Antioxidants as antidepressants: fact or fiction?

The Association of Redox Regulatory Drug Target Genes with Psychiatric Disorders: A Mendelian Randomization Study

Redox regulatory drug (RRD) targets may be considered potential novel drug targets of psychosis due to the fact that the brain is highly susceptible to oxidative stress imbalance. The aim of the present study is to identify potential associations between RRD targets' perturbation and the risk of psychoses; to achieve this, Mendelian randomization analyses were conducted. The expression quantitative trait loci (eQTL) and protein QTL data were used to derive the genetic instrumental variables. We obtained the latest summary data of genome-wide association studies on seven psychoses as outcomes, including schizophrenia (SCZ), bipolar disorder (BD), major depressive disorder (MDD), attention-deficit/hyperactivity disorder, autism, obsessive-compulsive disorder and anorexia nervosa. In total, 95 unique targets were included in the eQTL panel, and 48 targets in the pQTL one. Genetic variations in the vitamin C target (OGFOD2, OR = 0.784, p = 2.14 × 10-7) and melatonin target (RORB, OR = 1.263, p = 8.80 × 10-9) were significantly related to the risk of SCZ. Genetic variation in the vitamin E (PRKCB, OR = 0.248, p = 1.24 × 10-5) target was related to an increased risk of BD. Genetic variation in the vitamin C target (P4HTM: cerebellum, OR = 1.071, p = 4.64 × 10-7; cerebellar hemisphere, OR = 1.092, p = 1.98 × 10-6) was related to an increased risk of MDD. Cognitive function mediated the effects on causal associations. In conclusion, this study provides supportive evidence for a causal association between RRD targets and risk of SCZ, BD or MDD, which were partially mediated by cognition.

Catechin Protects against Lipopolysaccharide-induced Depressive-like Behaviour in Mice by Regulating Neuronal and Inflammatory Genes

BACKGROUND

Many studies have suggested that tea has antidepressant effects; however, the underlying mechanism is not fully studied. As the main anti-inflammatory polyphenol in tea, catechin may contribute to the protective role of tea against depression.

OBJECTIVE

The objective of this study is to prove that catechin can protect against lipopolysaccharide (LPS)-induced depressive-like behaviours in mice, and then explore the underlying molecular mechanisms.

METHODS

Thirty-one C57BL/6J mice were categorized into the normal saline (NS) group, LPS group, catechin group, and amitriptyline group according to their treatments. Elevated Plus Maze (EPM), Tail Suspension Test (TST), and Open Field Test (OFT) were employed to assess depressive- like behaviours in mice. RNA sequencing (RNA-seq) and subsequent Bioinformatics analyses, such as differential gene analysis and functional enrichment, were performed on the four mouse groups.

RESULTS

In TST, the mice in the LPS group exhibited significantly longer immobility time than those in the other three groups, while the immobility times for the other three groups were not significantly different. Similarly in EPM, LPS-treated mice exhibited a significantly lower percentage in the time/path of entering open arms than the mice in the other three groups, while the percentages of the mice in the other three groups were not significantly different. In OFT, LPS-treated mice exhibited significantly lower percentages in the time/path of entering the centre area than those in the other three groups. The results suggested that the LPS-induced depression models were established successfully and catechin can reverse (LPS)-induced depressive-like behaviours in mice. Finally, RNA-seq analyses revealed 57 differential expressed genes (DEGs) between LPS and NS with 19 up-regulated and 38 down-regulated. Among them, 13 genes were overlapped with the DEGs between LPS and cetechin (in opposite directions), with an overlapping p-value < 0.001. The 13 genes included Rnu7, Lcn2, C4b, Saa3, Pglyrp1, Gpx3, Lyz2, S100a8, S100a9, Tmem254b, Gm14288, Hbb-bt, and Tmem254c, which might play key roles in the protection of catechin against LPS-induced depressive-like behaviours in mice. The 13 genes were significantly enriched in defense response and inflammatory response, indicating that catechin might work through counteracting changes in the immune system induced by LPS.

CONCLUSION

Catechin can protect mice from LPS-induced depressive-like behaviours through affecting inflammatory pathways and neuron-associated gene ontologies.

Assessment of the therapeutic potential of lutein and beta-carotene nanodispersions in a rat model of fibromyalgia

Fibromyalgia (FM) is a chronic disorder characterized by widespread musculoskeletal pain, fatigue, and cognitive impairment. Despite the availability of various treatment options, FM remains a challenging condition to manage. In the present study, we investigated the efficacy of formulated nanodispersions of lutein and beta-carotene in treating FM-related symptoms induced by reserpine in female Wistar rats. Several techniques have been implemented to assess this efficacy at various levels, including biochemical, bioelectrical, and behavioral. Namely, oxidative stress markers, monoamine levels, electrocorticography, pain threshold test, and open field test were conducted on control, FM-induced, and FM-treated groups of animals. Our results provided compelling evidence for the efficacy of carotenoid nanodispersions in treating FM-related symptoms. Specifically, we found that the dual action of the nanodispersion, as both antioxidant and antidepressant, accounted for their beneficial effects in treating FM. With further investigation, nano-carotenoids and particularly nano-lutein could potentially become an effective alternative treatment for patients with FM who do not respond to current treatment options.

Dietary total antioxidant capacity and serum 8-OHdG in patients with schizophrenia

BACKGROUND

Dietary total antioxidant capacity serves as an indicator for dietary quality and reflects daily antioxidant intake. This study aimed to determine the oxidative stress status of patients with schizophrenia and to examine the relationship between dietary total antioxidant capacity (dTAC) and 8-hydroxy-2'-deoxyguanosine (8-OHdG), a marker for oxidative stress.

METHODS

This study was conducted in Turkey and involved 40 patients diagnosed with schizophrenia or schizoaffective disorder according to the Diagnostic and Statistical Manual of Mental Disorders, 5th ed., and 30 healthy controls matched for age and gender. The participants' sociodemographic characteristics and nutritional habits were determined through face-to-face interviews and through the use of questionnaires. The dTAC and dietary oxidative balance scores were calculated using a three-day dietary intake record. 8-OHdG levels were analyzed in the serum samples collected from the subjects.

RESULTS

Dietary ferric reducing antioxidant power (FRAP-1, FRAP-2), Trolox equivalence antioxidant capacity (TEAC), and oxygen radical absorbance capacity (H-ORAC) values were lower in patients with schizophrenia than in the healthy controls (P < 0.05). Serum 8-OHdG levels were found similar in both groups (P > 0.05).

CONCLUSION

Nutritional interventions are needed in patients with schizophrenia given that insufficient antioxidant intake may increase oxidative stress, which in turn affects disease development. Therefore, healthy nutrition, especially sufficient intake of dietary antioxidants, should be encouraged in patients with schizophrenia.

Relationship of depression with empathy, emotional intelligence, and symptoms of a weakened immune system

Introduction

Previous studies have used different individual scales to examine the relationship of depression with emotional intelligence, empathy, and immune-based diseases. In this study, we used a combination of psychometric scales to examine the relationships of depression with emotional intelligence (intrapersonal and interpersonal), empathy (affective and cognitive), and symptoms of weakened immune system.

Methods

This cross-sectional prospective study examined 158 volunteers (39 males and 119 females). A score of 10 or more on the Beck Depression Inventory-II (BDI-II) was used to define depression. The Cognitive and Affective Empathy Test (TECA) was used to assess empathy, and the Profile of Emotional Competence (PEC) was used to assess the self-perception of intrapersonal and interpersonal competence. The symptoms of a weakened immune system (WIS) were assessed by measurements of permanent tiredness, frequent infections and colds, slow wound healing, persistent and recurrent diarrhea, recurring herpes, insomnia and difficulty sleeping, and dry eyes.

Results

The total PEC score and intrapersonal PEC score had negative correlations with depression, and the WIS score had a positive correlation with depression. The TECA score had no significant correlation with depression or the WIS score, but had positive correlations with the total PEC score, intrapersonal PEC score, and interpersonal PEC score.

Conclusion

The total PEC score, intrapersonal PEC score, and WIS score were significantly associated with depression. The TECA score was not significantly associated with depression or the WIS score. Our findings suggest that improving intrapersonal emotional skills may improve function of the immune system and reduce the symptoms of depression. We suggest that further studies examine the effect of targeted improvement of interpersonal skills (empathy) on depression.

Biomarkers of Postpartum Depression: A Narrative Review

Postpartum depression (PPD) is a disorder that impairs the formation of the relationship between mother and child, and reduces the quality of life for affected women to a functionally significant degree. Studying markers associated with PPD can help in early detection, prevention, or monitoring treatment. The purpose of this paper is to review biomarkers linked to PPD and to present selected theories on the pathogenesis of the disease based on data from biomarker studies. The complex etiology of the disorder reduces the specificity and sensitivity of markers, but they remain a valuable source of information to help clinicians. The biggest challenge of the future will be to translate high-tech methods for detecting markers associated with postpartum depression into more readily available and less costly ones. Population-based studies are needed to test the utility of potential PPD markers.

