Turmeric / curcumin and health outcomes: A meta-review of systematic reviews

From the kitchen to the medicine cabinet: Examples of functional herbs and spices

In many cultures, "food as medicine" has existed for centuries as the foundation of health. It is a practice built on the knowledge that food and diet play important roles in disease prevention and management. Foods possessing therapeutic properties are often referred to as functional foods. Many herbs and spices contain numerous nutritional and non-nutritional components that can interact with pharmacologically relevant receptors, either directly or indirectly via their metabolites, to regulate cellular biochemical processes. Although opinions are changing, the concept of food as a therapeutic intervention goes against conventional Western medicine. To provide guidance to clinicians interested in using these products, members of the Food as Medicine working group of the Nutrition Committee NASPGHAN, as part of a two-part review series, have identified frequently used foods, supplements, herbs, and spices that are utilized for therapeutic intent and have created summaries of commonly used indications, doses, and caveats. In this review, the focus is the use of select herbs and spices for medicinal purposes. Gaps in our knowledge in how to effectively use these agents in pediatric patients are discussed. Evidence supporting their use for management of gastrointestinal conditions, especially in the pediatric population, is provided when available. Circumstances in clinical settings and patient indications may require actions different from those recommended in this review and professional judgment should prevail.

Protective effects of curcumin against spinal cord injury

Background

In parallel with population aging, the prevalence of neurological and neurodegenerative diseases has been dramatically increasing over the past few decades. Neurodegenerative diseases reduce the quality of life of patients and impose a high cost on the health system. These slowly progressive diseases can cause functional, perceptual, and behavioral deficits in patients. Therefore, neurodegenerative impairments have always been an interesting subject for scientists and clinicians. One of these diseases is spinal cord injury (SCI). SCI can lead to irreversible damage and is classified into two main subtypes: traumatic and non-traumatic, each with very different pathophysiological features.

Aims

This review aims to gather relevant information about the beneficial effects of curcumin (Cur), with specific emphasis on its anti-inflammatory properties towards spinal cord injury (SCI) patients.

Materials & Methods

The review collates data from extensive in-vitro, in-vivo, and clinical trials documenting the effects of CUR on SCI. It examines the modulation of pathophysiological pathways and regulation of the inflammatory cascades after CUR administration.

Results

Various pathophysiological processes involving the nuclear factor erythroid 2-related factor 2 (Nrf2), nuclear factor kappa B (NF-kB), and transforming growth factor beta (TGF-β) signaling pathways have been suggested to exacerbate damages resulting from SCI. CUR administration showed to modulate these signaling pathways which lead to attenuation of SCI complications.

Discussion

Anti-inflammatory compounds, particularly CUR, can modulate these pathophysiological pathways and regulate the inflammatory cascades. CUR, a well-known natural product with significant anti-inflammatory effects, has been extensively documented in experimental and clinical trials.

Conclusion

Curcumin's potential to alter key steps in the Nrf2, NF-kB, and TGF-β signaling pathways suggests that it may play a role in attenuating SCI complications.

Consumption of dietary turmeric promotes fat browning and thermogenesis in association with gut microbiota regulation in high-fat diet-fed mice

This study was designed to verify the anti-obesity effect of dietary turmeric powder (TP) as a traditional cooking spice and its underlying mechanism. The HFD-fed C57BL/6J mice were supplemented with or without TP (8%) for 12 weeks. The results indicated that the glucolipid metabolism disorder of high-fat diet (HFD)-fed mice was significantly ameliorated through the supplementation of TP. The consumption of TP also induced beige-fat development and brown adipose tissue (BAT)-derived nonshivering thermogenesis in HFD-fed obese mice. 16S rDNA-based microbiota or targeted metabolomics analysis indicated that TP ameliorated the intestinal microbiota dysbiosis and microbial metabolism abnormality caused by HFD, reflected by dramatically increasing the relative abundance of Muribaculaceae, Candidatus_Saccharimonas, and Bifidobacterium and production of short-chain fatty acids (SCFAs) and succinate. Interestingly, TP-induced BAT thermogenesis and iWAT browning were highly correlated with the reconstruction of the gut microbiome and formation of SCFAs and succinate. Collectively, these findings manifest beneficial actions of TP on the promotion of adipose browning and thermogenesis in association with gut microbiota reconstruction, and our findings may provide a promising way for preventing obesity.

