Oxidative stress, anti-oxidants and the cross-sectional and longitudinal association with depressive symptoms: results from the CARDIA study

Association between consumption of fruits and vegetables in midlife and depressive symptoms in late life: the Singapore Chinese Health Study

OBJECTIVES

Epidemiological evidence of how midlife intake of fruits and vegetables affects the likelihood of depressive symptoms in late life remains limited and controversial. We examined this association in an Asian cohort.

DESIGN

Prospective population-based cohort study.

SETTING

Chinese living in Singapore.

PARTICIPANTS

A total of 13,738 adults from the Singapore Chinese Health Study.

MEASUREMENTS

The consumption of 14 fruits and 25 vegetables were assessed using a validated 165-item food-frequency questionnaire at baseline (1993-1998), when participants were aged 45-74 years (mean age 52.4 years). Depressive symptoms were evaluated using the Geriatric Depression Scale during the third follow-up interviews (2014-2016), when participants were aged 61-96 years (mean age 72.5 years), and depression was defined by ≥5 out of 15 scores. Multivariable logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

After a mean follow-up of 19.6 years, depressive symptoms were identified among 3,180 participants. Consumption of fruits was inversely associated with the odds of depressive symptoms in a dose-response manner: comparing extreme quartiles, the OR (95% CI) of depressive symptoms was 0.71 (0.63-0.81; P-trend <0.01). Intake of several types of fruits, especially orange, tangerine, banana, papaya and watermelon, was associated with reduced odds, and this inverse association was similar across subgroups of fruits categorized by glycemic index. Conversely, intake of vegetables was not associated with the odds of depressive symptoms.

CONCLUSIONS

Our findings support population-based recommendation of having sufficient fruit intake early in life to reduce the likelihood of depressive symptoms in late life.

Dissecting Causal Associations of Diet-Derived Circulating Antioxidants with Six Major Mental Disorders: A Mendelian Randomization Study

Although observational studies have suggested associations between circulating antioxidants and many mental disorders, causal inferences have not been confirmed. Mendelian randomization (MR) analyses were conducted using summary-level statistics from genome-wide association studies (GWASs) to explore whether genetically determined absolute circulating antioxidants (i.e., ascorbate, retinol, β-carotene, and lycopene) and metabolites (i.e., α- and γ-tocopherol, ascorbate, and retinol) were causally associated with the risk of six major mental disorders, including anxiety disorders (AD), major depressive disorder (MDD), bipolar disorder (BIP), schizophrenia (SCZ), post-traumatic stress disorder (PTSD), and obsessive-compulsive disorder (OCD). MR analyses were performed per specific-outcome databases, including the largest GWAS published to date (from 9725 for OCD to 413,466 for BIP participants), UK Biobank (over 370,000 participants), and FinnGen (over 270,000 participants), followed by meta-analyses. We found no significant evidence that genetically determined diet-derived circulating antioxidants were significantly causally associated with the risk of the six above-mentioned major mental disorders. For absolute antioxidant levels, the odds ratios (ORs) ranged from 0.91 (95% CI, 0.67-1.23) for the effect of β-carotene on OCD to 1.18 (95% CI, 0.90-1.54) for the effect of ascorbate on OCD. Similarly, for antioxidant metabolites, ORs ranged from 0.87 (95% CI, 0.55-1.38) for the effect of ascorbate on MDD to 1.08 (95% CI, 0.88-1.33) for the effect of ascorbate on OCD. Our study does not support significant causal associations of genetically determined diet-derived circulating antioxidants with the risk of major mental disorders.

Associations of dietary Provitamin A carotenoid intake with depressive symptoms in midlife women: Results from the study of Women's Health Across the Nation

BACKGROUND

To study the association of Provitamin A (pro-A) carotenoid intake from diet with depressive symptoms in midlife women.

METHODS

Data for this cross-sectional study were retrieved from baseline assessment of the Study of Women's Health Across the Nation (SWAN). Logistic regression and restricted cubic spline models were performed to examine the association pro-A carotenoid intake with depressive symptoms.

RESULTS

A total of 3054 midlife women aged 42-52 years were included in the present study. In overall midlife women, pro-A carotenoid intake was inversely associated with depressive symptoms (CES-D score ≥16). In premenopausal women, pro-A carotenoid intake was inversely associated with depressive symptoms after adjustment for age, race/ethnicity, total family income, education, physical activity, BMI, use of antidepressant, dietary total caloric, protein, carbohydrate, fat, vitamin C, vitamin E and pro-A carotenes in model 1. In fully adjusted model, after additional adjustment for day of cycle, FSH and SHBG, this association remained statistically significant. The fully adjusted odds ratios (ORs) with 95 % CI of depressive symptoms were 0.685 (0.450-1.043) in quartile 4 compared with quartile 1 for pro-A carotenoid intake. However, in early perimenopausal women, no statistically significant difference was observed between pro-A carotenoid intake and depressive symptoms after adjustment for confounders.

LIMITATIONS

This was a cross-sectional study, limiting causal inferences. Assessment of CES-D was based on a self-report scale.

CONCLUSION

Pro-A carotenoid intake may be inversely associated with depression symptoms in premenopausal women, but not in early perimenopausal women.

The emergence of psychoanalytical electrochemistry: the translation of MDD biomarker discovery to diagnosis with electrochemical sensing

The disease burden and healthcare costs of psychiatric diseases along with the pursuit to understand their underlying biochemical mechanisms have led to psychiatric biomarker investigations. Current advances in evaluating candidate biomarkers for psychiatric diseases, such as major depressive disorder (MDD), focus on determining a specific biomarker signature or profile. The origins of candidate biomarkers are heterogenous, ranging from genomics, proteomics, and metabolomics, while incorporating associations with clinical characterization. Prior to clinical use, candidate biomarkers must be validated by large multi-site clinical studies, which can be used to determine the ideal MDD biomarker signature. Therefore, identifying valid biomarkers has been challenging, suggesting the need for alternative approaches. Following validation studies, new technology must be employed to transition from biomarker discovery to diagnostic biomolecular profiling. Current technologies used in discovery and validation, such as mass spectroscopy, are currently limited to clinical research due to the cost or complexity of equipment, sample preparation, or measurement analysis. Thus, other technologies such as electrochemical detection must be considered for point-of-care (POC) testing with the needed characteristics for physicians' offices. This review evaluates the advantages of using electrochemical sensing as a primary diagnostic platform due to its rapidity, accuracy, low cost, biomolecular detection diversity, multiplexed capacity, and instrument flexibility. We evaluate the capabilities of electrochemical methods in evaluating current candidate MDD biomarkers, individually and through multiplexed sensing, for promising applications in detecting MDD biosignatures in the POC setting.

