Effects of Highly Absorbable Curcumin in Patients with Impaired Glucose Tolerance and Non-Insulin-Dependent Diabetes Mellitus

Goreisan suppresses cardiac remodeling and dysfunction in a new mouse model with diabetic cardiomyopathy

BACKGROUND

The global increase in diabetes, driven by aging populations and lifestyle changes, has led to an increase in the incidence of diabetic cardiomyopathy (DCM). DCM is characterized by metabolic abnormalities, oxidative stress, and inflammation, leading to cardiac remodeling and dysfunction. Goreisan (GRS), a traditional Japanese Kampo medicine, is commonly used to treat fluid control such as edema, due to its diuretic effect. In this study, we examined the effects of GRS on DCM.

METHODS

We first established a new mouse model of DCM and then evaluated the effects of GRS on DCM using a recently developed model.

RESULTS

The DCM mouse model developed cardiac hypertrophy, fibrosis, and dysfunction by nine weeks, which was ameliorated by GRS administration. GRS suppressed apoptosis and protein degradation by inhibiting Akt dephosphorylation and oxidative stress in DCM mice. In contrast, no differences in inflammatory cytokine levels were observed, regardless of GRS administration.

CONCLUSION

GRS has potential efficacy in preventing DCM onset and development.

The Dynamic Role of Curcumin in Mitigating Human Illnesses: Recent Advances in Therapeutic Applications

Herbal medicine, particularly in developing regions, remains highly popular due to its cost-effectiveness, accessibility, and minimal risk of adverse effects. Curcuma longa L., commonly known as turmeric, exemplifies such herbal remedies with its extensive history of culinary and medicinal applications across Asia for thousands of years. Traditionally utilized as a dye, flavoring, and in cultural rituals, turmeric has also been employed to treat a spectrum of medical conditions, including inflammatory, bacterial, and fungal infections, jaundice, tumors, and ulcers. Building on this longstanding use, contemporary biochemical and clinical research has identified curcumin-the primary active compound in turmeric-as possessing significant therapeutic potential. This review hypothesizes that curcumin's antioxidant properties are pivotal in preventing and treating chronic inflammatory diseases, which are often precursors to more severe conditions, such as cancer, and neurological disorders, like Parkinson's and Alzheimer's disease. Additionally, while curcumin demonstrates a favorable safety profile, its anticoagulant effects warrant cautious application. This article synthesizes recent studies to elucidate the molecular mechanisms underlying curcumin's actions and evaluates its therapeutic efficacy in various human illnesses, including cancer, inflammatory bowel disease, osteoarthritis, atherosclerosis, peptic ulcers, COVID-19, psoriasis, vitiligo, and depression. By integrating diverse research findings, this review aims to provide a comprehensive perspective on curcumin's role in modern medicine and its potential as a multifaceted therapeutic agent.

Bibliometric Analysis of Curcumin Based on CiteSpace: Landscapes, Hotspots, and Frontiers

Curcumin, the main active compound in turmeric, has garnered significant interest for its wide range of pharmacological properties. In this study, CiteSpace was used to visually analyze curcumin-related publications to elucidate the current landscape and explore emerging frontiers in curcumin research. In total, 23,184 publications on curcumin from January 1, 2014, to December 31, 2023, were scrutinized. The analysis revealed that publication volume consistently increased over time. The top 10 countries contributed 90.87% of the publications, highlighting the global significance of curcumin research. China generated 31.34% of the total corpus due to its strong research capabilities and traditional medicine culture. The top 10 institutions contributed 11.21% of the articles, revealing notable collaborations. Among the prolific authors, Amirhossein Sahebkar produced 246 publications, whereas Preetha Anand garnered the most citations. Keyword analysis revealed prevalent trends such as "fabrication", "combination", "extract", "natural products", "colorectal cancer", and "resveratrol". Reference analysis emphasized research on therapeutic and modulatory effects, anticancer potential, and interdisciplinary topics, such as molecular biology, chemistry, and nutrition. More importantly, we simplified cluster relationships by selecting the top 30% of cluster dependency paths. For instance, the references within the #1 polymeric micelle cite literature from the #2 anticancer potential, #3 modulatory effect, and #4 therapeutic effect, indicating that clusters 2, 3, and 4 serve as knowledge foundations for cluster 1. This interconnectedness highlights how the information in these clusters can contribute to the knowledge of curcumin in various studies. This study provides an overview of the research trends and critical themes related to curcumin, offering insights for future research directions and emphasizing the interdisciplinary and global scope of curcumin research.