Curcuminoid Contents in Rhizomes of Some Zingiberaceous Plants Sold via Online Platforms: Influence of Species and Cultivation Location

Zingiberaceous plants are versatile and find application in various fields, including food, medicine, and cosmetics. Recently, turmeric and other Zingiberaceous plants have become readily available through online platforms. However, the quality, specifically the curcuminoid content, has not been adequately assessed. In light of this issue, this study is aimed at analyzing the curcuminoid contents, including bisdemethoxycurcumin, demethoxycurcumin, and curcumin, using high-performance liquid chromatography. The analysis targets the rhizomes of Zingiber montanum (ZM), Curcuma aromatica (CA), Curcuma wanenlueanga (CW), Curcuma zedoaria (CZ), and sixteen Curcuma longa (CL) samples sold on online platforms. The influence of species and cultivation locations was evaluated, compared, and clustered. The results indicated that CL exhibited the highest curcuminoid contents, followed by CA, CZ, ZM, and CW, respectively. Curcumin was not detected in CW, while bisdemethoxycurcumin and demethoxycurcumin were absent in ZM. Cluster analysis revealed that CW was closely related to ZM, and CA was closely related to CZ, while CL was not closely related to either cluster. Among the sixteen CL samples, the most commonly found curcuminoids were curcumin, followed by bisdemethoxycurcumin and demethoxycurcumin, respectively. Three samples contained curcuminoid contents of less than 5%, failing to meet the standard level specified in the Thai Herbal Pharmacopoeia. Furthermore, ten samples had total curcuminoid contents higher than 10%, with three samples exceeding 15%. The top three samples with the highest total curcuminoid contents from different locations were as follows: Tha Yang District, Phetchaburi Province (17.02%); Phop Phra District, Tak Province (16.97%); and Pak Tho District, Ratchaburi Province (15.45%). Cluster analysis revealed that CL samples could be grouped into two major categories: low curcuminoid and high curcuminoid groups. This study offers valuable insights for consumers seeking high-quality rhizomes of Zingiberaceous plants with high curcuminoids, through online platforms. By focusing on the curcuminoid content, consumers can make informed decisions when purchasing Zingiberaceous plants online. This information not only aids in selecting superior quality rhizomes but also enhances the overall consumer experience by ensuring the potency and efficacy of the purchased products.

Turmeric and curcumin as adjuncts in controlling Helicobacter pylori-associated diseases: a narrative review

Non-antibiotic adjuncts may improve Helicobacter pylori infection control. Our aim was to emphasize curcumin benefits in controlling H. pylori infection. We discussed publications in English mostly published since 2020 using keyword search. Curcumin is the main bioactive substance in turmeric. Curcumin inhibited H. pylori growth, urease activity, three cag genes, and biofilms through dose- and strain-dependent activities. Curcumin also displayed numerous anticancer activities such as apoptosis induction, anti-inflammatory and anti-angiogenic effects, caspase-3 upregulation, Bax protein enhancement, p53 gene activation, and chemosensitization. Supplementing triple regimens, the agent increased H. pylori eradication success in three Iranian studies. Bioavailability was improved by liposomal preparations, lipid conjugates, electrospray-encapsulation, and nano-complexation with proteins. The agent was safe at doses of 0.5->4 g daily, the most common (in 16% of the users) adverse effect being gastrointestinal upset. Notably, curcumin favorably influences the intestinal microbiota and inhibits Clostridioides difficile. Previous reports showed the inhibitory effect of curcumin on H pylori growth. Curcumin may become an additive in the therapy of H. pylori infection, an adjunct for gastric cancer control, and an agent beneficial to the intestinal microbiota. Further examination is necessary to determine its optimal dosage, synergy with antibiotics, supplementation to various eradication regimens, and prophylactic potential.

