Impact of Hydrocortisone and of CRH Infusion on the Hypothalamus-Pituitary-Adrenocortical Axis of Septic Male Mice.

PURPOSE: Sepsis is hallmarked by high plasma cortisol/corticosterone (CORT), low adrenocorticotropic hormone (ACTH), and high pro-opiomelanocortin (POMC). While corticotropin-releasing hormone-(CRH) and arginine-vasopressin (AVP)-driven pituitary POMC expression remains active, POMC processing into ACTH becomes impaired. Low ACTH is accompanied by loss of adrenocortical structure, although steroidogenic enzymes remain expressed. We hypothesized that treatment of sepsis with hydrocortisone (HC) aggravates this phenotype whereas CRH infusion safeguards ACTH-driven adrenocortical structure. METHODS: In a fluid-resuscitated, antibiotics-treated mouse model of prolonged sepsis, we compared the effects of HC and CRH infusion with placebo on plasma ACTH, POMC, and CORT; on markers of hypothalamic CRH and AVP signaling and pituitary POMC processing; and on the adrenocortical structure and markers of steroidogenesis. In adrenal explants, we studied the steroidogenic capacity of POMC. RESULTS: During sepsis, HC further suppressed plasma ACTH, but not POMC, predominantly by suppressing sepsis-activated CRH/AVP-signaling pathways. In contrast, in CRH-treated sepsis, plasma ACTH was normalized following restoration of pituitary POMC processing. The sepsis-induced rise in markers of adrenocortical steroidogenesis was unaltered by CRH and suppressed partially by HC, which also increased adrenal markers of inflammation. Ex vivo stimulation of adrenal explants with POMC increased CORT as effectively as an equimolar dose of ACTH. CONCLUSIONS: Treatment of sepsis with HC impaired integrity and function of the hypothalamic-pituitary-adrenal axis at the level of the pituitary and the adrenal cortex while CRH restored pituitary POMC processing without affecting the adrenal cortex. Sepsis-induced high-circulating POMC may be responsible for ongoing adrenocortical steroidogenesis despite low ACTH.

The Type of Fat in the Diet Influences Regulatory Aminopeptidases of the Renin-Angiotensin System and Stress in the Hypothalamic-Pituitary-Adrenal Axis in Adult Wistar Rats.

(1) Background: Prolonged feeding with a high-fat diet (HFD) acts as a stressor by activating the functions of the hypothalamic-pituitary-adrenal gland (HPA) stress axis, accompanied of hypertension by inducing the renin-angiotensin-aldosterone system. Angiotensinases enzymes are regulatory aminopeptidases of angiotensin metabolism, which together with the dipeptidyl peptidase IV (DPP-IV), pyroglutamyl- and tyrosyl-aminopeptidase (pGluAP, TyrAP), participate in cognitive, stress, metabolic and cardiovascular functions. These functions appear to be modulated by the type of fat used in the diet. (2) Methods: To analyze a possible coordinated response of aminopeptidases, their activities were simultaneously determined in the hypothalamus, adenohypophysis and adrenal gland of adult male rats fed diets enriched with monounsaturated (standard diet (S diet) supplemented with 20% virgin olive oil; VOO diet) or saturated fatty acids (diet S supplemented with 20% butter and 0.1% cholesterol; Bch diet). Aminopeptidase activities were measured by fluorimetry using 2-Naphthylamine as substrates. (3) Results: the hypothalamus did not show differences in any of the experimental diets. In the pituitary, the Bch diet stimulated the renin-angiotensin system (RAS) by increasing certain angiotensinase activities (alanyl-, arginyl- and cystinyl-aminopeptidase) with respect to the S and VOO diets. DPP-IV activity was increased with the Bch diet, and TyrAP activity decrease with the VOO diet, having both a crucial role on stress and eating behavior. In the adrenal gland, both HFDs showed an increase in angiotensinase aspartyl-aminopeptidase. The interrelation of angiotensinases activities in the tissues were depending on the type of diet. In addition, correlations were shown between angiotensinases and aminopeptidases that regulate stress and eating behavior. (4) Conclusions: Taken together, these results support that the source of fat in the diet affects several peptidases activities in the HPA axis, which could be related to alterations in RAS, stress and feeding behavior.

Transcriptomic study of the mechanism by which the Kai Yu Zhong Yu recipe improves oocyte quality in a stressed mouse model.

