Effect of a water extract of Curcuma longa on emotional states in healthy participants

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.

Curcuma longa extract reduces serum inflammatory markers and postprandial hyperglycemia in healthy but borderline participants with overweight and glycemia in the normal/prediabetes range: a randomized, double-blind, and placebo-controlled trial

The spice turmeric, which has the Latin name Curcuma longa (C. longa), has various physiological effects. This study evaluated the effects of a hot water mixture with supercritical carbon dioxide C. longa extracts, CLE, and the potential active components of C. longa, turmeronols A and B and bisacurone on inflammation and glucose metabolism. First, we investigated the effect of CLE and the potential active components of C. longa on lipopolysaccharide-induced inflammation in RAW264.7 macrophages. We found a significant decrease in the production of interleukin (IL)-1β, IL-6, tumor necrosis factor (TNF)-α, and nitric oxide with CLE, turmeronol A, and bisacurone, Significant inhibition of each of these substances was also observed, except for TNF-α with turmeronol B. The second part of our work was a 12-week randomized, double-blind, placebo-controlled study in healthy but borderline adults aged 40 to 69 years with overweight and normal/prediabetes glycemia. We compared blood inflammatory and glycometabolic markers in the CLE (n = 55) and placebo groups (n = 55). We found significantly lower serum high-sensitivity C-reactive protein and hemoglobin A1c levels in the CLE group. This group also showed significant improvements in postprandial hyperglycemia and insulin sensitivity indices. Our findings indicate that CLE may reduce low-grade inflammation and thus improve insulin sensitivity and postprandial hyperglycemia. Clinical trial registration: https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000051492, UMIN-CTR, UMIN000045106.

Turmeronols (A and B) from Curcuma longa have anti-inflammatory effects in lipopolysaccharide-stimulated BV-2 microglial cells by reducing NF-κB signaling

Turmeronols (A and B), bisabolane-type sesquiterpenoids found in turmeric, reduce inflammation outside the brain in animals; however, their effects on neuroinflammation, a common pathology of various neurodegenerative diseases, are not understood. Inflammatory mediators produced by microglial cells play a key role in neuroinflammation, so this study evaluated the anti-inflammatory effects of turmeronols in BV-2 microglial cells stimulated with lipopolysaccharide (LPS). Pretreatment with turmeronol A or B significantly inhibited LPS-induced nitric oxide (NO) production; mRNA expression of inducible NO synthase; production of interleukin (IL)-1β, IL-6, and tumor necrosis factor α and upregulation of their mRNA expression; phosphorylation of nuclear factor-κB (NF-κB) p65 proteins and inhibitor of NF-κB kinase (IKK); and nuclear translocation of NF-κB. These results suggest that these turmeronols may prevent the production of inflammatory mediators by inhibiting the IKK/NF-κB signaling pathway in activated microglial cells and can potentially treat neuroinflammation associated with microglial activation.

A Hot Water Extract of Curcuma longa L. Improves Fasting Serum Glucose Levels in Participants with Low-Grade Inflammation: Reanalysis of Data from Two Randomized, Double-Blind, Placebo-Controlled Trials

The dietary spice Curcuma longa L. (C. longa), also known as turmeric, has various biological effects. A hot water extract of C. longa was shown to have anti-inflammatory activities in preclinical and clinical studies. Chronic low-grade inflammation is associated with the disruption of glucose homeostasis, but the effect of C. longa extract on glucose metabolism in humans is poorly understood. Therefore, we investigated the effect of C. longa extracts on serum glucose levels in the presence of low-grade inflammation. We reanalyzed our published data from two randomized, double-blind, placebo-controlled trials in overweight participants aged 50 to 69 years and performed a stratified analysis using the inflammatory marker high-sensitivity C-reactive protein (hsCRP). In both studies, participants took a test food with a hot water extract of C. longa (C. longa extract group, n = 45 per study) or without C. longa extract (placebo group, n = 45 per study) daily for 12 weeks, and we measured the levels of serum hsCRP and fasting serum glucose. The mean baseline hsCRP value was used to stratify participants into two subgroups: a low-hsCRP subgroup (baseline mean hsCRP < 0.098 mg/dL) and a high-hsCRP subgroup (baseline mean hsCRP ≥ 0.098 mg/dL). In the low-hsCRP subgroup, we found no significant difference in fasting serum glucose levels between the two groups in either study, but in the high-hsCRP subgroup, the C. longa extract group had significantly lower levels of serum hsCRP (p < 0.05) and fasting serum glucose (p < 0.05) than the placebo group in both studies. In conclusion, a hot water extract of C. longa may help to improve systemic glucose metabolism in people with chronic low-grade inflammation.