Effects of curcumin/turmeric supplementation on the liver enzymes, lipid profiles, glycemic index, and anthropometric indices in non-alcoholic fatty liver patients: An umbrella meta-analysis

Non-alcoholic fatty liver disease (NAFLD) is one of the leading causes of chronic liver disease worldwide. The evidence for curcumin's effects on patients with NAFLD is accumulating; however, meta-analyses have reported mixed results. The current umbrella meta-analysis aimed to assess the present evidence and provide an accurate estimate of the overall effects of curcumin/turmeric on NAFLD patients. The Web of Science, Scopus, PubMed, ScienceDirect, and Google Scholar databases were searched till March 2023 using MeSH terms and related keywords based on the PICO criteria. Meta-analysis studies evaluating the effects of curcumin/turmeric supplementation on NAFLD patients that reported the effect sizes (ES) and corresponding confidence intervals (CI) were eligible for inclusion in this study. All articles were screened by considering the eligibility criteria by two independent reviewers and required data were extracted from the included meta-analyses. The meta-analysis was performed utilizing a random-effects model by STATA software. Findings of 11 meta-analyses of 99 randomized controlled trials comprising 5546 participants revealed that curcumin/turmeric supplementation reduced AST (ES = -1.072, 95% CI (-1.656, -0.488), p = 0.000), ALT (ES = -0.625, 95% CI (-1.170, -0.134), p = 0.014), and TG (ES = -0.469, 95% CI (-1.057, 0.119), p = 0.128) levels, and HOMA-IR (ES = -0.291, 95% CI (-0.368, -0.214), p = 0.000), BMI (ES = -0.205, 95% CI (-0.304, -0.107), p = 0.000), and WC (ES = -1.290, 95% CI (-2.038, -0.541), p = 0.001) in comparison to the control group. However, the effects of curcumin on GGT, ALP, TC, LDL-C, HDL-C, FBS, and HbA1C levels and body weight were not significant. The findings suggest the beneficial effects of curcumin/turmeric supplementation in patients with NAFLD, such as improving liver function, decreasing serum TG levels, ameliorating insulin resistance, and reducing general and central obesity. Nevertheless, high-quality research is further required to prove these achievements.

Preparation of sodium alginate/Cur-PLA hydrogel beads for curcumin encapsulation

The low bioavailability of hydrophobic compounds, however, limits their medicinal use. Hydrogel beads made of biopolymers can be employed as controlled delivery systems and as a carrier to carry curcumin molecules. In this study, encapsulation of curcumin is done within the hydrogel by using Polylactic acid. The prepared SA/Cur-PLA and SA/Cur beads were examined using FTIR, SEM, TGA, NMR, and, XRD to study the interaction between drug and polymer. The developed bead's curcumin encapsulation efficiency was found to be 81.47 % in SA/Cur-PLA. Curcumin's release kinetics have been studied in systems (SGF, pH 1.2, and SCF, pH 7.4) that simulate oral consumption, which possess good pH sensitivity. The in vitro drug release studies of SA/Cur-PLA beads suggest that the curcumin release was significantly increased in a controlled manner and within 12 h, the cumulative release of curcumin was accomplished. In vitro hemolysis study shows a 7.93 % hemolysis rate which suggests that the produced bead is hemocompatible. For SA/Cur-PLA and SA/Cur, cytotoxicity evaluation and antimicrobial study was performed. Results show that both hydrogels are cytocompatible and antimicrobial in nature. It was found that biopolymer-based hydrogel beads enhanced the bioavailability of curcumin, antioxidant, biodegradable, and considered an effective carrier for the oral delivery of several hydrophobic nutraceuticals.