Association of dietary and plasma carotenoids with urinary F2-isoprostanes

PURPOSE

Carotenoids may protect against chronic diseases including cancer and cardiometabolic disease by mitigating oxidative stress and/or inflammation. We cross-sectionally evaluated associations between carotenoids and biomarkers of oxidative stress or inflammation.

METHODS

From 2003 to 2009, the Sister Study enrolled 50,884 breast cancer-free US women aged 35-74. Post-menopausal participants (n = 512) were randomly sampled to measure carotenoids and biomarkers of oxidative stress. Dietary carotenoid consumption was assessed using a validated 110-item Block 1998 food frequency questionnaire; use of β-carotene-containing supplements was also assessed. Plasma carotenoids were quantified, adjusting for batch. Urinary markers of lipid peroxidation, 8-iso-prostaglandin F_2α (8-iso-PGF_2α) and its metabolite (8-iso-PGF_2α-M) were also measured. Since the biomarker 8-iso-PGF_2α can reflect both oxidative stress and inflammation, we used a modeled 8-iso-PGF_2α to prostaglandin F_2α ratio approach to distinguish effects reflecting oxidative stress versus inflammation. Multivariable linear regression was used to assess the associations of dietary and plasma carotenoids with the estimated biomarker concentrations.

RESULTS

Total plasma carotenoids were inversely associated with 8-iso-PGF_2α-M concentrations (P for trend across quartiles = 0.009). Inverse trends associations were also seen for α-carotene and β-carotene. In contrast, lutein/zeaxanthin showed associations with both 8-iso-PGF_2α and 8-iso-PGF_2α-M concentrations. The inverse association for total carotenoids appeared to be specific for oxidative stress (chemical 8-iso-PGF_2α; P_{highest vs. lowest quartile} = 0.04 and P for trend across quartiles = 0.02). The pattern was similar for α-carotene. However, lutein/zeaxanthin tended to have a stronger association with enzymatic 8-iso-PGF_2α, suggesting an additional anti-inflammatory effect. Supplemental β-carotene was inversely associated with both 8-iso-PGF_2α and 8-iso-PGF_2α-M concentrations, as well as with both chemical and enzymatic 8-iso-PGF_2α. Dietary carotenoids were not associated with either biomarker.

CONCLUSION

Plasma carotenoids and supplemental β-carotene were associated with lower concentrations of 8-iso-PGF_2α metabolite. Plasma carotenoids associations may reflect antioxidant effects.

Impact of citrus fruit intake on the mental health of patients with chronic heart failure

BACKGROUND

The full impact of the intake of citrus fruits on the risk of depression in individuals with chronic heart failure (HF) is unknown. Here, we examined the associations between the estimated habitual intakes of citrus fruits and depressive symptoms in patients with chronic HF.

METHODS

We enrolled 150 stable outpatients with chronic HF who had a history of worsening HF. To assess the patients' daily dietary patterns, we used a brief self-administered diet-history questionnaire to calculate the daily consumption of foods and nutrients. To assess the patients' mental state, we used a nine-item Patient Health Questionnaire (PHQ-9).

RESULTS

Twelve patients (8%) were identified as having moderate-to-severe depression (PHQ-9 score ≥10). The patients with PHQ-9 ≥10 had lower daily intakes of citrus fruits compared to those with no or mild depressive symptoms (PHQ-9 <10). The daily intakes of various antioxidants, including vitamin C, β-carotene, and β-cryptoxanthin, all of which are abundant in citrus fruits, were reduced in the patients with PHQ-9 ≥10, accompanied by higher serum levels of 8-isoprostane (an oxidative stress marker). A multivariate logistic regression analysis using forward selection showed that a lowered daily intake of citrus fruits was an independent predictor of the comorbidity of moderate-to-severe depression in patients with chronic HF, after adjustment for age, gender, and the hemoglobin value.

CONCLUSIONS

A lower daily consumption of citrus fruits was associated with higher prevalence of depression in patients with chronic HF. Our findings support the hypothesis that a daily consumption of citrus fruits has a beneficial effect on the prevention and treatment of depression in chronic HF patients.

Metformin alleviates monoamine oxidase-related vascular oxidative stress and endothelial dysfunction in rats with diet-induced obesity

In the past decade, monoamine oxidase (MAO) with 2 isoforms, MAO-A and B, has emerged as an important source of mitochondrial reactive oxygen species (ROS) in cardio-metabolic pathologies. We have previously reported that MAO-related oxidative stress mediates endothelial dysfunction in rodent models of diabetes and diabetic patients; however, the role of MAO in the vascular impairment associated to obesity has not been investigated so far. Metformin (METF), the first-line drug in the therapy of type 2 diabetes mellitus, has been reported to elicit vasculoprotective effects via partially elucidated mechanisms. The present study was purported to assess the effects of METF on MAO expression, ROS production and vasomotor function of aortas isolated from rats with diet-induced obesity. After 24 weeks of high calorie junk food (HCJF) diet, isolated aortic rings were prepared and treated with METF (10 μM, 12 h incubation). Measurements of MAO expression (quantitative PCR and immune histochemistry), ROS production (spectrometry and immune-fluorescence) and vascular reactivity (myograph studies) were performed in rat aortic rings. MAO expression was upregulated in aortic rings isolated from obese rats together with an increase in ROS production and an impairment of vascular reactivity. METF decreased MAO expression and ROS generation, reduced vascular contractility and improved the endothelium-dependent relaxation in the diseased vascular preparations. In conclusion, METF elicited vascular protective effects via the mitigation of MAO-related oxidative stress in the rat model of diet-induced obesity.

Association of habitual intake of fruits and vegetables with depressive symptoms: the AusDiab study

PURPOSE

To investigate the relationship of habitual FV intake, different types of FV, and vegetable diversity with depressive symptoms.

METHODS

Australian men and women (n = 4105) aged > 25 years from the Australian Diabetes, Obesity and Lifestyle Study were included. Dietary intake was assessed using a Food Frequency Questionnaire at baseline, 5 and 12 years. Depressive symptoms were assessed using the validated 10-item Centre for Epidemiology Studies Short Depression Scale at 12 years. Multiple logistic regression models were used to investigate the association between the exposures of interest and depressive symptoms using odds ratios (OR) and 95% confidence intervals (CI) across quartiles of FV intake and vegetable diversity. Analyses were multivariable-adjusted for confounding factors.

RESULTS

At 12 years, 425 (10.4%) participants had "any depressive symptoms". Habitual FV intake was inversely associated with depressive symptoms at 12 years. After adjustment, participants in quartile 2 of FV intake (Q2; median 317 g/day) had a 20% lower odds of having any depressive symptoms (OR [95% CI] 0.80 [0.69, 0.95]) in comparison to those in the lowest quartile of FV intake (Q1; median 223 g/day). Yellow/orange/red and leafy green vegetables were the key vegetable types driving this association. Higher vegetable diversity (4-6 different vegetables/day) was associated with a 24-42% lower odds of having depressive symptoms when compared to < 3 different vegetables/day. The associations remained similar after further adjusting for diet quality.