Biochemical basis and therapeutic potential of mitochondrial uncoupling in cardiometabolic syndrome

Mild uncoupling of oxidative phosphorylation is an intrinsic property of all mitochondria, allowing for adjustments in cellular energy metabolism to maintain metabolic homeostasis. Small molecule uncouplers have been extensively studied for their potential to increase metabolic rate, and recent research has focused on developing safe and effective mitochondrial uncoupling agents for the treatment of obesity and cardiometabolic syndrome (CMS). Here, we provide a brief overview of CMS and cover the recent mechanisms by which chemical uncouplers regulate CMS-associated risk-factors and comorbidities, including dyslipidemia, insulin resistance, steatotic liver disease, type 2 diabetes, and atherosclerosis. Additionally, we review the current landscape of uncoupling agents, focusing on repurposed FDA-approved drugs and compounds in advanced preclinical or early-stage clinical development. Lastly, we discuss recent molecular insights by which chemical uncouplers enhance cellular energy expenditure, highlighting their potential as a new addition to the current CMS drug landscape, and outline several limitations that need to be addressed before these agents can successfully be introduced into clinical practice.

Curcumin Attenuates Hyperglycemia and Inflammation in Type 2 Diabetes Mellitus: Quantitative Analysis of Randomized Controlled Trial

Controlling hyperglycemia and inflammation in type 2 diabetes (T2D) remains an important approach to control diabetes. The use of phytochemicals found in natural herbs has been investigated widely, and there are inconsistent findings in clinical trials, likely associated with a small sample size. A meta-analysis of clinical trials was performed by conducting a comprehensive literature search on PubMed, Scopus, EBSCOHost, and Web of Sciences. The search terms included Curcumin longa, turmeric, curcumin, curcuma xanthorrhiza, diferuloylmethane, and type 2 diabetes. Data were analyzed using an online meta-analysis tool, Jamovi version 2.4.8 and IBM SPSS statistics version 29. The data were reported as either mean difference (MD) or standard mean difference (SMD) and 95% confidence intervals. The evidence from 18 trials with 1382 T2D with a mean age of 55.9 years was analyzed. Supplementation with curcumin led to a significant decrease in fasting blood glucose, MD = -11.48 mg/dL, 95%CI (-14.26, -8.70), p < 0.01 and glycated hemoglobin, MD = -0.54%, 95%CI (-0.73, -0.35), p < 0.01. Additionally, there was a significant decrease in C-Reactive Protein in curcumin compared to a placebo, SMD = -0.59, 95%CI (-1.11, -0.07), p = 0.03. The findings observed in this study suggest that curcumin can ameliorate hyperglycemia and inflammation in T2D compared to a placebo. While the potential benefits were observed, it is recommended that future trials focus on finding a suitable dose and duration of intervention and incorporate formulation in curcumin to enhance its absorption.

Is Curcumin Intake Really Effective for Chronic Inflammatory Metabolic Disease? A Review of Meta-Analyses of Randomized Controlled Trials

This review aimed to examine the effects of curcumin on chronic inflammatory metabolic disease by extensively evaluating meta-analyses of randomized controlled trials (RCTs). We performed a literature search of meta-analyses of RCTs published in English in PubMed®/MEDLINE up to 31 July 2023. We identified 54 meta-analyses of curcumin RCTs for inflammation, antioxidant, glucose control, lipids, anthropometric parameters, blood pressure, endothelial function, depression, and cognitive function. A reduction in C-reactive protein (CRP) levels was observed in seven of ten meta-analyses of RCTs. In five of eight meta-analyses, curcumin intake significantly lowered interleukin 6 (IL-6) levels. In six of nine meta-analyses, curcumin intake significantly lowered tumor necrosis factor α (TNF-α) levels. In five of six meta-analyses, curcumin intake significantly lowered malondialdehyde (MDA) levels. In 14 of 15 meta-analyses, curcumin intake significantly reduced fasting blood glucose (FBG) levels. In 12 of 12 meta-analyses, curcumin intake significantly reduced homeostasis model assessment of insulin resistance (HOMA-IR). In seven of eight meta-analyses, curcumin intake significantly reduced glycated hemoglobin (HbA1c) levels. In eight of ten meta-analyses, curcumin intake significantly reduced insulin levels. In 14 of 19 meta-analyses, curcumin intake significantly reduced total cholesterol (TC) levels. Curcumin intake plays a protective effect on chronic inflammatory metabolic disease, possibly via improved levels of glucose homeostasis, MDA, TC, and inflammation (CRP, IL-6, TNF-α, and adiponectin). The safety and efficacy of curcumin as a natural product support the potential for the prevention and treatment of chronic inflammatory metabolic diseases.