A Scoping Review of the Clinical Evidence for the Health Benefits of Culinary Doses of Herbs and Spices for the Prevention and Treatment of Metabolic Syndrome

Metabolic syndrome (MetS) is a growing global health problem. Evidence suggests that diets rich in phytochemical-containing herbs and spices can contribute to reducing the risk of chronic diseases. This review assesses the scope of evidence supporting the use of herbs and spices in the diet for the prevention or treatment of MetS and its associated health conditions. A search of the PubMed, Scopus and Google Scholar databases was carried out to assess the available clinical evidence for culinary doses of commonly used herbs and spices. Trials that were measuring health factors related to metabolic disorders in healthy individuals, or the health of individuals with MetS or associated diseases, were included. Out of a total of 1738 papers identified, there were 142 relevant studies on black pepper, chilli, cardamom, cinnamon, coriander, cumin, fennel, fenugreek, garlic, ginger, nigella seed, rosemary, sage and turmeric. No relevant research was found for cloves, mint, oregano, parsley or thyme. Cinnamon, fenugreek and ginger were the herbs/spices with the most published trials on them and that showed promise for glycaemic control. Cardamom appears to have potential to reduce inflammatory markers, and cinnamon, ginger and turmeric to reduce blood lipids. Patients with type 2 diabetes were the population most likely to be included in studies, but the preventative benefits of herbs/spices in healthy populations were also investigated, particularly for chilli, ginger and cinnamon. There is evidence for the beneficial effect of culinary doses of many common herbs/spices in the prevention and treatment of MetS and associated disorders.

Effects of curcumin/turmeric supplementation on liver function in adults: A GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials

INTRODUCTION

Liver conditions are major burdens upon health systems around the world. Turmeric /curcumin is believed to possess therapeutic features in ameliorating various metabolic disorders. In this systematic review and meta-analysis of the randomized controlled trials (RCTs), we examined the effect of turmeric/curcumin supplementation on some liver function tests (LFTs).

METHODS

We comprehensively searched online databases (i.e. PubMed, Scopus, Web of Science, Cochrane Library, and Google Scholar) from inception up to October 2022. Final outcomes included aspartate aminotransferase (AST), alanine aminotransferase (ALT), and gamma-glutamyl transferase (GGT). Weighted mean differences (WMDs) were reported. In case of between-study heterogeneity, subgroup analysis was conducted. Non-linear dose-response analysis was carried out to detect the potential effect of dosage and duration. The registration code is CRD42022374871.

RESULTS

Thirty-one RCTs were included in the meta-analysis. Turmeric/curcumin supplementation significantly reduced blood levels of ALT (WMD = -4.09 U/L; 95 % CI = -6.49, -1.70) and AST (WMD = -3.81 U/L; 95 % CI = -5.71, -1.91), but not GGT (WMD: -12.78 U/L; 95 % CI: -28.20, 2.64). These improvements, though statistically significant, do not ensure clinical effectiveness.

CONCLUSION

It seems that turmeric/curcumin supplementation might be effective in improving AST and ALT levels. However, further clinical trials are needed to examine its effect on GGT. Quality of the evidence across the studies was low for AST and ALT and very low for GGT. Therefore, more studies with high quality are needed to assess this intervention on hepatic health.

Dietary Turmeric Consumption Alleviates Ulcerative Colitis via Restoring Tryptophan Metabolism and Alleviating Gut Microbiota Dysbiosis in Mice

This study was designed to first verify the protective capacity of turmeric powder (TP) as a traditional cooking spice against dextran sulfate sodium (DSS)-induced intestinal inflammation and intestine microbiota imbalance. The DSS-induced mice were fed a standard rodent chow supplemented with or without TP (8%) for 37 days. The results indicated that the pathological phenotype, gut barrier disruption, and colon inflammation of DSS-induced mice were significantly improved through supplementation of TP. In addition, 16S rRNA-based microbiota or targeted metabolomics analysis indicated that TP ameliorated intestinal microbiota dysbiosis caused by DSS and particularly enhanced the abundances of probiotics correlated with tryptophan metabolism, such as Lactobacillus and Bifidobacterium, where the cecal tryptophan was metabolized to indole-3-propionic acid and indole-3-acetic acid. Consumption of TP markedly enhanced the expression levels of colonic aromatic hydrocarbon receptors and further increased the expressions of intestinal tight junction proteins and interleukin-22 in the colitis mice. Collectively, these findings manifest the protective actions of dietary TP consumption against ulcerative colitis via restoring the intestinal microbiota disorders, promoting microbial metabolism, and improving intestinal barrier damage.