Dietary Carotene Intake and Suicidal Ideation in Korean Females: Analysis of Data From the Korea National Health and Nutrition Examination Survey (2012, 2013, and 2015)

OBJECTIVE

The suicide rate in Korea was the highest among countries in the Organisation for Economic Co-operation and Development in 2019. In a previous study, higher intake of vegetables and fruits was associated with a lower risk of suicidal ideation, and carotene-rich fruits and vegetables lowered the risk of depression. This study aimed to examine the direct relationship between carotene intake and suicidal ideation, adjusting for the effect on depression.

METHODS

This study used data from the Korea National Health and Nutrition Examination Survey (KNHANES) conducted in 2012, 2013, and 2015. Carotene intake was assessed through a food intake frequency survey with a 24-hour recall. Suicidal ideation and depression were assessed using the mental health section of the KNHANES. We applied logistic regression to assess the relationship between carotene intake and suicidal ideation, adjusting for potential confounders.

RESULTS

A total of 5,480 females aged 19-64 years were included in this study. Carotene intake was significantly lower in the suicidal ideation group (3,034.5±1,756.4 μg/day) than in the nonsuicidal ideation group (3,225.4±1,795.1 μg/day) (p=0.015). We found a significant inverse association between carotene intake and the risk of suicidal ideation after adjusting for potential confounders (odds ratio=0.934, 95% confidence interval=0.873-0.999).

CONCLUSION

These results suggest that carotene intake may be inversely associated with the risk of suicidal ideation. Our findings may inform the development of new nutritional interventions to prevent increases in the risk of suicide worldwide.

Apigenin attenuates depressive-like behavior via modulating monoamine oxidase A enzyme activity in chronically stressed mice

Chronic stress is a risk factor for depression and is characterized by elevated levels of brain monoamine oxidase A (MAOA). Mounting evidence has shown that MAOA is a biochemical link between stress and depression. Apigenin (API), a natural flavonoid, as demonstrated in vitro inhibitory effect on MAOA, is suggestive of antidepressant-like activity. However, the in vivo inhibitory effect of API on MAOA and how it affects depression still remain unclear. Here, we report the probable mechanisms of action of API in chronic unpredictable mild stress (CUMS)-induced depression in mice. Treatment with API reversed anhedonia, and reduced anxiety and immobility time in behavioral studies. API reduced brain corticosterone and malondialdehyde (MDA) levels but increased brain levels of glutathione and superoxide dismutase. Furthermore, interleukin-6 and tumor necrosis factor-α were attenuated by API. It also restored cell loss and inhibited the activity of MAOA in the hippocampal brain regions and prefrontal cortex. Comparative binding affinity of API for MAOA (-7.7 kcal/mol) through molecular docking studies was greater than that of reference compound, clorgyline (-6.8 kcal/mol). Favorable hydrophobic interactions important to API binding at MAOA binding cavity was revealed to include conventional hydrogen bond (Cys323 and Tyr444), π-Sulfur (Cys323), π-π Stacked (Tyr407), π-π T-shaped (Phe208), π-lone pair and π-alkyl (Ile335, Ile180) interactions. These results suggest that API is a potent, selective, reversible inhibitor of MAOA with capability of attenuating CUMS-induced depression via inhibiting MAOA enzyme activity and altering other pathomechanisms.

Association between autoimmune diseases of the nervous system and schizophrenia: A systematic review and meta-analysis of cohort studies

INTRODUCTION

Numerous studies have found an association between autoimmune diseases of the nervous system (ADNS) and schizophrenia (SCZ), but the findings remain controversial. We conducted the first meta-analysis to summarize the current evidence from cohort studies that evaluated the association between ADNS and SCZ.

METHODS

PubMed, Web of Science, and Embase were comprehensively searched until May 30, 2022 for articles on the association between ADNS and SCZ. Every included study was reported effect size with 95% CIs for the association between ADNS and SCZ. Meta-regression and subgroup analysis were used to assess the heterogeneity.

RESULTS

A total of 8 cohort studies with 12 cohorts were included in the meta-analysis. We observed a significant association between ADNS and SCZ (RR = 1.42; 95%CI, 1.18-1.72). Subgroup analysis showed that the risk of SCZ was significantly increased when ADNS were used as exposure factors (RR = 1.48; 95%CI, 1.15-1.89), whereas with SCZ did not observe an increased risk of subsequent ADNS (RR = 1.33; 95%CI, 0.92-1.92); multiple sclerosis (MS) was positively associated with SCZ (RR = 1.36; 95%CI, 1.12-1.66), but no significant association was found between Guillain-Barre syndrome (GBS) and SCZ (RR = 1.90; 95%CI, 0.87-4.17). Meanwhile, we found location was the source of heterogeneity.

LIMITATIONS

High heterogeneity was observed (I² = 92.0%), and only English literature was included in the meta-analysis.

CONCLUSIONS

We found a positive association between ADNS and SCZ, and the association was different across the different types of ADNS. The results of the study are helpful for clinicians to carry out targeted preventive measures for ADNS and SCZ.

Antioxidant and Anti-Inflammatory Effects of Carotenoids in Mood Disorders: An Overview

Depression has a multifactorial etiology comprising family history and unemployment. This review aims to summarize the evidence available for the antioxidant and anti-inflammatory effects of carotenoids in mood disorders. This review article’s methodologies were based on a search of the PubMed database for all linked published papers. Epidemiological studies indicate that a diet rich in vegetables, fruits, nuts, fish, and olive oil may prevent the development of depression. Antioxidant supplementation has been found to combat various stress-induced psychiatric disorders, including depression and anxiety. A growing body of evidence indicates that carotenoids have both antioxidant and anti-inflammatory. Studies also suggest that poor dietary intake, particularly low intakes of fruit and vegetables and high intakes of fast food and other convenience foods, may increase the risk of developing depression. Thus, dietary interventions have the potential to help mitigate the risk of mental health decline in both the general population and those with mood disorders. Considering that carotenoids have both antioxidant and anti-inflammatory effects, it is expected that they might exert a promising antidepressant effect. Nevertheless, further studies (including interventional and mechanistic studies) assessing the effect of carotenoids on preventing and alleviating depression symptoms are needed.

Gut microbiota: A new target for traditional Chinese medicine in the treatment of depression

ETHNIC PHARMACOLOGICAL RELEVANCE

The causes of depression are complex. Many factors are involved in its pathogenesis, including the individual's biological and social environment. Although numerous studies have reported that the gut microbiota plays a significant role in depression, drugs that regulate the gut microbiota to treat depression have not yet been comprehensively reviewed. At the same time, more and more attention has been paid to the characteristics of traditional Chinese medicine (TCM) in improving depression by regulating gut microbiota. In ancient times, fecal microbiota transplantation was recorded in TCM for the treatment of severe diseases. There are also records in Chinese ancient books about the use of TCM to adjust gut microbiota to treat diseases, which has opened up a unique research field in TCM. Therefore, this article focuses on the pharmacological effects, targets, and mechanisms of TCM in improving depression by mediating the influence of gut microbiota.

AIM OF THIS REVIEW

To summarize the role the gut microbiota plays in depression, highlight potential regulatory targets, and elucidate the anti-depression mechanisms of TCMs through regulation of the gut microbiota.

METHODS

A systematic review of 256 clinical trials and pharmaceutical studies published until June 2022 was conducted in eight electronic databases (Web of Science, PubMed, SciFinder, Research Gate, ScienceDirect, Google Scholar, Scopus, and China Knowledge Infrastructure), according to the implemented PRISMA criteria, using the search terms "traditional Chinese medicine," "depression," and "gut microbiota."

RESULTS

Numerous studies reported the effects of different gut bacteria on depression and that antidepressants work through the gut microbiota. TCM preparations based on compound Chinese medicine, the Chinese Materia Medica, and major bioactive components exerted antidepressant-like effects by improving levels of neurotransmitters, short-chain fatty acids, brain-derived neurotrophic factor, kynurenine, and cytokines via regulation of the gut microbiota.

CONCLUSION

This review summarized the anti-depression effects of TCM on the gut microbiota, providing evidence that TCMs are safe and effective in the treatment of depression and may provide a new therapeutic approach.

Isoliquiritigenin ameliorates paroxetine-induced sexual dysfunction in male albino mice

Paroxetine (PRX), a widely prescribed antidepressant, often leads to sexual dysfunction. The available management options such as sildenafil (SDF), are associated with side effects. The present study investigates the fertility-boosting properties of isoliquiritigenin (ISL) on PRX-induced sexual dysfunction in male mice. We allocated fertile mice into six different groups (n = 5): group I- DMSO; group II- PRX; group III- co-administered PRX and SDF; group IV- ISL alone; group V- co-administered PRX and ISL (low dose); and, group VI- co-administered PRX and ISL (high dose). 14 days post treatment, animals were sacrificed, and the weights of the testis and epididymis were evaluated. Furthermore, sperm parameters, testicular and epididymal antioxidant levels, serum testosterone and nitric oxide (NO) levels, histoarchitecture of testis and epididymis, and markers of cellular toxicity were assessed. Results revealed that the PRX administration reduced organ weights, sperm count, intact acrosome, catalase (CAT), superoxide dismutase (SOD), glutathione (GSH), serum testosterone, and NO levels, and increased sperm abnormalities and MDA levels (a biomarker for lipid peroxidation). Additionally, we observed damage in the testis and epididymis. The toxicity biomarker study revealed a higher concentration of SGOT, SGPT, and ALP enzymes in the PRX-treated group. However, the co-administration of PRX with ISL ameliorated the adverse effect of PRX on the parameters mentioned above. The PRX+ISL (high) results were almost at par with the PRX+SDF group. The group that received ISL alone showed overall improvements. In conclusion, our comprehensive panel of tests indicates that ISL could be helpful in managing sexual dysfunction.