Innovative Delivery Systems for Curcumin: Exploring Nanosized and Conventional Formulations

Curcumin, a polyphenol with a rich history spanning two centuries, has emerged as a promising therapeutic agent targeting multiple signaling pathways and exhibiting cellular-level activities that contribute to its diverse health benefits. Extensive preclinical and clinical studies have demonstrated its ability to enhance the therapeutic potential of various bioactive compounds. While its reported therapeutic advantages are manifold, predominantly attributed to its antioxidant and anti-inflammatory properties, its efficacy is hindered by poor bioavailability stemming from inadequate absorption, rapid metabolism, and elimination. To address this challenge, nanodelivery systems have emerged as a promising approach, offering enhanced solubility, biocompatibility, and therapeutic effects for curcumin. We have analyzed the knowledge on curcumin nanoencapsulation and its synergistic effects with other compounds, extracted from electronic databases. We discuss the pharmacokinetic profile of curcumin, current advancements in nanoencapsulation techniques, and the combined effects of curcumin with other agents across various disorders. By unifying existing knowledge, this analysis intends to provide insights into the potential of nanoencapsulation technologies to overcome constraints associated with curcumin treatments, emphasizing the importance of combinatorial approaches in improving therapeutic efficacy. Finally, this compilation of study data aims to inform and inspire future research into encapsulating drugs with poor pharmacokinetic characteristics and investigating innovative drug combinations to improve bioavailability and therapeutic outcomes.

Combined supplementation with hesperidin, phytosterols and curcumin decreases adiposity and improves metabolic health in ovariectomized rats

In recent years many women have looked for alternative therapies to address menopause. Hesperidin, phytosterols and curcumin are bioactive compounds that can ameliorate some cardiovascular risk factors associated with menopause, although there are no data concerning the effects of their combined supplementation. We used ovariectomized (OVX) rats, a postmenopausal model with oestrogen deficiency, to evaluate whether supplementation with a multi-ingredient (MI) including hesperidin, phytosterols and curcumin for 57 days would display beneficial effects against fat mass accretion and metabolic disturbances associated with menopause. Twenty OVX rats were orally supplemented with either MI (OVX-MI) or vehicle (OVX). Furthermore, 10 OVX rats orally received the vehicle along with subcutaneous injections of 17β-oestradiol biweekly (OVX-E2), whereas 10 rats were sham operated and received oral and injected vehicles (control group; SH). MI supplementation partly counteracted the fat mass accretion observed in OVX animals, which was evidenced by decreased total fat mass, adiposity index, the weight of retroperitoneal, inguinal and mesenteric white adipose tissue (MWAT) depots and MWAT adipocyte hypertrophy. These effects were accompanied by a significant decrease in the circulating levels of leptin and the mRNA levels of the fatty acid uptake-related genes Lpl and Cd36 in MWAT. These results were very similar to those observed in OVX-E2 animals. OVX-MI rats also displayed a higher lean body mass, lean/fat mass ratio, adiponectin-to-leptin ratio and insulin sensitivity than their OVX counterparts. Our findings can pave the way for using this MI formulation as an alternative therapy to manage obesity and to improve the cardiometabolic health of menopausal women.

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.

Targeting endothelial cells with golden spice curcumin: A promising therapy for cardiometabolic multimorbidity

Cardiometabolic multimorbidity (CMM) is an increasingly significant global public health concern. It encompasses the coexistence of multiple cardiometabolic diseases, including hypertension, stroke, heart disease, atherosclerosis, and T2DM. A crucial component to the development of CMM is the disruption of endothelial homeostasis. Therefore, therapies targeting endothelial cells through multi-targeted and multi-pathway approaches hold promise for preventing and treatment of CMM. Curcumin, a widely used dietary supplement derived from the golden spice Carcuma longa, has demonstrated remarkable potential in treatment of CMM through its interaction with endothelial cells. Numerous studies have identified various molecular targets of curcumin (such as NF-κB/PI3K/AKT, MAPK/NF-κB/IL-1β, HO-1, NOs, VEGF, ICAM-1 and ROS). These findings highlight the efficacy of curcumin as a therapeutic agent against CMM through the regulation of endothelial function. It is worth noting that there is a close relationship between the progression of CMM and endothelial damage, characterized by oxidative stress, inflammation, abnormal NO bioavailability and cell adhesion. This paper provides a comprehensive review of curcumin, including its availability, pharmacokinetics, pharmaceutics, and therapeutic application in treatment of CMM, as well as the challenges and future prospects for its clinical translation. In summary, curcumin shows promise as a potential treatment option for CMM, particularly due to its ability to target endothelial cells. It represents a novel and natural lead compound that may offer significant therapeutic benefits in the management of CMM.