CONCLUSION

A FV-rich diet, consisting of a diverse range of vegetables, particularly yellow/orange/red and leafy green vegetables may help to lower depressive symptoms. Promoting such a diet, particularly in men and women with a low FV intake, may have a significant public health impact.

Skin autofluorescence of advanced glycation end products and course of affective disorders in the lifelines cohort study, a prospective investigation

BACKGROUND

Skin autofluorescence (SAF), indicating concentration of advanced glycation end products in the skin and oxidative stress, is cross-sectionally associated with affective disorders. Prospective studies of oxidative stress markers will help to clarify the pathophysiological role of oxidative stress.

METHODS

Data of a population-based cohort study were used. Presence of major depressive disorder, dysthymia, generalised anxiety disorder, panic disorder or social phobia was assessed at baseline and at 5-year follow-up with the Mini-International Neuropsychiatric Interview. Associations between SAF at baseline and incidence and persistence/recurrence of affective disorders were assessed with logistic regression.

RESULTS

Of 43,267 participants with no disorder at baseline, 2885 (6.7%) developed an incident disorder during follow-up. In 1360 of 3648 participants (37.3%) with an affective disorder at baseline, a persisting/recurrent disorder was present at follow-up. A modest association existed between SAF and incident affective disorders (OR=1.07 [95%CI 1.03-1.12], P<.001), specifically major depressive disorder (OR=1.11 [95%CI 1.04-1.19], P=.003); this association lost statistical significance after adjustment for sociodemographic factors. Associations between SAF and persistence/recurrence were not significant.

LIMITATIONS

Many confounders might also act as intermediate: extensive adjustment for confounders caused overfitting and possibly masked effects of SAF on course of affective disorders. Relatively small sample sizes for analyses of SAF and persistence/recurrence of affective disorders resulted in a low power.

CONCLUSIONS

Increased SAF modestly raises the odds of incident affective disorders, particularly major depressive disorder, providing evidence that oxidative stress plays a role in subsequent occurrence of affective disorders. However, significance of effects faded after adjustment for socioeconomic status.

Association between skin autofluorescence of advanced glycation end products and affective disorders in the lifelines cohort study

BACKGROUND

Oxidative stress may be a mechanistic link between affective disorders (depressive and anxiety disorders) and somatic disease. Advanced glycation end products are produced under the influence of oxidative stress and in the skin (measured by skin autofluorescence [SAF]) serve as marker for cumulative oxidative stress. Aim of study was to determine whether SAF is associated with presence of affective disorders.

METHODS

Participants in the Lifelines cohort study who had completed the Mini-International Neuropsychiatric Interview for affective disorders and a SAF-measurement were included. Cross-sectional associations between SAF and presence of the following psychiatric disorders were investigated through logistic regression analyses adjusted for sociodemographic factors, cardiometabolic parameters, and somatic morbidities: major depressive disorder, dysthymia, generalised anxiety disorder, panic disorder or social phobia.

RESULTS

Of 81,041 included participants (41.7% male, aged 18-91 years), 6676 (8.2%) were cases with an affective disorder. SAF was associated with presence of affective disorders (OR=1.09 [95%CI 1.07-1.12], P<.001 adjusted for sociodemographic factors). Association with major depressive disorder was strongest and significant after adjustment for all confounders (OR=1.31 [95%CI 1.25-1.36], P<.001 in the crude model; OR=1.12 [95%CI 1.07-1.17], P<.001 in the fully adjusted model). For other disorders, associations lost significance after adjustment for cardiometabolic parameters and somatic morbidities.

LIMITATIONS

Persons of non-Western descent and severely (mentally or physically) ill individuals were underrepresented.

CONCLUSIONS

SAF was associated with presence of affective disorders, suggesting a link between these disorders and cumulative oxidative stress. For major depressive disorder, this association was strongest and independent of sociodemographic, cardiometabolic factors, and somatic morbidities.

Non-alcoholic fatty liver disease (NAFLD) as a neglected metabolic companion of psychiatric disorders: common pathways and future approaches

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is characterized by hepatic steatosis in over 5% of the parenchyma in the absence of excessive alcohol consumption. It is more prevalent in patients with diverse mental disorders, being part of the comorbidity driving loss of life expectancy and quality of life, yet remains a neglected entity. NAFLD can progress to non-alcoholic steatohepatitis (NASH) and increases the risk for cirrhosis and hepatic carcinoma. Both NAFLD and mental disorders share pathophysiological pathways, and also present a complex, bidirectional relationship with the metabolic syndrome (MetS) and related cardiometabolic diseases.

MAIN TEXT

This review compares the demographic data on NAFLD and NASH among the global population and the psychiatric population, finding differences that suggest a higher incidence of this disease among the latter. It also analyzes the link between NAFLD and psychiatric disorders, looking into common pathophysiological pathways, such as metabolic, genetic, and lifestyle factors. Finally, possible treatments, tailored approaches, and future research directions are suggested.

CONCLUSION

NAFLD is part of a complex system of mental and non-communicable somatic disorders with a common pathogenesis, based on shared lifestyle and environmental risks, mediated by dysregulation of inflammation, oxidative stress pathways, and mitochondrial function. The recognition of the prevalent comorbidity between NAFLD and mental disorders is required to inform clinical practice and develop novel interventions to prevent and treat these complex and interacting disorders.

The association between antioxidant intake, dietary pattern and depressive symptoms in older Australian men: the Concord Health and Ageing in Men Project

PURPOSE

The objectives of the study were to evaluate the associations between antioxidant intake, dietary patterns and depressive symptoms among older men.

METHOD

794 men participated in a detailed diet history interview at the Concord Health and Ageing in Men Project 3rd wave (considered baseline nutrition) and 781 men participated at the 4th wave (considered 3-year follow-up). Depressive symptoms were measured using the Geriatric Depression Scale (GDS ≥ 5). Dietary adequacy of antioxidant intake was assessed by comparing participants' median intake of vitamin A, E, C and zinc to the Nutrient Reference Values for Australia. Attainment of NRVs of antioxidant was categorised into a dichotomised variable 'poor' (meeting ≤ 2) or 'good' (meeting ≥ 3). Individual antioxidant nutrient was categorised into quartiles. The Australian and Mediterranean diet scores were assessed as predictor variables.

RESULTS

The prevalence of GDS ≥ 5 was 12.8% at baseline nutrition and 13.2% of men developed GDS ≥ 5 at a 3-year follow-up. There was a significant cross-sectional association between poor antioxidant intake and GDS ≥ 5 in adjusted analyses [OR: 1.95 (95% CI 1.03, 3.70)]. Poor antioxidant intake at baseline nutrition remained prospectively associated with incident GDS ≥ 5 [OR: 2.46 (95% CI 1.24, 4.88)] in adjusted analyses. This association was also found for the lowest quartile of zinc [OR 2.72 (95% CI 1.37, 5.42)] and vitamin E intake [OR 2.18 (95% CI 1.05, 4.51)]. None of the other antioxidants and dietary patterns had a significant association with incident depressive symptoms.