ETHNOPHARMACOLOGICAL RELEVANCE: The Kai Yu Zhong Yu recipe (KYZY) is a classic herbal formula in traditional Chinese medicine (TCM) that has been used to treat infertility associated with psychological stress for more than three hundred years. AIM OF THE STUDY: Psychological stress has major impacts on fertility, with variable outcomes depending on the nature, strength, and duration of the stress. Stress can directly disturb ovulation, oocyte quality, maturation, and embryo development. The aim of this study is to investigate the molecular mechanism by which KYZY improves oocyte developmental potential under psychological stress. MATERIALS AND METHODS: ICR female mice aged 4-5 weeks were randomly divided into five groups: control, stressed in the chronic unpredictable stress model (CUSM), and stressed plus KYZY treatment at 38.2 g/kg (KYZYH), 19.1 g/kg (KYZYM), or 9.6 g/kg (KYZYL). Ovary function was assessed by measuring serum levels of estradiol (E2), luteinizing hormone (LH), follicle-stimulating hormone (FSH), and anti-Müllerian hormone (AMH). Oocyte quality was evaluated in terms of reactive oxygen species (ROS) levels, apoptotic DNA fragmentation, and mitochondria distribution. We used RNA sequencing (RNAseq) to identify differentially expressed genes (DEGs) between groups and then further analyzed the DEGs for gene ontology (GO) term enrichment and protein-protein interactions. RESULTS: Mice in the stressed group had reduced serum E2, LH, and FSH as well as increased ROS levels, increased apoptosis, and disturbed mitochondria distribution in oocytes. Treatment with KYZY at all three doses reversed or ameliorated these negative effects of stress. DEG analysis identified 187 common genes between the two comparisons (stressed vs. control and KYZYM vs. stressed), 33 of which were annotated with six gene ontology (GO)'s biological process (BP) terms: cell differentiation, apoptosis, ATP synthesis, protein homo-oligomerization, neuron migration, and negative regulation of peptidase activity. Protein-protein interaction network analysis of DEGs identified key hub genes. Notably, the genes Atp5o and Cyc1 were both involved in the ATP synthesis and among the top three hub genes, suggesting that regulation of oocyte mitochondrial electron transport and ATP synthesis is important in the response to stress and also is a possible mechanism of action for KYZY. CONCLUSIONS: KYZY was effective in ameliorating the adverse effects of stress on oocyte competence, possibly by targeting the mitochondrial respiratory chain and ATP synthase.

Melatonin Administration Accelerates Puberty Onset in Mice by Promoting FSH Synthesis.

Although melatonin has been extensively studied in animal reproduction, the mechanism of melatonin in puberty remains elusive. This study was designed to explore the effect of intraperitoneal administration of melatonin on puberty onset in female mice. The injection of melatonin into postnatal days 10 mice at a dose of 15 mg/kg accelerated the puberty onset in mice. Mechanistically, there was no difference in physical growth and serum Leptin levels after melatonin administration. Meanwhile, the serum levels of reproductive hormones involved in hypothalamic-pituitary-ovarian axis, such as FSH and estrogen level in serum were increased. The mRNA levels of GnRH and GnRHr were not affected by melatonin, while the expressions of FSHß in pituitary and Cyp19a1 in ovary were significantly up-regulated. In addition, melatonin still promoted FSH synthesis after ovariectomy. Furthermore, the enhanced activity of ERK1/2 signaling verified that the expression of FSHß increased in pituitary. We confirmed that melatonin promoted the FSH synthesis in pituitary, thereby increased serum estrogen levels and ultimately accelerated puberty onset. However, these effects of melatonin may be pharmacological due to the high dose. This study would help us to understand the functions of melatonin in pubertal regulation comprehensively.

The Volatile Oil of Zanthoxylum bungeanum Pericarp Improved the Hypothalamic-Pituitary-Adrenal Axis and Gut Microbiota to Attenuate Chronic Unpredictable Stress-Induced Anxiety Behavior in Rats.