Effects of curcumin/turmeric supplementation on glycemic indices in adults: A grade-assessed systematic review and dose-response meta-analysis of randomized controlled trials

INTRODUCTION

Glycemic control is of utmost importance both as a preventive measure in individuals at risk of diabetes and in the management of patients with disturbed glycemia. Turmeric/curcumin has been extensively studied in this field. In the present systematic review and meta-analysis, we aimed at investigating the impact of turmeric/curcumin supplementation on glycemic control.

METHODS

Major online databases (PubMed, Scopus, Web of Science, Cochrane Library and Google Scholar) were systematically searched from inception up to October 2022. Relevant randomized controlled trials (RCTs) meeting our eligible criteria were included. Weighted mean differences (WMDs) with confidence intervals (CIs) were expressed using a random-effect model. Subgroup analyses were conducted to find the sources of heterogeneities. To detect risk of bias in the included studies, we used the Cochrane risk-of-bias tool. The registration number was CRD42022374874.

RESULTS

Out of 4182 articles retrieved from the initial search, 59 RCTs were included. Our findings suggested that turmeric/curcumin supplementation was significantly effective in improving fasting blood sugar (WMD: 4.60 mg/dl; 95% CI: 5.55, -3.66), fasting insulin levels (WMD: 0.87 μIU/ml; 95% CI: 1.46, -0.27), hemoglobin A1c (HbA1c) (WMD: 0.32%; 95% CI: 0.45, -0.19), and homeostatic model assessment of insulin resistance (HOMA-IR) (WMD: 0.33; 95% CI: 0.43, -0.22).

CONCLUSION

Our results indicate that turmeric/curcumin supplementation can be considered as a complementary method in the management of disturbed glycemia.

Phytochemicals for the treatment of metabolic diseases: Evidence from clinical studies

With the continuous improvement of people's living standard, the incidence of metabolic diseases is gradually increasing in recent years. There is growing interest in finding drugs to treat metabolic diseases from natural compounds due to their good efficacy and limited side effects. Over the past few decades, many phytochemicals derived from natural plants, such as berberine, curcumin, quercetin, resveratrol, rutin, and hesperidin, have been shown to have good pharmacological activity against metabolic diseases in preclinical studies. More importantly, clinical trials using these phytochemicals to treat metabolic diseases have been increasing. This review comprehensively summarizes the clinical progress of phytochemicals derived from natural plants in the treatment of several metabolic diseases, including type 2 diabetes mellitus (T2DM), obesity and non-alcoholic fatty liver disease (NAFLD). Accumulating clinical evidence shows that a total of 18 phytochemicals have good therapeutic effects on the three metabolic diseases by lowering blood glucose and lipid levels, reducing insulin resistance, enhancing insulin sensitivity, increasing energy expenditure, improving liver function, and relieving inflammation and oxidative stress. The information will help us better understand the medicinal value of these phytochemicals and promote their clinical application in the treatment of metabolic diseases.

The effect of phytochemicals in prediabetic patients: A systematic review of randomized controlled trials

This study aimed to perform a systematic review to evaluate the effect of phytochemical consumption on the cardiometabolic parameters of prediabetic patients. A comprehensive search was conducted in PubMed, Scopus and ISI Web of Science, and Google Scholar up to June 2022 to find randomized controlled trials investigating the effects of phytochemicals alone or in combination with other nutraceuticals on prediabetic patients. Twenty-three studies with 31 treatment arms comprising 2177 individuals were included in this study. Totally, in 21 arms, phytochemicals had positive effects on at least one measured cardiometabolic factor. In 13 out of 25 arms, fasting blood glucose (FBG) and in 10 out of 22 arms, hemoglobin A1c (HbA1c) significantly decreased compared with the control group. Furthermore, phytochemicals had beneficial effects on 2-h postprandial and postprandial glucose, serum insulin, insulin sensitivity, and insulin resistance as well as inflammatory factors including high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor α (TNF-α), and interleukin 6 (IL-6). Triglyceride (TG) was the abundant improved factor in the lipid profile. However, no sufficient evidence for notable positive effects of phytochemicals on blood pressure and anthropometry indices was observed. Phytochemical supplementation may have beneficial impacts on prediabetic patients by ameliorating glycemic status.