CONCLUSION

Inadequacy of antioxidant intake, particularly zinc and vitamin E, is associated with increased risk of clinically significant depressive symptoms in older men.

Nutrient patterns and depressive symptoms among Australian adults

PURPOSE

Much of the current literature on the associations between diet and depression focus on single nutrients rather than nutrient patterns (NPs). We investigated the association between NPs and depressive symptoms (DepS) in an Australian adult population.

METHODS

DepS were examined at two different time points, in 2010 (Stage 3, n = 1743, 49.0% males) and 2015 [North West 2015 (NW15), n = 1,024, 46.6% males] of the North West Adelaide Health Study (NWAHS). Dietary habits were evaluated using a food frequency questionnaire (FFQ) at Stage 3. DepS were assessed using the Center for Epidemiological Studies Depression (CES-D) scale at Stage 3 and NW15. Principal component analysis was used to identify NPs as well as the factor structure of the CES-D. Log- and negative binomial regression analyses were used to assess the association between NPs and DepS scores. Ordinal logistic regression analysis was undertaken between the NPs and identified factors of the CES-D score.

RESULTS

Three NPs (from the FFQ) and two-factors (from the CES-D score) were obtained. After adjusting for known confounding variables, a 'plant-sourced' NP (β-carotene, fibre, vitamin C, potassium and α-carotene) was inversely associated with DepS at Stage 3 [prevalence ratio (PR)_Q4VsQ1, 0.78; 95% CI 0.66-0.92; p = 0.003], whereas an 'animal-sourced' (ω-3 fatty acid, monounsaturated fat, vitamin E and cholesterol) or 'mixed-source' (phosphorous, protein, vitamin B2, iodine and zinc) NP was not associated with DepS. There was an inverse relationship between the 'plant-sourced' NP and the '(absence of) positive-affect' factor from the CES-D in both stages.

CONCLUSION

The 'plant-sourced' NP is consistently and inversely associated with DepS; however, longitudinal studies are recommended to confirm these results.

Intakes of Specific Categories of Vegetables and Fruits Are Inversely Associated With Depressive Symptoms Among Adults

BACKGROUND

Epidemiological evidence on the relationships between intakes of different categories of vegetables and fruits and depressive symptoms is very limited and inconsistent, especially with no evidence from the general population. This study aimed to estimate their relationships among a large general population.

METHODS

The cross-sectional design was based on the National Health and Nutrition Examination Survey (2007-2014) and included 16,925 adults. Dietary information was attained from two nonconsecutive 24-hr dietary recalls. Patient Health Questionnaire was applied for measuring depressive symptoms. The associations between vegetables and fruits intakes and depressive symptoms were appraised utilizing logistic regression and restricted cubic spline.

RESULTS

Compared with the lowest category of intake, the most-adjusted odds ratios of depressive symptoms for the highest intake category of tomatoes and tomato mixtures were 0.81 (95% confidence interval [CI], 0.66-0.99), and 0.64 (95% CI, 0.48-0.85) for dark-green vegetables, 0.67 (95% CI, 0.53-0.84) for other vegetables, 0.48 (95% CI, 0.29-0.79) for berries, 0.67 (95% CI, 0.55-0.82) for total vegetables, and 0.70 (95% CI, 0.57-0.86) for total fruits, and for the medium categories of bananas and dried fruits were 0.62 (95% CI, 0.41-0.95) and 0.39 (95% CI, 0.19-0.81), respectively. After sensitivity analysis further excluding subjects with co-morbid health conditions, these findings remained significant, except for bananas. An L-shaped relationship was observed between depressive symptoms and intake of total vegetables, while the association was linear with total fruits intake.

CONCLUSIONS

Intakes of tomatoes and tomato mixtures, dark-green vegetables, other vegetables, berries, dried fruits, total vegetables, and total fruits were inversely related to depressive symptoms among adults.

The Effect of Lycopene Supplementation on Mood Status and Quality of Life in Infertile Men: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial

Background

Infertility is a major worldwide problem which is caused by several factors such as environmental, physiological, and genetic conditions. Lycopene is considered to be one of the most important antioxidants that can contribute to reducing or preventing the psychological damage that leads to infertility. Thus, the aim of this study was to evaluate the effect of lycopene supplementation on depression, anxiety and stress scales and quality of life in infertile men.

Materials and Methods

In this randomized clinical trial, 44 infertile men with oligozoospermia were randomly divided into the following two groups: the experimental group was supplemented with 25 mg lycopene, once per day for 12 weeks, and the control group received a placebo, for 12 weeks. Anthropometric and dietary data, physical activity, mood status, including depression, anxiety, stress, and quality of life scores were recorded pre- and post-intervention. Depression, anxiety and stress were assessed using a 21-item questionnaire (DASS-21) and quality of life was examined using the WHO 26-qustion questionnaire (WHOQOL).

Results

The baseline age and body mass index (BMI) were not significantly different between the two groups (age: 31.89 ± 2.51 and 32.15 ± 2.16 years old for intervention and placebo, respectively; P=0.732 and BMI: 27.20 ± 1.68 and 26.53 ± 1.53; for intervention and placebo, respectively; P=0.206). There were no significant differences in depression, anxiety and stress values between the two groups; however, depression score significantly decreased in both groups compared to the baseline levels (P=0.028 and P=0.031). No significant differences were observed in four domains of quality of life, except for psychological domain that was improved in the lycopene group compared to the baseline values (P=0.049).

Conclusion

Short term supplementation of lycopene had no effect on mood status and quality of life, except for psychological status in infertile men (Registration number: IRCT20171105037249N1).

Dietary intake of carotenoids and fiber is inversely associated with aggression score in adolescent girls

BACKGROUND

Violence and aggression are considered to be important public health issues. There is limited data on the association between dietary intake and aggression score.

AIM

We aimed to examine the relationship between the dietary intake and aggressive behavior in Iranian adolescent girls.

METHODS

The study was carried out among 670 girls aged 12-18 years. A valid and reliable food frequency questionnaire (FFQ) containing 147 food items was used to estimate dietary intake of the study participants. Aggression score was determined using a validated Persian version of the Buss-Perry questionnaire. We analyzed our data using crude and adjusted models.

