Is there a role for curcumin in the treatment of bipolar disorder?

Curcumin as a Multifunctional Spice Ingredient against Mental Disorders in Humans: Current Clinical Studies and Bioavailability Concerns

BACKGROUND

Mental disorders in terms of depression, anxiety, and stress are one of the major causes of burden globally. Over the last two decades, the use of plant-based substances in the treatment of mental disorders in combination or not with medication has increasingly attracted the interest of the scientific research community. However, even if there is a plethora of naturally occurring bioactive compounds, most of them have low bioavailability, rendering them unable to insert into the bloodstream to exert their biological activities.

METHODS

This is a comprehensive narrative review that critically summarizes and scrutinizes the new approaches to the treatment of mental disorders using curcumin, also highlighting its bioavailability properties. The most accurate were searched using effective and relevant keywords.

RESULTS

This narrative review reveals substantial evidence that curcumin can exert significant effects on several mental disorders. However, despite the low cost, the extensive and confirmed potency of curcumin and its involvement in signaling pathways and the scientifically confirmed data regarding its molecular mechanisms of action against mental disorders, this naturally occurring compound presents low oral bioavailability. Pharmaceutical technology has provided solutions to increase the bioavailability of curcumin. Combination with piperine, galactomannosides, liposomal formulation or nanoformulation overcomes the bioavailability and solubility disadvantages.

CONCLUSIONS

Although curcumin demonstrates anti-anxiety, anti-depressive and anti-stress properties, studies on humans are limited and heterogeneous. Further research is highly recommended to determine the most functional formula, dose, duration, and possible side effects of curcumin on mental disorders in humans. Based on the current knowledge, the curcumin nanoformulation and Theracurmin, a form of colloidal submicroscopic particles, seem to be the most effective bioavailable formulations, which may be examined in future clinical human studies.

The effect of adding curcumin to sodium valproate in treatment of patients with bipolar disorder in the acute phase of mania: A randomized double-blind clinical trial

BACKGROUND

Inflammatory processes play a role in the etiopathogenesis of bipolar disorder type 1. Full therapeutic responses are seldom seen and the ongoing inflammatory processes in the brain could lead to neuronal loss. Curcumin, a relatively safe herbal compound, has been shown to have anti-inflammatory effects. The present randomized double-blind clinical trial study aimed to investigate the effect of adding curcumin to the treatment regimen of BID.

MATERIALS AND METHODS

This randomized double-blind clinical trial was conducted on 78 patients diagnosed with BID according to the Diagnostic and Statistical Manual of Mental Disorders (DSM 5) criteria. The sample were divided into two groups. Patients in both groups received sodium valproate starting at a dose of 600 milligrams per day and administered up to 20 milligrams per kilogram per day or the highest dosage of the patient's tolerance. Patients in the intervention group also received curcumin as nanomicelle in soft gelatin capsules 40 milligrams per day. The control group received placebo tablets with the same characteristics as the curcumin tablets. They were assessed by a psychiatrist using the Young Mania Rating Scale (YMRS), Mini-Mental State Examination (MMSE), Clinical Global Impression (CGI), and a medication side effect questionnaire at the beginning of the study, as well as in the first, second, and fourth weeks of the study.

RESULTS

Among the 78 patients chosen to participate in the project, 54 people completed the trial. No specific side effect was observed in the two groups. Both groups showed an increase in their MMSE scores compared to the beginning of the study (value of p < 0.001). Although this increase was not statistically different between the two groups (value of p = 0.68). The YMRS score of both groups decreased significantly by the end of the study (value of p < 0.001); however, this decrease was not significantly different between the two groups (value of p = 0.64). In addition, the two groups experienced a significant increase in their CGI scores throughout the study (value of p < 0.001), this increase however was not statistically different between the two groups (value of p = 0.88).

CONCLUSION

The present study suggested that curcumin may not be a useful adjuvant agent in the management of patients with BID receiving sodium valproate as treatment.Clinical trial registration: Iranian Registry of Clinical Trials (IRCT), identifier IRCT2016102530504N1.