BACKGROUND: Anxiety disorders (ADs) are the most prevalent mental disorders worldwide. Stress-induced activation of the hypothalamic-pituitary-adrenal (HPA) axis and dysbiosis of gut microbiota seem to contribute to the onset of ADs. This study was designed to investigate the ameliorative effect of volatile oil of Zanthoxylum bungeanum (VOZB) on chronic unpredictable stress (CUS) induced anxiety behavior, as well as the altered HPA axis and gut microbiota. METHODS: Experimental rats were exposed to the CUS for 14 consecutive days. Meanwhile, VOZB was administered at doses of 50, 100 and 200 mg/kg/day for 14 days. The anxiety behavior was evaluated by elevated plus-maze (EPM) and open field (OF). The protein expressions and mRNA levels of corticotropin-releasing hormone (CRH) and glucocorticoid receptor (GR) in hypothalamus was determined, as well the hormone levels of HPA axis in serum. Furthermore, gut microbiota was detected by16S rRNA gene sequencing. The chemical constituents of VOZB were identified by GC-MS analysis. RESULTS: VOZB treatment (100 and 200 mg/kg/day) increased the ratio of open-arm entries and time in EPM test, as well as the central zone entries and time in OF test. Moreover, VOZB treatment reduced the protein expressions and mRNA levels of CRH, but elevated those of GR in hypothalamus. Similarly, the hormone levels of the HPA axis in serum were decreased by VOZB treatment. Besides, VOZB treatment restored the CUS-induced dysbiosis of gut microbiota, raising the Sobs and Chao indexes, inhibiting Lachnospiraceae, but facilitating Bacteroidales_S24-7_group, Lactobacillaceae, and Prevotellaceae. Additionally, Sobs and Chao indexes were negatively correlated to the serum corticosterone and CRH levels. CONCLUSION: VOZB showed an ameliorative effect on CUS-induced anxiety behavior, potentially via inhibiting activation of the HPA axis and restoring the dysbiosis of gut microbiota, thus improving the stress-induced abnormality of the microbiota-gut-brain axis.

Total glycosides from stems of Cistanche tubulosa alleviate depression-like behaviors: bidirectional interaction of the phytochemicals and gut microbiota.

BACKGROUND: As the most frequently used kidney-yang tonifying herb in traditional Chinese medicine, dried succulent stems of Cistanche tubulosa (Schenk) Wight (CT) have been shown to be effective in the treatment of depression. However, the antidepressant components and their underlying mechanism remain unclear. PURPOSE: To explore the active components of CT against depression, as well as the potential mechanisms. STUDY DESIGN AND METHODS: Behavioral despair tests were used to assess the antidepressant activities of polysaccharides, oligosaccharides and different glycoside-enriched fractions separated from CT, as well as the typical gut microbiota metabolites including 3-hydroxyphenylpropionic acid (3-HPP) and hydroxytyrosol (HT). Furthermore, the effects of bioactive fractions and metabolites on chronic unpredictable mild stress (CUMS) model were explored with multiple pharmacodynamics and biochemical analyses. Changes in colonic histology and the intestinal barrier were observed by staining and immunohistochemical analysis. Gut microbial features and tryptophan-kynurenine metabolism were explored using 16S rRNA sequencing and western-blotting, respectively. RESULTS: Total glycosides (TG) dramatically alleviated depression-like behaviors compared to different separated fractions, reflecting in the synergistic effects of phenylethanoid and iridoid glycosides on the hyperactivation of the hypothalamic-pituitary-adrenal (HPA) axis, severe neuro- and peripheral inflammation, and deficiencies in 5-hydroxytryptamine (5-HT) and brain-derived neurotrophic factor in the hippocampus. Moreover, TG mitigated low-grade inflammation in the colon and intestinal barrier disruption, and the abundances of several bacterial genera highly correlated with the HPA axis and inflammation in CUMS rats. Consistently, the expression of indoleamine 2, 3-dioxygenase 1 (IDO1) in the colon was significantly reduced after TG administration, accompanied by the suppression of tryptophan-kynurenine metabolism. On the other hand, HT also exerted a marked antidepressant effect by ameliorating HPA axis function, pro-inflammatory cytokine release, and tryptophan-kynurenine metabolism, while it was unable to largely adjust the disordered gut microbiota in the same manner as TG. Surprisingly, superior to fluoxetine, TG and HT could further improve dysfunction of the hypothalamic-pituitary-gonadal axis and abnormal cyclic nucleotide metabolism. CONCLUSION: TG are primarily responsible for the antidepressant activity of CT; its effect might be achieved through the bidirectional interaction of the phytochemicals and gut microbiota, and reflect the advantage of CT in the treatment of depression.

What's new in atopic eczema? An analysis of systematic reviews published in 2018. Part 1: prevention and topical therapies.

