Korean Curcuma longa L. induces lipolysis and regulates leptin in adipocyte cells and rats

The effect of curcumin supplementation on circulating adiponectin and leptin concentration in adults: a GRADE-assessed systematic review and meta-analysis of randomised controlled trials

Curcumin is a phytocompound found in the root of turmeric, a common herbal ingredient in many Asian cuisines. The compound contains anti-inflammatory activity, which is mediated through an upregulation of adiponectin and reduction of leptin. Results of randomised controlled trials (RCT) have shown that the effects of curcumin on adipokines are conflicting. Therefore, the current systematic review and meta-analysis of RCT were conducted with the aim of elucidating the role of curcumin supplementation on serum adiponectin and leptin. The search included PubMed, Embase, Cochrane Library, Scopus, Web of Science and Google Scholar from inception to August 2023. For net changes in adipokines, standardised mean differences (SMD) were calculated using random effects models. Thirteen RCT with fourteen treatment arms were eligible for inclusion in this meta-analysis. Curcumin supplementation was effective in increasing serum adiponectin (SMD = 0·86, 95 % CI (0·33, 1·39), P < 0·001; I2 = 93·1 %, P < 0·001) and reducing serum leptin (SMD = -1·42, 95 % CI (-2·29, -0·54), P < 0·001; I2 = 94·7 %, P < 0·001). In conclusion, curcumin supplementation significantly increased circulating adiponectin and decreased leptin levels in adults.

Hydroxylated polymethoxyflavones reduce the activity of pancreatic lipase, inhibit adipogenesis and enhance lipolysis in 3T3-L1 mouse embryonic fibroblast cells

Hydroxylated polymethoxyflavones (HPMFs) have been shown to possess various anti-disease effects, including against obesity. This study investigates the anti-obesity effects of HPMFs in further detail, aiming to gain understanding of their mechanism of action in this context. The current study demonstrates that two HPMFs; 3'-hydroxy-5,7,4',5'-tetramethoxyflavone (3'OH-TetMF) and 4'-hydroxy-5,7,3',5'-tetramethoxyflavone (4'OH-TetMF) possess anti-obesity effects. They both significantly reduced pancreatic lipase activity in a competitive manner as demonstrated by molecular docking and kinetic studies. In cell studies, it was revealed that both of the HPMFs suppress differentiation of 3T3-L1 mouse embryonic fibroblast cells during the early stages of adipogenesis. They also reduced expression of key adipogenic and lipogenic marker genes, namely peroxisome proliferator-activated receptor-gamma (PPAR-γ), CCAAT/enhancer-binding protein α and β (C/EBP α and β), adipocyte binding protein 2 (aP2), fatty acid synthase (FASN), and sterol regulatory element-binding protein 1 (SREBF 1). They also enhanced the expression of cell cycle genes, i.e., cyclin D1 (CCND1) and C-Myc, and reduced cyclin A2 expression. When further investigated, it was also observed that these HPMFs accelerate lipid breakdown (lipolysis) and enhance lipolytic gene expression. Moreover, they also reduced the secretion of proteins (adipokines), including pro-inflammatory cytokines, from mature adipocytes. Taken together, this study concludes that these HPMFs have anti-obesity effects, which are worthy of further investigation.

The Effects of Antioxidants from Natural Products on Obesity, Dyslipidemia, Diabetes and Their Molecular Signaling Mechanism

Obesity is a risk factor that leads to the development of other diseases such as dyslipidemia and diabetes. These three metabolic disorders can occur simultaneously, hence, the treatment requires many drugs. Antioxidant compounds have been reported to have activities against obesity, dyslipidemia and diabetes via several mechanisms. This review aims to discuss the antioxidant compounds that have activity against obesity, dyslipidemia and diabetes together with their molecular signaling mechanism. The literature discussed in this review was obtained from the PUBMED database. Based on the collection of literature obtained, antioxidant compounds having activity against the three disorders (obesity, dyslipidemia and diabetes) were identified. The activity is supported by various molecular signaling pathways that are influenced by these antioxidant compounds, further study of which would be useful in predicting drug targets for a more optimal effect. This review provides insights on utilizing one of these antioxidant compounds as opposed to several drugs. It is hoped that in the future, the number of drugs in treating obesity, dyslipidemia and diabetes altogether can be minimized consequently reducing the risk of side effects.