LQFM212, a piperazine derivative, exhibits potential antioxidant effect as well as ameliorates LPS-induced behavioral, inflammatory and oxidative changes

AIMS

Oxidative stress, impaired antioxidant defense and neuroinflammation are often associated with the onset and progression of neuropsychiatric diseases. Conversely, several piperazine compounds presents beneficial neuropharmacological effects as well as antioxidant activity, and some derivatives combine both activities. LQFM212 (2,6-di-tert-butyl-4-((4-(2-hydroxyethyl)piperazin-1-yl)methyl)phenol) was synthesized to produce effects on CNS and to have an additional antioxidant effect. Previous preclinical tests have been shown anxiolytic- and antidepressant-like effects of LQFM212 in mice. Herein, the main objective was to verify the possible antioxidant potential and the effects of LQFM212 against behavioral changes, inflammatory and oxidative markers induced by lipopolysaccharide (LPS).

MAIN METHODS

Initially, antioxidant potential of LQFM212 was evaluated by electrochemical assays. Afterwards, the effects of oral treatment with LQFM212 were evaluated in mice using LPS-induced models of systemic or local inflammation.

KEY FINDINGS

In LPS-induced neuroinflammation, LQFM212 treatment reverted changes caused by LPS, demonstrated by attenuated anxiogenic- and depressive-like behaviors, reduced pro-inflammatory cytokines (TNF-α and IL-1β) and increased anti-inflammatory cytokines (IL-4 and IL-10) on serum, and also improved oxidative stress-related changes (levels of nitrite, malondialdehyde, glutathione and carbonylated protein, and superoxide dismutase, catalase, myeloperoxidase and cholinesterase activities) on brain cortex and hippocampus. However, LQFM212 treatment did not attenuate the inflammatory changes in LPS-induced pleurisy model.

SIGNIFICANCE

LQFM212 presents antioxidant activity and ameliorates behavioral, inflammatory and oxidative changes after LPS-induced neuroinflammation model. These effects do not seem to be secondary to a peripheral anti-inflammatory action of LQFM212, since this compound failed to attenuate the inflammatory changes in LPS-induced pleurisy model.

The Role of Equilibrium between Free Radicals and Antioxidants in Depression and Bipolar Disorder

Background: Increasing evidence suggests that the presence of oxidative stress and disorders of the antioxidant defense system are involved in a wide range of neuropsychiatric disorders, such as bipolar disorder, schizophrenia and major depression, but the exact mechanism remains unknown. This review focuses on a better appreciation of the contribution of oxidative stress to depression and bipolar disorder. Methods: This review was conducted by extracting information from other research and review studies, as well as other meta-analyses, using two search engines, PubMed and Google Scholar. Results: As far as depression is concerned, there is agreement among researchers on the association between oxidative stress and antioxidants. In bipolar disorder, however, most of them observe strong lipid peroxidation in patients, while regarding antioxidant levels, opinions are divided. Nevertheless, in recent years, it seems that on depression, there are mainly meta-analyses and reviews, rather than research studies, unlike on bipolar disorder. Conclusions: Undoubtedly, this review shows that there is an association among oxidative stress, free radicals and antioxidants in both mental disorders, but further research should be performed on the exact role of oxidative stress in the pathophysiology of these diseases.

Dietary Intake of Carotenoids and Risk of Depressive Symptoms: A Systematic Review and Meta-Analysis

Given the important role of oxidative stress in the pathogenesis of depression, the potential role of dietary antioxidant supplementation in the prevention of depression has attracted considerable attention. Most studies suggest that dietary carotenoids may play a role in maintaining depressive symptoms due to their antioxidant activity, but some studies concluded the contrary. This study conducted a meta-analysis of observational studies to test the relationship between carotenoid supplements and depressive symptoms. After a comprehensive search of the Cochrane Library, PubMed, Embase Scopus, and Web of Science databases from their inception to 28 July 2022, 12 publications met the inclusion and exclusion criteria, of which 8 were cross-sectional studies, 3 were case−control studies, and 1 was a cohort study, involving a total of 33,466 participants. Pooled meta-analysis found that intake of total carotenoids (OR = 0.61, 95% CI [0.53, 0.71], p < 0.01), beta-carotene (OR = 0.61, 95% CI [0.52, 0.70], p < 0.01), alpha-carotene (OR = 0.71, 95% CI [0.60, 0.83], p < 0.01), lycopene (OR = 0.71, 95% CI [0.55, 0.90], p < 0.01), lutein, and/or corn xanthin (OR = 0.53, 95% CI [0.43, 0.66], p < 0.01) was significantly inversely associated with depressive symptoms, while beta-cryptoxanthin (OR = 1.07, 95% CI [0.52, 2.21], p = 0.86) had no significance. At the same time, this meta-analysis was free of publication bias and heterogeneity. Although further studies are needed to elucidate the causal relationship between carotenoids and depressive symptoms, and to further reveal the mechanism of their association, the results of our meta-analysis suggest that carotenoids are protective factors for depressive symptoms, and dietary intake may help in reducing the risk of depressive symptoms.

Increased Levels of Autoantibodies against ROS-Modified Proteins in Depressed Individuals with Decrease in Antibodies against SARS-CoV-2 Antigen (S1-RBD)

Coronavirus 2019 (COVID-19) disease management is highly dependent on the immune status of the infected individual. An increase in the incidence of depression has been observed during the ongoing COVID-19 pandemic. Autoantibodies against in vitro reactive oxygen species (ROS) modified BSA and Lys as well as antibodies against receptor binding domain subunit S1 (S1-RBD) (S1-RBD-Abs) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were estimated using direct binding and competition ELISA. Serum samples were also tested for fasting blood glucose (FBG), malondialdehyde (MDA), carbonyl content (CC), interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α). Significant structural changes were observed in ROS modified BSA and Lys. Female depressed subjects who were also smokers (F-D-S) showed the highest levels of oxidative stress (MDA and CC levels). Similarly, increased levels of autoantibodies against ROS modified proteins were detected in F-D-S subjects, in males who were depressed and in smokers (M-D-S) compared to the other subjects from the rest of the groups. However, contrary to this observation, levels of S1-RBD-Abs were found to be lowest in the F-D-S and M-D-S groups. During the pandemic, large numbers of individuals have experienced depression, which may induce excessive oxidative stress, causing modifications in circulatory proteins. Thus, the formation of neo-antigens is induced, which lead to the generation of autoantibodies. The concomitant effect of increased autoantibodies with elevated levels of IFN-γ and TNF-α possibly tilt the immune balance toward autoantibody generation rather than the formation of S1-RBD-Abs. Thus, it is important to identify individuals who are at risk of depression to determine immune status and facilitate the better management of COVID-19.

Dark chocolate: An overview of its biological activity, processing, and fortification approaches

Dark chocolate gets popularity for several decades due to its enormous health benefits. It contains several health-promoting factors (bioactive components - polyphenols, flavonoids, procyanidins, theobromines, etc, and vitamins and minerals) that positively modulate the immune system of human beings. It confers safeguards against cardiovascular diseases, certain types of cancers, and other brain-related disorders like Alzheimer's disease, Parkinson's disease, etc. Dark chocolate is considered a functional food due to its anti-diabetic, anti-inflammatory, and anti-microbial properties. It also has a well-established role in weight management and the alteration of a lipid profile to a healthy direction. But during the processing of dark chocolate, several nutrients are lost (polyphenol, flavonoids, flavan 3 ol, ascorbic acid, and thiamine). So, fortification would be an effective method of enhancing the overall nutrient content and also making the dark chocolate self-sufficient. Thus, the focus of this review study is to gather all the experimental studies done on dark chocolate fortification. Several ingredients were used for the fortification, such as fruits (mulberry, chokeberries, and elderberries), spices (cinnamon), phytosterols, peanut oil, probiotics (mainly Lactobacillus, bacillus spices), prebiotics (inulin, xanthan gum, and maltodextrin), flavonoids, flavan-3-ols, etc. Those fortifications were done to raise the total antioxidant content as well as essential fatty acid content simultaneously reducing total calorie content. Sometimes, the fortification was done to improve physical properties like viscosity, rheological propertiesand also improve overall consumer acceptance by modifying its bitter taste.

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Dark chocolate gets popularity for several decades due to its enormous health benefits.

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Dark chocolate is considered a functional food due to its health benefits.

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During the processing of dark chocolate, several nutrients are lost.

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Fortification would be an effective method of enhancing the overall nutrient content.

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This review study is to gather all the experimental studies done on dark chocolate fortification.

Phenolic Acids as Antidepressant Agents

Depression is a psychiatric disorder affecting the lives of patients and their families worldwide. It is an important pathophysiology; however, the molecular pathways involved are not well understood. Pharmacological treatment may promote side effects or be ineffective. Consequently, efforts have been made to understand the molecular pathways in depressive patients and prevent their symptoms. In this context, animal models have suggested phytochemicals from medicinal plants, especially phenolic acids, as alternative treatments. These bioactive molecules are known for their antioxidant and antiinflammatory activities. They occur in some fruits, vegetables, and herbal plants. This review focused on phenolic acids and extracts from medicinal plants and their effects on depressive symptoms, as well as the molecular interactions and pathways implicated in these effects. Results from preclinical trials indicate the potential of phenolic acids to reduce depressive-like behaviour by regulating factors associated with oxidative stress, neuroinflammation, autophagy, and deregulation of the hypothalamic-pituitary-adrenal axis, stimulating monoaminergic neurotransmission and neurogenesis, and modulating intestinal microbiota.

