin (1 g/kg diet; w/w), respectively, for 16 weeks. HFD caused increases in hepatic lipid levels, production of reactive oxygen species, and lipid peroxidation. Further, HO-1 expression was significantly decreased. Histopathological examination showed hepatic fat accumulation and slight fibrotic changes. Curcumin treatment reduced hepatic lipids and oxidative stress parameters, and HO-1 expression was significantly increased. These findings suggest that increased HO-1 expression, along with suppressed oxidative stress as well as reduced hepatic fat accumulation and fibrotic changes, contribute to the beneficial effects of curcumin in attenuating the pathogenesis of fatty liver induced metabolic diseases.

Evaluation of cardiovascular biomarkers in patients with age-related wet macular degeneration

AIM

To evaluate levels of homocysteine, asymmetric dimethylarginine (ADMA), and nitric oxide (NO), as well as activity of endothelial NO synthase (eNOS), in patients with age-related macular degeneration (AMD).

METHODS

The levels of homocysteine, ADMA, and NO and activity of eNOS in patients who were diagnosed with wet AMD by fundus fluorescein angiography (n=30) were compared to a control group with no retinal pathology (n=30).

RESULTS

Levels of homocysteine and ADMA were found to be significantly higher in the wet AMD group than in the control group (P<0.001), whereas NO levels and eNOS activity were higher in the control group (P<0.001). In the wet AMD group, we detected a 2.64- and 0.33-fold increase in the levels of ADMA and homocysteine, respectively, and a 0.49- and 2.41-fold decrease in the eNOS activity and NO level, respectively.

CONCLUSION

Elevated levels of homocysteine and ADMA were observed in patients with wet AMD. Increased ADMA may be responsible for the diminished eNOS activity found in these patients, which in turn contributes to the decrease in NO levels, which likely plays a role in the pathogenesis of AMD.

Dietary contributors to hypertension in adults reviewed

Recent national surveys which measured respondents' blood pressure (BP) levels have shown a high prevalence of hypertension amongst the Irish population, with approximately two-thirds of men and over half of women aged 45 years and over affected. Higher prevalence rates are observed with advancing age. Established diet- and lifestyle-related risk factors for hypertension such as high salt intake, high alcohol consumption and physical inactivity are pervasive in Ireland and are believed to contribute significantly to the high national prevalence of this condition. Additional dietary deficits have been implicated in the development of hypertension, however, including low fruit and vegetable intake, low dairy food consumption and low intake of oily fish. Deficiencies of single micro-nutrients such as folate, riboflavin, vitamin C and vitamin D have also been recently recognised as risk factors for hypertension. For each of these factors, there is evidence that the food and nutrient intakes of many Irish adults fall short of the ideal. These dietary and nutritional deficits, when superimposed on Ireland's existing health-subversive behaviours and escalating rates of obesity, constitute a potent constellation of risk factors for hypertension. However, they also represent viable and potentially effective targets for health promotion initiatives. This review aims to describe the main nutritional, dietary and lifestyle contributors to hypertension in Ireland with a view to informing future interventions aimed at alleviating Ireland's burden of hypertensive disease.

Correlation between anthropometric measurement, lipid profile, dietary vitamins, serum antioxidants, lipoprotein (a) and lipid peroxides in known cases of 345 elderly hypertensive South Asian aged 56-64 y-A hospital based study

OBJECTIVE

To address the association of dietary vitamins, anthropometric profile, lipid profile, antioxidant enzymes and lipid peroxidation in hypertensive participant compared with normotensive healthy controls.

METHODS

Dietary intake of vitamins was assessed by 131 food frequency questionnaire items in both hypertensive participants and normotensive age-sex matched healthy controls. The associated changes in serum antioxidants and lipid peroxidation were also assessed along with lipid profile and anthropometric measurements in both groups of subjects under study.

RESULTS

Dietary vitamins intake was higher in hypertensive participants excepting for vitamin B2 and ascorbic acid compared to normotensive controls. Anthropometric variables in the hypertensive showed significant differences in weight, body mass index, waist circumference, hip circumference, waist-hip ratio and mid-arm circumference. The total cholesterol, low-density lipoprotein cholesterol, triglyceride were significantly higher (P<0.001) in hypertensive except high-density lipoprotein cholesterol which was significantly higher (P<0.001) in normotensive. The serum endogenous antioxidants and enzyme antioxidants were significantly decreased in hypertensive except serum albumin levels compared to normotensive along with concomitant increase in serum lipoprotein (a) malondialdehyde and conjugated diene levels.