The Multifaceted Actions of Curcumin in Obesity

Obesity remains a pervasive health concern worldwide with concomitant comorbidities such as cardiovascular diseases, diabetes, inflammation, and other metabolic disorders. A wealth of data validates dietary and lifestyle modifications such as restricting caloric intake and increasing physical activity to slow the obesity development. Recently, the advent of phytochemicals such as curcumin, the active ingredient in turmeric, has attracted considerable research interest in tracking down their possible effects in protection against obesity and obesity-related comorbidities. According to the existing literature, curcumin may regulate lipid metabolism and suppress chronic inflammation interacting with white adipose tissue, which plays a central role in the complications associated with obesity. Curcumin also inhibits the differentiation of adipocyte and improves antioxidant properties. In the present review, we sought to deliberate the possible effects of curcumin in downregulating obesity and curtailing the adverse health effects of obesity.

Curcuma longa extract improves serum inflammatory markers and mental health in healthy participants who are overweight: a randomized, double-blind, placebo-controlled trial

Background

The dietary spice Curcuma longa, also known as turmeric, has various biological effects. Both a water extract and a supercritical carbon dioxide extract of C. longa showed anti-inflammatory activities in animal studies. However, the anti-inflammatory effect in humans of a mixture of these two C. longa extracts (CLE) is poorly understood. Therefore, we investigated the effect of CLE containing anti-inflammatory turmeronols on chronic inflammation and general health.

Methods

We performed a randomized, double-blind, placebo-controlled study in healthy subjects aged 50 to 69 years with overweight. Participants took two capsules containing CLE (CLE group, n = 45) or two placebo capsules (placebo group, n = 45) daily for 12 weeks, and serum inflammatory markers were measured. Participants also completed two questionnaires: the Medical Outcomes Study (MOS) 36-Item Short-Form Health Survey (SF-36) and the Profile of Mood States (POMS) scale. Treatment effects were analyzed by two way analysis of variance followed by a t test (significance level, p <  0.05).

Results

After the intervention, the CLE group had a significantly lower body weight (p <  0.05) and body mass index (p < 0.05) than the placebo group and significantly lower serum levels of C-reactive protein (p < 0.05) and complement component 3 (p < 0.05). In addition, the CLE group showed significant improvement of the MOS SF-36 mental health score (p < 0.05) and POMS anger-hostility score (p < 0.05).

Conclusion

CLE may ameliorate chronic low-grade inflammation and thus help to improve mental health and mood disturbance.

Trial registration

UMIN-CTR, UMIN000037370. Registered 14 July 2019, https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000042607

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-021-00748-8.

Amber Extract Reduces Lipid Content in Mature 3T3-L1 Adipocytes by Activating the Lipolysis Pathway

Amber-the fossilized resin of trees-is rich in terpenoids and rosin acids. The physiological effects, such as antipyretic, sedative, and anti-inflammatory, were used in traditional medicine. This study aims to clarify the physiological effects of amber extract on lipid metabolism in mouse 3T3-L1 cells. Mature adipocytes are used to evaluate the effect of amber extract on lipolysis by measuring the triglyceride content, glucose uptake, glycerol release, and lipolysis-related gene expression. Our results show that the amount of triacylglycerol, which is stored in lipid droplets in mature adipocytes, decreases following 96 h of treatment with different concentrations of amber extract. Amber extract treatment also decreases glucose uptake and increases the release of glycerol from the cells. Moreover, amber extract increases the expression of lipolysis-related genes encoding perilipin and hormone-sensitive lipase (HSL) and promotes the activity of HSL (by increasing HSL phosphorylation). Amber extract treatment also regulates the expression of other adipocytokines in mature adipocytes, such as adiponectin and leptin. Overall, our results indicate that amber extract increases the expression of lipolysis-related genes to induce lipolysis in 3T3-L1 cells, highlighting its potential for treating various obesity-related diseases.