Role of Curcumin in the Management of Schizophrenia: A Narrative Review

Nutraceutical agents and food supplements are commonly used as treatment adjuncts in neuropsychiatric disorders. Curcumin, a bioactive agent obtained from the rhizome of Curcuma longa, with its antioxidant and anti-inflammatory properties, has gained much research attention in the last few decades. In this narrative review, we intend to summarize the evidence available for curcumin as an add-on agent in the management of schizophrenia. We searched PubMed/EBSCO for both human and animal trials utilizing curcumin in the management of schizophrenia. We obtained ten articles (five preclinical and five clinical) from the focused literature search. Clinical research utilizing curcumin in schizophrenia is limited to negative and cognitive symptoms. Available preclinical studies suggest curcumin's utility in ameliorating extrapyramidal and metabolic side effects when given as an adjunct with antipsychotics. Curcumin, as an add-on agent, appears promising to improve the negative and cognitive symptoms of schizophrenia. Notably, curcumin was tolerable and safe in all the randomized human clinical trials. The poor oral bioavailability is, however, a limiting factor in its widespread use.

Therapeutic approaches employing natural compounds and derivatives for treating bipolar disorder: emphasis on experimental models of the manic phase

Bipolar disorder (BD) is a complex psychiatric disease characterized by mood swings that include episodes of mania and depression. Given its cyclical nature, BD is especially hard to model; however, the standard practice has been to mimic manic episodes in animal models. Despite scientific advances, the pathophysiology of BD is not fully understood, and treatment remains limited. In the last years, natural products have emerged as potential neuroprotective agents for the treatment of psychiatric diseases. Thus, the aim of this review was to explore the therapeutic potential of natural compounds and derivatives against BD, taking into account preclinical and clinical studies. Reliable articles indexed in databases such as PubMed, Web of Science and Science Direct were used. In clinical studies, treatment with herbal plants extracts, omega-3, inositol, n-acetylcysteine and vitamin D has been associated with a clinical improvement in symptoms of mania and depression in BD patients. In animal models, it has been shown that red fruits extracts, curcumin, quercetin, gallic acid, alpha-lipoic acid and carvone can modulate many neurochemical pathways involved in the pathophysiology of manic episodes. Thus, this review appointed the advances in the consumption of natural compounds and derivatives as an important therapeutic strategy to mitigate the symptoms of BD.

Effects of Curcumin on Depression and Anxiety: A Narrative Review of the Recent Clinical Data

Depressive and anxiety disorders affect a significant proportion of the global population and constitute one of the highest disease burdens worldwide. Conventional pharmacological treatments are traditionally the first line of therapy for individuals affected by these conditions although these are only successful approximately half of the time and are often associated with undesirable side effects. This review describes the use of the natural substance curcumin as a potential alternative treatment of these mental disorders. With this in mind, we analyzed the effects of curcumin in eight clinical studies of depression and five studies of anxiety and assessed these using psychiatric symptom scores and molecular biomarker readouts.

Targeting the immune system in the treatment of bipolar disorder

RATIONALE

Immune dysfunction has been strongly implicated in the pathophysiology of bipolar disorder (BD). As such, numerous clinical trials have investigated the effects of anti-inflammatory agents in the treatment of BD.

OBJECTIVES

Review clinical studies evaluating the effects of anti-inflammatory agents in the treatment of BD during all illness phases (e.g., depression, mania, and euthymia).

METHODS

Relevant databases were searched from inception to August 27, 2018 for clinical studies evaluating the effects of anti-inflammatory agents in BD.

RESULTS

The majority of identified clinical trials evaluated adjunctive anti-inflammatory agents in the acute treatment of bipolar depression, demonstrating antidepressant effects with N-acetylcysteine (NAC), pioglitazone, minocycline, and coenzyme Q10, along with mixed evidence for omega-3s, and non-steroidal anti-inflammatory drugs (NSAIDs). The anti-manic effects of adjunctive anti-inflammatory agents have been minimally studied, with some promising preliminary results supporting potential anti-manic effects of adjunctive celecoxib and NAC. Maintenance studies are also limited, with inadequate evidence to support mood stabilizing effects of anti-inflammatories while euthymic. Regardless of illness phase, early results suggest that anti-inflammatory agents are likely most beneficial in the subgroup of BD with immune dysregulation.