Curcumin encapsulated polylactic acid nanoparticles embedded in alginate/gelatin bioinks for in situ immunoregulation: Characterization and biological assessment

Curcumin is a known naturally occurring anti-inflammatory agent derived from turmeric, and it is commonly used as a herbal food supplement. Here, in order to overcome the inherent hydrophobicity of curcumin (Cur), polylactic acid (PLA) nanoparticles (NPs) were synthesised using a solvent evaporation, and an oil-in-water emulsion method used to encapsulate curcumin. Polymeric NPs also offer the ability to control rate of drug release. The newly synthesised NPs were analysed using a scanning electron microscope (SEM), where results show the NPs range from 50 to 250 nm. NPs containing graded amounts of curcumin (0 %, 0.5 %, and 2 %) were added to cultures of NIH3T3 fibroblast cells for cytotoxicity evaluation using the Alamar Blue assay. Then, the curcumin NPs were incorporated into an alginate/gelatin solution, prior to crosslinking using a calcium chloride solution (200 nM). These hydrogels were then characterised with respect to their chemical, mechanical and rheological properties. Following hydrogel optimization, hydrogels loaded with NP containing 2 % curcumin were selected as a candidate as a bioink for three-dimensional (3D) printing. The biological assessment for these bioinks/hydrogels were conducted using THP-1 cells, a human monocytic cell line. Cell viability and immunomodulation were evaluated using lactate dehydrogenase (LHD) and a tumour necrosis factor alpha (TNF-α) enzyme-linked immunosorbent (ELISA) assay, respectively. Results show that the hydrogels were cytocompatible and supressed the production of TNF-α. These bioactive hydrogels are printable, supress immune cell activation and inflammation showing immense potential for the fabrication of tissue engineering constructs.

Zingiberaceae plants/curcumin consumption and multiple health outcomes: An umbrella review of systematic reviews and meta-analyses of randomized controlled trials in humans

This umbrella review is to recapitulate and grade the available evidence of associations between consumption of Zingiberaceae plants/curcumin (Cur) and multiple health-related outcomes. This study included 161 meta-analyses of randomized controlled trials in 76 articles with 67 unique health outcomes. Data on heterogeneity and publication bias are considered to assess the quality of evidence. Based on the different impact of Zingiberaceae plants/Cur on human health, the advantages outweigh the disadvantages. Zingiberaceae plants/Cur can mainly improve metabolic syndrome, non-alcoholic fatty liver disease, cardiovascular disease, and some chronic inflammatory diseases, likewise, obviously relief the pain of osteoarthritis and related diseases. Ginger supplements have been shown to improve vomiting during pregnancy and to relieve nausea and vomiting caused by chemotherapy and surgery. The surgery is any type of surgery, including laparoscopic surgery, gynecological surgery and mixed surgery. Beneficial associations were found with Cur intervention in gastrointestinal, neurological and oral diseases. Zingiberaceae plants/Cur are generally safe and favorable for multiple health outcomes in humans. High-quality research is further needed to prove the observed associations.

Extraction of curcumin from turmeric residue (Curcuma longa L.) using deep eutectic solvents and surfactant solvents

Using waste materials to extract biologically active ingredients with green solvents is a new trend for sustainable development. Herein, different types of deep eutectic solvents (DESs) and surfactant solvents (SSs) were used to extract curcumin from turmeric residues (TRs), among which choline chloride-propylene glycol (ChCl-Pro) showed the highest yield. The optimized extraction conditions included a ChCl : Pro ratio of 1 : 2, water content in the DESs of 20%, solid : liquid ratio of 1 : 40 maintained for 60 min at 50 °C, and a TR particle size of 0.18 mm. The extraction yield was 54.2 mg g^-1, which was 1.31 times higher than when methanol was used as a solvent. Distilled water was used to recover curcumin from the DES extract with a recovery yield of 99.7%. Furthermore, the antioxidant and acetylcholinesterase (AChE) inhibitory activities of the recovered curcumin were evaluated, with IC₅₀ values of 25.58 ± 0.51 and 19.12 ± 0.83 μg mL^-1, respectively. This study highlights the promising potential of using green solvents to extract bioactive compounds from waste materials.