This review is part of a series of annual updates that summarize the evidence base for atopic eczema (AE). The aim is to provide a succinct guide for clinicians on the key findings from 14 systematic reviews on the prevention and topical treatment of AE published or indexed in 2018. Various supplements, including long-chain polyunsaturated fatty acids, vitamin D and the probiotic Lactobacillus rhamnosus GG, given prenatally and postnatally, have not been shown to prevent AE in infants, although mixed strains of probiotics may decrease the risk of AE if given to the mother during pregnancy and to the infant for the first 6 months of life. In the postnatal period, there is no evidence that hydrolysed formula, compared with cow's milk formula (CMF), reduces the risk of AE in partially breastfed infants. However, weak evidence suggests that a specific partially hydrolysed whey formula decreases the risk of AE compared with CMF. No specific skin practices can be recommended to reduce the eczema risk in healthy term babies. There is weak evidence of a low risk of reversible hypothalamic-pituitary-adrenal axis suppression following 2-4 weeks of treatment with low-potency topical steroids, and conflicting evidence as to whether bleach bathing affects skin flora or AE severity. A single study demonstrated that the topical Janus kinase inhibitor tofacitinib at 2% significantly reduces the Eczema Area and Severity Index compared with vehicle. Topical naltrexone cream 1% improves pruritus (measured using a visual analogue scale) by 30% more than placebo. There is weak evidence that topical alternative therapies, including antioxidants, micronutrients and some herbal medicines, may improve AE.

N-3 PUFA Have Antidepressant-like Effects Via Improvement of the HPA-Axis and Neurotransmission in Rats Exposed to Combined Stress.

Early life and adulthood stress increase vulnerability for mental illness, and eventually trigger depression. N-3 polyunsaturated fatty acids (PUFA) have antidepressant effects, but their effect on rats exposed to combined stress has been not investigated. This study aimed to investigate whether n-3 PUFA supplementation had antidepressant-like effects in rat models of depression induced by a combination of chronic mild stress (CMS) and maternal separation (MS) through the modulation of the hypothalamic-pituitary-adrenal (HPA) axis and neurotransmission. Rats were fed the n-3 PUFA diet during the pre-weaning or post-weaning period or for lifetime, and allocated to different groups based on the type of induced stress: non-stress (NS), CMS + MS, or CMS alone. N-3 PUFA improved the depressive behaviors of the CMS alone and CMS + MS groups and modulated the HPA-axis by reducing the circulating adrenocorticotropic hormone, corticosterone, and corticotropin-releasing factor expression, and increasing glucocorticoid receptor expression. N-3 PUFA also modulated brain phospholipid fatty acid concentration, thus reducing inflammatory cytokines; improved the serotonergic pathway, thus increasing the expression of the brain-derived neurotrophic factor (BDNF), cAMP response element-binding protein (CREB), serotonin-1A receptor, and serum levels of serotonin; but did not affect glutamatergic neurotransmission. Furthermore, n-3 PUFA decreased the hippocampal expression of microRNA-218 and -132, increased that of microRNA-155, and its lifetime supplementation was more beneficial than pre- or post-weaning supplementation. This study suggests that n-3 PUFA has an antidepressant effect in rats exposed to combined stress, through the improvement of the HPA-axis abnormalities, the BDNF-serotonergic pathway, and the modulation of microRNAs.

Gastrodiae Rhizoma Water Extract Ameliorates Hypothalamic-Pituitary-Adrenal Axis Hyperactivity and Inflammation Induced by Chronic Unpredictable Mild Stress in Rats.

Gastrodiae Rhizoma is a highly valuable traditional herbal medicine commonly used to treat neurological disorders. The present study is designed to determine the antidepressant-like effect of the Gastrodiae Rhizoma water extract (GRWE) on a depression model and the potential mechanisms. The chronic unpredictable mild stress (CUMS) rat model was used to induce depression. The sucrose preference test, open field test, forced swimming test, and tail suspension test were performed to assess the depressive-like behaviors, respectively. Hypothalamic-pituitary-adrenal (HPA) function was measured via plasma corticosterone (CORT), adrenocorticotrophic hormone (ACTH), hypothalamic corticotropin-releasing factor (CRF), and glucocorticoid receptor (GR) concentrations. Plasma concentrations of proinflammatory cytokines including interleukin-1ß (IL-1ß), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) were also evaluated. The results showed that GRWE significantly attenuates the behavioral abnormalities in CUMS rats, as shown by elevated sucrose consumption, raised locomotor activity, and reduced immobility duration. Moreover, GRWE treatment reduced CORT, ACTH, CRF, and GR levels and decreased the plasma IL-1ß, IL-6, and TNF-α concentrations. These findings indicate that GRWE improves depressive behaviors in a chronic stress model of rats; its effect may be ascribed to the modulation of the HPA axis activity and inflammatory response.

Effects of dietary fatty acids on the social life of male Guinea pigs from adolescence to adulthood.