Effects of turmeric (Curcuma longa) supplementation on glucose metabolism in diabetes mellitus and metabolic syndrome: An umbrella review and updated meta-analysis

AIMS

This study aims to comprehensively review the existing evidence and conduct analysis of updated randomized controlled trials (RCTs) of turmeric (Curcuma longa, CL) and its related bioactive compounds on glycemic and metabolic parameters in patients with type 2 diabetes (T2DM), prediabetes, and metabolic syndrome (MetS) together with a sub-group analysis of different CL preparation forms.

METHODS

An umbrella review (UR) and updated systematic reviews and meta-analyses (SRMAs) were conducted to evaluate the effects of CL compared with a placebo/standard treatment in adult T2DM, prediabetes, and MetS. The MEDLINE, Embase, The Cochrane Central Register of Control Trials, and Scopus databases were searched from inception to September 2022. The primary efficacy outcomes were hemoglobin A1C (HbA1C) and fasting blood glucose (FBG). The corrected covered area (CCA) was used to assess overlap. Mean differences were pooled across individual RCTs using a random-effects model. Subgroup and sensitivity analyses were performed for various CL preparation forms.

RESULTS

Fourteen SRMAs of 61 individual RCTs were included in the UR. The updated SRMA included 28 studies. The CCA was 11.54%, indicating high overlap across SRMAs. The updated SRMA revealed significant reduction in FBG and HbA1C with CL supplementation, obtaining a mean difference (95% confidence interval [CI]) of -8.129 (-12.175, -4.084) mg/dL and -0.134 (-0.304, -0.037) %, respectively. FBG and HbA1C levels decreased with all CL preparation forms as did other metabolic parameters levels. The results of the sensitivity and subgroup analyses were consistent with those of the main analysis.

CONCLUSION

CL supplementation can significantly reduce FBG and HbA1C levels and other metabolic parameters in T2DM and mitigate related conditions, including prediabetes and MetS.

TRIAL REGISTRATION

PROSPERO (CRD42016042131).

The effect of curcumin supplementation on weight loss and anthropometric indices: an umbrella review and updated meta-analyses of randomized controlled trials

BACKGROUND

Curcumin supplementation may promote weight loss and ameliorate obesity-related complications through its antioxidative and anti-inflammatory properties.

OBJECTIVE

An umbrella review and updated meta-analysis of randomized controlled trials (RCTs) was conducted to evaluate the effect of curcumin supplementation on anthropometric indices.

METHODS

Systematic reviews and meta-analyses (SRMAs) of RCTs were identified from electronic databases (Medline, Scopus, Cochrane, and Google Scholar) up to 31 March, 2022, without language restriction. SRMAs were included if they assessed curcumin supplementation on any of the following: BMI, body weight (BW), or waist circumference (WC). Subgroup analyses were performed, stratifying by patient types, severity of obesity, and curcumin formula. The study protocol was a priori registered.

RESULTS

From an umbrella review, 14 SRMAs with 39 individual RCTs were included with a high degree of overlap. In addition, searching was updated from the last search of included SRMAs in April 2021 up to 31 March, 2022, and we found 11 additional RCTs, bringing the total up to 50 RCTs included in the updated meta-analyses. Of these, 21 RCTs were deemed of high risk of bias. Curcumin supplementation significantly reduced BMI, BW, and WC with mean differences (MDs) of -0.24 kg/m2 (95% CI: -0.32, -0.16 kg/m2), -0.59 kg (95% CI: -0.81, -0.36 kg), and -1.32 cm (95% CI: -1.95, -0.69 cm), respectively. The bioavailability-enhanced form reduced BMI, BWs, and WC more, with MDs of -0.26 kg/m2 (95% CI: -0.38, -0.13 kg/m2), -0.80 kg (95% CI: -1.38, -0.23 kg) and -1.41 cm (95% CI: -2.24, -0.58 cm), respectively. Significant effects were also seen in subgroups of patients, especially in adults with obesity and diabetes.

