Identification of markers of depression and neurotoxicity in pesticide exposed agriculture workers.

Earlier, we reported that chronic exposure to pesticides causes a reduction in the acetylcholinesterase activity and hematological and biochemical alterations in agriculture workers. In continuation with that, the present study aimed to investigate the pesticide-induced neurochemical imbalance and its association with behavior alterations in agricultural workers. A significant increase in depressive symptoms, assessed by the Beck Depression Inventory-II was observed in pesticide exposed workers as compared to the unexposed. A decrease in the level of dopamine in plasma and levels of dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acids, norepinephrine, serotonin, and hydroxyindoleacetic acid in urine was also observed. An increase in the levels of MAO-A and MAO-B has also been observed in these individuals. The decreased levels of neurotransmitters in the blood and urine have been linked with increased levels of MAO and pesticide residues in plasma and urine. Furthermore, these changes were associated with a higher incidence of depression in agricultural workers.

Urinary volatilome analysis in a mouse model of anxiety and depression.

Psychiatric disorders including depression and anxiety comprise a broad range of conditions with different symptoms. We have developed a mouse model of depression/anxiety in mice deficient in the St3gal4 gene. In this study, we performed a comparative analysis of urinary volatile organic compounds (VOCs) in St3gal4-deficient (St3gal4-KO) and wild-type mice using gas chromatography-mass spectrometry, and we screened 18 putative VOCs. Principal component analysis (PCA) based on these VOCs identified a major group of 11 VOCs, from which two groups were clarified by hierarchical clustering analysis. One group including six VOCs (pentanoic acid, 4-methyl-, ethyl ester; 3-heptanone, 6-methyl; benzaldehyde; 5,9-undecadien-2-ol, 6,10-dimethyl; and unknown compounds RI1291 and RI1237) was correlated with the startle response (r = 0.620), which is related to an unconscious defensive response. The other group including two VOCs (beta-farnesene and alpha-farnesene) comprised pheromones which increased in KO mice. Next, male mice underwent a social behavior test with female mice in the estrus stage, showing reduced access of KO male mice to female mice. Comparative analysis of urinary VOCs before and after encounters revealed that the six VOCs were not changed by these encounters. However, in WT mice, the two farnesenes increased after the encounters, reaching the level observed in KO mice, which was not altered following the encounter. Taken together, these results indicated that St3gal4 was involved in modulating urinary VOCs. Moreover, VOC clusters discovered by comparison of St3gal4-KO mice with WT mice were correlated with differential emotional behaviors.

Rapid Progression of Knee Pain and Osteoarthritis Biomarkers Greatest for Patients with Combined Obesity and Depression: Data from the Osteoarthritis Initiative.

OBJECTIVE: To compare the progression of biochemical biomarkers of osteoarthritis (OA), knee pain, and function between nonobese patients (NON), obese patients without depression (OBESE), and obese patients with comorbid depression (O + D). DESIGN: Utilizing the FNIH OA Biomarkers Consortium dataset, we categorized knee OA patients into NON, OBESE, and O + D groups based on body mass index and Center for Epidemiological Studies-Depression (CES-D) scores. Subjective symptoms (Knee injury and Osteoarthritis Outcome Score Quality of Life subscale (KOOS QOL), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) Pain and Physical Function scores, and the Short Form-12 (SF-12) Physical Component Score [PCS]) and objective measures of cartilage degradation and bone remodeling (urinary CTXII and CTXIα) were compared among groups at baseline and 2-year follow-up. RESULTS: Of the 600 patients, 282 (47%) were NON, 285 (47.5%) OBESE, and 33 (5.5%) O + D. The O + D group had significantly worse pain and function both at baseline and 2-year follow-up (P < 0.001 for all comparisons) as evidenced by self-reported measures on KOOS QOL, WOMAC Pain, WOMAC Physical Function, and SF-12 PCS. The O + D group also demonstrated significant increases in CTXII (P = 0.01) and CTXIα (P = 0.005), whereas the NON and OBESE groups did not. CONCLUSIONS: The combination of inferior knee pain, physical function, and significantly greater increases in biomarkers of cartilage degradation and bony remodelling suggest a more rapid progression for obese OA patients with comorbid depression. The link between systemic disease, inflammatory burden, and progressive cartilage degradation is in line with increasing concerns about a degenerative synovial environment in early osteoarthritic knees that progress to treatment failure with biologic restoration procedures.

