Neuroprotection of reduced thyroid hormone with increased estrogen and progestogen in postpartum depression

Potential therapeutic effects of Chinese herbal medicine in postpartum depression: Mechanisms and future directions

ETHNOPHARMACOLOGICAL RELEVANCE

Postpartum depression (PPD) is a common psychiatric disorder in women after childbirth. Per data from epidemiologic studies, PPD affects about 5%-26.32% of postpartum mothers worldwide. Biological factors underlying this condition are multiple and complex and have received extensive inquiries for the roles they play in PPD. Chinese herbal medicine (CHM), which is widely used as a complementary and alternative therapy for neurological disorders, possesses multi-component, multi-target, multi-access, and low side effect therapeutic characteristics. CHM has already shown efficacy in the treatment of PPD, and a lot more research exploring the mechanisms of its potential therapeutic effects is being conducted.

AIM OF THE REVIEW

This review provides an in-depth and comprehensive overview of the underlying mechanisms of PPD, as well as samples the progress made in researching the potential role of CHM in treating the disorder.

MATERIALS AND METHODS

Literature was searched comprehensively in scholarly electronic databases, including PubMed, Web of Science, Scopus, CNKI and WanFang DATA, using the search terms "postpartum depression", "genetic", "hormone", "immune", "neuroinflammation", "inflammation", "neurotransmitter", "neurogenesis", "brain-gut axis", "traditional Chinese medicine", "Chinese herbal medicine", "herb", and an assorted combination of these terms.

RESULTS

PPD is closely associated with genetics, as well as with the hormones, immune inflammatory, and neurotransmitter systems, neurogenesis, and gut microbes, and these biological factors often interact and work together to cause PPD. For example, inflammatory factors could suppress the production of the neurotransmitter serotonin by inducing the regulation of tryptophan-kynurenine in the direction of neurotoxicity. Many CHM constituents improve anxiety- and depression-like behaviors by interfering with the above-mentioned mechanisms and have shown decent efficacy clinically against PPD. For example, Shen-Qi-Jie-Yu-Fang invigorates the neuroendocrine system by boosting the hormone levels of hypothalamic pituitary adrenal (HPA) and hypothalamic pituitary gonadal (HPG) axes, regulating the imbalance of Treg/T-helper cells (Th) 17 and Th1/Th2, and modulating neurotransmitter system to play antidepressant roles. The Shenguiren Mixture interferes with the extracellular signal-regulated kinase (ERK) pathway to enhance the number, morphology and apoptosis of neurons in the hippocampus of PPD rats. Other herbal extracts and active ingredients of CHM, such as Paeoniflorin, hypericin, timosaponin B-III and more, also manage depression by remedying the neuroendocrine system and reducing neuroinflammation.

CONCLUSIONS

The pathogenesis of PPD is complex and diverse, with the main pathogenesis not clear. Still, CHM constituents, like Shen-Qi-Jie-Yu-Fang, the Shenguiren Mixture, Paeoniflorin, hypericin and other Chinese Medicinal Formulae, active monomers and Crude extracts, treats PPD through multifaceted interventions. Therefore, developing more CHM components for the treatment of PPD is an essential step forward.

Effects of Chaihu Shugan San on Brain Functional Network Connectivity in the Hippocampus of a Perimenopausal Depression Rat Model

In this study, we used Chaihu Shugan San (CSS), a traditional Chinese herbal formula, as a probe to investigate the involvement of brain functional network connectivity and hippocampus energy metabolism in perimenopausal depression. A network pharmacology approach was performed to discover the underlying mechanisms of CSS in improving perimenopausal depression, which were verified in perimenopausal depression rat models. Network pharmacology analysis indicated that complex mechanisms of energy metabolism, neurotransmitter metabolism, inflammation, and hormone metabolic processes were closely associated with the anti-depressive effects of CSS. Thus, the serum concentrations of estradiol (E2), glutamate (Glu), and 5-hydroxytryptamine (5-HT) were detected by ELISA. The brain functional network connectivity between the hippocampus and adjacent brain regions was evaluated using resting-state functional magnetic resonance imaging (fMRI). A targeted metabolomic analysis of the hippocampal tricarboxylic acid cycle was also performed to measure the changes in hippocampal energy metabolism using liquid chromatography-tandem mass spectrometry (LC-MS/MS). CSS treatment significantly improved the behavioral performance, decreased the serum Glu levels, and increased the serum 5-HT levels of PMS + CUMS rats. The brain functional connectivity between the hippocampus and other brain regions was significantly changed by PMS + CUMS processes but improved by CSS treatment. Moreover, among the metabolites in the hippocampal tricarboxylic acid cycle, the concentrations of citrate and the upregulation of isocitrate and downregulation of guanosine triphosphate (GTP) in PMS + CUMS rats could be significantly improved by CSS treatment. A brain functional network connectivity mechanism may be involved in perimenopausal depression, wherein the hippocampal tricarboxylic acid cycle plays a vital role.