CONCLUSIONS

Curcumin supplementation significantly reduces anthropometric indices, and bioavailability-enhanced formulas are preferred. Augmenting curcumin supplement with lifestyle modification should be an option for weight reduction. This trial was registered at PROSPERO as CRD42022321112 (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022321112).

Role of Turmeric and Curcumin in Prevention and Treatment of Chronic Diseases: Lessons Learned from Clinical Trials

Turmeric (Curcuma longa) has been used for thousands of years for the prevention and treatment of various chronic diseases. Curcumin is just one of >200 ingredients in turmeric. Almost 7000 scientific papers on turmeric and almost 20,000 on curcumin have been published in PubMed. Scientific reports based on cell culture or animal studies are often not reproducible in humans. Therefore, human clinical trials are the best indicators for the prevention and treatment of a disease using a given agent/drug. Herein, we conducted an extensive literature survey on PubMed and Scopus following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The keywords "turmeric and clinical trials" and "curcumin and clinical trials" were considered for data mining. A total of 148 references were found to be relevant for the key term "turmeric and clinical trials", of which 70 were common in both PubMed and Scopus, 44 were unique to PubMed, and 34 were unique to Scopus. Similarly, for the search term "curcumin and clinical trials", 440 references were found to be relevant, of which 70 were unique to PubMed, 110 were unique to Scopus, and 260 were common to both databases. These studies show that the golden spice has enormous health and medicinal benefits for humans. This Review will extract and summarize the lessons learned about turmeric and curcumin in the prevention and treatment of chronic diseases based on clinical trials.

Antioxidant and anti-inflammatory effects of curcumin/turmeric supplementation in adults: A GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials

Turmeric and its prominent bioactive compound, curcumin, have been the subject of many investigations with regard to their impact on inflammatory and oxidative balance in the body. In this systematic review and meta-analysis, we summarized the existing literature on randomized controlled trials (RCTs) which examined this hypothesis. Major databases (PubMed, Scopus, Web of Science, Cochrane Library and Google Scholar) were searched from inception up to October 2022. Relevant studies meeting our eligibility criteria were obtained. Main outcomes included inflammatory markers (i.e. C-reactive protein(CRP), tumour necrosis factorα(TNF-α), interleukin-6(IL-6), and interleukin 1 beta(IL-1β)) and markers of oxidative stress (i.e. total antioxidant capacity (TAC), malondialdehyde(MDA), and superoxide dismutase (SOD) activity). Weighted mean differences (WMDs) were reported. P-values < 0.05 were considered significant. Sixty-six RCTs were included in the final analysis. We observed that turmeric/curcumin supplementation significantly reduces levels of inflammatory markers, including CRP (WMD: -0.58 mg/l, 95 % CI: -0.74, -0.41), TNF-α (WMD: -3.48 pg/ml, 95 % CI: -4.38, -2.58), and IL-6 (WMD: -1.31 pg/ml, 95 % CI: -1.58, -0.67); except for IL-1β (WMD: -0.46 pg/ml, 95 % CI: -1.18, 0.27) for which no significant change was found. Also, turmeric/curcumin supplementation significantly improved anti-oxidant activity through enhancing TAC (WMD = 0.21 mmol/l; 95 % CI: 0.08, 0.33), reducing MDA levels (WMD = -0.33 µmol /l; 95 % CI: -0.53, -0.12), and SOD activity (WMD = 20.51 u/l; 95 % CI: 7.35, 33.67). It seems that turmeric/curcumin supplementation might be used as a viable intervention for improving inflammatory/oxidative status of individuals.

Curcumin Formulations for Better Bioavailability: What We Learned from Clinical Trials Thus Far?

Curcumin has been credited with a wide spectrum of pharmacological properties for the prevention and treatment of several chronic diseases such as arthritis, autoimmune diseases, cancer, cardiovascular diseases, diabetes, hemoglobinopathies, hypertension, infectious diseases, inflammation, metabolic syndrome, neurological diseases, obesity, and skin diseases. However, due to its weak solubility and bioavailability, it has limited potential as an oral medication. Numerous factors including low water solubility, poor intestinal permeability, instability at alkaline pH, and fast metabolism contribute to curcumin's limited oral bioavailability. In order to improve its oral bioavailability, different formulation techniques such as coadministration with piperine, incorporation into micelles, micro/nanoemulsions, nanoparticles, liposomes, solid dispersions, spray drying, and noncovalent complex formation with galactomannosides have been investigated with in vitro cell culture models, in vivo animal models, and humans. In the current study, we extensively reviewed clinical trials on various generations of curcumin formulations and their safety and efficacy in the treatment of many diseases. We also summarized the dose, duration, and mechanism of action of these formulations. We have also critically reviewed the advantages and limitations of each of these formulations compared to various placebo and/or available standard care therapies for these ailments. The highlighted integrative concept embodied in the development of next-generation formulations helps to minimize bioavailability and safety issues with least or no adverse side effects and the provisional new dimensions presented in this direction may add value in the prevention and cure of complex chronic diseases.