Urinary Alzheimer-Associated Neuronal Thread Protein is not Elevated in Patients with Subjective Cognitive Decline and Patients with Depressive State.

Subjective cognitive decline (SCD) is a risk factor for Alzheimer's disease (AD). Urinary Alzheimer-associated neuronal thread protein (AD7c-NTP) has been identified as a biomarker for AD. It was hypothesized that if urinary AD7c-NTP were also elevated in SCD, as it is in prodromal AD (mild cognitive impairment stage), it could be a convenient and efficient clinical biomarker for the early diagnosis of SCD. SCD is often accompanied by a depressive state (DS), and the impact of DS on urinary AD7c-NTP levels remains unknown. A total of 297 right-handed Chinese Han subjects were recruited, including 98 subjects with SCD, 92 patients with DS, and 107 well-matched cognitively normal controls (NC). The levels of AD7c-NTP in urine samples were measured using an enzyme-linked immunosorbent assay AD7c-NTP kit. Our results demonstrated that urinary AD7c-NTP levels in the SCD group (0.7561±0.5657 ng/mL) were not significantly higher than in either the DS (0.7527±0.5607 ng/mL) or NC (0.7214±0.5077 ng/mL) groups. Furthermore, urinary AD7c-NTP levels were not correlated with Hamilton Depression Rating Scale and Hamilton Anxiety Scale scores, but they were negatively associated with Mini-Mental State Examination scores (r = -0.222, p = 0.033) and Montreal Cognitive Assessment-Basic scores (r = -0.207, p = 0.048). Urinary AD7c-NTP level is not elevated in SCD and is unaffected by DS. Urinary AD7c-NTP may therefore not be a good potential biomarker for SCD and DS, although it may become elevated with more severe cognitive decline.

Urinary metabolic disturbance in the olfactory bulbectomized rats and the modulatory effects of fluoxetine.

AIMS: The present study aims to investigate the impacts of olfactory bulbectomy (OBX) on urinary metabolic profile and tryptophan metabolites in prefrontal cortex (PFC) of rats, and to explore the regulation effects of fluoxetine. MAIN METHODS: OBX model was developed by aspiration of olfactory bulbs. After fluoxetine treatment (10 mg/kg) for 14 days, urine samples were collected and behavior tests were applied. Tryptophan (TRP) metabolites and neurotransmitters in PFC were determined by prominence ultrafast liquid chromatography-QTRAP-mass spectrometry, and tryptophan hydroxylase 2 (TPH2) and indoleamine-2,3-dioxygenase 1 (IDO1) were evaluated by western blot. Urinary metabolites were analyzed by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry-based metabonomics strategy. KEY FINDING: OBX rats showed hyperlocomotion in open field, hyperactivity in open arm and despair status, and fluoxetine reserved these behavioral abnormalities. The levels of TRP, 5-HIAA, 5-HIAA/5-HT ratio and DA increased, while kynurenine and 5-HT decreased in PFC of OBX rats. The activities of TPH2 and IDO1were inhibited after OBX. Twenty-six altered metabolites were identified as potential biomarkers in OBX rats involved in tryptophan metabolism, gut microbiota metabolism, energy metabolism, purine metabolism, ascorbate and aldarate metabolism, and tyrosine metabolism. Among them, 15 abnormal metabolites were corrected by fluoxetine to some extent. SIGNIFICANCE: Our results revealed that urinary metabolic profile changed greatly in OBX rats, and identified biomarkers might be helpful for the diagnosis of agitated depression. The regulation effects of fluoxetine on urinary metabolic profile and tryptophan metabolites in PFC might contribute to its antidepressant action in OBX rats.

Sodium and potassium excretion predict increased depression in urban adolescents.