The Anti-Obesity Effect of Traditional Chinese Medicine on Lipid Metabolism

With the improvement of living conditions and the popularity of unhealthy eating and living habits, obesity is becoming a global epidemic. Obesity is now recognized as a disease that not only increases the risk of metabolic diseases such as type 2 diabetes (T2D), non-alcoholic fatty liver disease (NAFLD), cardiovascular disease (CVD), and cancer but also negatively affects longevity and the quality of life. The traditional Chinese medicines (TCMs) are highly enriched in bioactive compounds and have been used for the treatment of obesity and obesity-related metabolic diseases over a long period of time. In this review, we selected the most commonly used anti-obesity or anti-hyperlipidemia TCMs and, where known, their major bioactive compounds. We then summarized their multi-target molecular mechanisms, specifically focusing on lipid metabolism, including the modulation of lipid absorption, reduction of lipid synthesis, and increase of lipid decomposition and lipid transportation, as well as the regulation of appetite. This review produces a current and comprehensive understanding of integrative and systematic mechanisms for the use of TCMs for anti-obesity. We also advocate taking advantage of TCMs as another therapy for interventions on obesity-related diseases, as well as stressing the fact that more is needed to be done, scientifically, to determine the active compounds and modes of action of the TCMs.

Curcumin Attenuates Sarcopenia in Chronic Forced Exercise Executed Aged Mice by Regulating Muscle Degradation and Protein Synthesis with Antioxidant and Anti-inflammatory Effects

The aim of the current study is to investigate the effects of spray dry powders of Curcuma longa containing 40% curcumin (CM-SD), as a new aqueous curcumin formula, on sarcopenia in chronic forced exercise executed 10 month old ICR mice. CM-SD (80 and 40 mg/kg) increased calf thicknesses and strengths, total body and calf protein amounts, and muscle weights in both gastrocnemius and soleus muscles. mRNA expressions regarding muscle growth and protein synthesis were induced, while those of muscle degradation significantly declined in CM-SD treatment. CM-SD decreased serum biochemical markers, lipid peroxidation, and reactive oxygen species and increased endogenous antioxidants and enzyme activities. It also reduced immunoreactive myofibers for apoptosis and oxidative stress markers but increased ATPase in myofibers. These results suggest that CM-SD can be an adjunct therapy to exercise-based remedy that prevents muscle disorders including sarcopenia by anti-apoptosis, anti-inflammation, and antioxidation-mediated modulation of gene expressions related to muscle degradation and protein synthesis.

Curcumin Ameliorated Oxidative Stress and Inflammation-Related Muscle Disorders in C2C12 Myoblast Cells

The purpose of the current study was to investigate antioxidant and anti-inflammatory effects of spray dry powder containing 40% curcumin (CM-SD) in C2C12 myoblast cells. CM-SD increased DPPH radical scavenging activity in a dose-dependent manner, and up to 30 μg/mL of CM-SD did not express cytotoxicity in C2C12 cells. Exposure to hydrogen peroxide (H2O2) drastically decreased the viability of C2C12 cells, but pre-treatment of CM-SD significantly increased the cell viability (p < 0.01). CM-SD significantly transactivated the nuclear factor erythroid-2-related factor 2 (Nrf2)-dependent luciferase activity in a dose-dependent manner and enhanced the levels of heme oxygenase (HO)-1, glutamate cysteine ligase catalytic subunit (GCLC), and NAD(P)H-dependent quinone oxidoreductase (NQO)-1. CM-SD also significantly reduced reactive oxygen species (ROS) production and lipid peroxidation and restored glutathione (GSH) depletion in H2O2-treated C2C12 cells. Moreover, CM-SD significantly reduced lipopolysaccharides (LPS)-mediated interleukin (IL)-6 production in the conditioned medium. Results from the current study suggest that CM-SD could be a useful candidate against oxidative stress and inflammation-related muscle disorders.