CONCLUSIONS

Several proof-of-concept clinical trials have shown promising results for anti-inflammatory agents in the treatment of bipolar depression with moderate effect sizes and good tolerability. The effects of anti-inflammatory agents during manic and euthymic periods remains uncertain. Future larger studies, using stratified samples, enriched for participants with immune dysfunction, are required to determine the role of immune modulating agents in the treatment of BD.

Mapping inflammation onto mood: Inflammatory mediators of anhedonia

Evidence supports inflammatory involvement in mood and cognitive symptoms across psychiatric, neurological and medical disorders; however, inflammation is not a sensitive or specific characteristic of these diagnoses. The National Institute of Mental Health Research Domain Criteria (RDoC) ask for a shift away from symptom-based diagnoses toward a transdiagnostic neurobiological focus in the study of brain illnesses. The RDoC matrix may provide a useful framework for integrating the effects of inflammation on brain function. Based on preclinical and clinical findings, relevant relationships span negative and positive valence systems, cognitive systems, systems for social processes and arousal/regulatory systems. As an exemplar, we consider the psychopathological domain of anhedonia, conceptualizing the relevance of inflammation (e.g., cellular immunity) and downstream processes (e.g., indoleamine 2,3-dioxygenase activation and oxidative inactivation of tetrahydrobiopterin) across RDoC units of analysis (e.g., catecholamine neurotransmitter molecules, nucleus accumbens medium spiny neuronal cells, dopaminergic mesolimbic and mesocortical reward circuits, animal paradigms, etc.). We discuss implications across illnesses affecting the brain, including infection, major depressive disorder, stroke, Alzheimer's disease and type 2 diabetes.

Dysregulation of the NF-κB pathway as a potential inducer of bipolar disorder

A century of investigations enhanced our understanding of bipolar disorder although it remains a complex multifactorial disorder with a mostly unknown pathophysiology and etiology. The role of the immune system in this disorder is one of the most controversial topics in genetic psychiatry. Though inflammation has been consistently reported in bipolar patients, it remains unclear how the immunologic process influences the disorder. One of the core components of the immune system is the NF-κB pathway, which plays an essential role in the development of innate and adaptive immunity. Remarkably, the NF-κB pathway received only little attention in bipolar studies, as opposed to studies of related psychiatric disorders where immune dysregulation has been proposed to explain the neurodegeneration in patient conditions. If immune dysregulation can also explains the neurodegeneration in bipolar disorder, it will underscore the role of the immune system in the chronicity and pathophysiology of the disorder and may promote personalized therapeutic strategies. This is the first review to summarize the current knowledge of the pathophysiological functions of NF-κB in bipolar disorder.

Taking the fuel out of the fire: evidence for the use of anti-inflammatory agents in the treatment of bipolar disorders

BACKGROUND

Inflammation has emerged as a potentially important factor - and thus putative pharmacological target - in the pathology of bipolar disorders. However to date no systematic evaluations of the efficacy of add on anti-inflammatory treatment for the depressive and manic episodes have been carried out.

METHODS

Sixteen articles were ultimately identified - by computer searches of databases (including PsycINFO, MEDLINE, and EMBASE), supplemented by hand searches and personal communication - as meeting study inclusion criteria.

RESULTS

Anti-manic effects were evaluated in two trials, one of adjunctive n-acetyl cysteine (NAC), one of omega-3 fatty acids (O3FA), and significant improvements only emerged for NAC. Celecoxib had a rapid but short-lived antidepressant effect. Despite limited effects of O3FA on symptoms, imaging data demonstrated alterations in neuronal functioning that might have longer-term therapeutic effects. Evidence was strongest for adjunctive NAC in bipolar depression though conclusions are limited by small sample sizes.

LIMITATIONS

Definitive conclusions are limited by the paucity of data, small study sizes, and the variability in methodology used.

CONCLUSIONS

Current evidence for aspirin or celecoxib is insufficient though further investigation of the potential of celecoxib in early illness onset is warranted. Variable evidence exists for add-on O3FA though an indication of short-term treatment effects on membrane fluidity and neuronal activity suggest longer follow-up assessment is needed. The strongest evidence emerged for NAC in depression and future studies must address the role of illness duration and patients׳ baseline medications on outcomes. Careful consideration of lithium toxicity in the elderly and renal impaired is essential.