This study examined the prospective role of urinary sodium and potassium excretion in depressive symptoms among urban, low-income adolescents, and whether these relationships vary by gender. A total of 84 urban adolescents (mean age 13.36 years; 50% male; 95% African American) self-reported on their depressive symptoms at baseline and 1.5 years later. At baseline, the youth also completed a 12-h (overnight) urine collection at home which was used to measure sodium and potassium excretion. After adjusting for baseline depressive symptoms, age, BMI percentile, and pubertal development, greater sodium excretion and lower potassium excretion predicted more severe depressive symptoms at follow-up, with no significant gender differences. The results suggest that consumption of foods high in sodium and low in potassium contributes to the development of depressive symptoms in early adolescence, and that diet is a modifiable risk factor for adolescent depression. Interventions focusing on diet may improve mental health in urban adolescents.

Metabolomic signatures and microbial community profiling of depressive rat model induced by adrenocorticotrophic hormone.

BACKGROUND: Adrenocorticotrophic hormone (ACTH)-treatment rat model has been utilized as a widely accepted model of treatment-resistant depression. Metabolomic signatures represent the pathophysiological phenotype of diseases. Recent studies in gut microbiota and metabolomics analysis revealed the dramatic role of microbiome in psychoneurological system diseases, but still, the mechanisms underlying gut microbiome-host interaction remain unclear. METHODS: Male Wistar rats were s.c. injection of ACTH fragment 1-24 for 14 days to induce treatment-resistant depression. Depression-related behavioral tests, analysis of serum monoamine neurotransmitters and hypothalamic-pituitary-adrenal (HPA) axis-related hormones were determined for assessment of ACTH-induced depression rat model. A gas chromatography-time-of-flight mass spectrometer based urinary metabolomic signatures integrated 16S rRNA sequence analysis based gut microbial profiling was performed, as well as Spearman's correlation coefficient analysis was used to manifest the covariation between the differential urinary metabolites and gut microbiota of genus level. RESULTS: Chronic injection of ACTH-induced depression-like phenotype (increased immobility time in forced swimming test and tail suspension test) was accompanied by peripheral serotonin down-regulation and HPA axis overactivation (ACTH and corticosterone up-regulation). Urinary metabolomics analysis indicated that pyruvic acid, L-threonine, mannitol, D-gluconic acid, 4-hydroxybenzoic acid, D-arabitol, myo-inositol and ascorbic acid levels were reduced in ACTH-treated rats' urine, while hippurate level was elevated. In addition, microbial community profiling revealed bacterial enrichment (e.g. Ruminococcus, Klebsiella) and reduction (e.g. Akkermansia, Lactobacillus) in the ACTH-induced depression rat model. Correlation analysis showed that Akkermansia and Lactobacillus were closely relevant to metabolites myo-inositol and hippurate, which were included in host inositol phosphate metabolism, and phenylalanine, tyrosine and tryptophan biosynthesis. CONCLUSIONS: Depression rat model induced by ACTH is associated with disturbance of pyruvate metabolism, ascorbate and aldarate metabolism, inositol phosphate metabolism, glycine, serine and threonine metabolism, and glycolysis or gluconeogenesis, as well as changes in microbial community structure. Gut microbiota may participate in the mediation of systemic metabolomic changes in ACTH-induced depression model. Therefore, integrated metabolomic signatures and gut microbial community profiling would provide a basis for further studies on the pathogenesis of depression.

Development of an underivatized LC-MS/MS method for quantitation of 14 neurotransmitters in rat hippocampus, plasma and urine: Application to CUMS induced depression rats.