Natural Antioxidants from Plant Extracts in Skincare Cosmetics: Recent Applications, Challenges and Perspectives

In recent years, interest in the health effects of natural antioxidants has increased due to their safety and applicability in cosmetic formulation. Nevertheless, efficacy of natural antioxidants in vivo is less documented than their prooxidant properties in vivo. Plant extracts rich in vitamins, flavonoids, and phenolic compounds can induce oxidative damage by reacting with various biomolecules while also providing antioxidant properties. Because the biological activities of natural antioxidants differ, their effectiveness for slowing the aging process remains unclear. This review article focuses on the use of natural antioxidants in skincare and the possible mechanisms underlying their desired effect, along with recent applications in skincare formulation and their limitations.

Gut microbiota-dependent catabolites of tryptophan play a predominant role in the protective effects of turmeric polysaccharides against DSS-induced ulcerative colitis

Gut barrier dysfunction is triggered by gut microbiota dysbiosis that is closely associated with ulcerative colitis. Recently, more attention has been devoted to the ability of the non-digestively colon-targeted plant polysaccharides to regulate the function and composition of the intestinal microbiota. Here, we first studied the prophylactic capacity of turmeric polysaccharides (TPS) to ameliorate dextran sulfate sodium (DSS)-induced gut microbiota imbalance. The results revealed that TPS administration could greatly improve the pathological phenotype, gut barrier disruption and colon inflammation in colitis mice. Besides, targeted metabolomics or 16S rRNA-based microbiota analysis demonstrated that TPS alleviated gut microbiota dysbiosis caused by DSS, especially increasing the abundance of probiotics associated with tryptophan metabolism, such as Lactobacillus and Clostridia-UCG-014, where the cecal tryptophan catabolite indole-3-acetic acid (IAA) and its ligand aryl hydrocarbon receptor (AhR) expressions were sharply increased by TPS treatment in colitis mice. Expectedly, TPS was found to exert its gut barrier functions through the activation of AhR to upregulate epithelial tight junction proteins. These findings highlight the protective effects of TPS against ulcerative colitis by modulating the gut microbiota and improving microbial metabolites and gut barrier function.

Application of Natural Preservatives for Meat and Meat Products against Food-Borne Pathogens and Spoilage Bacteria: A Review

Meat and meat products are excellent sources of nutrients for humans; however, they also provide a favorable environment for microbial growth. To prevent the microbiological contamination of livestock foods, synthetic preservatives, including nitrites, nitrates, and sorbates, have been widely used in the food industry due to their low cost and strong antibacterial activity. Use of synthetic chemical preservatives is recently being considered by customers due to concerns related to negative health issues. Therefore, the demand for natural substances as food preservatives has increased with the use of plant-derived and animal-derived products, and microbial metabolites. These natural preservatives inhibit the growth of spoilage microorganisms or food-borne pathogens by increasing the permeability of microbial cell membranes, interruption of protein synthesis, and cell metabolism. Natural preservatives can extend the shelf-life and inhibit the growth of microorganisms. However, they can also influence food sensory properties, including the flavor, taste, color, texture, and acceptability of food. To increase the applicability of natural preservatives, a number of strategies, including combinations of different preservatives or food preservation methods, such as active packaging systems and encapsulation, have been explored. This review summarizes the current applications of natural preservatives for meat and meat products.

