Studies

Click on the circles above for information on each health topic

Curcumin and major depression: A randomised, double-blind, placebo-controlled trial investigating the potential of peripheral biomarkers to predict treatment response and antidepressant mechanisms of change

A recent randomised, double-blind, placebo controlled study conducted by our research group, provided partial support for the efficacy of supplementation with a patented curcumin extract (500 mg, twice daily) for 8 weeks in reducing depressive symptoms in people with major depressive disorder. In the present paper, a secondary, exploratory analysis of salivary, urinary and blood biomarkers collected during this study was conducted to identify potential antidepressant mechanisms of action of curcumin. Pre and post-intervention samples were provided by 50 participants diagnosed with major depressive disorder, and the Inventory of Depressive Symptomatology self-rated version (IDS-SR30) was used as the primary depression outcome measure. Compared to placebo, 8 weeks of curcumin supplementation was associated with elevations in urinary thromboxane B2 (p<0.05), and substance P (p<0.001); while placebo supplementation was associated with reductions in aldosterone (p<0.05) and cortisol (p<0.05). Higher baseline plasma endothelin-1 (rs=-0.587; p<0.01) and leptin (rs=-0.470; p<0.05) in curcumin-treated individuals was associated with greater reductions in IDS-SR30 score after 8 weeks of treatment. Our findings demonstrate that curcumin supplementation influences several biomarkers that may be associated with its antidepressant mechanisms of action. Plasma concentrations of leptin and endothelin-1 seem to have particular relevance to treatment outcome. Further investigations using larger samples sizes are required to elucidate these findings, as the multiple statistical comparisons completed in this study increased the risk of type I errors.

Source: Lopresti AL, Maes M, Meddens MJ, Maker GL, Arnoldussen E, Drummond PD.
View Study

Efficacy and Safety of Curcumin in Major Depressive Disorder: A Randomized Controlled Trial.

Curcumin, an active ingredient of Curcuma longa Linn (Zingiberaceae), has shown potential antidepressant-like activity in animal studies. The objectives of this trial were to compare the efficacy and safety of curcumin with fluoxetine in patients with major depressive disorder (MDD). Herein, 60 patients diagnosed with MDD were randomized in a 1:1:1 ratio for six weeks observer-masked treatment with fluoxetine (20 mg) and curcumin (1000 mg) individually or their combination. The primary efficacy variable was response rates according to Hamilton Depression Rating Scale, 17-item version (HAM-D17 ). The secondary efficacy variable was the mean change in HAM-D17 score after six weeks. We observed that curcumin was well tolerated by all the patients. The proportion of responders as measured by the HAM-D17 scale was higher in the combination group (77.8%) than in the fluoxetine (64.7%) and the curcumin (62.5%) groups; however, these data were not statistically significant (P = 0.58). Interestingly, the mean change in HAM-D17 score at the end of six weeks was comparable in all three groups (P = 0.77). This study provides first clinical evidence that curcumin may be used as an effective and safe modality for treatment in patients with MDD without concurrent suicidal ideation or other psychotic disorders.

Source: Sanmukhani J, Satodia V, Trivedi J, Patel T, Tiwari D, Panchal B, Goel A, Tripathi CB. Phytother Res. 2013 Jul 6. doi: 10.1002/ptr.5025.

 

Antidepressant effects of curcumin in the forced swim test and olfactory bulbectomy models of depression in rats.

 

Curcuma longa is a major constituent of Xiaoyao-san, the traditional Chinese medicinal formula, which has been used to effectively manage stress and depression-related disorders in China. Curcumin is the active component of curcuma longa, and we hypothesized that curcumin would have an influence on depressive-like behaviors. The purpose of the present study was to confirm the putative antidepressant effect of chronic administrations of curcumin (1.25, 2.5, 5 and 10 mg/kg, p.o.) in the forced swimming test and bilateral olfactory bulbectomy (OB) models of depression in rats. In the first study, chronic treatment with curcumin (14 days) reduced the immobility time in the forced swimming test. In the second experiment, curcumin reversed the OB-induced behavioral abnormalities such as hyperactivity in the open field, as well as deficits in step-down passive avoidance. In addition, OB-induced low levels of serotonin (5-HT), noradrenaline (NA), high 5-hydroxyindoleacetic acid (5-HIAA) and 4-dihydroxyphenylacetic acid (DOPAC) in the hippocampus were observed, and were completely reversed by curcumin administration. A slight decrease in 5-HT, NA and dopamine (DA) levels was found in the frontal cortex of OB rats which was also reversed by curcumin treatment. These results confirm the antidepressant effects of curcumin in the forced swim and the OB models of depression in rats, and suggest that these antidepressant effects may be mediated by actions in the central monoaminergic neurotransmitter systems.

Source: Xu Y, Ku BS, Yao HY, Lin YH, Ma X, Zhang YH, Li XJ. Pharmacol Biochem Behav. 2005;82(1):200-6.

 

Potentials of curcumin as an antidepressant.