Sensitive and comprehensive measurement of systemic metabolites of tryptophan, phenylalanine and glutamate metabolism in biological samples is effective for understanding the pathogenesis of depression and other neurological diseases. Therefore, this study developed an underivatized liquid chromatography tandem mass spectrometry (LC-MS/MS) method for simultaneous monitoring the 3 components of glutamate metabolism in rat hippocampus and 11 components of tryptophan and phenylalanine metabolism in rat hippocampus, plasma and urine, and applied it to investigate their changes in rats induced by chronic unpredictable mild stress (CUMS). The investigated analytes are as follows: tryptophan, serotonin, 5-hydroxyindoleacetic acid, kynurenine, kynurenic acid, xanthurenic acid, 3-hydroxyanthranilic acid, quinolinic acid, phenylalanine, tyrosine, tyramine, glutamate, glutamine and gamma-aminobutyric acid. The method was verified to be sensitive and effective with satisfactory linearity, accuracies in the range of 78.2%-120.4%, and precisions less than 17.8% for all identified analytes. A series of significant changes in CUMS-induced rats can be detected: tryptophan, serotonin and tyrosine levels decreased and quinolinic acid increased in both hippocampus and plasma. In addition, the kynurenine/tryptophan ratios increased in hippocampus and plasma, the kynurenic acid/quinolinic acid ratios of plasma and urine were significantly reduced. These findings demonstrated that the CUMS procedure could lead to the central and peripheral imbalances of tryptophan and phenylalanine metabolism. In conclusion, a LC-MS/MS method for simultaneous measurement of several neurotransmitters in rat hippocampus, plasma and urine was developed and successfully applied to investigation of the central and peripheral changes in CUMS-induced rats. The method would be expected to provide applicability to the study of the mechanisms of depression and other related diseases associated with these neurotransmitters.

Urinary metabolite signature in bipolar disorder patients during depressive episode.

The first few episodes of bipolar disorder (BD) are highly likely to be depressive. This phenomenon causes many BD patients to be misdiagnosed as having major depression. Therefore, it is very important to correctly diagnose BD patients during depressive episode. Here, we conducted this study to identify potential biomarkers for young and middle-aged BD patients during depressive episode. Both gas chromatography-mass spectroscopy (GC-MS) and nuclear magnetic resonance (NMR) spectroscopy were used to profile the urine samples from the recruited subjects. In total, 13 differential metabolites responsible for the discrimination between healthy controls (HCs) and patients were identified. Most differential metabolites had a close relationship with energy homeostasis. Meanwhile, a panel consisting of five differential metabolites was identified. This panel could effectively distinguish the patients from HCs with an AUC of 0.998 in the training set and 0.974 in the testing set. Our findings on one hand could be helpful in developing an objective diagnostic method for young and middle-aged BD patients during depressive episode; on the other hand could provide critical insight into the pathological mechanism of BD and the biological mechanisms responsible for the transformation of different episodes.

Association of antenatal depression with oxidative stress and impact on spontaneous preterm birth.

OBJECTIVE: To determine whether antenatal depression is associated with oxidative stress and inflammation, and secondarily, whether the association between antenatal depression and spontaneous preterm birth (SPTB) is mediated by these biomarkers. STUDY DESIGN: The primary outcome included urine oxidative stress biomarkers 8-hydroxydeoxyguanosine (8-OHdG) and 8-isoprostane and plasma inflammatory biomarkers measured at 10, 18, and 26 weeks and averaged within individual. Linear and logistic regression models were used, adjusting for age, race, parity, and pre-pregnancy body mass index. RESULTS: Among 462 women, 8-isoprostane was higher among depressed women (geometric mean: 299.96 pg/mL vs. 237.01 pg/mL; p = 0.001). In multivariable analyses, antenatal depression was significantly associated with an increase in average 8-isoprostane (ß: 0.25; 95% CI: 0.05-0.44; p = 0.01). The association of antenatal depression with SPTB was partially mediated by 8-isoprostane. Antenatal depression was not associated with 8-OHdG or inflammatory biomarkers. CONCLUSIONS: Antenatal depression was associated with higher oxidative stress across pregnancy, namely 8-isoprostane, and may impact SPTB via oxidative stress.

Premenstrual Syndrome, Inflammatory Status, and Mood States in Soccer Players.