RESULTS

Participants in the fourth quartile of aggression score had significantly higher energy intake compared with those in the first quartile (2808±949 vs 2629±819, p-trend = 0.01). Dietary intakes of soluble fiber (0.42±0.37 vs 0.35±0.29, p = 0.03) and insoluble fiber (2.17±1.65 vs 1.82±1.36, p = 0.02) were significantly higher in the first quartile than in the fourth quartile. In addition, the strongest negative correlations were found between aggression score and dietary soluble fiber (p = 0.003) and insoluble fiber intake (p = 0.001). Moreover, aggression score was negatively correlated with dietary α-carotene (p = 0.02) and β-carotene (p = 0.04) intake. These associations remained significant even after adjustment for potential confounders.

CONCLUSIONS

Our results indicated that dietary intakes of fiber, α-carotene, and β-carotene were inversely associated with aggression score. Moreover, a significant positive association was observed between energy intake and aggression score in adolescent girls.

Dietary total antioxidant capacity as a preventive factor against depression in climacteric women

Depression is characterized by physical or psychological distress and in many cases can lead to suicide.

Association of dietary patterns with depressive symptoms in Chinese postmenopausal women

Many components in diet have regulated oxidative stress, inflammatory reaction and even balance oestrogen levels. Because these factors are closely associated with depressive symptoms in postmenopausal women, it is considered that dietary factors are able to prevent and control depressive symptoms. On the other hand, a dietary pattern that considers the correlations and synergies between foods and nutrients is expected to have a greater impact on disease risk. The aim of the present study is to evaluate whether dietary patterns are associated with depressive symptoms in Chinese postmenopausal women. A cross-sectional study of 2051 postmenopausal women (mean age: 58·8 (sd 7·4) years) was conducted in Tianjin, China. Dietary consumption was assessed by a valid self-administered FFQ. Principal component analysis was used to derive three major dietary patterns: ‘healthy’, ‘sweets’ and ‘traditional Tianjin’ from eighty-eight food items. Depressive symptoms were assessed using the Zung Self-Rating Depression Scale, and cut-off point of 48 indicating serious depressive symptoms. The association between quartile of dietary patterns and depressive symptoms was assessed using multiple logistic regression analysis. The multivariable-adjusted OR of having depressive symptoms for increasing quartile of dietary patterns were as follows: healthy, 1·00, 0·79 (95 % CI 0·49, 1·28), 0·62 (95 % CI 0·37, 1·04) and 0·57 (95 % CI 0·33, 0·97); sweets, 1·00, 0·75 (95 % CI 0·42, 1·3), 1·08 (95 % CI 0·64, 1·81) and 1·66 (95 % CI 1·03, 2·71); and traditional Tianjin, 1·00, 1·02 (95 % CI 0·58, 1·79), 0·96 (95 % CI 0·54, 1·71) and 2·53 (95 % CI 1·58, 4·16), respectively. The present study demonstrated that a healthy dietary pattern was inversely associated with depressive symptoms. On the contrary, greater adherence to sweets and traditional Tianjin dietary patterns was associated with a higher prevalence of depressive symptoms.

Evaluating Longitudinal Associations Between Depressive Symptoms, Smoking, and Biomarkers of Cardiovascular Disease in the CARDIA Study

OBJECTIVE

The aim of the study was to evaluate associations between 15-year trajectories of co-occurring depressive symptoms and smoking with biomarkers of cardiovascular disease at year 15.

METHODS

In the Coronary Artery Risk Development in Young Adults study, we modeled trajectories of depressive symptoms (Center for Epidemiologic Studies-Depression scale [CES-D]) and smoking (cigarettes per day [CPD]) among 3614 adults followed from year 0 (ages 18-30 years) through year 15 (ages 33-45 years). Biomarkers of inflammation (high-sensitivity C-reactive protein), oxidative stress (superoxide dismutase, F2-isoprostanes), and endothelial dysfunction (soluble intercellular adhesion molecule 1, soluble P-selectin) were assessed at year 15. We conducted separate linear regression analyses with CES-D trajectory, CPD trajectory, and their interaction with each of the five biomarkers.

RESULTS

The sample was 56% women, 47% black, and 40 years old on average at year 15. The CES-D trajectory by CPD trajectory interaction was not associated with any of the biomarkers (all p's > .01). Removing the interaction term, CES-D trajectory was associated with inflammation: higher levels of high-sensitivity C-reactive protein were observed in the subthreshold (β = 0.57, p = .004) and increasing depressive symptoms (β = 1.36, p < .001) trajectories compared with the no depression trajectory. CPD trajectory was associated with oxidative stress and endothelial dysfunction: compared with never smokers, heavy smokers had significantly higher levels of F2-isoprostanes (β = 6.20, p = .001), soluble intercellular adhesion molecule 1 (β = 24.98, p < .001), and soluble P-selectin (β = 2.91, p < .001).

CONCLUSIONS

Co-occurring depressive symptoms and smoking do not seem to synergistically convey risk for cardiovascular disease via processes of inflammation, oxidative stress, or endothelial dysfunction. Nonetheless, these results advance our understanding of the complex relationships between modifiable risk factors and chronic disease.

Behavioral defects induced by chronic social defeat stress are protected by Momordica charantia polysaccharides via attenuation of JNK3/PI3K/AKT neuroinflammatory pathway

Background

The aim of this study was to evaluate the protective effects of Momordica charantia polysaccharides (MCP) on depressive-like behaviors.

Methods

The chronic social defeat stress (CSDS) mice model was used to evaluate the effects of MCP and their underlying mechanisms. Social interaction test (SIT), sucrose preference test (SPT), and tail suspension test (TST) were performed for behavioral assessments. Expression levels of inflammation mediators and phosphatidylinositol 3-kinase (PI3K) activity were determined using commercial ELISA kits. The expression of key proteins in the c-Jun N-terminal protein kinase (JNK3)/PI3K/protein kinase B (AKT) pathway were measured using western blot and RT-PCR.

Results

The results showed that chronic administration of MCP (100, 200, 400 mg/kg/day) significantly prevented depressive-like behaviors in CSDS mice as assessed by SIT, TST and SPT. Elevated levels of proinflammatory cytokines [tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1 beta (IL-1β)], and expression of JNK3, c-Jun, P-110β proteins were observed in the hippocampus of CSDS mice. Moreover, the activity of PI3K and phosphorylation level of AKT were reduced in the hippocampus of CSDS mice. Interestingly, the administration of MCP reversed these changes. Furthermore, the protective effects of MCP on CSDS mice were partly inhibited by the PI3K inhibitor, LY294002.

Conclusions

In conclusion, the protective effects of MCP against depressive-like behaviors in CSDS mice might be due to a reduction in neuroinflammation and the down-regulation of the JNK3/PI3K/AKT pathway in the hippocampus.