Association of spontaneous abortion with bipolar disorder and major depression based on inverse probability treatment weighting of multigroup propensity scores: Evidence from the UK Biobank

BACKGROUND

Few studies have explored the association between the number of SAs and bipolar disorder and major depression (BDMD). This study aims to investigate the association between SA and BDMD, and the possible dose-response relationship between them.

METHODS

We conducted a cross-sectional study of 13,200 female UK Biobank participants. Participants were classified into BDMD and no-BDMD groups based on their BDMD status. The number of SAs was grouped into non-SA, occasional SA (OSA), and recurrent SA (RSA). Baseline characteristics of the three groups were balanced using inverse probability treatment weighting (IPTW) based on propensity scores. The three-knots restricted cubic spline regression model was utilized to assess the dose-response relationship between the number of SAs and BDMD.

RESULTS

The IPTW-adjusted multivariate logistic regression revealed that SA was an independent risk factor for BDMD, with adjusted OR of 1.12 (95 % CI: 1.07-1.19) and 1.32 (95 % CI: 1.25-1.40) in the OSA and RSA groups, respectively. The strength of this association amplified as the number of SAs (P for trend <0.001). There was a nonlinear relationship between the number of SAs and the risk of BDMD, with an approximately inverted L-shaped curve.

LIMITATIONS

The information of the SA and BDMD status relied on self-reported by volunteers, and the study sample was mostly of European descent.

CONCLUSIONS

Women who reported experiencing multiple SAs are more likely to have BDMD. Therefore, it is imperative to provide psychological care and interventions for women in the postpartum period.

Association of psychological distress and DNA methylation: A 5-year longitudinal population-based twin study

AIM

To identify the psychological distress (PD)-associated 5'-cytosine-phosphate-guanine-3' sites (CpGs), and investigate the temporal relationship between dynamic changes in DNA methylation (DNAm) and PD.

METHODS

This study included 1084 twins from the Chinese National Twin Register (CNTR). The CNTR conducted epidemiological investigations and blood withdrawal twice in 2013 and 2018. These included twins were used to perform epigenome-wide association studies (EWASs) and to validate the previously reported PD-associated CpGs selected from previous EWASs in PubMed, Embase, and the EWAS catalog. Next, a cross-lagged study was performed to examine the temporality between changes in DNAm and PD in 308 twins who completed both 2013 and 2018 surveys.

RESULTS

The EWAS analysis of our study identified 25 CpGs. In the validation analysis, 741 CpGs from 29 previous EWASs on PD were selected for validation, and 101 CpGs were validated to be significant at a false discovery rate <0.05. The cross-lagged analysis found a unidirectional path from PD to DNAm at 14 CpGs, while no sites showed significance from DNAm to PD.

CONCLUSIONS

This study identified and validated PD-related CpGs in a Chinese twin population, and suggested that PD may be the cause of changes in DNAm over time. The findings provide new insights into the molecular mechanisms underlying PD pathophysiology.

Resveratrol alleviates postpartum depression-like behavior by activating autophagy via SIRT1 and inhibiting AKT/mTOR pathway

BACKGROUND

Postpartum depression (PPD) causes maternal mortality, and has a high disability rate. In recent years, studies have suggested the Sirt1 gene to be involved in the pathogenesis of depression. Resveratrol (RSV), an activator of Sirt1, has been investigated in depressive behavior. However, its effect on PPD remains to be thoroughly elucidated.