OBJECTIVE: To evaluate the relationship between the inflammatory profile and mood states in the different phases of the menstrual cycle in soccer players with and without premenstrual syndrome (PMS). METHODS: Data on the menstrual cycle and mood states were collected using the Daily Symptom Report and the Brunel Mood Scale. Cytokine and stress hormone concentrations were measured in urine by flow cytometry before and after a game in the luteal phase and in the follicular phase of one menstrual cycle. RESULTS: In all, 59.6% of the athletes had PMS. The PMS group showed higher concentrations of interleukin (IL)-1ß, IL-6, and IL-8 than the athletes without PMS. After the game, IL-6 decreased in the follicular phase and the luteal phase. The tumor necrosis factor-α levels were higher in the group without PMS during the post-game follicular phase than before the game. In the PMS group, tension was higher in the follicular phase before the game and depression was higher in the pre-game luteal phase than in the group without PMS. The PMS group also presented a negative correlation between depression and IL-10 levels in the pre-game follicular phase. Finally, in the pre-game luteal phase were found positive correlations between growth hormone and IL-10. CONCLUSION: PMS influences the inflammatory condition related to mood states and stress hormones in female soccer players.

Liquid chromatography-mass spectrometry-based urinary metabolomics study on a rat model of simulated microgravity-induced depression.

The pathophysiological mechanism of depression is complex and its etiology remains unclear. Metabolomics can be used to monitor multiple metabolic pathways simultaneously, thereby investigating the mechanisms of depression onset and its regulation. Therefore, we studied the metabolic profile of urine samples from a rat model of depression for identifying potential metabolic biomarkers associated with depression. The depression model of rats was induced by 14-d simulated microgravity (SMG) treatment. Principal component analysis and orthogonal partial least squares discriminate analysis were performed to classify and identify the differences of endogenous metabolites in urine between the normal and depressed rats. Multivariate statistical analysis revealed distinct separation between the urinary metabolic profiles of SMG-treated and control rats. Citric acid, oxalosuccinic acid, creatine, proline, cyclic AMP, L-dihydroxyphenylalanine (DOPA), phenylacetylglycine, 5-hydroxyindole acetaldehyde, succinylcholine, deoxyuridine, 3-hydroxyhippuric acid, glutamine, and 5-hydroxytryptophan levels were significantly reduced, whereas indole-3-acetaldehyde, xanthurenic acid, taurine, kynurenic acid, hippuric acid, 5-hydroxyindoleacetic acid, 2-phenylethanol glucuronide, 2-isopropyl-3-oxosuccinate, and adrenaline levels were elevated significantly in model group. These biochemical changes were related to tryptophan, arginine, proline, and phenylalanine metabolism, and perturbations in energy metabolism. These details of depression will be helpful to the clinical diagnosis of depression caused by space and gravity.

The association between urinary Alzheimer-associated neuronal thread protein and cognitive impairment in late-life depression: a controlled pilot study.

Accumulation of tau protein is associated with both Alzheimer's disease (AD) and late-life depression (LLD). Alzheimer-associated neuronal thread protein (AD7c-NTP), which is closely linked with the tau protein, is elevated in the cerebrospinal fluid and urine of AD patients. This study examined the association between urinary AD7c-NTP and late-life depression with cognitive impairment. One hundred and thirty-eight subjects were recruited into late-life depression with cognitive impairment (LLD-CI, n=52), late-life depression without cognitive impairment (LLD-NCI, n=29), AD (n=27), and healthy control (HC, n=30) groups. The level of urinary AD7c-NTP was measured using the enzyme-linked immunosorbent assay method. The Montreal Cognitive Assessment scale (MoCA), Hamilton Rating Scale for Depression (HRSD) and Hamilton Anxiety Rating Scale (HAMA) were used to assess cognitive functions and depressive and anxiety symptoms in the AD and LLD groups. Urinary levels of AD7c-NTP in the LLD-CI group (1.0±0.7ng/ml) were significantly higher than both the LLD-NCI (0.5±0.3ng/ml) and HC groups (0.5±0.3ng/ml), but lower than in the AD group (1.6±1.7 ng/ml). No significant associations were found in the level of urinary AD7c-NTP in relation to age, gender, education and MoCA in the LLD-CI group. The level of urinary AD7c-NTP appears to be associated with cognitive impairment in late-life depression and may be a potential biomarker for early identification of cognitive impairment in LLD.

Elevated levels of 8-oxoGuo and 8-oxodG in individuals with severe mental illness - An autopsy-based study.