Dietary intake of polyunsaturated fatty acids (PUFAs) or saturated fatty acids (SFAs) differently modulates neurophysiological and behavioral functions in response to altered hypothalamic-pituitary-adrenal (HPA)-axis activity and an individual's development. In this context, an individual's social environment, including social interactions and social hierarchies, is closely related to hormone concentrations and possibly interacts with dietary fatty acid effects. We investigated if dietary supplementation with walnut oil (high in PUFAs) and coconut fat (high in SFAs), compared to a control group, affects body mass gain, cortisol and testosterone concentrations, plasma fatty acids, and social behavior in male domestic guinea pigs from adolescence to adulthood. For analyses of cortisol and testosterone concentrations, social interactions were included as covariates in order to consider effects of social behavior on hormone concentrations. Our results revealed that SFAs increased escalated conflicts like fights and stimulated cortisol and testosterone concentrations, which limited body mass gain and first-year survival. PUFAs did not remarkably affect social behavior and hormone concentrations, but enabled the strongest body mass gain, which probably resulted from an energetic advantage. Neither sociopositive nor agonistic behaviors explained age-specific differences in hormone concentrations between groups. However, a high number of subdominant individuals and lower testosterone concentrations were related to increased cortisol concentrations in adult PUFA males. Our findings demonstrate the importance of dietary fatty acids regarding behavioral and endocrine developmental processes and adaptations to the social environment by modulating HPA-axis function and body homeostasis.

Dietary arachidonic acid improves age-related excessive enhancement of the stress response.

OBJECTIVE: The aim of this study is to understand whether the responsiveness of the hypothalamic-pituitary-adrenal (HPA) axis to stress increases excessively with aging in senescence-accelerated mice-prone 10 (SAMP10) and to investigate the role of arachidonic acid (ARA) in this process. MATERIALS AND METHODS: The area under the curve of CORT concentration (CORT-AUC), an index of the HPA axis responsiveness to stress, was assessed in SAMP10 subjected to a 30-minute restraint stress up to 120 minutes after the restraint stress onset. Furthermore, the HPA axis responsiveness was evaluated in aged SAMP10 fed 0.4% ARA-containing diet (ARA group) or control diet (CON group) for 4 weeks. Three weeks later, these mice were divided into a group with a 30-minute restraint stress (CON-S or ARA-S group) and a group without restraint stress (CON-NS or ARA-NS group). Hippocampi were collected after stress release and fatty acid and glucocorticoid receptor (GR) protein levels were evaluated in the nucleus and cytosol. RESULTS: The CORT-AUC of aged SAMP10 was 21% significantly higher than that of young SAMP10. In the ARA group, hippocampal ARA was 0.5% significantly higher than that in the CON group. CORT-AUC in the ARA group was 24% significantly lower than that in the CON group. The ratio of GR protein levels in the nucleus and cytosol in the ARA-S group was 1.72 times significantly higher than that in the ARA-NS group but no difference was observed between the CON-S and CON-NS groups. CONCLUSIONS: Dietary ARA seems to suppress age-related excessive enhancement of the HPA axis responsiveness via attenuation of age-related decline in hippocampal GR translocation into the nucleus after stress loading, which may contribute to an improvement of mental health.

Effects of neuromedin U-8 on stress responsiveness and hypothalamus-pituitary-adrenal axis activity in male C57BL/6J mice.

Neuromedin U (NMU) is a highly conserved neuropeptide that has been implicated in the stress response. To better understand how it influences various aspects of the stress response, we studied the effects of intracerebroventricular NMU-8 administration on stress-related behavior and activity of the hypothalamus-pituitary-adrenal (HPA) axis in male C57BL/6J mice. We investigated these NMU-8 effects when mice remained in their home cage and when they were challenged by exposure to forced swim stress. NMU-8 administration resulted in increased grooming behavior in mice that remained in their home cage and in a significant increase in c-Fos immunoreactivity in the paraventricular hypothalamus (PVH) and arcuate nucleus (ARC). Surprisingly, NMU-8 administration significantly decreased plasma corticosterone concentrations. Furthermore, NMU-8 administration increased immobility in the forced swim test in both naïve mice and mice that were previously exposed to swim stress. The effect of NMU-8 on c-Fos immunoreactivity in the PVH was dependent on previous exposure to swim stress given that we observed no significant changes in mice exposed for the first time to swim stress. In contrast, in the ARC we observed a significant increase in c-Fos immunoreactivity regardless of previous stress exposure. Interestingly, NMU-8 administration also significantly decreased plasma corticosterone concentrations in mice that were exposed to single forced swim stress, while this effect was no longer observed when mice were exposed to forced swim stress for a second time. Taken together, our data indicate that NMU-8 regulates stress responsiveness and suggests that its effects depend on previous stress exposure.