CONCLUSIONS

Based on the observations, our study concludes that hypertension is caused due to interplay of several confounding factors namely anthropometry, lipid profile, depletion of endogenous antioxidants and rise in oxidative stress.

Defective homocysteine metabolism: potential implications for skeletal muscle malfunction

Hyperhomocysteinemia (HHcy) is a systemic medical condition and has been attributed to multi-organ pathologies. Genetic, nutritional, hormonal, age and gender differences are involved in abnormal homocysteine (Hcy) metabolism that produces HHcy. Homocysteine is an intermediate for many key processes such as cellular methylation and cellular antioxidant potential and imbalances in Hcy production and/or catabolism impacts gene expression and cell signaling including GPCR signaling. Furthermore, HHcy might damage the vagus nerve and superior cervical ganglion and affects various GPCR functions; therefore it can impair both the parasympathetic and sympathetic regulation in the blood vessels of skeletal muscle and affect long-term muscle function. Understanding cellular targets of Hcy during HHcy in different contexts and its role either as a primary risk factor or as an aggravator of certain disease conditions would provide better interventions. In this review we have provided recent Hcy mediated mechanistic insights into different diseases and presented potential implications in the context of reduced muscle function and integrity. Overall, the impact of HHcy in various skeletal muscle malfunctions is underappreciated; future studies in this area will provide deeper insights and improve our understanding of the association between HHcy and diminished physical function.

Curcumin decreases oxidative stress in mitochondria isolated from liver and kidneys of high-fat diet-induced obese mice

Oxidative stress plays a key role in obesity and diabetes-related mitochondrial dysfunction. Mitochondrial dysfunction is characterized by increased oxidative damage, nitric oxide (NO) synthesis, and a reduced ratio of adenosine-5'-triphosphate (ATP) production/oxygen consumption. Curcumin represents a potential antioxidant and anti-inflammatory agent. In this study, our objective was to determine the effect of curcumin treatment on oxidative stress and mitochondrial dysfunction in high-fat diet (HFD)-induced obese mice (OM). These results suggest that curcumin treatment increased oxygen consumption and significantly decreased lipid and protein oxidation levels in liver mitochondria isolated from HFD-induced OM compared with those in the untreated OM (UOM). In kidney mitochondria, curcumin treatment significantly increased oxygen consumption and decreased lipid and protein peroxidation levels in HFD-induced OM when compared with those in UOM. Curcumin treatment neither has any effect on body weight gain nor have any effects on mitochondrial NO synthesis. These findings suggest that obesity induces oxidative stress and mitochondrial dysfunction, whereas curcumin may have a protective role against obesity-induced oxidative stress and mitochondrial dysfunction.

Reduced-energy cranberry juice increases folic acid and adiponectin and reduces homocysteine and oxidative stress in patients with the metabolic syndrome

The metabolic syndrome (MetS) comprises pathological conditions that include insulin resistance, arterial hypertension, visceral adiposity and dyslipidaemia, which favour the development of CVD. Some reports have shown that cranberry ingestion reduces cardiovascular risk factors. However, few studies have evaluated the effect of this fruit in subjects with the MetS. The objective of the present study was to assess the effect of reduced-energy cranberry juice consumption on metabolic and inflammatory biomarkers in patients with the MetS, and to verify the effects of cranberry juice concomitantly on homocysteine and adiponectin levels in patients with the MetS. For this purpose, fifty-six individuals with the MetS were selected and divided into two groups: control group (n36) and cranberry-treated group (n20). After consuming reduced-energy cranberry juice (0·7 litres/d) containing 0·4 mg folic acid for 60 d, the cranberry-treated group showed an increase in adiponectin (P= 0·010) and folic acid (P= 0·033) and a decrease in homocysteine (P< 0·001) in relation to baseline values and also in comparison with the controls (P< 0·05). There was no significant change in the pro-inflammatory cytokines TNF-α, IL-1 and IL-6. In relation to oxidative stress measurements, decreased (P< 0·05) lipoperoxidation and protein oxidation levels assessed by advanced oxidation protein products were found in the cranberry-treated group when compared with the control group. In conclusion, the consumption of cranberry juice for 60 d was able to improve some cardiovascular risk factors. The present data reinforce the importance of the inverse association between homocysteine and adiponectin and the need for more specifically designed studies on MetS patients.