Inflamed moods: a review of the interactions between inflammation and mood disorders

Mood disorders have been recognized by the World Health Organization (WHO) as the leading cause of disability worldwide. Notwithstanding the established efficacy of conventional mood agents, many treated individuals continue to remain treatment refractory and/or exhibit clinically significant residual symptoms, cognitive dysfunction, and psychosocial impairment. Therefore, a priority research and clinical agenda is to identify pathophysiological mechanisms subserving mood disorders to improve therapeutic efficacy. During the past decade, inflammation has been revisited as an important etiologic factor of mood disorders. Therefore, the purpose of this synthetic review is threefold: 1) to review the evidence for an association between inflammation and mood disorders, 2) to discuss potential pathophysiologic mechanisms that may explain this association and 3) to present novel therapeutic options currently being investigated that target the inflammatory-mood pathway. Accumulating evidence implicates inflammation as a critical mediator in the pathophysiology of mood disorders. Indeed, elevated levels of pro-inflammatory cytokines have been repeatedly demonstrated in both major depressive disorder (MDD) and bipolar disorder (BD) patients. Further, the induction of a pro-inflammatory state in healthy or medically ill subjects induces 'sickness behavior' resembling depressive symptomatology. Potential mechanisms involved include, but are not limited to, direct effects of pro-inflammatory cytokines on monoamine levels, dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, pathologic microglial cell activation, impaired neuroplasticity and structural and functional brain changes. Anti-inflammatory agents, such as acetyl-salicylic acid (ASA), celecoxib, anti-TNF-α agents, minocycline, curcumin and omega-3 fatty acids, are being investigated for use in mood disorders. Current evidence shows improved outcomes in mood disorder patients when anti-inflammatory agents are used as an adjunct to conventional therapy; however, further research is needed to establish the therapeutic benefit and appropriate dosage.

Targeting the inflammatory pathway as a therapeutic tool for major depression

In the last decades convergent findings from several lines of evidence has revealed a robust association between major depressive disorder (MDD) and inflammatory pathways. Despite this, the translation of these findings into new and better treatments for MDD has not occurred. The objective of this study is to comprehensively review what is already known with reasonable certainty on inflammatory pathways in MDD, to clarify some points that have been insufficiently studied and to discuss the implications of these findings for future studies targeting inflammatory pathways as a therapeutic tool for individuals with MDD.

Neuroprotective and antioxidant effects of curcumin in a ketamine-induced model of mania in rats

Bipolar disorder (BD) is a chronic and debilitating illness characterized by recurrent manic and depressive episodes. Our research investigates the protective effects of curcumin, the main curcuminoid of the Indian spice turmeric, in a model of mania induced by ketamine administration in rats. Our results indicated that ketamine treatment (25 mg/kg, for 8 days) induced hyperlocomotion in the open-field test and oxidative damage in prefrontal cortex (PFC) and hippocampus (HP), evaluated by increased lipid peroxidation and decreased total thiol content. Moreover, ketamine treatment reduced the activity of the antioxidant enzymes superoxide dismutase and catalase in the HP. Pretreatment of rats with curcumin (20 and 50 mg/kg, for 14 days) or with lithium chloride (45 mg/kg, positive control) prevented behavioral and pro-oxidant effects induced by ketamine. These findings suggest that curcumin might be a good compound for preventive intervention in BD, reducing the episode relapse and the oxidative damage associated with the manic phase of this disorder.

Curcumin conjugated silica nanoparticles for improving bioavailability and its anticancer applications

Curcumin, a yellow bioactive component of Indian spice turmeric, is known to have a wide spectrum of biological applications. In spite of various astounding therapeutic properties, it lacks in bioavailability mainly due to its poor solubility in water. In this work, we have conjugated curcumin with silica nanoparticles to improve its aqueous solubility and hence to make it more bioavailable. Conjugation and loading of curcumin with silica nanoparticles was further examined with transmission electron microscope (TEM) and thermogravimetric analyzer. Cytotoxicity analysis of synthesized silica:curcumin conjugate was studied against HeLa cell lines as well as normal fibroblast cell lines. This study shows that silica:curcumin conjugate has great potential for anticancer application.