Effects of curcumin/turmeric supplementation on obesity indices and adipokines in adults: A grade-assessed systematic review and dose-response meta-analysis of randomized controlled trials

In the present study, we explored the effect of curcumin/turmeric supplementation on anthropometric indices of obesity, leptin, and adiponectin. We searched PubMed, Scopus, Web of Science, Cochrane Library, and Google Scholar up to August 2022. Randomized clinical trials (RCTs) investigating the impact of curcumin/turmeric on obesity indices and adipokines were included. We applied the Cochrane quality assessment tool to evaluate the risk of bias. The registration number is CRD42022350946. Sixty eligible RCTs, with a total sample size of 3691 individuals were included for quantitative analysis. We found that supplementation with curcumin/turmeric significantly reduced body weight (WMD: -0.82 kg, 95% CI: -1.30, -0.35; p = 0.001), body mass index (WMD: -0.30 kg/m² , 95% CI: -0.53, -0.06, p = 0.013), waist circumference (WMD: -1.31 cm, 95% CI: -1.94, -0.69, p < 0.001), body fat percentage (WMD: -0.88%, 95% CI: -1.51, -0.25, p = 0.007), leptin (WMD = -4.46 ng/mL; 95% CI: -6.70, -2.21, p < 0.001), and increased adiponectin (WMD = 2.48 μg/mL; 95% CI: 1.34, 3.62, p < 0.001). Overall, our study shows that supplementation with curcumin/turmeric significantly improves anthropometric indices of obesity and adiposity-related adipokines (leptin and adiponectin). However, due to high between-studies heterogeneity, we should interpret the results with caution.

Curcumin Supplementation and Human Disease: A Scoping Review of Clinical Trials

Medicinal properties of turmeric (Curcuma longa L.), a plant used for centuries as an anti-inflammatory, are attributed to its polyphenolic curcuminoids, where curcumin predominates. Although "curcumin" supplements are a top-selling botanical with promising pre-clinical effects, questions remain regarding biological activity in humans. To address this, a scoping review was conducted to assess human clinical trials reporting oral curcumin effects on disease outcomes. Eight databases were searched using established guidelines, yielding 389 citations (from 9528 initial) that met inclusion criteria. Half focused on obesity-associated metabolic disorders (29%) or musculoskeletal disorders (17%), where inflammation is a key driver, and beneficial effects on clinical outcomes and/or biomarkers were reported for most citations (75%) in studies that were primarily double-blind, randomized, and placebo-controlled trials (77%, D-RCT). Citations for the next most studied disease categories (neurocognitive [11%] or gastrointestinal disorders [10%], or cancer [9%]), were far fewer in number and yielded mixed results depending on study quality and condition studied. Although additional research is needed, including systematic evaluation of diverse curcumin formulations and doses in larger D-RCT studies, the preponderance of current evidence for several highly studied diseases (e.g., metabolic syndrome, osteoarthritis), which are also clinically common, are suggestive of clinical benefits.

Therapeutic Effect of Curcumin on Metabolic Diseases: Evidence from Clinical Studies

Metabolic diseases have become a serious threat to human health worldwide. It is crucial to look for effective drugs from natural products to treat metabolic diseases. Curcumin, a natural polyphenolic compound, is mainly obtained from the rhizomes of the genus Curcuma. In recent years, clinical trials using curcumin for the treatment of metabolic diseases have been increasing. In this review, we provide a timely and comprehensive summary of the clinical progress of curcumin in the treatment of three metabolic diseases, namely type 2 diabetes mellitus (T2DM), obesity and non-alcoholic fatty liver disease (NAFLD). The therapeutic effects and underlying mechanisms of curcumin on these three diseases are presented categorically. Accumulating clinical evidence demonstrates that curcumin has good therapeutic potential and a low number of side effects for the three metabolic diseases. It can lower blood glucose and lipid levels, improve insulin resistance and reduce inflammation and oxidative stress. Overall, curcumin may be an effective drug for the treatment of T2DM, obesity and NAFLD. However, more high-quality clinical trials are still required in the future to verify its efficacy and determine its molecular mechanisms and targets.