HM-chromanone inhibits adipogenesis by regulating adipogenic transcription factors and AMPK in 3T3-L1 adipocytes

Portulaca oleracea L. is used as a folk medicine in many countries because of its wide range of pharmacological effects. HM-chromanone, isolated from P. oleracea using bioassay-guided fractionation and HPLC, belongs to the homoisoflavonoid group and has been shown to exert several biological effects. In this study, we evaluated whether HM-chromanone inhibits adipogenesis by regulating adipogenic transcription factors in 3T3-L1 adipocytes. The results showed that HM-chromanone suppresses adipocyte differentiation and adipogenesis in a dose-dependent manner in 3T3-L1 adipocytes. The HM-chromanone-treated adipocytes exhibited lower triglyceride accumulation and leptin secretion, and higher glycerol and adiponectin secretion than the control adipocytes. Microscopic observation using oil red O staining revealed a dose-dependent reduction in the number of lipid droplets in the HM-chromanone-treated adipocytes compared to the control group. HM-chromanone significantly down-regulated the protein expression of major adipogenic transcription factors sterol regulatory element binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor γ (PPARγ), and CCAAT/enhancer binding protein α (C/EBPα) and markedly inhibited several key adipogenic enzymes including fatty acid synthase (FAS) and acetyl-CoA carboxylase (ACC). In addition, adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL) were both more activated in the HM-chromanone-treated adipocytes than in the control adipocytes. HM-chromanone also promoted the phosphorylation of 5' Adenosine monophosphate-activated protein kinase (AMPK), which inhibits adipogenesis through the regulation of adipogenic transcription factors. These results suggest that HM-chromanone may be an effective anti-adipogenesis agent that functions via the suppression of adipogenic transcription factors and the activation of AMPK.

Antidiabetic Properties of Curcumin I: Evidence from In Vitro Studies

Type 2 diabetes mellitus (T2DM) is a growing metabolic disease characterized by insulin resistance and hyperglycemia. Current preventative and treatment strategies for T2DM and insulin resistance lack in efficacy resulting in the need for new approaches to prevent and manage/treat the disease better. In recent years, epidemiological studies have suggested that diets rich in fruits and vegetables have beneficial health effects including protection against insulin resistance and T2DM. Curcumin, a polyphenol found in turmeric, and curcuminoids have been reported to have antioxidant, anti-inflammatory, hepatoprotective, nephroprotective, neuroprotective, immunomodulatory and antidiabetic properties. The current review (I of II) summarizes the existing in vitro studies examining the antidiabetic effects of curcumin, while a second (II of II) review summarizes evidence from existing in vivo animal studies and clinical trials focusing on curcumin’s antidiabetic properties.

Polar Curcuma longa extract inhibits leptin release by adipose tissue derived from overweight and obese people

Obesity escalates at an alarming rate worldwide. It is associated with chronic low-grade inflammation, which is implicated in the pathogenesis of type 2 diabetes and cardiovascular diseases. Adipose tissue is a primary site of obesity-induced pro-inflammatory factors such as leptin. Curcuminoids are potent anti-inflammatory agents; however, evidence on the polar fraction of Curcuma longa is scarce and the effect on leptin release has never been investigated. Therefore, we will investigate the influence of aqueous C. longa extract on leptin release from human subcutaneous adipose tissue (SAT). To achieve this, SAT explants were obtained from patients who underwent abdominal surgery. Patients were both males (67%) and females (33%). Their average body mass index (BMI) and age were 33.4 kg/m2 and 43 years, respectively. Tissue explants were treated in triplicate with or without 0.1 and 1 mg/mL aqueous C. longa extracts and incubated for 24 and 48 h. Enzyme-linked immunosorbent assay (ELISA) was used to determine the concentration of leptin secreted by SAT. We have shown that 24 h treatment of SAT with 0.1 and 1 mg/mL of C. longa polar extract inhibited the release of leptin, while 48 h treatment of SAT with only 1 mg/mL of C. longa polar extract inhibited leptin release. Concentration of basal leptin released from SAT derived from females was higher than from males. However, this could be because females were morbidly obese. Our data demonstrate for the first time the inhibitory effect of aqueous C. longa extract on leptin release, shedding light on the role of leptin and adipose tissue in the mechanism of C. longa in reducing low-grade inflammation. This avoids the poor solubility and consequently the low bioavailability disadvantages of curcuminoids.