Longitudinal associations between 4-hydroxynonenal and depression in coronary artery disease patients

Depressive symptoms in patients with coronary artery disease (CAD) attenuate the cardiovascular benefits of cardiac rehabilitation (CR). Given that oxidative stress may be an important mechanism underlying depression, this study aimed to understand the longitudinal relationship between lipid peroxidation markers and depression in CAD. Serum levels of early (lipid hydroperoxides, LPH) and late (4‑hydroxy‑2-nonenal, 4-HNE; 8-isoprotane, 8-ISO) lipid peroxidation markers were measured in 120 CAD patients undergoing CR. The Structured Clinical Interview for DSM Axis I Disorders - Depression Module (SCID) was used to diagnose depression at baseline and the Center for Epidemiological Studies Depression Scale (CES-D) was used to measure depressive symptom severity. Multivariate mixed models compared the trajectories of serum LPH, 4-HNE, and 8-ISO between depressed and non-depressed CAD patients undergoing 6 months of CR. Similar models evaluated the associations between serum LPH, 4-HNE, and 8-ISO and CES-D score over the course of CR. Serum 4-HNE decreased less in CAD patients with depression compared to those without. In addition, a decrease in 4-HNE concentrations was significantly associated with a decrease in CES-D scores over 6 months. These findings suggest that 4-HNE may be an important marker of depressive symptoms in CAD and may be involved in its progression.

Fruit and vegetable consumption is associated with improved mental and cognitive health in older adults from non-Western developing countries

OBJECTIVES

Consumption of fruits and vegetables has been shown to contribute to mental and cognitive health in older adults from Western industrialized countries. However, it is unclear whether this effect replicates in older adults from non-Western developing countries. Thus, the present study examined the contribution of fruit and vegetable consumption to mental and cognitive health in older persons from China, India, Mexico, Russia, South Africa and Ghana.

DESIGN

Representative cross-sectional and cross-national study.Setting/SubjectsWe used data from the WHO Study on Global Ageing and Adult Health (SAGE), sampled in 2007 to 2010. Our final sample size included 28 078 participants.

RESULTS

Fruit and vegetable consumption predicted an increased cognitive performance in older adults including improved verbal recall, improved delayed verbal recall, improved digit span test performance and improved verbal fluency; the effect of fruit consumption was much stronger than the effect of vegetable consumption. Regarding mental health, fruit consumption was significantly associated with better subjective quality of life and less depressive symptoms; vegetable consumption, however, did not significantly relate to mental health.

CONCLUSIONS

Consumption of fruits is associated with both improved cognitive and mental health in older adults from non-Western developing countries, and consumption of vegetables is associated with improved cognitive health only. Increasing fruit and vegetable consumption might be one easy and cost-effective way to improve the overall health and quality of life of older adults in non-Western developing countries.

Zeaxanthin improved diabetes-induced anxiety and depression through inhibiting inflammation in hippocampus

It is generally accepted that inflammation plays a key role in anxiety and depression induced by diabetes. However, the underlying mechanism and effective treatment method of these diabetes-associated behavior disorders remain to be determined. In the present study, we attempted to illuminate the implication of zeaxanthin in anxiety, depression and neuroinflammation caused by hyperglycemia, and further elaborate the relevant mechanism under these neuropsychiatric disorders. In the current work, diabetic rats were induced by high glucose and fat diet followed by a single intraperitoneal injection of streptozocin, and zeaxanthin was orally administration every day (From 6th to 19th week). Diabetes-associated anxiety and depression were assessed using open field test (OFT) and Forced swimming test (FST) respectively. Moreover, the levels of interleukin-6 (IL-6), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in hippocampus were tested using ELISA and WB. Data showed that long-term zeaxanthin treatment improve diabetic symptoms and alleviate anxiety and depression in diabetic rats. Furthermore, excessive production of IL-6, IL-1β and TNF-α could be reduced with zeaxanthin treatment. In conclusion, we suggested that zeaxanthin can ameliorate diabetes-associated anxiety and depression, inhibit inflammation in diabetic rats. Our results could provide a potential therapeutic approach for the treatment of abnormal behavior induced by hyperglycemia.

Antioxidants linked with physical, cognitive and psychological frailty: Analysis of candidate biomarkers and markers derived from the MARK-AGE study

Frailty among elderly people leads to an increased risk for negative health outcomes. To prevent frailty, we need a better understanding of the underlying mechanisms and early detection of individuals at risk. Both may be served by identifying candidate (bio)markers, i.e. biomarkers and markers, for the physical, cognitive, and psychological frailty domains. We used univariate (Rank-ANOVA) and multivariate (elastic net) approaches on the RASIG study population (age range: 35-74 years, n = 2220) of the MARK-AGE study to study up to 331 (bio)markers between individuals with and without frailty for each domain. Biomarkers and markers identified by both approaches were studied further regarding their association with frailty using logistic regression. Univariately, we found lower levels of antioxidants, including β-cryptoxanthin and zeaxanthin, in those who were physically, cognitively or psychologically frail. Additionally, self-reported health was worse in these three frail groups. Multivariately, we observed lower levels of β-cryptoxanthin and zeaxanthin in the cognitively frail. Levels of these carotenoids were inversely associated with the risk of being cognitively frail after adjusting for confounders. Antioxidants and self-reported health are potential (bio)markers to detect persons at risk of becoming frail. The biomarkers identified may indicate the involvement of inflammation in frailty, especially for physical and cognitive frailty.

Oxidative stress in drug-naïve first episode patients with schizophrenia and major depression: effects of disease acuity and potential confounders

Oxidative stress and immune dysregulation have been linked to schizophrenia and depression. However, it is unknown whether these factors are related to the pathophysiology or whether they are an epiphenomenon. Inconsistent oxidative stress-related findings in previous studies may have resulted from the use of different biomarkers which show disparate aspects of oxidative stress. Additionally, disease severity, medication, smoking, endocrine stress axis activation and obesity are potential confounders. In order to address some of these shortcomings, we have analyzed a broader set of oxidative stress biomarkers in our exploratory study, including urinary 8-iso-prostaglandin F2α (8-iso-PGF2α), 8-OH-2-deoyxguanosine (8-OH-2-dG), and blood levels of malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione S-transferase (GST) in acutely ill drug-naïve first episode patients with schizophrenia (n = 22), major depression (n = 18), and controls (n = 43). Possible confounding factors were considered, and patients were followed-up after 6 weeks of treatment. No differences were observed regarding 8-OH-2-dG, MDA and GST. At baseline, 8-iso-PGF2α levels were higher in patients with schizophrenia (p = 0.004) and major depression (p = 0.037), with a trend toward higher SOD concentrations in schizophrenia (p = 0.053). After treatment, schizophrenia patients showed a further increase in 8-iso-PGF2α (p = 0.016). These results were not related to age, sex, disease severity, medication or adipose tissue mass. However, 8-iso-PGF2α was associated with smoking, endocrine stress axis activation, C-reactive protein levels and low plasma concentrations of brain-derived neurotrophic factor. This study suggests a role of lipid peroxidation particularly in drug-naïve acutely ill schizophrenia patients and highlights the importance of taking into account other confounding factors in biomarker studies.