Autoantibodies Against ROS-Human Serum Albumin-A Potent Immunological marker in Depressed Individuals with Smoking History

Background: Depression is one of the significant problems in adults that accounts for up to five percent of cases worldwide.

Methods: Volunteers were divided into eight groups, and their serum samples were tested for FBG, carbonyl contents, IFN-γ and TNF-α. Reactive oxygen species (ROS) modified human serum albumin (HSA) (ROSHSA) was used as an antigen and levels of serum autoantibodies were estimated by direct binding and inhibition ELISA in all subjects.

Results: Significant biophysical structural modifications were observed in ROS-HSA with increased carbonyl contents compared to native-HSA (N-HSA). Significantly high levels of carbonyl content (2.68 ± 0.33 nmol/mg protein; p > 0.001) and pro-inflammatory cytokines IFN-γ (7.4 ± 0.61 pg/ml; p > 0.001) and TNF-α (1.47 ± 0.23 pg/ml; p > 0.001) were detected in serum samples from F-D-S. Similarly, a high level of autoantibodies against ROS-HSA was observed in females who were depressed and smokers (F-D-S) group (0.89 ± 0.07; p > 0.001) compared to males who were both depressed and smokers (M-D-S) (0.66 ± 0.049). Furthermore, inhibition ELISA results exhibited high recognition of serum autoantibodies from F-D-S subjects (78.6 ± 5.7 mean maximum percentage inhibition MMPI) compared to M-D-S (58.8 ± 5.2 MMPI) subjects.

Conclusion: Incoherence, long term unchecked chronic psychological stress may cause oxidation of blood proteins, which subsequently result in structural alterations of biomolecules, thus generating new-epitopes, capable of inducing autoantibodies specific for ROS-modified proteins. These autoantibodies may be a potential marker for subjects suffering from depression to understand the state of immune imbalance.

Effects of electroconvulsive therapy on nitrosative stress and oxidative DNA damage parameters in patients with a depressive episode

BACKGROUND

Few studies have investigated the relationship between electroconvulsive therapy (ECT) and markers of nitrosative stress and oxidative DNA damage.

OBJECTIVE

The aim of this study is to examine changes in nitrosative stress and oxidative DNA damage in patients with a depressive episode treated with ECT.

METHODS

The current study included 48 patients with a depressive episode treated with ECT and 30 healthy control participants. First, the serum nitrosative stress markers of nitric oxide (NO•), nitric oxide synthase (NOS), and peroxynitrite (ONOO-) and the oxidative DNA damage marker 8-hydroxy-2'-deoxyguanosine (8-OHdG) were compared between the study and control groups. These parameters were also compared pre- and post-treatment for the study group.

RESULTS

NO•, NOS, and ONOO- levels were significantly higher in patients with depressive disorder (DD) than in the control group. NO• and NOS levels significantly decreased in the ECT group after treatment while 8-OHdG levels significantly increased.

CONCLUSIONS

The study findings suggest that ECT may have reduced nitrosative stress levels while increasing oxidative DNA damage. More research is now needed to better understand the issue.KEY POINTSNitrosative stress levels can increase in patients with depressive disorder.Electroconvulsive therapy may reduce nitrosative stress while increasıng oxidative DNA damage.These results suggest that nitrosative stress plays an important role in the mechanism of action of electroconvulsive therapy.

Markers of elevated oxidative stress in oligodendrocytes captured from the brainstem and occipital cortex in major depressive disorder and suicide

Major depressive disorder (MDD) and suicide have been associated with elevated indices of oxidative damage in the brain, as well as white matter pathology including reduced myelination by oligodendrocytes. Oligodendrocytes highly populate white matter and are inherently susceptible to oxidative damage. Pathology of white matter oligodendrocytes has been reported to occur in brain regions that process behaviors that are disrupted in MDD and that may contribute to suicidal behavior. The present study was designed to determine whether oligodendrocyte pathology related to oxidative damage extends to brain areas outside of those that are traditionally considered to contribute to the psychopathology of MDD and suicide. Relative telomere lengths and the gene expression of five antioxidant-related genes, SOD1, SOD2, GPX1, CAT, and AGPS were measured in oligodendrocytes laser captured from two non-limbic brain areas: occipital cortical white matter and the brainstem locus coeruleus. Postmortem brain tissues were obtained from brain donors that died by suicide and had an active MDD at the time of death, and from psychiatrically normal control donors. Relative telomere lengths were significantly reduced in oligodendrocytes of both brain regions in MDD donors as compared to control donors. Three antioxidant-related genes (SOD1, SOD2, GPX1) were significantly reduced and one was significantly elevated (AGPS) in oligodendrocytes from both brain regions in MDD as compared to control donors. These findings suggest that oligodendrocyte pathology in MDD and suicide is widespread in the brain and not restricted to brain areas commonly associated with depression psychopathology.

Bioavailability of Hesperidin and Its Aglycone Hesperetin—Compounds Found in Citrus Fruits as a Parameter Conditioning the Pro-Health Potential (Neuroprotective and Antidiabetic Activity)—Mini-Review

Hesperidin and hesperetin are polyphenols that can be found predominantly in citrus fruits. They possess a variety of pharmacological properties such as neuroprotective and antidiabetic activity. However, the bioavailability of these compounds is limited due to low solubility and restricts their use as pro-healthy agents. This paper described the limitations resulting from the low bioavailability of the presented compounds and gathered the methods aiming at its improvement. Moreover, this work reviewed studies providing pieces of evidence for neuroprotective and antidiabetic properties of hesperidin and hesperetin as well as providing a detailed look into the significance of reported modes of action in chronic diseases. On account of a well-documented pro-healthy activity, it is important to look for ways to overcome the problem of poor bioavailability.

Pomegranate and Its Components, Punicalagin and Ellagic Acid, Promote Antidepressant, Antioxidant, and Free Radical-Scavenging Activity in Ovariectomized Rats

Previous reports described the antidepressant-like action of the aqueous extract of pomegranate (Punica granatum: AEPG). Thus we evaluated the effect of AEPG and the main compounds found in the extract, punicalagin (PNCG) and ellagic acid (EA), on forced swimming test and the redox environment (reactive oxygen species [ROS] production, lipoperoxidation [LPX], and cellular function) in the brain of rats treated with 3 weeks post ovariectomy exposed ex vivo to pro-oxidants. Also, we selected PNCG and EA to study their antidepressant-like effects (0.001, 0.01, 0.1, 1.0, and 10 mg/kg) in the forced swimming test and their scavenging capacities in chemical combinatorial assays (expressed as IC₅₀ values). We observed a 2-fold increase in the formation of ROS and LPX in the brain after exposure to FeSO₄. However, these effects were significantly attenuated when rats were treated with AEPG, PNCG, and EA (1 mg/kg and 0.010 mg/kg for 14 days). AEPG and EA significantly increased the cellular function values of brains that had been affected by the effect of FeSO₄ and with ONOO^–. PNCG and EA significantly reduced immobility behavior at the lower doses used in this study. The capacity of scavenging compounds to eliminate radicals was for hydroxyl radical (^⋅OH), superoxide anion (O2^⋅⁣–), and peroxynitrite (ONOO^–) as follows: AEPG > punicalagin > ellagic acid. In conclusion, the AEPG and their active compounds PNCG and EA promote antidepressant-like actions and antioxidant activity as they attenuate oxidative damage and prevent cellular dysfunction in ovariectomized rat brains.

Medicinal Plants for Anti-neurodegenerative diseases in West Africa

ETHNOPHARMACOLOGICAL RELEVANCE

Neurodegenerative diseases are neuronal diseases that affect the brain components by degenerating the structure and function of the central or peripheral nervous system progressively. It is a leading cause of death and affects huge amount of people worldwide. Plant-based medicines have been utilised in the therapies for many illnesses that have defied western treatments, including neurodegenerative diseases.

AIM OF THIS REVIEW

This review presents an overview of the major neurodegenerative diseases and reported prominent medicinal plants used in managing those diseases in West Africa.

METHODS

Scientific articles regarding medicinal plants and their usefulness in managing neurodegenerative diseases in West Africa were pooled from different scientific databases. We used the Preferred Reporting Items for Systematic Reviews and Meta-Analyses to filter articles based on their relevance. Pharmacological activity, plant parts used, experimental models, and some isolated chemical compounds of those plants were summarised.

RESULTS

In the West Africa region, Fabaceae (19%) and Solanaceae (13%) have the highest representation of plant families used to treat neurological diseases, while Apocynaceae, Asteraceae, Euphorbiaceae have also been utilised. Flavonoids, alkaloids, phenolic compounds, terpenoids, coumarins present in those plants and their derivatives are reported to possess neuro-protective effects. Biochemical enzymes correlating to antioxidants, anti-inflammatory effects are the potential targets against neurodegenerative diseases.