Repeated caffeine administration aggravates post-traumatic stress disorder-like symptoms in rats.

BACKGROUND: Caffeine is the widely consumed central nervous system stimulant in form of coffee and other beverages. However, the repeated administration of caffeine induces anxiety, disturbance in hypothalamic-pituitary-adrenal (HPA) axis and psychiatric symptoms in humans. As much evidence links PTSD to HPA axis dysfunction, and anxiety is a hallmark symptom, repeated and/or large doses of caffeine may exacerbate symptoms of PTSD. OBJECTIVE: In our present study, we evaluated the effect of repeated administration of caffeine on stress re-stress (SRS) model of PTSD. METHODS: As per the protocol, male rats were restrained for 2 h followed by 20 min forced swim and halothane anaesthesia on day 2 (D-2). Then the rats were re-stressed (forced swim) at 6-days interval between D-8 to D-32. After exposure to SRS, depressive, anxiety-like behaviour, and cognitive functions were evaluated by forced swim test (FST), elevated plus maze (EPM) and Y-maze tests respectively. Caffeine (10, 20 and 30 mg/kg, i.p.) dosing was started from D-8 and continued up to D-32. The corticosterone level was measured in plasma followed by serotonin and glucocorticoid receptor (GR) and mineralocorticoid receptors (MR) estimation in hippocampus (HIP), prefrontal cortex (PFC) and amygdala (AMY). RESULTS: SRS-induced depressive and anxiety-like behaviour was aggravated by caffeine at dose of 20 and 30 mg/kg. Caffeine (30 mg/kg) treated control animals showed depressive, anxiety-like behaviour and cognitive impairments. SRS-induced decrease in plasma corticosterone level and increase in serotonin (5HT) levels in the PFC, HIP and AMY were not altered by caffeine. Caffeine did not modulate the SRS-induced decrease in glucocorticoid receptor (GR) and mineralocorticoid receptor (MR). In contrast, caffeine per se decreased GR and MR expression and their ratio in unstressed animals. CONCLUSION: Repeated intake of caffeine aggravates PTSD-like symptoms in stress-exposed rats and induces PTSD-like symptoms in unstressed rats by altering the expression of glucocorticoid receptors.

Organophosphorus pesticide triazophos: A new endocrine disruptor chemical of hypothalamus-pituitary-adrenal axis.

The organophosphorus pesticide, triazophos (TAP) was banned to use in agriculture in several countries due to its high toxicity. However, TAP was still widely used and frequently detected in foods. Recently, many studies reported the endocrine-disrupting effect of pesticides, especially the hypothalamic-pituitary-thyroid and hypothalamic-pituitary-gonadal axis. In this study, adult male Wistar rats were exposed to TAP at the dose of 0.164 and 1.64 mg/kg bodyweight (~1/500th and 1/50th of LD50) for 24 weeks and serum contents of hormones were measured. TAP exposure significantly reduced serum contents of adrenocorticotropic hormone, corticosterone and epinephrine in rats (p < .05), leading to the delay in glucose homeostasis during the insulin tolerance test and decrease in serum contents of total cholesterol, triglyceride and low density lipoprotein. Molecular docking results suggested TAP may be an antagonist of glucocorticoid receptor which decreased significantly in the liver of rats, resulting in the decreased expression of 11ß-hydroxysteroid dehydrogenase 1 and PEPCK1. This study revealed that TAP is a potential endocrine disruptor, especially in the hypothalamus-pituitary-adrenal system and may disturb the metabolism by affecting glucocorticoid receptor. This study provided new evidence about the toxicity of TAP and it was necessary to strictly control the usage of TAP in food.

Antidepressant-like effects of dietary gardenia blue pigment derived from genipin and tyrosine.

Gardenia blue pigments derived from genipin reacting with amino acids have been used as natural food colorants for nearly 30 years in East Asia. However, their pharmacological effects, especially antidepressant-like effects, have not been reported so far. In this study, one of the gardenia blue pigments, was obtained from the reaction of genipin with tyrosine (genipin-tyrosine derivant (GTD)), and its antidepressant-like effects were investigated in lipopolysaccharide (LPS) or chronic unpredictable mild stress (CUMS) models. The results showed that GTD could attenuate depressive-like behaviors in both animal models. GTD reversed the LPS-induced cytokine increase of TNF-α, IL-6, and corticosterone (CORT) in mice plasma and hippocampus. In CUMS rats, GTD treatment significantly reduced hypothalamic-pituitary-adrenal (HPA) axis-related stress hormone levels in plasma including those of CORT, adrenocorticotropic hormone (ACTH), and corticotropin-releasing hormone (CRH). Besides, GTD increased plasma testosterone and hippocampal brain-derived neurotrophic factor (BDNF) levels in CUMS rats. GTD increased serotonin (5-HT), dopamine (DA), and norepinephrine (NE) in rat hippocampus and corpus striatum. Consistently, hippocampal metabolomic analysis demonstrated that GTD restored monoamine neurotransmitter metabolism, mitochondrial oxidative function, and membrane structural integrity. Our data suggested that GTD produced antidepressant-like activity through the restoration of the HPA axis hormone balance and the regulation of neurotransmitter release.