METHODS

We employed a mice model with bilateral oophorectomy combined with hormone-simulated pregnancy to assess postpartum depression-like behavior. The behavioral tests were performed 2 days after the withdrawal of estradiol benzoate. RSV was administered subcutaneously to the PPD model mice. Several behavioral tests were executed, including the open field test, forced swimming test, and tail suspension test. Western blot analyses and immunofluorescence staining were used to evaluate protein expression levels of SIRT1, autophagy markers, and the AKT/mTOR.

RESULTS

Postpartum depressive-like behavior was triggered following the withdrawal of estradiol benzoate after hormone-stimulated-pregnancy. RSV improved postpartum depressive-like behavior of mice via its upregulation of the SIRT1 and autophagy markers, such as Beclin1, ATG5 and LC3B. Also, the downregulation of the p62 protein expression was observed. More importantly, we also detected the inhibition of phosphorylated AKT and mTOR in the hippocampus of postpartum depressive-like mice.

CONCLUSION

RSV could alleviate postpartum depression-like behavior in mice by stimulating the SIRT1, induce autophagy and inhibit the AKT/ mTOR signaling pathway.

Progesterone and contraceptive progestin actions on the brain: A systematic review of animal studies and comparison to human neuroimaging studies

In this review we systematically summarize the effects of progesterone and synthetic progestins on neurogenesis, synaptogenesis, myelination and six neurotransmitter systems. Several parallels between progesterone and older generation progestin actions emerged, suggesting actions via progesterone receptors. However, existing results suggest a general lack of knowledge regarding the effects of currently used progestins in hormonal contraception regarding these cellular and molecular brain parameters. Human neuroimaging studies were reviewed with a focus on randomized placebo-controlled trials and cross-sectional studies controlling for progestin type. The prefrontal cortex, amygdala, salience network and hippocampus were identified as regions of interest for future preclinical studies. This review proposes a series of experiments to elucidate the cellular and molecular actions of contraceptive progestins in these areas and link these actions to behavioral markers of emotional and cognitive functioning. Emotional effects of contraceptive progestins appear to be related to 1) alterations in the serotonergic system, 2) direct/indirect modulations of inhibitory GABA-ergic signalling via effects on the allopregnanolone content of the brain, which differ between androgenic and anti-androgenic progestins. Cognitive effects of combined oral contraceptives appear to depend on the ethinylestradiol dose.

Neuroprotective Effects of Estrogen Through BDNF-Transient Receptor Potential Channels 6 Signaling Pathway in the Hippocampus in a Rat Model of Perimenopausal Depression

Estradiol (E₂) has been proven to be effective in treating perimenopausal depression (PD); however, the downstream signaling pathways have not been fully elucidated. Transient receptor potential channels 6 (TRPC6) plays a vital role in promoting neuronal development and the formation of excitatory synapses. At present, we found that the serum levels of E₂ and brain-derived neurotrophic factor (BDNF) declined significantly in the women with PD compared to perimenopausal women, which was accompanied by a clear reduction in TRPC6 levels. To further reveal the effects of TRPC6 on neuronal survival and excitability, the PD-like rat model was established by the total removal of left ovary and 80% removal of right ovary followed by 21 days of the chronic unpredictable mild stress. Intragastric administration of E₂ (2 mg/kg), intraperitoneal injection of BDNF/TrB signaling pathway inhibitor (K252a, 100 μg/kg) and TRPC6 agonist (OAG, 0.6 mg/kg), and intracerebroventricular infusion of anti-BDNF antibody for blocking BDNF (0.5 μg/24 μl/rat) daily for 21 days were conducted. The levels of BDNF and TRPC6 in rat serum were lower in PD rats compared to the control rats; the depression-like behavior was induced, the neuronal death rate in the hippocampus increased, and the thickness of postsynaptic density (PSD) and the number of asymmetric synapses decreased significantly in the PD group. E₂ treatment greatly upregulated the serum levels of BDNF and TRPC6, the neuronal excitability indicated by an elevation in the PSD thickness and the numbers of asymmetric synapses, and these actions were reversed by K252a; co-administration of TRPC6 agonist and K252a improved neuronal degeneration and increased the neuronal excitability induced in the E₂-treated PD rats. K252a or anti-BDNF antibody inhibited the increased neuronal BDNF and TRPC6 expression in E₂-treated PD rats; co-treatment of TRPC6 agonist and anti-BDNF antibody reduced neuronal death and increased the BDNF and TRPC6 expression in the hippocampal CA1 neurons in the E₂-treated PD rats. These results suggest that the neuroprotective role of E₂ in PD is closely related to enhance the activity of BDNF/TRPC6 pathway and is helpful to provide new prevention and strategies.