ACMG Practice Guideline: lack of evidence for MTHFR polymorphism testing

MTHFR polymorphism testing is frequently ordered by physicians as part of the clinical evaluation for thrombophilia. It was previously hypothesized that reduced enzyme activity of MTHFR led to mild hyperhomocysteinemia which led to an increased risk for venous thromboembolism, coronary heart disease, and recurrent pregnancy loss. Recent meta-analyses have disproven an association between hyperhomocysteinemia and risk for coronary heart disease and between MTHFR polymorphism status and risk for venous t-hromboembolism. There is growing evidence that MTHFR polymorphism testing has minimal clinical utility and, therefore should not be ordered as a part of a routine evaluation for thrombophilia.

Induction of hemeoxygenase-1 reduces renal oxidative stress and inflammation in diabetic spontaneously hypertensive rats

The renoprotective mechanisms of hemeoxygenase-1 (HO-1) in diabetic nephropathy remain to be investigated. We hypothesize that HO-1 protects the kidney from diabetic insult via lowering renal oxidative stress and inflammation. We used control and diabetic SHR with or without HO-1 inducer cobalt protoporphyrin (CoPP) treatment for 6 weeks. Urinary albumin excretion levels were significantly elevated in diabetic SHR compared to control and CoPP significantly attenuated albumin excretion. Immuno-histochemical analysis revealed an elevation in TGF-β staining together with increased urinary collagen excretion in diabetic versus control SHR, both of which were reduced with CoPP treatment. Renal oxidative stress markers were greater in diabetic SHR and reduced with CoPP treatment. The increase in renal oxidative stress was associated with an elevation in renal inflammation in diabetic SHR. CoPP treatment also significantly attenuated the markers of renal inflammation in diabetic SHR. In vitro inhibition of HO with stannous mesoporphyrin (SnMP) increased glomerular NADPH oxidase activity and inflammation and blocked the anti-oxidant and anti-inflammatory effects of CoPP. These data suggest that the reduction of renal injury in diabetic SHR upon induction of HO-1 are associated with decreased renal oxidative stress and inflammation, implicating the role of HO-1 induction as a future treatment of diabetic nephropathy.

Dietary methyl-consuming compounds and metabolic syndrome

The metabolic syndrome, a major risk factor for type 2 diabetes and cardiovascular disease, is a cluster of metabolic abnormalities including obesity, insulin resistance, hypertension and dyslipidemia. Although systemic oxidative stress and aberrant methylation status are known to have important roles in the development of metabolic syndrome, how they occur remains unclear. The metabolism of methyl-consuming compounds generates reactive oxygen species and consumes labile methyl groups; therefore, a chronic increase in the levels of methyl-consuming compounds in the body can induce not only oxidative stress and subsequent tissue injury, but also methyl-group pool depletion and subsequent aberrant methylation status. In the past few decades, the intake amount of methyl-consuming compounds has substantially increased primarily due to pollution, food additives, niacin fortification and high meat consumption. Thus, increased methyl consumers might have a causal role in the development and prevalence of metabolic syndrome and its related diseases. Moreover, factors that decrease the elimination/metabolism of methyl-consuming compounds and other xenobiotics (for example, sweat gland inactivity and decreased liver function) or increase the generation of endogenous methyl-consuming compounds (for example, mental stress-induced increase in catecholamine release) may accelerate the progression of metabolic syndrome. Based on current nutrition knowledge and the available evidence from epidemiological, ecological, clinical and laboratory studies on metabolic syndrome and its related diseases, this review outlines the relationship between methyl supply-consumption imbalance and metabolic syndrome, and proposes a novel mechanism for the pathogenesis and prevalence of metabolic syndrome and its related diseases.

Serum superoxide dismutase and malondialdehyde levels in a group of Chinese patients with age-related macular degeneration

BACKGROUND AND AIMS

The aim of this study was to investigate superoxide dismutase (SOD) activity together with malondialdehyde (MDA) levels in a group of Chinese patients with age-related macular degeneration (AMD).