Elevated systemic oxidative stress levels of 8-oxoGuo and 8-oxodG have been reported in individuals with severe mental illness (SMI). As no previous studies have addressed the link between local levels of 8-oxoGuo and 8-oxodG in the central nervous system (CNS), measured in cerebrospinal fluid (CSF), and urinary systemic levels, we employed autopsy-based material to elucidate this aspect. Additionally, we investigated the impact of 8-oxoGuo and 8-oxodG levels on the prevalence of somatic co-morbidities. Based on post mortem samples from deceased individuals with SMI (N = 107), we found significantly elevated urinary levels of both 8-oxoGuo and 8-oxodG compared to mentally healthy living controls. While we found an association between urinary and CSF 8-oxodG levels (r = 0.50, P < 0.001), a similar correlation was not evident for 8-oxoGuo (r = 0.15, P = 0.16). Additionally, the two r-values were significantly different (P < 0.001). Neither marker in urine or CSF was associated with obesity-related variables, metabolic syndrome or type 2 diabetes. The post mortem interval did not affect the results, but the agonal phase seemingly introduced bias. This study provided novel insights into the cellular oxidative stress levels in individuals with SMI. We demonstrated that increased oxidative stress locally and systemically is correlated and is a clear phenomenon in SMI. Although post mortem measurements contain some weaknesses, our study indicates DNA as the main site of oxidative stress modifications in the CNS in SMI. This may provide novel opportunities for treatment modalities. Additionally, our study demonstrated the applicability of post mortem material investigating systemic and local 8-oxoGuo and 8-oxodG levels.

The relationship between diurnal cortisol secretion and climacteric-related symptoms.

OBJECTIVES: Chronic stress, also associated with climacteric-related symptoms, may influence cortisol secretion. We studied cortisol metabolism in peri- and postmenopausal women with diverse climacteric-related symptoms. STUDY DESIGN AND MAIN OUTCOME MEASURES: The study population was 35 women, aged 45-70 years. Plasma cortisol levels were measured from blood samples collected every 20 min over 24 h. Urinary cortisol was analysed from 24-hour urine collections. Climacteric-related symptoms (vasomotor, sleep, depressive, anxiety, cognitive, sexual, menstrual, and somatic) were evaluated with the Women's Health Questionnaire (WHQ). Associations between cortisol variables (24-hour, night, day, maximum, minimum, morning baseline, cortisol awakening response (CAR), area under the curve, slope, and 24-hour urinary cortisol) and the symptoms were first examined with a correlation analysis. Then, the women were divided into two groups according to their climacteric symptomatology, and differences in cortisol variables between the groups were investigated. Diurnal cortisol curves by symptomatology were also analyzed visually. RESULTS: In the correlation analysis, more frequent vasomotor symptoms were associated with a higher CAR (rs = 0.37, p = 0.039) and lower 24-hour urinary cortisol excretion (rs= -0.45, p = 0.012), and more frequent depressive symptoms were associated with a higher minimum cortisol level (rs = 0.33, p = 0.0498). When the women were divided into two groups, women with more frequent vasomotor (p = 0.012) or somatic symptoms (p = 0.021) had a lower 24-hour urinary cortisol excretion than less symptomatic women. CONCLUSIONS: Although previous studies have reported associations between climacteric-related symptoms and cortisol secretion, these two factors were not substantially interrelated in our study.

Clinical and biochemical assessment of depressive symptoms in patients with Alkaptonuria before and after two years of treatment with nitisinone.