Major depression, a debilitating psychiatric disorder, is predicted to be the second most prevalent human illness by the year 2020. Various antidepressants, ranging from monoamine oxidase inhibitors to recently developed dual reuptake inhibitors, are prescribed for alleviating the symptoms of depression. Despite the availability of these blockbuster molecules, approximately 30% of depressed patients do not respond to the existing drug therapies and the remaining 70% fails to achieve complete remission. Moreover, antidepressants are associated with a plethora of side effects and drug-drug/drug-food interactions. In this context, novel approaches are being tried to find more efficacious and safer drugs for the treatment of major depression. Curcumin is one such molecule that has shown promising efficacy in various animal models of major depression. Although the mechanism of the antidepressant effect of curcumin is not fully understood, it is hypothesized to act through inhibiting the monoamine oxidase enzyme and modulating the release of serotonin and dopamine. Moreover, evidences have shown that curcumin enhances neurogenesis, notably in the frontal cortex and hippocampal regions of the brain. The use of curcumin in clinics for the treatment of major depression is limited due to its poor gastrointestinal absorption. The present review attempts to discuss the pharmacological profile along with molecular mechanisms of the antidepressant effect of curcumin in animal models of depression. A need for clinical trials in order to explore the antidepressant efficacy and safety profile of curcumin is emphasized.

Source: Kulkarni S, Dhir A, Akula KK. Scientific World Journal. 2009;9:1233-41.

 

Antidepressant-like effects of curcumin on serotonergic receptor-coupled AC-cAMP pathway in chronic unpredictable mild stress of rats.

Serotonergic receptors take their physiologic effects by affecting adenylyl cyclase (AC) catalytic activity and cyclic adenosine monophosphate (cAMP) concentration. AC-cAMP second messenger pathway has been recently suggested to play an important role in depression. Therefore, the compound that regulates the signal pathway may have potential as antidepressant. Curcumin is the main component of Curcuma longa L, a well-known indigenous herb with comprehensive bioactivities. In the present study, we investigated the effects of chronic unpredictable mild stress (CUMS) and curcumin on behaviours and serotonergic receptor-coupled AC-cAMP signal pathway in rats. Curcumin produced beneficial effects on the stressed rats by effectively improving CUMS-induced low sucrose consumption and reducing serum corticosterone levels in rats. Moreover, curcumin enhanced AC activity and cAMP levels in platelet and various brain regions, and up-regulated mRNA expressions of AC subtypes AC 2, AC 8 and cAMP response element binding protein (CREB) in the hippocampus, cortex and hypothalamus of the CUMS rats. Curcumin also attenuated CUMS-induced reductions of 5-hydroxytryptamine (5-HT) levels and high expressions of central 5-HT(1A/1B/7) receptors in rats. These results suggested that the potent antidepressant property of curcumin might be attributed to its improvement of AC-cAMP pathway as well as CREB via suppressing central 5-HT(1A/1B/7) receptors in the CUMS rats. Our findings provided a basis for examining the interaction of serotonergic receptors and AC-cAMP pathway in depression and curcumin treatment.

Source:  Li YC, Wang FM, Pan Y, Qiang LQ, Cheng G, Zhang WY, Kong LD. Prog Neuropsychopharmacol Biol Psychiatry. 2009;33(3):435-49.

 

Evaluation of antidepressant like activity of curcumin and its combination with fluoxetine and imipramine: an acute and chronic study.

Curcumin is the active ingredient of commonly used spice Curuma longa Linn. In the present study, the antidepressant like activity of curcumin and its combination with fluoxetine and imipramine was studied in acute model (three doses 24, 5 and 1 h before test) of forced swimming test (FST) in glass jar and tail suspension test (TST) in mice and in chronic model (14 day study) of FST with water wheel in rats. All the tests were carried out in the following seven groups (n = 6 in each group), drugs being given orally (doses for mice): Group 1 (vehicle), group 2 (curcumin 50 mg/kg), group 3 (curcumin 100 mg/kg), group 4 (fluoxetine 20 mg/kg), group 5 (imipramine 15 mg/kg), group 6 (curcumin 100 mg/kg plus fluoxetine 20 mg/kg) and group 7 (curcumin 100 mg/kg plus imipramine 15 mg/kg). Equivalent doses for rats were used. Both the acute model of FST and TST, and the chronic model of FST with water wheel showed significant antidepressant like activity of curcumin in 100 mg/kg dose as compared to vehicle control (p < 0.05). The effect of curcumin (100 mg/kg) was similar to that of fluoxetine and imipramine (p > 0.05) but its addition to fluoxetine and imipramine did not improve their antidepressant activity (p > 0.05). Curcumin increased both the swimming and climbing behavior in FST, thus its antidepressant like activity could be due to an increase in serotonin, norepinephrine and dopamine levels in the brain. Curcumin can be a useful antidepressant especially in cases which respond to drugs having mixed effects on serotonin and catecholamines levels in the brain.

Source: Sanmukhani J, Anovadiya A, Tripathi CB. Acta Pol Pharm. 2011 Sep-Oct;68(5):769-75.