Effects of chronic folate deficiency and sex differences on depression‑like behavior in mice

Although previous studies have reported that serum folate levels are negatively associated with depression in women but not men, it remains unclear whether folate deficiency can directly lead to depression and whether sex difference serves a role in this condition, since the potential mechanism remains elusive. Therefore, the present study aimed to investigate whether folate deficiency results in differences in parameters associated with depression between males and females. CD-1 mice received either a standard control diet or a folate-deficient diet from 10 to 38 weeks of age, following which behavioral assays, such as an open field test, sucrose preference test and forced swim test were performed throughout week 38. Serum and cerebral cortex samples were subsequently collected for assessment. Serum folate, homocysteine, estradiol (E2) and testosterone levels were measured using chemiluminescence, enzymatic cycling assay and electrochemiluminescence immunoassays. The cerebral cortex was used for western blot analysis, to detect the expression levels of estrogen receptor β (ERβ), PI3K/AKT pathway and caspase-3. The results revealed that compared with those in female mice that received standard control diet, female mice that received folate-deficient diet exhibited lower E2 concentrations, lower sucrose preferences (as determined through the sucrose preference test), longer durations of immobility (as determined in the forced swim test) and less time spent in the central areas of the open field test. Western blotting demonstrated that the expression levels of ERβ and the phosphorylation levels of PI3K and AKT were decreased, whilst the expression levels of cleaved caspase-3 were increased, in the cerebral cortex of female mice that received folate-deficient diet. However, no differences in E2 concentration, behavioral assay parameters or protein levels of ERβ, phosphorylated (p-)PI3K, p-AKT and cleaved caspase-3 could be observed in male mice regardless of whether they received standard control or folate-deficient diets. Collectively, these results revealed that folate deficiency only led to depression-like behavior in female mice. This may be associated with reduced E2 levels, which may inhibit the PI3K/AKT pathway and upregulate the expression of cleaved caspase-3 to promote neuronal apoptosis.

Sex hormone levels in females of different ages suffering from depression

Background

There are only a few studies on sex hormones in females of different ages suffering from depression, and their conclusions are not uniform until now. This study aimed to investigate the correlation between the severity of depression in females and factors such as sex hormones and differences in sex hormone levels in females of different ages, exploring variations after treatment.

Methods

A total of 169 females with depression were selected and divided into the first-episode (91 cases) and recurrent (78 cases) groups. Then, on the basis of their age, the first-episode patients were divided into the young (48 cases, age < 45 years), perimenopausal (20 cases, 45–55 years), and elderly groups (23 cases, age > 55 years); the patients with recurrent depression were classified into the young (37 cases, age < 45 years), perimenopausal (19 cases, 45–55 years), and elderly groups (22 cases, age > 55 years). The patients were assessed in accordance with the International Classification of Diseases of mental and behavioral disorders. The serum progesterone, prolactin, estradiol, and testosterone levels in the patients were measured, and differences in sex hormone levels of the groups were analyzed.

Results

The estradiol level was negatively correlated with age and the prolactin level was positively correlated with occupation. The severity of depression in females was found to be negatively correlated with age. The serum progesterone and estradiol levels in the young group were significantly higher than those in the elderly group, regardless of the first episode or recurrence. Estradiol levels in the perimenopausal and elderly groups with first-episode depression were significantly higher than those in the same group with recurrent depression. However, there was no significant difference in the serum progesterone, prolactin, estradiol, and testosterone levels in the recurrent group before and after treatment.

Conclusions

Sex hormone levels, especially estradiol, varied among females of different ages suffering from depression. Recurrent depression also has a certain effect on sex hormone levels in females. Not only should the age and relapse be considered when studying the sex hormone levels of females with depression, but also attention should be paid to whether the patients have used antidepressants before their sexual hormonal testing.