Fruits and vegetables intake and its subgroups are related to depression: a cross-sectional study from a developing country

BACKGROUND

The association of fruits and vegetables (FV) specific subgroups consumption and depression has not been investigated in healthy adult populations. Therefore, the aim of our study was to determine the relationship between intake of FV as well as their subgroups and depression.

METHODS

This cross-sectional study was conducted on 400 women attending healthcare centers. The scores of depression, anxiety, and stress were measured using the 21-item depression, anxiety and stress scales questionnaire. The participants' anthropometric and physical activity data were collected and the 147-item semi-quantitative FFQ was used for estimating the FV intake.

RESULTS

After adjustment for confounding variables, the participants in the lower quartiles of total FV, total vegetables, total fruits, citrus, other fruits and green leafy vegetables intake were more likely to experience depression compared to those in the higher quartiles (p trend < 0.03).

CONCLUSION

Our findings suggest that higher intake of total FV and some of its specific subgroups might be associated with depression.

Conditional Human Immunodeficiency Virus Transactivator of Transcription Protein Expression Induces Depression-like Effects and Oxidative Stress

BACKGROUND

The prevalence of major depression in those with HIV/AIDS is substantially higher than in the general population. Mechanisms underlying this comorbidity are poorly understood. HIV-transactivator of transcription (Tat) protein, produced and excreted by HIV, could be involved. We determined whether conditional Tat protein expression in mice is sufficient to induce depression-like behaviors and oxidative stress. Further, as oxidative stress is associated with depression, we determined whether decreasing or increasing oxidative stress by administering methylsulfonylmethane (MSM) or diethylmaleate (DEM), respectively, altered depression-like behavior.

METHODS

GT-tg bigenic mice received intraperitoneal saline or doxycycline (Dox, 25-100 mg/kg/day) to induce Tat expression. G-tg mice, which do not express Tat protein, also received Dox. Depression-like behavior was assessed with the tail suspension test (TST) and the two-bottle saccharin/water consumption task. Reactive oxygen/nitrogen species (ROS/RNS) were assessed ex vivo. Medial frontal cortex (MFC) oxidative stress and temperature were measured in vivo with 9.4-Tesla proton magnetic resonance spectroscopy (MRS).

RESULTS

Tat expression increased TST immobility time in an exposure-dependent manner and reduced saccharin consumption. MSM decreased immobility time while DEM increased it in saline-treated GT-tg mice. Tat and MSM behavioral effects persisted for 28 days. Tat and DEM increased while MSM decreased ROS/RNS levels. Tat expression increased MFC glutathione levels and temperature.

CONCLUSIONS

Tat expression induced rapid and enduring depression-like behaviors and oxidative stress. Increasing/decreasing oxidative stress increased/decreased, respectively, depression-like behavior. Thus, Tat produced by HIV may contribute to the high depression prevalence among those with HIV. Further, mitigation of oxidative stress could reduce depression severity.

Severity of anxiety- but not depression- is associated with oxidative stress in Major Depressive Disorder

BACKGROUND

Oxidative stress is implicated in both depression and anxiety, but it is currently unclear whether this relates to syndromal diagnoses or trans-diagnostic dimensional symptoms. We examined the relationship between oxidative stress and severity of depression and anxiety symptoms in individuals with Major Depressive Disorder (MDD).

METHODS

Plasma oxidative stress markers F2-isoprostanes and oxidized glutathione (GSSG), and the antioxidant reduced glutathione (GSH), were assessed in 69 physically healthy, medication-free MDD subjects. Symptoms of anxiety and depression were assessed using the Hamilton Anxiety (HAM-A) and Hamilton Depression (HAM-D) Rating Scales. Total HAM-A and HAM-D scores, along with "core" anxiety and depression subscales, and individual HAM-D items "psychic anxiety" and "depressed mood," were related to oxidative stress markers. Analyses controlled for age, sex, BMI, and smoking.

RESULTS

Total HAM-A ratings were positively associated with F2-isoprostanes (β=.26, p=.042) and GSSG (β=.25, p=.049), but not GSH (β=.05, p=.711). Core anxiety severity was positively associated with F2-isoprostanes (β=.34, p=.012) and GSSG, although this did not reach significance (β=.24, p=.074). None of the biological markers were significantly associated with total HAM-D or core depression ratings (all p>.13). Subjects scoring high on "psychic anxiety" had elevated F2-isoprostanes (p=.030) and GSSG (p=.020). This was not seen with "depressed mood" scores (all p>.12).

LIMITATIONS

We assessed peripheral oxidative markers, but their relationship to the brain is unclear.

CONCLUSIONS

Oxidative stress is more closely related to anxiety than depression symptoms in MDD. This highlights the importance of relating oxidative stress to specific symptoms and could provide new insights into the biological correlates of affective disorders.

Olfactory bulbectomy in mice triggers transient and long-lasting behavioral impairments and biochemical hippocampal disturbances

Major depressive disorder (MDD) is a neuropsychiatric disease that is associated with profound disturbances in affected individuals. Elucidating the pathophysiology of MDD has been frustratingly slow, especially concerning the neurochemical events and brain regions associated with disease progression. Thus, we evaluated the time-course (up to 8weeks) behavioral and biochemical effects in mice that underwent to a bilateral olfactory bulbectomy (OBX), which is used to modeling depressive-like behavior in rodents. Similar to the symptoms in patients with MDD, OBX induced long-lasting (e.g., impairment of habituation to novelty, hyperactivity and an anxiety-like phenotype) and transient (e.g., loss of self-care and motivational behavior) behavioral effects. Moreover, OBX temporarily impaired hippocampal synaptosomal mitochondria, in a manner that would be associated with hippocampal-related synaptotoxicity. Finally, long-lasting pro-oxidative (i.e., increased levels of reactive oxygen species and nitric oxide and decreased glutathione levels) and pro-inflammatory (i.e., increased levels of pro-inflammatory cytokines IL-1, IL-6, TNF-α and decreased anti-inflammatory cytokine IL-10 levels) effects were induced in the hippocampus by OBX. Additionally, these parameters were transiently affected in the posterior and frontal cortices. This study is the first to suggest that the transient and long-lasting behavioral effects from OBX strongly correlate with mitochondrial, oxidative and inflammatory parameters in the hippocampus; furthermore, these effects show a weak correlation with these parameters in the cortex. Our findings highlight the underlying mechanisms involved in the biochemical time course of events related to depressive behavior.