METHODS

Serum SOD activity and MDA levels were analysed in 56 AMD patients with subtypes (early dry, geographic atrophy, and wet) and 34 healthy controls matched with age and sex.

RESULTS

Serum MDA levels were significantly higher in AMD (3.68 ± 1.06 nmol/mL) than in controls (2.83 ± 0.43 nmol/mL; p=0.000), and was significantly higher in wet AMD (3.79 ± 0.79 nmol/mL) than in early dry AMD (3.26 ± 0.99 nmol/mL; p=0.038). Serum SOD activity was significantly higher in AMD (87.12 ± 13.22 U/mL) than in controls (79.91 ± 11.80 U/mL; p=0.012), and slightly higher in wet AMD (89.52 ± 16.25 U/mL) than in GA (83.62 ± 9.75 U/mL; p=0.275) and early dry AMD (81.64 ± 18.90 U/mL; p=0.093). There was a positive correlation between serum MDA levels and SOD activities in AMD patients and controls (r=0.320, p=0.002).

CONCLUSIONS

The observed increase in SOD activity in our study may be related to increased MDA levels, as a compensatory regulation in response to oxidative stress in AMD patients. The present data also demonstrate that oxido-reduction disturbance may be hypothesized in the pathogenesis of AMD.

Opposite modulation of time course of quantal release in two parts of the same synapse by reactive oxygen species

Reactive oxygen species (ROS) are potent regulators of transmitter release in chemical synapses, but the mechanism of this action remains almost unknown. Presynaptic modulation can change either the release probability or the time course of quantal release, which was recently recognized as an efficient mechanism determining synaptic efficiency. The nonuniform structure and a big size of the frog neuromuscular junction make it a useful model to study the action of ROS in compartments different in release probability and in time course of transmitter release. The time course (or kinetics) of quantal release could be estimated by measuring the dispersion of the synaptic delays for evoked uniquantal endplate currents (EPCs) under low release probability. Using two-electrode recording technique, the action of ROS on kinetics and release probabilities were studied at the proximal and distal parts within the same neuromuscular junction. The stable ROS hydrogen peroxide (H2O2) increased the dispersion of synaptic delays of EPCs (i.e. desynchronized quantal release) within the distal part but decreased delay dispersion (synchronized quantal release) within the proximal part of the same synapse. Unlike the opposite modulation of kinetics, H2O2 reduced release probability in both distal and proximal parts. Since ATP is released from motor nerve terminals together with acetylcholine and can be involved in ROS signaling, we tested the presynaptic action of ATP. In the presence of the pro-oxidant Fe2+, extracellular ATP, similarly to H2O2, induced significant desynchronization of release in the distal regions. The antioxidant N-acetyl-cysteine attenuated the inhibitory action of ATP on release probability and abolished the action of H2O2 and ATP in the presence of Fe2+, on release kinetics. Our data suggest that ROS induced during muscle activity could change the time course of transmitter release along the motor nerve terminal to provide fine tuning of synaptic efficacy.

Glutathione-related antioxidant defense system in elderly patients treated for hypertension

The purpose of this study was to analyze glutathione antioxidant defense system in elderly patients treated for hypertension. Studies were carried out in the blood collected from 18 hypertensive and 15 age- and sex-matched controls, all subjects age over 60. Hypertensives were on their usual antihypertensive treatment at the time of blood collection. The concentration of glutathione (GSH) in whole blood and activities of glutathione peroxidase (GPx-1), glutathione transferase (GST), and glutathione reductase (GR) in erythrocytes were measured. The data from patients and controls were compared using independent-samples t test. P value of 0.05 and less was considered statistically significant. We observed increased glutathione-related antioxidant defense in treated hypertensive elderly patients (HT) when compared with healthy controls (C). Mean GSH concentration was significantly higher in HT when compared with C: 3.1 ± 0.29 and 2.6 ± 0.25 mmol/L, respectively, P < 0.001. Mean activity of GR was significantly higher in HT group if compared with C: 83.4 ± 15.25 U/g Hb versus 64.2 ± 8.26 U/g Hb, respectively, P < 0.001. Mean activity of GST was significantly higher in HT group compared with C: 3.0 ± 0.60 mmol CDNB-GSH/mgHb/min and 2.6 ± 0.36 mmol CDNB-GSH/mgHb/min, respectively, P < 0.05. No difference in GPx activity was observed between two groups. These results show that glutathione-related antioxidant defense system was enhanced in elderly hypertensive patients treated for their conditions. This suggests important role of glutathione system in blood pressure regulation. Alterations in concentration and activity of antioxidants observed during antihypertensive medication are likely to be related to the effect of the treatment on NO bioavailability.