A novel method based on machine vision system and deep learning to detect fraud in turmeric powder

Assessing the quality of food and spices is particularly important in ensuring proper human nutrition. The use of computer vision method as a non-destructive technique in measuring the quality of food and spices has always been taken into consideration by researchers. Due to the high nutritional value of turmeric among the spices as well as the fraudulent motives to gain economic profit from the selling of this product, its quality assessment is very important. The lack of marketability of grade 3 chickpeas (small and broken chickpeas) and their very low price have made them a good choice to be mixed with turmeric in powder form and sold in the market. In this study, an improved convolutional neural network (CNN) was used to classify turmeric powder images to detect fraud. CNN was improved through the use of gated pooling functions. We also show with a combined approach based on the integration of average pooling and max pooling that the accuracy and performance of the proposed CNN has increased. In this study, 6240 image samples were prepared in 13 categories (pure turmeric powder, chickpea powder, chickpea powder mixed with food coloring, 10, 20, 30, 40 and 50% fraud in turmeric). In the preprocessing step, unwanted parts of the image were removed. The data augmentation (DA) was used to reduce the overfitting problem on CNN. Also in this research, MLP, Fuzzy, SVM, GBT and EDT algorithms were used to compare the proposed CNN results with other classifiers. The results showed that prevention of the overfitting problem using gated pooling, the proposed CNN was able to grade the images of turmeric powder with 99.36% accuracy compared to other classifiers. The results of this study also showed that computer vision, especially when used with deep learning (DL), can be a valuable method in evaluating the quality and detecting fraud in turmeric powder.

The Demethoxy Derivatives of Curcumin Exhibit Greater Differentiation Suppression in 3T3-L1 Adipocytes Than Curcumin: A Mechanistic Study of Adipogenesis and Molecular Docking

Curcumin is a known anti-adipogenic agent for alleviating obesity and related disorders. Comprehensive comparisons of the anti-adipogenic activity of curcumin with other curcuminoids is minimal. This study compared adipogenesis inhibition with curcumin, demethoxycurcumin (DMC), and bisdemethoxycurcumin (BDMC), and their underlying mechanisms. We differentiated 3T3-L1 cells in the presence of curcuminoids, to determine lipid accumulation and triglyceride (TG) production. The expression of adipogenic transcription factors and lipogenic proteins was analyzed by Western blot. A significant reduction in Oil red O (ORO) staining was observed in the cells treated with curcuminoids at 20 μM. Inhibition was increased in the order of curcumin < DMC < BDMC. A similar trend was observed in the detection of intracellular TG. Curcuminoids suppressed differentiation by downregulating the expression of peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT/enhancer-binding protein α (C/EBPα), leading to the downregulation of the lipogenic enzymes acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS). AMP-activated protein kinase α (AMPKα) phosphorylation was also activated by BDMC. Curcuminoids reduced the release of proinflammatory cytokines and leptin in 3T3-L1 cells in a dose-dependent manner, with BDMC showing the greatest potency. BDMC at 20 μM significantly decreased leptin by 72% compared with differentiated controls. Molecular docking computation indicated that curcuminoids, despite having structural similarity, had different interaction positions to PPARγ, C/EBPα, and ACC. The docking profiles suggested a possible interaction of curcuminoids with C/EBPα and ACC, to directly inhibit their expression.

(Poly)phenols in Inflammatory Bowel Disease and Irritable Bowel Syndrome: A Review

(Poly)phenols (PPs) may have a therapeutic benefit in gastrointestinal (GI) disorders, such as irritable bowel syndrome (IBS) or inflammatory bowel disease (IBD). The aim of this review is to summarise the evidence-base in this regard. Observational evidence does not give a clear indication that PP intake has a preventative role for IBD or IBS, while interventional studies suggest these compounds may confer symptomatic and health-related quality of life improvements in known patients. There are inconsistent results for effects on markers of inflammation, but there are promising reports of endoscopic improvement. Work on the effects of PPs on intestinal permeability and oxidative stress is limited and therefore conclusions cannot be formed. Future work on the use of PPs in IBD and IBS will strengthen the understanding of clinical and mechanistic effects.