CONCLUSION

Medicinal plants for anti-neurodegenerative diseases in West Africa have been documented with their neuropharmacological activities. Plant families such as Fabaceae, Solanaceae, Apocynaceae, Asteraceae, and Euphorbiaceae could be a major natural source for discovery of anti-neurodegenerative drugs, thus the metabolites from them should be given priority for neurological research. This review will provide clues for further investigations on the screening and development of anti-neurodegenerative natural products from West African medicinal plants.

Oxidative and Nitrosative Stress in Major Depressive Disorder: A Case Control Study

Introduction: The role of increased oxidative stress and alterations to the nitric oxide (NO) pathway have been implicated in major depressive disorder (MDD). The two pathways interact closely with each other but have not been studied simultaneously in MDD. This study aimed to assess and compare the levels of oxidative and nitrosative stress in the neutrophils (PMNs) of drug-naive MDD patients and their first-degree relatives. Methods: 29 drug-naive MDD patients and 27 healthy first-degree relatives and healthy controls aged 18–45 years were included in this study. An assessment of the levels of reactive oxygen species (ROS), nitrites, neuronal NO synthase (nNOS), and myeloperoxidase in PMNs, and cortisol in serum was carried out. Results: Compared to healthy controls, the generation of free radicals, myeloperoxidase activity, and nNOS mRNA expression in PMNs, and cortisol level in serum were significantly higher in drug-naive depression patients. Indeed, increased levels of myeloperoxidase and serum cortisol were also noted in first-degree relatives. The total nitrite content in the PMNs and plasma however was significantly lower in both patients and first-degree relatives. Interestingly, a positive correlation was established in the ROS levels in the PMNs, plasma and neutrophil nitrite, and the serum cortisol level between MDD patients and their first-degree relatives. Conclusion: The results of this study contribute towards a better understanding of the familial association of depressive disorder, and demonstrate for the first time that neutrophil ROS/RNS, plasma nitrite, and serum cortisol levels are positively correlated between MDD patients and their first-degree relatives. However, further studies in larger, more diverse samples are needed to extend these pathways as potential biomarkers to identify persons at high risk for psychopathology at an early stage.

Antioxidant Activity of Fluoxetine and Vortioxetine in a Non-Transgenic Animal Model of Alzheimer's Disease

Depression is a risk factor for the development of Alzheimer’s disease (AD). A neurobiological and clinical continuum exists between AD and depression, with neuroinflammation and oxidative stress being involved in both diseases. Second-generation antidepressants, in particular selective serotonin reuptake inhibitors (SSRIs), are currently investigated as neuroprotective drugs in AD. By employing a non-transgenic AD model, obtained by intracerebroventricular (i.c.v.) injection of amyloid-β (Aβ) oligomers in 2-month-old C57BL/6 mice, we recently demonstrated that the SSRI fluoxetine (FLX) and the multimodal antidepressant vortioxetine (VTX) reversed the depressive-like phenotype and memory deficits induced by Aβ oligomers rescuing the levels of transforming growth factor-β1 (TGF-β1). Aim of our study was to test FLX and VTX for their ability to prevent oxidative stress in the hippocampus of Aβ-injected mice, a brain area strongly affected in both depression and AD. The long-term intraperitoneal (i.p.) administration of FLX (10 mg/kg) or VTX (5 and 10 mg/kg) for 24 days, starting 7 days before Aβ injection, was able to prevent the over-expression of inducible nitric oxide synthase (iNOS) and NADPH oxidase 2 (Nox2) induced by Aβ oligomers. Antidepressant pre-treatment was also able to rescue the mRNA expression of glutathione peroxidase 1 (Gpx1) antioxidant enzyme. FLX and VTX also prevented Aβ-induced neurodegeneration in mixed neuronal cultures treated with Aβ oligomers. Our data represent the first evidence that the long-term treatment with the antidepressants FLX or VTX can prevent the oxidative stress phenomena related to the cognitive deficits and depressive-like phenotype observed in a non-transgenic animal model of AD.

Acupuncture Relieves Stress-Induced Depressive Behavior by Reducing Oxidative Stress and Neuroapoptosis in Rats

Oxidative stress is closely related to the occurrence of depression. Acupuncture has been proved to be an effective method for treating depression. In order to explore the mechanism of the antidepressant effect of acupuncture, this study performed acupuncture prevention on chronic unpredictable mild stress (CUMS) depression model rats, and observed the effect of acupuncture on hippocampal oxidative stress and Nrf2 signaling pathway. Male SD rats were randomly divided into control group, CUMS group, acupuncture group, and fluoxetine group (n = 10/group). Fluoxetine, a common antidepressant, was used as a positive control drug in this study. In the fluoxetine group, rats were given fluoxetine (2.1 mg/kg) intragastrically once a day for 28 days. The acupoints of Shangxing (GV23) and Fengfu (GV16) were applied in acupuncture group, once every other day for 14 times in total. Behavioral tests and biological detections were used to evaluate the effects of the interventions and the changes of factors related to oxidative stress, Nrf2 pathway, and neuronal apoptosis. The results showed that both acupuncture and fluoxetine could increase sugar preference rate in SPT and decrease immobility time in FST in depression model rats. It also significantly decreased oxidative stress products such as ROS and H2O2, and elevated the protein and mRNA expressions of Nrf2 and HO-1. From Nissl’s staining, there were more abundant nerve cells in two intervention groups compared with CUMS group. Plus, acupuncture down-regulated the expression levels of Bax and caspase-3 and up-regulated the expression of Bcl-2. Our findings indicate that acupuncture improved depression-like behaviors of CUMS rats. And CUMS-induced depression-like behaviors in rats were related to oxidative stress and neuronal apoptosis in hippocampus. Acupuncture showed antidepressant effects in reducing oxidative stress products via regulating the Nrf2/HO-1 signaling pathway so that prevented neuronal apoptosis.

Polyphenols inhibiting MAPK signalling pathway mediated oxidative stress and inflammation in depression

Depression is one of the most debilitating psychiatric disorders affecting people of all ages worldwide. Despite significant heterogeneity between studies, increased inflammation and oxidative stress have been found in depression. Oxidative stress and inflammation are involved in the pathogenesis of depression. In the current review, we discussed the markers of oxidative stress and inflammation in depressive disorder and the association between these markers and the antidepressant treatment. The role of natural polyphenols in regulating various cell signaling pathways related to oxidative stress and inflammation has also been reviewed. The inhibitory effect of polyphenols on several cell signaling pathways reveals the vital role of polyphenols in the prevention and treatment of depressive disorder. Understanding the mechanism of polyphenols implicated in the regulation of cell signaling pathways is essential for the identification of lead compounds and the development of novel effective compounds for the prevention and treatment of depressive disorder.

The association between dietary patterns and depression in adolescents: A cross-sectional study

INTRODUCTION AND PURPOSE

So far, few studies have examined the relationship between dietary patterns and depression in adolescents. The aim of the present study was to determine this relationship in a sample of adolescent Iranian girls.

MATERIALS AND METHODS

347 female high school students aged 14-17 years living in Shiraz, Iran participated in this cross-sectional study. General and physical activity questionnaires, 3-d dietary recalls, and Beck Depression Inventory-Second Edition (BDI-II) were completed for all individuals and their anthropometric characteristics were measured. The major dietary patterns were then identified using principal component factor analysis.

FINDINGS

In total, 2 major dietary patterns were identified. After adjusting for potential confounders in multivariate linear regression analysis, the Western pattern (characterized by high consumption of French fries, hydrogenated fats, mayonnaise, sweets and desserts, high-fat dairy, refined grains, red or processed meats, pickles, organ meats and soft drinks and low consumption of low-fat dairy) was positively (standardized β coefficient: 0.510, P < 0.001) and the healthy pattern (characterized by high intake of vegetables, legumes, boiled potatoes, poultry, fish, vegetable oils, olives, fruits and fruit juices and low-fat dairy and low intake of refined grains) was inversely associated (standardized β coefficient: -0.508, P < 0.001) with BDI-II score.

CONCLUSION

Overall, findings of this study indicate that certain dietary patterns are associated with depression in adolescent Iranian girls. However, more studies are needed to further confirm these findings.

Mental depression: Relation to different disease status, newer treatments and its association with COVID-19 pandemic (Review)

The present study aimed to review major depression, including its types, epidemiology, association with different diseases status and treatments, as well as its correlation with the current COVID-19 pandemic. Mental depression is a common disorder that affects most individuals at one time or another. During depression, there are changes in mood and behavior, accompanied by feelings of defeat, hopelessness, or even suicidal thoughts. Depression has a direct or indirect relation with a number of other diseases including Alzheimer's disease, stroke, epilepsy, diabetes, cardiovascular disease and cancer. In addition, antidepressant drugs have several side effects including sedation, increased weight, indigestion, sexual dysfunction, or a decrease in blood pressure. Stopping medication may cause a relapse of the symptoms of depression and pose a risk of attempted suicide. The pandemic of COVID-19 has affected the mental health of individuals, including patients, individuals contacting patients and medical staff with a number of mental disorders that may adversely affect the immune ability of their bodies. Some of the drugs currently included in the protocols for treating COVID-19 may negatively affect the mental health of patients. Evidence accumulated over the years indicates that serotonin (5HT) deficiencies and norepinephrine (NE) in the brain can lead to mental depression. Drugs that increase levels of NE and 5HT are commonly used in the treatment of depression. The common reason for mood disorders, including mania and bipolar disease are not clearly understood. It is assumed that hyperactivity in specific parts of the brain and excessive activity of neurotransmitters may be involved. Early diagnosis and developing new treatment strategies are essential for the prevention of the severe consequences of depression. In addition, extensive research should be directed towards the investigation of the mental health disturbances occurring during and/or after COVID-19 infection. This may lead to the incorporation of a suitable antidepressant into the current treatment protocols.