OBJECTIVE: Concerns exist over hypertyrosinaemia that is observed following treatment with nitisinone. It has been suggested that tyrosine may compete with tryptophan for uptake into the central nervous system, and or inhibit tryptophan hydroxylase activity reducing serotonin production. At the National Alkaptonuria (AKU) Centre nitisinone is being used off-licence to treat AKU, and there is uncertainty over whether hypertyrosinaemia may alter mood. Herein results from clinical and biochemical assessments of depression in patients with AKU before and after treatment with nitisinone are presented. PATIENTS AND METHODS: 63 patients were included pre-nitisinone treatment, of these 39 and 32 patients were followed up 12 and 24 months after treatment. All patients had Becks Depression Inventory-II (BDI-II) assessments (scores can range from 0 to 63, the higher the score the more severe the category of depression), and where possible urinary monoamine neurotransmitter metabolites and serum aromatic amino acids were measured as biochemical markers of depression. RESULTS: Mean (±standard deviation) BDI-II scores pre-nitisinone, and after 12 and 24 months were 10.1(9.6); 9.8(10.0) and 10.5(9.9) (p ≥ 0.05, all visits). Paired scores (n = 32), showed a significant increase at 24 months compared to baseline 10.5(9.9) vs. 8.6 (7.8) (p = 0.03). Serum tyrosine increased at least 6-fold following nitisinone (p ≤ 0.0001, all visits), and urinary 3-methoxytyramine (3-MT) increased at 12 and 24 months (p ≤ 0.0001), and 5-hydroxyindole acetic acid (5-HIAA) decreased at 12 months (p = 0.03). CONCLUSIONS: BDI-II scores were significantly higher following 24 months of nitisinone therapy in patients that were followed up, however the majority of these patients remained in the minimal category of depression. Serum tyrosine and urinary 3-MT increased significantly following treatment with nitisinone. In contrast urinary 5-HIAA did not decrease consistently over the same period studied. Together these findings suggest nitisinone does not cause depression despite some observed effects on monoamine neurotransmitter metabolism.

Urinary phthalate metabolites concentrations and symptoms of depression in an elderly population.

BACKGROUND: Animal studies have reported an association between phthalates and depression, although there is limited evidence from epidemiological studies. We investigated the association between phthalate exposure and symptoms of depression in an elderly population. METHODS: Repeated measures surveys up to three times were conducted during the study period (2012-2014) in the 535 elderly subjects. We measured the following urinary phthalate metabolite levels: mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP), mono(2-ethyl-5-oxohexyl) phthalate (MEOHP), mono-(2-ethyl-5-carboxypentyl) phthalate (MECPP), mono-n-butyl phthalate (MnBP), and mono-benzyl phthalate (MBzP). MEHHP, MEOHP, and MECPP are metabolites of diethylhexyl phthalates (DEHP). MnBP and MBzP are metabolites of dibutyl phthalate and butyl benzyl phthalate, respectively. The phthalate metabolite concentrations were evaluated to identify associations with the symptoms of depression using the Korean version of the Geriatric Depression Scale-Short Form (SGDS-K). After factor analysis of the components of SGDS-K, we evaluated the association between phthalate exposure and SGDS-K subgroups to determine which symptoms of depression were affected by phthalate exposure. RESULTS: Concentrations of DEHP metabolites were positively associated with the risk of depressive symptoms in the elderly population (Odds ratio (95% confidence interval); 1.92 (1.17-3.13) for sum of three DEHP metabolites), while we found no significant association between depressive symptoms and either MnBP or MBzP. When we evaluated the associations between phthalate metabolite concentrations and the SDGS-K subgroup, we found that affective and spiritual symptoms were significantly associated with DEHP metabolite concentrations. CONCLUSIONS: Our study suggests that DEHP exposure is associated with depressive symptoms, particularly, the affective and spiritual symptoms, among the elderly population.

Probiotics Affect One-Carbon Metabolites and Catecholamines in a Genetic Rat Model of Depression.

SCOPE: Probiotics may influence one-carbon (C1) metabolism, neurotransmitters, liver function markers, or behavior. METHODS AND RESULTS: Male adult Flinders Sensitive Line rats (model of depression, FSL; n = 22) received Lactobacillus helveticus R0052 and Bifidobacterium longum R0175 (109 or 1010 colony-forming units per day) or vehicle for 10 weeks. The controls, Flinders Resistant Line rats (FRL, n = 8), only received vehicle. C1-related metabolites were measured in plasma, urine, and different tissues. Monoamine concentrations were measured in plasma, hippocampus, and prefrontal cortex. Vehicle-treated FSL rats had higher plasma concentrations of betaine, choline, and dimethylglycine, but lower plasma homocysteine and liver S-adenosylmethionine (SAM) than FRLs. FSL rats receiving high-dose probiotics had lower plasma betaine and higher liver SAM compared to vehicle-treated FSL rats. FSLs had higher concentrations of norepinephrine, dopamine, and serotonin than FRLs across various brain regions. Probiotics decreased plasma dopamine in FSLs in a dose-dependent manner. There were no detectable changes in liver function markers or behavior. CONCLUSIONS: Probiotics reduced the flow of methyl groups via betaine, increased liver SAM, and decreased plasma dopamine and norepinephrine. Since these changes in methylation and catecholamine pathways are known to be involved in several diseases, future investigation of the effect of probiotics is warranted.