Identification of the Ingredients and Mechanisms of Curcumae Radix for Depression Based on Network Pharmacology and Molecular Docking

Background

Curcumae Radix (CR), derived from the dry roots of Curcuma longa L., family Zingiberaceae, is widely used to treat depression. However, the ingredients and mechanisms of CR are still unclear. The purpose of this study was to solve this problem using network pharmacology and molecular docking.

Methods

The active ingredients of CR were screened through TCMSP, and the depression-related genes were obtained through the Genetic Association, GeneCards, and OMIM databases. Then, DisGeNET score was performed to evaluate the correlation between co-genes and depression. Topological analysis was conducted to screen hub genes and proteins, molecular docking was performed to evaluate the binding ability of the hub protein with active ingredients, and gene ontology (Go) function analysis, gene tissue localization, and KEGG pathway analysis were conducted to explore the function and location of genes, as well as the mechanism of CR for treating depression.

Results

Eight ingredients of CR were screened based on pharmacokinetic properties, five of which are closely related to depression, including (E)−5-hydroxy-7-(4-hydroxyphenyl)−1-phenyl-1-heptene, (E)−1,7-diphenyl-3-hydroxy-1-hepten-5-one, oxycurcumenol, β-sitosterol, and sitosterol. They interacted with 45 co-genes and co-proteins with a DisGeNET score ≥0.3. AR, NOS2, PTGS2, and TYK2 were pivot genes. EGFR, PTGS2, HSP90AA1, MAPK8, and ESR1 were hub proteins. PTGS2 was found to have good binding potential with oxycurcumenol, (E)−1,7-diphenyl-3-hydroxy-1-hepten-5-one and (E)−5-hydroxy-7-(4-hydroxyphenyl)−1-phenyl-1-heptene. Go functional analysis indicated that co-genes involved complex biological processes, cellular components and molecular functions. PER2, P2RX7, GRM1, TACR1, MAPK8, HCRTR1, EGFR, and TYK2 were highly expressed in the prefrontal cortex. The potential pathways for CR to exert antidepressant effects were calcium, estrogen, PI3K-Akt and ErbB signaling pathways.

Conclusions

This study revealed the ingredients, effective targets and mechanisms of CR in the treatment of depression, which provides a new perspective for the development of new antidepressants.

Postpartum Depression: Current Status and Possible Identification Using Biomarkers

Postpartum depression (PPD) is a serious health issue that can affect about 15% of the female population within after giving birth. It often conveys significant negative consequences to the offsprings. The symptoms and risk factors are somewhat similar to those found in non-postpartum depression. The main difference resides in the fact that PPD is triggered by postpartum specific factors, including especially biological changes in the hormone levels. Patients are usually diagnosed using a questionnaire onsite or in a clinic. Treatment of PPD often involves psychotherapy and antidepressant medications. In recent years, there have been more researches on the identification of biological markers for PPD. In this review, we will focus on the current research status of PPD, with an emphasis on the recent progress made on the identification of PPD biomarkers.

THE NEUROENDOCRINOLOGICAL ASPECTS OF PREGNANCY AND POSTPARTUM DEPRESSION

Introduction

Ties between the endocrine system and mental health are undeniably a consistent point of interest in modern day medicine. Furthermore, mental disturbances due to hormonal changes following childbirth have been mentioned in medical literature since Hippocrates. Considering the dramatic endocrine, paracrine and autocrine changes that occur during gestation, labour and postnatal phase, hormonal theories are not to be ignored in the treatment of postpartum disorders.

Results

Reproductive hormones are known to modulate behavioural, emotional and cognitive response, therefore rapid changes in estradiol and progesterone plasma concentrations during pregnancy and labour create a vulnerable terrain leading towards postpartum disorders. New research shows that women suffering from postpartum disorders have abnormal neural responses, suggesting a neuroendocrine explanation for postpartum syndromes.

Conclusion

To facilitate further research in this area, we present new information on several hormonal interactions and the psychiatric response involved in pregnancy and labour, offering an interdisciplinary outlook on pregnancy and postpartum disorders. There is enough evidence to suggest that estradiol, progesterone, oxytocin, cortisol and thyroid hormones are some of many hormones involved in postpartum syndromes and tackling their perinatal imbalance with pharmacological substituents or antagonists could be useful as an adjuvant form of treatment in future patients.