Circulating microRNAs and Molecular Oxidative Stress in Older Adults with Neuroprogression Disorders

BACKGROUND

circulating microRNAs are potential blood biomarkers differentially expressed in many diseases including neuro depression disorders. It controls the expression of human genes and associated cellular and physiological processes in normal and diseased cells. We aimed to evaluate the potential role of circulating miRNAs and their association with both stress hormones and cellular oxidative stress in neuro depression disorders occurred among older adults.

METHODS

a total of 70 healthy subjects were included in this study. Based upon the profile of mood states (POMS-32 score), the participants classified into two groups; healthy subjects (n =30) and depression (n =40). The expression of microRNAs; miR-124, miR-34a-5p, miR-135, and miR-451-a and their correlation with cellular oxidative stress parameters; cellular NO, genes of SOD2, CAT and iNOS, and hormones; cortisol and serotonin were estimated by a quantitative real-time RT-PCR, high-performance liquid chromatography, and ELISA Immunoassay techniques, respectively.

RESULTS

depression was reported in 57.14% of the participants. The results showed a significant increase (p =0.01) in the total mood scores, and relative depression domains in older adults with depression compared to healthy controls. The relative expression levels of miR-124, miR-34a-5p significantly increased and the expression levels of miR-135, and miR-451-a significantly decreased in older adults with depression compared to healthy controls. In addition, the levels of cortisol significantly increased and serotonin (5HT) significantly reduced in all participants with depression. Cellular oxidative stress analysis for depressed subjects showed that serum NO levels and the expression of iNO gene significantly increased conversely with a decline in the molecular expression antioxidative genes; SOD2, CAT, respectively. The results showed that cellular oxidative stress parameters correlated positively with depression scores, cortisol, and negatively with cellular serotonin levels. In depressed subjects, the relative expression of microRNAs correlated positively with depression score, NO, iNOS, cortisol, and negatively associated with SOD2, CAT, and serotonin.

CONCLUSION

The combination of cellular oxidative stress and hormonal levels strongly supports a role for circulating miRNAs; miR-124, miR-34a-5p, miR-135, and miR-451-a in the regulation of depression and mood disorders among older adults. The expressed microRNAs with their related association to cellular oxidative stress and adrenal hormones are a step towards understanding the role of these small RNA molecules in the progression of depression among older adults. Thus, cellular miRNAs might have a prognostic role in the diagnosis and as a target for treatment strategies in depressed subjects.

Exploring the Impact of Flavonoids on Symptoms of Depression: A Systematic Review and Meta-Analysis

Recent evidence suggests that diet modifies key biological factors associated with the development of depression. It has been suggested that this could be due to the high flavonoid content commonly found in many plant foods, beverages and dietary supplements. Our aim was to conduct a systematic review to evaluate the effects of dietary flavonoids on the symptoms of depression. A total of 46 studies met the eligibility criteria. Of these, 36 were intervention trials and 10 were observational studies. A meta-analysis of 36 clinical trials involving a total of 2788 participants was performed. The results showed a statistically significant effect of flavonoids on depressive symptoms (mean difference = −1.65; 95% C.I., −2.54, −0.77; p < 0.01). Five of the 10 observational studies included in the systematic review reported significant results, suggesting that a higher flavonoid intake may improve symptoms of depression. Further studies are urgently required to elucidate whether causal and mechanistic links exist, along with substantiation of functional brain changes associated with flavonoid consumption.

The triterpenoid ursolic acid ameliorates stress in Caenorhabditis elegans by affecting the depression-associated genes skn-1 and prdx2

INTRODUCTION

Depression is one of the leading causes of death worldwide. Lower antioxidant concentrations and increased oxidative stress levels contribute to the development of depression. Effective and tolerable medications are urgently needed. Nrf2 and PRDX2 are promising targets in the treatment of oxidative stress and, therefore, promising for the development of novel antidepressants. Ursolic acid (UA), a natural triterpenoid found in various plants is known to exert neuroprotective and antioxidant effects. Skn-1 (which corresponds to human Nrf2) and prdx2 deficient mutants of the nematode Caenorhabditis elegans are suitable models to study the effect of UA on these targets. Additionally, stress assays are used to mimic stress or depressed state.

METHODS

We examined the antioxidant activity of UA in Caenorhabditis elegans wildtype and skn-1- and prdx2-deficient strains by H2DCF-DA and juglone assays as well as osmotic and heat stress assays. Additionally, we analyzed the binding of UA to human PRDX2 and Skn-1 proteins by molecular docking and microscale thermophoresis.

RESULTS

UA exerted strong antioxidant activities. Additionally, induction of stress resistance towards osmotic and heat stress was observed. qRT-PCR revealed that UA upregulated the gene expression of skn-1 and prdx2. Molecular docking studies supported these findings.

CONCLUSION

Our findings implicate that the strong antioxidant activity of UA may exert anti-depressive effects by its interaction with the Skn-1 transcription factor, which is part of a detoxification network, and the antioxidant PRDX2 protein, which protects the organism from the detrimental effects of radical oxygen species.

Catalpol ameliorates depressive-like behaviors in CUMS mice via oxidative stress-mediated NLRP3 inflammasome and neuroinflammation

The purpose of the present study was to investigate whether catalpol exhibited neuroprotective effects in chronic unpredictable mild stress (CUMS) mice through oxidative stress-mediated nucleotide-binding oligomerization domain, leucine-rich repeat, and pyrin-domain-containing 3 (NLRP3) inflammasome and neuroinflammation. Deficits in behavioral tests, including open field test (OFT), forced swim test (FST), and elevated plus-maze test (EPM), were ameliorated following catalpol administration. To study the potential mechanism, western blots, quantitative real-time PCR (qRT-PCR) analysis and immunofluorescence imaging were performed on the hippocampus samples. We found that the defects of behavioral tests induced by CUMS could be reversed by the absence of NLRP3 and NLRP3 inflammasome might be involved in the antidepressant effects of catalpol on CUMS mice. Similar to the NLRP3 inflammasome, the expression of interleukin-1 beta (IL-1β), tumor necrosis factor alpha (TNF-α), and inducible nitride oxide synthase (iNOS) were increased after CUMS. The current study demonstrated that catalpol possessed anti-inflammatory effect on CUMS mice and inhibited microglial polarization to the M1 phenotype. In addition, the activity of mitochondrial oxidative stress might be involved in the NLRP3 activation, which was proved by the downregulation of NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), and cleaved IL-1β, after the administration of mitochondrion-targeted antioxidant peptide SS31. Taken together, we provided evidence that catalpol exhibited antidepressive effects on CUMS mice possibly via the oxidative stress-mediated regulation of NLRP3 and neuroinflammation.

Neuroinflammation as a Common Denominator of Complex Diseases (Cancer, Diabetes Type 2, and Neuropsychiatric Disorders)

The term neuroinflammation refers to inflammation of the nervous tissue, in general, and in the central nervous system (CNS), in particular. It is a driver of neurotoxicity, it is detrimental, and implies that glial cell activation happens prior to neuronal degeneration and, possibly, even causes it. The inflammation-like glial responses may be initiated in response to a variety of cues such as infection, traumatic brain injury, toxic metabolites, or autoimmunity. The inflammatory response of activated microglia engages the immune system and initiates tissue repair. Through translational research the role played by neuroinflammation has been acknowledged in different disease entities. Intriguingly, these entities include both those directly related to the CNS (commonly designated neuropsychiatric disorders) and those not directly related to the CNS (e.g., cancer and diabetes type 2). Interestingly, all the above-mentioned entities belong to the same group of "complex disorders". This review aims to summarize cumulated data supporting the hypothesis that neuroinflammation is a common denominator of a wide variety of complex diseases. We will concentrate on cancer, type 2 diabetes (T2DM), and neuropsychiatric disorders (focusing on mood disorders).

Targeting Xanthine Oxidase by Natural Products as a Therapeutic Approach for Mental Disorders

Mental disorders comprise diverse human pathologies, including depression, bipolar affective disorder, schizophrenia, and dementia that affect millions of people around the world. The causes of mental disorders are unclear, but growing evidence suggests that oxidative stress and the purine/adenosine system play a key role in their development and progression. Xanthine oxidase (XO) is a flavoprotein enzyme essential for the catalysis of the oxidative hydroxylation of purines -hypoxanthine and xanthine- to generate uric acid. As a consequence of the oxidative reaction of XO, reactive oxygen species (ROS) such as superoxide and hydrogen peroxide are produced and, further, contribute to the pathogenesis of mental disorders. Altered XO activity has been associated with free radical-mediated neurotoxicity inducing cell damage and inflammation. Diverse studies reported a direct association between an increased activity of XO and diverse mental diseases including depression or schizophrenia. Small-molecule inhibitors, such as the well-known allopurinol, and dietary flavonoids, can modulate the XO activity and subsequent ROS production. In the present work, we review the available literature on XO inhibition by small molecules and their potential therapeutic application in mental disorders. In addition, we discuss the chemistry and molecular mechanism of XO inhibitors, as well as the use of structure-based and computational methods to design specific inhibitors with the capability of modulating XO activity.