Salvianolic acid B abolished chronic mild stress-induced depression through suppressing oxidative stress and neuro-inflammation via regulating NLRP3 inflammasome activation.

This study was framed to investigate the molecular mechanism behind the anti-depressant effect of salvianolic acid B (SB) against unpredictable chronic mild stress (CMS) induced depression rat model. Control rats received only saline without CMS exposure, whereas CMS model rats were induced to several stress (CMS) for 6 weeks. Treatment group rats were induced with CMS for 6 weeks but received either 20 or 40 mg/kg of SB or 20 mg/kg imipramine (CMS+IMP) from the 4th week to 6th week. Treatment with SB or IMP significantly ameliorated body weight, sucrose consumption rate with shorter immobility time than the control group. Also, administration with SB or IMP could reverse the hyperactivity of hypothalamic-pituitary-adrenal axis as well as decreased inflammatory cytokines with improved antioxidant status. Furthermore, the protein expression of NLRP3 (inflammasome) was markedly downregulated upon treatment with SB (both 20 and 40 mg) or IMP and thereby confirming its potent anti-depressant activity. PRACTICAL APPLICATIONS: Salvianolic acid B (SB) is a phenolic acid extracted from Salvia militiorrhiza Bunge, a popular Chinese herb, which has been prescribed for various pathological conditions. SB has been previously reported with anti-depressant activity but, the in-depth mechanism behind the anti-depressant effect of SB against CMS is still elusive. Hence, the current study was plotted to explore the in-depth mechanism behind the anti-depressant effect of SB against CMS model of depression in rats. The outcome of the current study has confirmed the anti-depressant activity by abolishing oxidative stress, and neuroinflammatory response in the hippocampus through inhibiting NLRP3 inflammasome activation. Hence, SB can be prescribed to major depression patients with standard anti-depressant agents to abolish oxidative stress, neuro-inflammatory response, and related neurological changes.

Anxiolytic Effect of Essential Oils and Their Constituents: A Review.

Essential oils are usually used in aromatherapy to alleviate anxiety symptoms. In comparison to traditional drugs, essential oils have fewer side effects and more diversified application ways, including inhalation. This review provides a comprehensive overview of studies on anxiolytic effects of essential oils in preclinical and clinical trials. Most of the essential oils used in clinical studies have been proven to be anxiolytic in animal models. Inhalation and oral administration were two common methods for essential oil administration in preclinical and clinical trials. Massage was only used in the clinical trials, while intraperitoneal injection was only used in the preclinical trails. In addition to essential oils that are commonly used in aromatherapy, essential oils from many folk medicinal plants have also been reported to be anxiolytic. More than 20 compounds derived from essential oils have shown an anxiolytic effect in rodents, while two-thirds of them are alcohols and terpenes. Monoamine neurotransmitters, amino acid neurotransmitters, and the hypothalamic-pituitary-adrenal axis are thought to play important roles in the anxiolytic effects of essential oils.

Effect of lipopolysaccharide-induced immune stimulation and maternal fish oil and microalgae supplementation during late pregnancy on nursery pig hypothalamic-pituitary-adrenal function1.