Plasma reactive carbonyl species: Potential risk factor for hypertension

To study the role of oxidative stress in hypertension and pre-hypertension, this study analysed plasma levels of reactive carbonyl species (RCS) in 1204 Chinese Han adults. Results showed a statistically significant positive correlation (p < 0.001) between blood pressure and plasma RCS levels with or without being adjusted for covariates. Multivariate-adjusted odds ratio (OR) illustrated that, compared with the lowest quartile of plasma RCS levels, the highest quartile subjects had a 59% and a 130% increase in the risk for developing pre-hypertension and hypertension, respectively. The multi-interaction analysis manifested that the underlying mechanism of the increase of hypertensive risk or pre-hypertensive risk by overweight and unhealthy lifestyles might, at least in part, be through oxidative stress. In conclusion, these findings suggest that oxidative stress, as indicated by plasma RCS levels, are not the necessary consequence of pre-hypertension or hypertension, but reliable risk factors for developing pre-hypertension or hypertension in Chinese Han adults.

Reduced antioxidant defense in early onset first-episode psychosis: a case-control study

BACKGROUND

Our objective is to determine the activity of the antioxidant defense system at admission in patients with early onset first psychotic episodes compared with a control group.

METHODS

Total antioxidant status (TAS) and lipid peroxidation (LOOH) were determined in plasma. Enzyme activities and total glutathione levels were determined in erythrocytes in 102 children and adolescents with a first psychotic episode and 98 healthy controls.

RESULTS

A decrease in antioxidant defense was found in patients, measured as decreased TAS and glutathione levels. Lipid damage (LOOH) and glutathione peroxidase activity was higher in patients than controls. Our study shows a decrease in the antioxidant defense system in early onset first episode psychotic patients.

CONCLUSIONS

Glutathione deficit seems to be implicated in psychosis, and may be an important indirect biomarker of oxidative stress in early-onset schizophrenia. Oxidative damage is present in these patients, and may contribute to its pathophysiology.

Synergism in hyperhomocysteinemia and diabetes: role of PPAR gamma and tempol

BACKGROUND

Hyperhomocysteinemia (HHcy) and hyperglycemia cause diabetic cardiomyopathy by inducing oxidative stress and attenuating peroxisome proliferator- activated receptor (PPAR) gamma. However, their synergistic contribution is not clear.

METHODS

Diabetic Akita (Ins2+/-) and hyperhomocysteinemic cystathionine beta synthase mutant (CBS+/-) were used for M-mode echocardiography at the age of four and twenty four weeks. The cardiac rings from WT, Akita and hybrid (Ins2+/-/CBS+/-) of Akita and CBS+/- were treated with different doses of acetylcholine (an endothelial dependent vasodilator). High performance liquid chromatography (HPLC) was performed for determining plasma homocysteine (Hcy) level in the above groups. Akita was treated with ciglitazone (CZ) - a PPAR gamma agonist and tempol-an anti-oxidant, separately and their effects on cardiac remodeling were assessed.

RESULTS

At twenty four week, Akita mice were hyperglycemic and HHcy. They have increased end diastolic diameter (EDD). In their heart PPAR gamma, tissue inhibitor of metalloproteinase-4 (TIMP-4) and anti-oxidant thioredoxin were attenuated whereas matrix metalloproteinase (MMP)-9, TIMP-3 and NADPH oxidase 4 (NOX4) were induced. Interestingly, they showed synergism between HHcy and hyperglycemia for endothelial-myocyte (E-M) uncoupling. Additionally, treatment with CZ alleviated MMP-9 activity and fibrosis, and improved EDD. On the other hand, treatment with tempol reversed cardiac remodeling in part by restoring the expressions of TIMP-3,-4, thioredoxin and MMP-9.

CONCLUSIONS

Endogenous homocysteine exacerbates diabetic cardiomyopathy by attenuating PPAR gamma and inducing E-M uncoupling leading to diastolic dysfunction. PPAR gamma agonist and tempol mitigates oxidative stress and ameliorates diastolic dysfunction in diabetes.