The Potential of Hydrogen for Improving Mental Disorders

In 2007, Ohsawa and colleagues reported that molecular hydrogen (H₂) gas significantly reduced the infarct volume size in a rat model of cerebral infarction, which was, at least, partially due to scavenging hydroxyl radicals. Since then, multiple studies have shown that H₂ has not only anti-oxidative but also anti-inflammatory and anti-apoptotic properties, which has ignited interest in the clinical use of H₂ in diverse diseases. A growing body of studies has indicated that H₂ affects both mental and physical conditions. Mental disorders are characterized by disordered mood, thoughts, and behaviors that affect the ability to function in daily life. However, there is no sure way to prevent mental disorders. Although antidepressant and antianxiety drugs relieve symptoms of depression and anxiety, they have efficacy limitations and are accompanied by a wide range of side effects. While mental disorders are generally thought to be caused by a variety of genetic and/or environmental factors, recent progress has shown that these disorders are strongly associated with increased oxidative and inflammatory stress. Thus, H₂ has received much attention as a novel therapy for the prevention and treatment of mental disorders. This review summarizes the recent progress in the use of H₂ for the treatment of mental disorders and other related diseases. We also discuss the potential mechanisms of the biomedical effects of H₂ and conclude that H₂ could offer relief to people suffering from mental disorders.

Dietary carotenoids intake and depressive symptoms in US adults, NHANES 2015-2016

BACKGROUND

The data for effect of dietary specific carotenoids on depression are limited and controversial. Thus, this study aimed to examine the relationship between dietary carotenoids intakes and the prevalence of depressive symptoms.

METHODS

In the 2015-2016 United States National Health and Nutrition Examination Survey, 4,105 adults with complete data of dietary intake and assessment of depressive symptoms are enrolled. Dietary intake was assessed through two 24-h dietary recall interviews. Depression symptoms were assessed using the nine-item Patient Health Questionnaire. We used logistic regression to assess the relationship between diet carotenoids intake and the prevalence of depressive symptoms, adjusting for the main potential confounders. In addition, daily dietary carotenoids intake was adjusted for daily total energy intake based on the nutrient density model.

RESULTS

We found a significant inverse association between dietary beta-cryptoxanthin intake and depressive symptoms, with lowest prevalence in the third tertile (OR: 0.65, 95% CI: 0.47-0.90, p for trend < 0.001). Dose-response analyses revealed that the prevalence of depressive symptoms decreased with increasing intakes of beta-cryptoxanthin when reached the point above 110 ug/1000 Kcal. No such association was found for alpha-carotene, beta-carotene, lycopene, and lutein/zeaxanthin.

CONCLUSIONS

Increase the intake of beta-cryptoxathin-rich foods might protect from depressive symptoms. Further prospective studies are requested before dietary recommendation.

The efficacy and acceptability of curcumin for the treatment of depression or depressive symptoms: A systematic review and meta-analysis

INTRODUCTION

Curcumin, a potential natural substance is a promising complementary and alternative therapeutic intervention for depression or depressive symptoms. We undertook a systematic review and meta-analysis to evaluate the efficacy and acceptability.

METHODS

PubMed, EMBASE, PsycInfo, Web of Science, Cochrane Library and ClinicalTrials.gov were searched from the inception up until March 4, 2020. The Outcomes were depressive symptoms, response rates, drop-out rates, and adverse effects.

RESULTS

A total of 594 patients from ten trials were subjected to meta-analysis. Three trials were judged to be at high risk of bias, four at unclear risk of bias and three at low risk of bias. Most of the domains for risk of bias were at low risk or unclear risks and three domains at high risks. The pooling results suggested a significant difference in depression or depressive symptoms(SMD= -0.32, 95% CI: -0.50 to -0.13, I²=15%, n=594) and response rates (OR=3.20, 95% CI: 1.28-7.99, I²=35%, n=271). However, there was no difference between drop-out rates (OR=1.06, 95% CI: 0.58-1.93, I²=0%, n=594), digestive symptoms (OR=1.27, 95% CI: 0.69-2.32, I²=0%, n=284) and neurological symptoms (OR=1.08, 95% CI: 0.49-2.36, I²=0%, n=284). Subgroup analysis showed depression was associated with a reduction(SMD= -0.35, 95% CI: -0.56 to -0.15, I²=7%, n=432) but depressive symptoms were not (SMD= -0.17, 95% CI: -0.61 to 0.26, I²=40%, n=162).

CONCLUSIONS

The evidence quality is low, indicating that there is great uncertainty about the efficacy and acceptability of curcumin for the treatment of depression or depressive symptoms.

Peripheral Markers of Depression

Major Depressive Disorder (MDD) is a leading cause of disability worldwide, creating a high medical and socioeconomic burden. There is a growing interest in the biological underpinnings of depression, which are reflected by altered levels of biological markers. Among others, enhanced inflammation has been reported in MDD, as reflected by increased concentrations of inflammatory markers-C-reactive protein, interleukin-6, tumor necrosis factor-α and soluble interleukin-2 receptor. Oxidative and nitrosative stress also plays a role in the pathophysiology of MDD. Notably, increased levels of lipid peroxidation markers are characteristic of MDD. Dysregulation of the stress axis, along with increased cortisol levels, have also been reported in MDD. Alterations in growth factors, with a significant decrease in brain-derived neurotrophic factor and an increase in fibroblast growth factor-2 and insulin-like growth factor-1 concentrations have also been found in MDD. Finally, kynurenine metabolites, increased glutamate and decreased total cholesterol also hold promise as reliable biomarkers for MDD. Research in the field of MDD biomarkers is hindered by insufficient understanding of MDD etiopathogenesis, substantial heterogeneity of the disorder, common co-morbidities and low specificity of biomarkers. The construction of biomarker panels and their evaluation with use of new technologies may have the potential to overcome the above mentioned obstacles.

The impact of repetitive transcranial magnetic stimulation and fluoxetine on the brain lipidome in a rat model of chronic unpredictable stress

The antidepressant effect of repetitive transcranial magnetic stimulation (rTMS) has been extensively studied; growing evidence suggests that changes in lipid composition may be involved in the pathogenesis of depression and may be a targeted mechanism for treatment. However, the influence of rTMS on lipid composition and the differences between these effects compared to antidepressants like fluoxetine (Flx) have never been investigated. Using a chronic unpredictable stress (CUS) model in rats, we assessed the antidepressive effects of rTMS and Flx treatments and evaluated changes in lipid composition in the hippocampus and prefrontal cortex (PFC) using a mass spectrometry-based lipidomic approach. Both rTMS and Flx treatments ameliorated depressive-like behaviors induced by CUS. Moreover, changes in lipid composition, especially glycerophospholipids, sphingolipids, and glycerolipids induced by CUS in the hippocampus were more robust than those observed in the PFC. CUS led to decreased levels of 20 carbon-containing fatty acyls and polyunsaturated fatty acyls in the PFC, and decreased levels of acyl carnitines (AcCa) in both the hippocampus and PFC. Notably, rTMS treatment had higher impact than Flx on composition of glycerophospholipids and sphingolipids in the hippocampus that were altered by CUS, while Flx attenuated CUS-induced changes in the PFC to a greater extent than rTMS. However, neither was able to restore fatty acyls and AcCa to baseline levels. Altogether, modulation of the brain lipidome may be involved in the antidepressant action of rTMS and Flx, and the degree to which these treatments induce changes in lipid composition within the hippocampus and PFC might explain their differential antidepressant effects.

Insights into serotonergic and antioxidant mechanisms involved in antidepressant-like action of 2-phenyl-3-(phenylselanyl)benzofuran in mice

Monoaminergic and oxidative dysfunctions have been reported to play a role in depression. The present study investigated the antioxidant potential as well as the antidepressant-like action of 2-phenyl-3-(phenylselanyl)benzofuran (SeBZF1) in male Swiss mice. Time and dose-response curves were analyzed with the forced swim (FST) and tail suspension (TST) tests, in which SeBZF1 elicited antidepressant-like effects. Serotonergic mechanisms were investigated in the TST. The pre-administration of WAY100635 (selective 5-HT_1A receptor antagonist, 0.1 mg/kg, subcutaneous route), ketanserin (5-HT_2A/2C receptor antagonist, 1 mg/kg, intraperitoneal route, i.p.), and chlorophenylalaninemethyl ester (p-CPA) (selective tryptophan hydroxylase inhibitor, 100 mg/kg, i.p., for 4 days), but not of ondansetron (selective 5-HT₃ receptor antagonist, 1 mg/kg, i.p.), abolished the antidepressant-like action of SeBZF1 (50 mg/kg, intragastric route, i.g.). Co-administration of sub-effective doses of SeBZF1 (1 mg/kg, i.g.) and fluoxetine (5 mg/kg, i.p., selective serotonin reuptake inhibitor) was effective in producing anti-immobility effects in the TST, revealing a synergistic effect. Besides, p-CPA induced hippocampal oxidative stress, characterized by a reduction of total thiols and lipoperoxidation, which was reversed by SeBZF1 (50 mg/kg). The in vitro screening of the antioxidant action of SeBZF1 in brain tissue reinforced these results. Lastly, SeBZF1 did not cause systemic toxicity at a high dose (300 mg/kg). In summary, the present study demonstrated that SeBZF1 exerted antidepressant-like action in male mice which appears to be mediated by the serotonergic system. Moreover, SeBZF1 elicited in vitro antioxidant action in brain tissue, attenuated the hippocampal oxidative damage induced by 5-HT depletion in mice and showed no toxic signs.