The present study used Escherichia coli lipopolysaccharide (LPS) to investigate whether maternal immune challenge during late gestation altered programming of the offspring hypothalamus and hypothalamic-pituitary-adrenal axis (HPAA). In addition, interactions of maternal diet, supplementation with fish oil (FO) or microalgae (AL), and complex vs. simple weaning diets were investigated. Briefly, Landrace × Yorkshire sows (N = 48) were randomly assigned to diets supplemented with FO, AL, or a standard gestation control diet (CON) from day 75 of gestation (gd 75) until parturition. On gd 112, half the sows from each dietary treatment were immune challenged with LPS (10 µg/kg BW) or saline as a control. At 21 d postpartum, the offspring were weaned, and half the animals from each maternal treatment were allocated to either a complex or simple weaning diet. At 28 d postpartum, the offspring's hourly fever and 2-h cortisol responses to LPS immune challenge (40 µg/kg BW) were measured to assess hypothalamus and HPAA function. Results indicated that the maternal temperature of sows on the FO diet returned to baseline levels faster than sows on the AL and CON diets after LPS immune challenge (P < 0.05). In contrast, there was no difference in the maternal cortisol response across the dietary treatments (P > 0.10). Regardless of the dietary treatments, the maternal LPS immune challenge induced a greater cortisol response in male offspring (P = 0.05) and a greater fever response in female offspring (P = 0.03) when they were LPS immune challenged post-weaning. Male offspring from LPS-immune-challenged sows fed the FO and AL diets had a greater fever response than male offspring from the maternal CON diet group (P ≤ 0.05). Last, no effect of the complex or simple weaning diets was observed for the nursery pig cortisol or fever responses to LPS immune challenge. In conclusion, LPS immune challenge during late pregnancy altered responsiveness of the offspring hypothalamus and HPAA to this same microbial stressor, and a sex-specific response was influenced by maternal dietary supplementation with FO and AL.

Methanol stem bark extract of Adansonia digitata ameliorates chronic unpredictable mild stress-induced depression-like behavior: Involvement of the HPA axis, BDNF, and stress biomarkers pathways.

Background Adansonia digitata L. (Malvaceae) is used locally in the management of depressive illnesses, and its antidepressant-like effect has been previously reported. The present study was aimed at determining the effect of the methanol extract of the stem bark of A. digitata (MEAD) on chronic unpredictable mild stress (CUMS) and the possible mechanism responsible for its antidepressant activity. Methods Acute toxicity of MEAD was determined using the OECD guideline 420. The CUMS model was used to induce depression, and behavioral tests such as sucrose preference test (SPT), open field test (OFT), novel-object recognition test (NORT), and tail suspension test (TST) were carried out in mice. The concentrations of plasma cortisol and brain-derived neurotrophic factor (BDNF) protein in the brain were assessed using enzyme-linked immunosorbent assay kits. The levels of superoxide dismutase (SOD) and malondialdehyde (MDA) were assessed using colorimetric methods. Results The LD50 was established to be ≥5000 mg/kg. On CUMS-induced depression, MEAD significantly (p ≤ 0.05) and dose dependently reversed the weight loss, increased the line-crossing activity in OFT, increased sucrose consumption in SPT, decreased the duration of immobility in TST, and increased the novelty exploration time in NORT. The MEAD extract significantly (p ≤ 0.05) and dose dependently increased the levels of BDNF, decreased the levels of plasma cortisol, increased the levels of total SOD activity, and decreased the levels of plasma MDA. Conclusion Our findings show that MEAD ameliorates CUMS-induced depressive-like behavior and its effect is possibly mediated via the neuroendocrine, neurotrophic, and oxidative stress pathways.

Multiorgan toxicity induced by EtOH extract of Fructus Psoraleae in Wistar rats.

BACKGROUND: The fruits of Psoralea corylifolia L. (Fructus Psoraleae, FP) has a long history and a wide range of applications in the treatment of osteoporosis and leukoderma. Although it is well known that FP could cause hepatotoxicity and reproductive toxicity, less is known about its potential toxicity on multiple organs. PURPOSE: This study aims to determine the multiorgan toxicity of EtOH extract of FP (EEFP) and to investigate the underlying mechanisms through a systematic evaluation in Wistar rats. STUDY DESIGN AND METHODS: Wistar rats were orally administered with the EEFP at doses of 1.5, 1.0 and 0.5 g/kg for 28 days. Histopathologic and clinicopathologic analyses were performed, and the hormone levels in serum and the mRNA levels of enzymes related to the production of steroid hormones in adrenal glands were detected. The area of each band of adrenal glands and the steroid levels in the adrenal glands were also measured. RESULTS: After the treatment, both the histopathologic and clinicopathologic examination showed that EEFP caused liver, prostate, seminal vesicle and adrenal gland damage. Among the enzymes involved in the regulation of adrenal steroid hormone production, NET, VMAT2, and CYP11B1 were upregulated, while CYP17A1 was downregulated. Among the adrenal steroid hormones, COR and NE were upregulated, while levels of DHT and serum ACRH and CRH decreased. CONCLUSION: Our results indicated that adrenal gland, prostate, and seminal vesicles could also be the target organs of FP-induced toxicity. Abnormal enzyme and hormone production related to the hypothalamic pituitary adrenal (HPA) axis caused by the EEFP may be the potential toxic mechanism for changes in the adrenal gland and secondary sex organs of male rats.