Hot Water Extract of Curcuma longa L. Improves Serum Inflammatory Markers and General Health in Subjects with Overweight or Prehypertension/Mild Hypertension: A Randomized, Double-Blind, Placebo-Controlled Trial

To investigate the effect of a hot water extract of C. longa L. (WEC) containing anti-inflammatory agents, bisacurone, and turmeronol on chronic inflammation, a randomized double-blind placebo-controlled study was conducted in middle-aged and elderly subjects aged 50–69 years with overweight or prehypertension/mild hypertension. The subjects consumed 900 mg WEC tablets, containing 400 μg bisacurone, 80 μg turmeronol A and 20 μg turmeronol B (WEC group: n = 45), or placebo tablets without WEC (placebo group: n = 45) daily for 12 weeks. Serum inflammatory and metabolic markers were measured. The subjects also completed the MOS 36-item short-form health survey (SF-36) and the Profile of Mood States scale (POMS). In the WEC group, the serum levels of C-reactive protein, tumor necrosis factor-α, interleukin-6, and soluble vascular cell adhesion molecule-1 decreased significantly. Compared with the placebo group, the WEC group had significantly lower serum levels of glucose, hemoglobin A1c, and triglycerides, as well as higher serum levels of high-density lipoprotein cholesterol. The WEC group also showed significant improvement of SF-36 scores (for general health, vitality, mental health, and mental summary component) and POMS scores for positive mood states (vigor-activity and friendliness). In conclusion, WEC may ameliorate chronic low-grade inflammation, thus contributing to the improvement of associated metabolic disorders and general health.

Increase in subjective well-being and psychological health after application of C8-silk lipoamino acid functionalized pigments included in a foundation

OBJECTIVE

The aim of this study was to evaluate the effects of two foundations before (D0) and after 5 days of application (D6) on psychophysiological parameters in order to compare C8-silk lipoamino acid functionalized pigments (FA) versus pure pigments (FP).

METHODS

Assessment of self-esteem, stress, mood and emotion using psychological tests and evaluation of salivary cortisol concentrations were realized on 40 healthy females using a crossover study design at D0 and D6. Four saliva samples were taken on the awakening (C1), 30 min after the awakening (during the foundation application (C2)), 1 h after the foundation application (C3) and at 1900 h (C4) at DO and D6. Area under the curve was calculated in order to obtain information about the total amount of a given substance excreted in a specific time period.

RESULTS

Five days of daily application of the foundation containing the pigments treated with the C8-silk lipoamino acids induced a significant increase (P < 0.001) in self-esteem and pleasant emotion (P < 0.05), and a significant decrease in general stress (P < 0.05). This was not the case after the FP application. Cortisol concentrations presented a pronounced diurnal rhythm whatever the foundation used. At DO, no significant differences were observed between the groups. At D6, cortisol concentrations measured 30 min and 1 h after the FA application were significantly lower (P < 0.05: C6.2, P < 0.05 C6.3, respectively) than those reported after FP application. AUC, a global stress response indicator, was significantly lower in FA group as compared to FP group after 5 days of application. Subjects found a decrease in tiredness signs and thought that FA has a good coverage.

CONCLUSION

Our results show that incorporation of C8-silk lipoamino acid as agent of pigment functionalization brings new benefits to a foundation. Adopting a psychophysiological approach, which is not invasive to the subjects, we show the measurement of cortisol at the same time that psychological indicators provide a scientific approach to examine the beneficial effects of a cosmetic product.