The Changes of Expression and Methylation of Genes Involved in Oxidative Stress in Course of Chronic Mild Stress and Antidepressant Therapy with Agomelatine

Preclinical studies conducted so far suggest that oxidative stress processes may be associated with the mechanism of depression development. This study shows the effects of chronic administration of agomelatine on expression and the methylation status of Sod1, Sod2, Gpx1, Gpx4, Cat, Nos1, and Nos2 in the brain stricture and blood in the chronic mild stress (CMS) animal model of depression. The animals were exposed to the CMS procedure and treatment with agomelatine (10 mg/kg/day, IP) for five weeks and then were sacrificed. TaqMan Gene Expression Assay, Western blot, and methylation-sensitive high-resolution melting techniques were used to evaluate mRNA and protein expression of the genes, and the methylation status of their promoters. Gpx1, Gpx4, and Sod2 expression in the PBMCs and Sod1 and Sod2 expression in the brain were reduced in the stressed group after agomelatine administration. CMS caused an increase in the methylation of the third Gpx4 promoter in peripheral blood mononuclear cells and Gpx1 promoter in the cerebral cortex. Additionally, stressed rats treated with agomelatine displayed a significantly lower Gpx4 level in the hypothalamus. The results confirm the hypothesis that the CMS procedure and agomelatine administration change the expression level and methylation status of the promoter region of genes involved in oxidative and nitrosative stress.

The neuroprotective effect of Riparin IV on oxidative stress and neuroinflammation related to chronic stress-induced cognitive impairment

BACKGROUND

Cognitive impairment is identified as one of the diagnostic criteria for major depressive disorder and can extensively affect the quality of life of patients. Based on these findings, this study aimed to investigate the possible effects of Riparin IV (Rip IV) on cognitive impairment induced by chronic administration of corticosterone in mice.

METHODS

Female Swiss mice were divided into four groups: control (Control), corticosterone (Cort), Riparin IV (Cort + Rip IV), and Fluvoxamine (Cort + Flu). Three groups were administered corticosterone (20 mg/kg) subcutaneously during the 22-day study, while the control group received only vehicle. After the 14th day, the groups were administered medications: Riparin IV (Rip IV), fluvoxamine (Flu), or distilled water, by gavage, 1 h after the subcutaneous injections. After treatment, mice underwent behavioral testing, and brain areas were removed for oxidative stress and cytokine content assays.

RESULTS

The results revealed that Cort-treated mice developed a cognitive impairment and exhibited a neuroinflammatory profile with an oxidative load and Th1/Th2 cytokine imbalance. Rip IV treatment significantly ameliorated the cognitive deficit induced by Cort and displayed a neuroprotective effect.

CONCLUSION

The antidepressant-like ability of Rip IV treatment against chronic Cort-induced stress may be due to its potential to mitigate inflammatory damage and oxidative stress. The antioxidant and anti-inflammatory effect observed indicates Rip IV as a possible drug for antidepressant treatment of non-responsive patients with severe and cognitive symptoms.

Effects of venlafaxine on the expression level and methylation status of genes involved in oxidative stress in rats exposed to a chronic mild stress

Recent human and animal studies indicate that oxidative and nitrosative stress may play a role in the aetiology and pathogenesis of depression. This study investigates the effect of chronic administration of the serotonin‐norepinephrine reuptake inhibitor, venlafaxine, on the expression and methylation status of SOD1, SOD2, GPx1, GPx4, CAT, NOS1 and NOS2 in the brain and blood of rats exposed to a chronic mild stress (CMS) model of depression. Separate groups of animals were exposed to CMS for 2 or 7 weeks; the second group received saline or venlafaxine (10 mg/kg/d, IP) for 5 weeks. After completion of both stress conditions and drug administration, the mRNA and protein expression of selected genes and the methylation status of their promoters were measured in peripheral mononuclear blood cells (PBMCs) and in brain structures (hippocampus, amygdala, hypothalamus, midbrain, cortex, basal ganglia) with the use of TaqMan Gene Expression Assay, Western blot and methylation‐sensitive high‐resolution melting techniques. CMS caused a decrease in sucrose consumption, and this effect was normalized by fluoxetine. In PBMCs, SOD1, SOD2 and NOS2 mRNA expression changed only after venlafaxine administration. In brain, CAT, Gpx1, Gpx4 and NOS1 gene expression changed following CMS or venlafaxine exposure, most prominently in the hippocampus, midbrain and basal ganglia. CMS increased the methylation of the Gpx1 promoter in PBMCs, the second Gpx4 promoter in midbrain and basal ganglia, and SOD1 and SOD2 in hippocampus. The CMS animals treated with venlafaxine displayed a significantly higher CAT level in midbrain and cerebral cortex. CMS caused an elevation of Gpx4 in the hippocampus, which was lowered in cerebral cortex by venlafaxine. The results indicate that CMS and venlafaxine administration affect the methylation of promoters of genes involved in oxidative and nitrosative stress. They also indicate that peripheral and central tissue differ in their response to stress or antidepressant treatments. It is possible that that apart from DNA methylation, a crucial role of expression level of genes may be played by other forms of epigenetic regulation, such as histone modification or microRNA interference.

These findings provide strong evidence for thesis that analysis of the level of mRNA and protein expression as well as the status of promoter methylation can help in understanding the pathomechanisms of mental diseases, including depression, and the mechanisms of action of drugs effective in their therapy.

Oxidation-reduction mechanisms in psychiatric disorders: A novel target for pharmacological intervention

While neurotransmitter dysfunction represents a key component in mental illnesses, there is now a wide agreement for a central pathophysiological hub that includes hormones, neuroinflammation, redox mechanisms as well as oxidative stress. With respect to oxidation-reduction (redox) mechanisms, preclinical and clinical evidence suggests that an imbalance in the pro/anti-oxidative homeostasis toward the increased production of substances with oxidizing potential may contribute to the etiology and manifestation of different psychiatric disorders. The substantial and continous demand for energy renders the brain highly susceptible to disturbances in its energy supply, especially following exposure to stressful events, which may lead to overproduction of reactive oxygen and nitrogen species under conditions of perturbed antioxidant defenses. This will eventually induce different molecular alterations, including extensive protein and lipid peroxidation, increased blood-brain barrier permeability and neuroinflammation, which may contribute to the changes in brain function and morphology observed in mental illnesses. This view may also reconcile different key concepts for psychiatric disorders, such as the neurodevelopmental origin of these diseases, as well as the vulnerability of selective cellular populations that are critical for specific functional abnormalities. The possibility to pharmacologically modulate the redox system is receiving increasing interest as a novel therapeutic strategy to counteract the detrimental effects of the unbalance in brain oxidative mechanisms. This review will describe the main mechanisms and mediators of the redox system and will examine the alterations of oxidative stress found in animal models of psychiatric disorders as well as in patients suffering from mental illnesses, such as schizophrenia and major depressive disorder. In addition, it will discuss studies that examined the effects of psychotropic drugs, including antipsychotics and antidepressants, on the oxidative balance as well as studies that investigated the effectiveness of a direct modulation of oxidative mechanisms in counteracting the behavioral and functional alterations associated with psychiatric disorders, which supports the promising role of the redox system as a novel therapeutic target for the improved treatment of brain disorders.

Oleuropein Reverses Repeated Corticosterone-Induced Depressive-Like Behavior in mice: Evidence of Modulating Effect on Biogenic Amines

Depression is still one of challenging, and widely encountered disorders with complex etiology. The role of healthy diet and olive oil in ameliorating depression has been claimed. This study was designed to explore the effects of oleuropein; the main constituent of olive oil; on depression-like behaviors that are induced by repeated administration of corticosterone (40 mg/kg, i.p.), once a day for 21 days, in mice. Oleuropein (8, 16, and 32 mg/kg, i.p.) or fluoxetine (20 mg/kg, positive control, i.p.1) was administered 30 minutes prior to corticosterone injection. Sucrose consumption test, open-field test (OFT), tail suspension test (TST), and forced swimming test (FST) were performed. Reduced Glutathione (GSH), lipid peroxidation, and biogenic amines; serotonin, dopamine, and nor-epinephrine; levels were also analyzed in brain homogenates. Corticosterone treatment induced depression-like behaviors, it increased immobility time in the TST, OFT, and FST, decreased the number of movements in OFT, and decreased sucrose consumption. Corticosterone effect was associated with depletion of reduced glutathione and increase of lipid peroxidation, in addition to modification of biogenic amines; decreased serotonin and dopamine. Oleuropein or fluoxetine administration counteracted corticosterone-induced changes. In conclusion, oleuropein showed a promising antidepressant activity, that is evident by improving corticosterone-induced depression-like behaviors, and normalizing levels of biogenic amines.