Perinatal complications, lipid peroxidation, and mental health problems in a large community pediatric sample

Replicated evidence indicates that perinatal complications are associated with increased markers of oxidative stress and with mental health problems in children. However, there are fewer reports on the impact of perinatal complications in later phases of development. We aimed to investigate the estimated effects of perinatal complications on levels of lipid peroxidation and on psychopathology in children and adolescents. The study is part of the High Risk Cohort Study for Psychiatric Disorders; the population was composed by 554 students, 6-14 years of age. Serum levels of malondialdehyde, a product of lipid peroxidation, were measured by the TBARS method. A household interview with parents and caregivers was conducted and included inquiries about perinatal history, the Child Behavior Checklist (CBCL), and parent's evaluation, using the Mini International Psychiatric Interview (MINI). We created a cumulative risk index, conceptualized as each individual's cumulative exposure to perinatal complications. Results indicate that perinatal complications were associated with higher levels of TBARS. After adjusting for age, gender, socio-economic status, CBCL total problems score, parental psychopathology, and childhood maltreatment, children exposed to 3 or more perinatal complications had an 26.9% (95% CI 9.9%, 46.6%) increase in TBARS levels, relative to the unexposed group. Exploratory mediation analysis indicated that TBARS levels partially mediated the association between perinatal complications and externalizing problems. In conclusion, an adverse intrauterine and/or early life environment, as proxied by the cumulative exposure to perinatal complications, was independently associated with higher levels of lipid peroxidation in children and adolescents.

Oxidative stress in major depressive and anxiety disorders, and the association with antidepressant use; results from a large adult cohort

BACKGROUND

Oxidative stress has been implicated in the pathophysiology of major depressive disorder (MDD) and anxiety disorders and may be influenced by antidepressant use. This study investigated the association of oxidative stress, measured by plasma levels of F2-isoprostanes and 8-hydroxy-2'-deoxyguanosine (8-OHdG) reflecting oxidative lipid and DNA damage respectively, with MDD, anxiety disorders and antidepressant use in a large cohort.

METHOD

Data was derived from the Netherlands Study of Depression and Anxiety including patients with current (N = 1619) or remitted (N = 610) MDD and/or anxiety disorder(s) (of which N = 704 antidepressant users) and 612 controls. Diagnoses were established with the Composite International Diagnostic Interview. Plasma 8-OHdG and F2-isoprostanes were measured using LC-MS/MS. ANCOVA was performed adjusted for sampling, sociodemographic, health and lifestyle variables.

RESULTS

F2-isoprostanes did not differ between controls and patients, or by antidepressant use. Patients with current disorders had lower 8-OHdG (mean 42.1 pmol/l, 95% CI 40.4-43.8) compared to controls (45.0 pmol/l, 95% CI 42.9-47.2; p < 0.001) after adjustment for sampling, sociodemographics and lifestyle, but these differences disappeared after further adjustment for antidepressant use (p = 0.562). Antidepressant users had lower 8-OHdG levels (38.2 pmol/l, 95% CI 36.5-39.9) compared to controls (44.9 pmol/l, 95% CI 43.2-46.6; Cohen's d = 0.21, p < 0.001). Results for 8-OHdG were comparable across disorders (MDD and/or anxiety disorders), and all antidepressant types (SSRIs, TCAs, other antidepressants).

CONCLUSION

Contrary to previous findings this large-scale study found no increased oxidative stress in MDD and anxiety disorders. Antidepressant use was associated with lower oxidative DNA damage, suggesting antidepressants may have antioxidant effects.

Classifying oxidative stress by F2-isoprostane levels across human diseases: A meta-analysis

The notion that oxidative stress plays a role in virtually every human disease and environmental exposure has become ingrained in everyday knowledge. However, mounting evidence regarding the lack of specificity of biomarkers traditionally used as indicators of oxidative stress in human disease and exposures now necessitates re-evaluation. To prioritize these re-evaluations, published literature was comprehensively analyzed in a meta-analysis to quantitatively classify the levels of systemic oxidative damage across human disease and in response to environmental exposures.

In this meta-analysis, the F₂-isoprostane, 8-iso-PGF_2α, was specifically chosen as the representative marker of oxidative damage. To combine published values across measurement methods and specimens, the standardized mean differences (Hedges’ g) in 8-iso-PGF_2α levels between affected and control populations were calculated.

The meta-analysis resulted in a classification of oxidative damage levels as measured by 8-iso-PGF_2α across 50 human health outcomes and exposures from 242 distinct publications. Relatively small increases in 8-iso-PGF_2α levels (g<0.8) were found in the following conditions: hypertension (g=0.4), metabolic syndrome (g=0.5), asthma (g=0.4), and tobacco smoking (g=0.7). In contrast, large increases in 8-iso-PGF_2α levels were observed in pathologies of the kidney, e.g., chronic renal insufficiency (g=1.9), obstructive sleep apnoea (g=1.1), and pre-eclampsia (g=1.1), as well as respiratory tract disorders, e.g., cystic fibrosis (g=2.3).

In conclusion, we have established a quantitative classification for the level of 8-iso-PGF_2α generation in different human pathologies and exposures based on a comprehensive meta-analysis of published data. This analysis provides knowledge on the true involvement of oxidative damage across human health outcomes as well as utilizes past research to prioritize those conditions requiring further scrutiny on the mechanisms of biomarker generation.

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Oxidative damage is highly variable in human conditions as measured by F₂-isoprostanes.

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Respiratory tract and urogenital diseases have the highest F₂-isoprostanes.

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Cancer and cardiovascular diseases have surprisingly low F₂-isoprostanes.

Role of Keap1-Nrf2 signaling in depression and dietary intake of glucoraphanin confers stress resilience in mice

The transcription factor Keap1-Nrf2 system plays a key role in inflammation which is involved in depression. We found lower expression of Keap1 and Nrf2 proteins in the prefrontal cortex (PFC), CA3 and dentate gyrus (DG) of hippocampus in mice with depression-like phenotype compared to control mice. Serum levels of pro-inflammatory cytokines in Nrf2 knock-out (KO) mice were higher than those of wild-type mice, suggestive of enhanced inflammation in KO mice. Decreased brain-derived neurotrophic factor (BDNF) and its receptor tropomyosin-receptor-kinase B (TrkB) signaling in the PFC, CA3 and DG plays a role in the depression-like phenotype of Nrf2 KO mice. TrkB agonist 7,8-dihydroxyflavone, but not antagonist ANA-12, produced antidepressant effects in Nrf2 KO mice, by stimulating TrkB in the PFC, CA3 and DG. Pretreatment with Nrf2 activator sulforaphane (SFN) prevented the depression-like phenotype induced after repeated social defeat stress. Interestingly, dietary intake of 0.1% glucoraphanin (a precursor of SFN) containing food during juvenile and adolescent stages also prevented the depression-like phenotype evoked in adulthood, after repeated social defeat stress. These findings suggest that Keap1-Nrf2 system plays a key role in depression and that dietary intake of SFN-rich food during juvenile stages and adolescence can confer stress resilience in adulthood.