Perceived Stress, Depressive Symptoms, and Oxidative DNA Damage.

OBJECTIVE: Psychosocial stress may influence the risk of disease through its association with oxidative DNA damage. We examined whether perceived stress and depressive symptoms were associated with urinary excretion of 8-hydroxydeoxyguanosine (8-OHdG), with mutual interaction on 8-OHdG. METHODS: This cross-sectional study included 6517 individuals aged 45 to 74 years who participated, between 2010 and 2012, in a follow-up survey of an ongoing cohort study. Perceived stress during the past year was measured using a self-report questionnaire. Depressive symptoms were evaluated using the Zung Self-Rating Depression Scale. Urinary 8-OHdG concentrations were measured using a column switching high-pressure liquid chromatography system coupled to an electrochemical detector. RESULTS: Higher perceived stress was significantly associated with higher 8-OHdG (2.1% increase per one-category increase of stress; ptrend = .025), even after adjusting for sex, age, supplement use, psychosocial factors, psychotropic medication use, smoking, and body mass index. This association was modestly attenuated after further adjustment for physical activity, suggesting possible mediation or confounding by this factor. Depressive symptoms were not significantly associated with 8-OHdG. No significant interaction was detected between perceived stress and depressive symptoms on 8-OHdG. CONCLUSIONS: In a general Japanese population, we found a weak positive association between perceived stress and urinary excretion of 8-OHdG, whereas no association was observed between depressive symptoms and 8-OHdG. Further studies are needed to examine whether the association between perceived stress and 8-OHdG is modified by depressive symptoms.

Polychlorinated biphenyls and depression: cross-sectional and longitudinal investigation of a dopamine-related Neurochemical path in the German HELPcB surveillance program.

BACKGROUND: Exposure to polychlorinated biphenyls (PCBs) is associated with depressive symptomatology. A cause of depressive symptoms is a disturbance in the neurotransmitter system of dopamine (DA). Animal as well as human studies report that PCBs can influence the DA system. This study examined whether PCB-related depressive symptoms are affected by DA metabolites in humans with high PCB body burden. METHODS: This study is part of the German HELPcB surveillance program (Health Effects in high Level exposure to PCB) for occupationally exposed workers and their relatives. Data was collected from 178 participants on two measurement time points (t1 and t2) with a one-year time lag in between the two time points. PCBs were analyzed in plasma via human biomonitoring and a validated questionnaire was used to identify existence and severity of depressive symptoms. As a surrogate for DA, we measured its metabolites homovanillic acid (HVA) and vanillylmandelic acid (VMA) in urine. Mediation analyses were performed to test whether the association between PCB exposure and severity of depressive symptoms is mediated by urinary concentration of DA metabolites HVA and VMA. The mediation was tested with the SPSS macro MEDIATE. RESULTS: We found a significant mediation over time for lower-chlorinated, higher-chlorinated and dioxin-like PCBs. The positive association between PCB exposure with severity of depressive symptoms was mediated by the main DA metabolite HVA. At t1 a higher exposure with PCBs was associated with lower concentration in urinary HVA. A reduced HVA concentration at t1 was correlated with increased depressive symptoms severity at t2. No meditations were found for VMA. CONCLUSIONS: This work indicates that the association of PCB exposure and an increase of depressive symptoms after one year is mediated by the DA metabolite HVA as a surrogate for DA. These are first steps towards finding an explanation for an underlying neurochemical pathomechanism of PCB-related depressive symptomatology.