Targeting hippocampal phospholipid and tryptophan metabolism for antidepressant-like effects of albiflorin.

BACKGROUND: Current antidepressant therapy remains unsatisfactory due to its delayed clinical onset of action and the heterogeneity of depression. Targeting disturbed neurometabolic pathways could provide a novel therapeutic approach for the treatment of depression. Albiflorin is a phytomedicine isolated from the root of Peony (Paeonia albiflora Pall) with excellent clinical tolerance. Until now, the antidepressant-like activities of albiflorin in different subtypes of depression and its effects on neurometabolism are unknown. PURPOSE: The objective of this study was to investigate the rapid antidepressant-like effects of albiflorin in three common animal models of depression and elucidate the pharmaco-metabolic mechanisms of its action using a multi-omics approach. RESULTS: We found that albiflorin produces rapid antidepressant-like effects in chronic unpredictable mild stress (CUMS), olfactory bulbectomy (OBX), and lipopolysaccharide (LPS)-induced murine models of depression. Using a system-wide approach combining metabolomics, lipidomics, and transcriptomics, we showed that the therapeutic effects of albiflorin are highly associated with the rapid restoration of a set of common metabolic abnormities in the hippocampus across all three depression models, including phospholipid and tryptophan metabolism. Further mechanistic analysis revealed that albiflorin normalized the metabolic dysregulation in phospholipid metabolism by suppressing hippocampal cytosolic phospholipases A2 (cPLA2). Additionally, inhibition of cPLA2 overexpression by albiflorin corrects abnormal kynurenine pathway of tryptophan metabolism via the cPLA2-protein kinase B (Akt1)-indoleamine 2,3-dioxygenase 1(IDO1) regulatory loop and directs tryptophan catabolism towards more hippocampal serotonin biosynthesis. CONCLUSION: Our study contributed to a better understanding of the homogeneity in the metabolic mechanisms of depression and established a proof-of-concept for rapid treatment of depression through targeting dysregulated neurometabolic pathways.

Puerarin from Pueraria lobata alleviates the symptoms of irritable bowel syndrome-diarrhea.

As a functional bowel disorder, irritable bowel syndrome (IBS), especially IBS-diarrhea (IBS-D), affects approximately 9-20% of the population worldwide. Classical treatments for IBS usually result in some side effects and intestinal microbial disorders, which inhibit the clinical effects. Natural edible medicines with beneficial effects and few side effects have received more attention in recent years. Puerarin is the main active ingredient in pueraria and has been used in China to treat splenasthenic diarrhea and as a natural food in folk medicine for hundreds of years. However, there have been no reports of using puerarin in the treatment of IBS-D, and the underlying mechanism is also still unclear. In this study, a comprehensive model that could reflect the symptoms of IBS-D was established by combining neonatal maternal separation (NMS) and adult colonic acetic acid stimulation (ACAAS) in rats. The results showed that puerarin could reverse the abdominal pain and diarrhea in IBS-D rats. The therapeutic effect was realized by regulating the richness of the gut microbiota to maintain the stabilization of the intestinal micro-ecology. Furthermore, the possible mechanism might be related to the activity of the hypothalamic-pituitary-adrenal (HPA) axis by the suppressed expression of corticotropin-releasing hormone receptor (CRF) 1. At the same time, intestinal function was improved by enhancing the proliferation of colonic epithelial cells by upregulating the expression of p-ERK/ERK and by repairing the colonic mucus barrier by upregulating occludin expression. All these results suggest that puerarin could exert excellent therapeutic effects on IBS-D.

Gardenia fructus antidepressant formula for depression in diabetes patients: A systematic review and meta-analysis.

INTRODUCTION: Diabetes is closely related with depression. Gardenia fructus antidepressant formula (GFAF) is a Chinese herbal medicine that may be beneficial for depression in diabetic patients. This study aimed to evaluate the efficacy and safety of GFAF for depression in diabetes patients. METHODS: Randomized controlled trials (RCTs) were included. The patients were diagnosed as having diabetes mellitus with depression. The experimental interventions included GFAF alone or combined with another active treatment. The control interventions included no treatment, placebo or another active treatment. The primary outcome was reduction in the Hamilton Depression Scale (HAMD) scores. Secondary outcomes included reduction in the Self-rating Depression Scale (SDS) scores, response rate, adverse events, etc. PubMed, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wan fang database and Chinese Science and Technology Periodicals database (VIP) were searched from inception to May 2019 for potentially eligible studies. The meta-analysis was performed using RevMan 5.3 software. RESULTS: We identified 12 eligible RCTs including 822 diabetes patients with depression. Results of meta-analysis showed that the HAMD score was significantly reduced following GFAF treatment compared with no antidepressant treatment (SMD: -2.53, 95% CI: -4.80 to -0.27, P = 0.03). Another meta-analysis indicated that patients taking GFAF alone had lower HAMD scores compared with selective serotonin reuptake inhibitors (SSRI) treatment alone (SMD: -0.62, 95% CI: -1.07 to -0.18, P = 0.006). The HAMD scores in the GFAF plus SSRI treatment group were significantly decreased compared with the SSRI treatment group (SMD: -0.37, 95% CI: -0.69 to -0.06, P = 0.02). The same pattern of change was identified with the SDS scores. CONCLUSION: GFAF may be considered an alternative treatment for depression in patients with diabetes. However, more large-scale and well-designed RCTs are warranted.

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.

Current Rapid-Onset Antidepressants and Related Animal Models.

Depression is a common mental disease, and it is one of the most crippling diseases in the world. Although current pharmacotherapies contribute to the treatment of depression, the high incidence of a partial responses or no responses, and delayed onset of the antidepressants, make many patients to experience unsatisfactory results from treatment. In view of the high suicide rate during the period of drug onset, it is critical to find antidepressant drugs with rapid onset for the treatment of depression. This paper mainly reviews some drugs that have rapid antidepressant effect and their mechanisms, including monoaminergic receptor drugs, glutamate receptor drugs, mammalian target of rapamycin (mTOR) signaling agonist, gamma-aminobutyric acid energy (GABAergic) agonist and drug combinations. In addition, we introduce several rodent models currently used to assess antidepressant onset in this review: chronic unpredictable mild stress (CUMS), forced swimming test (FST) and tail suspension test (TST), olfactory bulbectomy (OBX) and other models, which provide a methodological approach for assessing the rapid onset of antidepressant drugs.