Regulatory Effects of Curcumin on Platelets: An Update and Future Directions

The rhizomatous plant turmeric, which is frequently used as a spice and coloring ingredient, yields curcumin, a bioactive compound. Curcumin inhibits platelet activation and aggregation and improves platelet count. Platelets dysfunction results in several disorders, including inflammation, atherothrombosis, and thromboembolism. Several studies have proved the beneficial role of curcumin on platelets and hence proved it is an important candidate for the treatment of the aforementioned diseases. Moreover, curcumin is also frequently employed as an anti-inflammatory agent in conventional medicine. In arthritic patients, it has been shown to reduce the generation of pro-inflammatory eicosanoids and to reduce edema, morning stiffness, and other symptoms. Curcumin taken orally also reduced rats' acute inflammation brought on by carrageenan. Curcumin has also been proven to prevent atherosclerosis and platelet aggregation, as well as to reduce angiogenesis in adipose tissue. In the cerebral microcirculation, curcumin significantly lowered platelet and leukocyte adhesion. It largely modulated the endothelium to reduce platelet adhesion. Additionally, P-selectin expression and mice survival after cecal ligation and puncture were improved by curcumin, which also altered platelet and leukocyte adhesion and blood-brain barrier dysfunction. Through regulating many processes involved in platelet aggregation, curcuminoids collectively demonstrated detectable antiplatelet activity. Curcuminoids may therefore be able to prevent disorders linked to platelet activation as possible therapeutic agents. This review article proposes to highlight and discuss the regulatory effects of curcumin on platelets.

Effects of curcumin, a bioactive component of turmeric, on type 2 diabetes mellitus and its complications: an updated review

Type 2 diabetes mellitus (T2DM) is a substantial issue in public health. Recently, there has been considerable interest in the effectiveness of using herbal supplements for T2DM. Among the herbal supplements, turmeric (Curcuma longa L.) has been attracting an avalanche of attention owing to its main component, curcumin. This review examines the physiological activities and mechanisms of action of curcumin associated with T2DM and its complications. The literature indicates that pro-inflammatory cytokines along with oxidative stress play a very important role in diabetes pathogenesis. Since inflammation is a main cause of disruption of the β cell structure, the anti-diabetic characteristic of curcumin is mainly attributed to its anti-inflammatory as well as anti-oxidant activities. In addition to these activities, curcumin has been developed as a promising prevention/treatment choice for diabetes complications by modulating various critical signal steps owing to the anti-hyperglycemic and anti-hyperlipidemic activities of curcumin. Studies on diabetic humans and animals have revealed that curcumin may have positive effects on oxidative stress and inflammation and may reduce fasting blood glucose levels, increase insulin sensitivity/secretion and regulate the lipid profile. Thus, it may prevent and treat diabetes by affecting various molecular targets.

Effect of natural polyphenols in Chinese herbal medicine on obesity and diabetes: Interactions among gut microbiota, metabolism, and immunity

With global prevalence, metabolic diseases, represented by obesity and type 2 diabetes mellitus (T2DM), have a huge burden on human health and medical expenses. It is estimated that obese population has doubled in recent 40 years, and population with diabetes will increase 1.5 times in next 25 years, which has inspired the pursuit of economical and effective prevention and treatment methods. Natural polyphenols are emerging as a class of natural bioactive compounds with potential beneficial effects on the alleviation of obesity and T2DM. In this review, we investigated the network interaction mechanism of "gut microbial disturbance, metabolic disorder, and immune imbalance" in both obesity and T2DM and systemically summarized their multiple targets in the treatment of obesity and T2DM, including enrichment of the beneficial gut microbiota (genera Bifidobacterium, Akkermansia, and Lactobacillus) and upregulation of the levels of gut microbiota-derived metabolites [short-chain fatty acids (SCFAs)] and bile acids (BAs). Moreover, we explored their effect on host glucolipid metabolism, the AMPK pathway, and immune modulation via the inhibition of pro-inflammatory immune cells (M1-like Mϕs, Th1, and Th17 cells); proliferation, recruitment, differentiation, and function; and related cytokines (TNF-α, IL-1β, IL-6, IL-17, and MCP-1). We hope to provide evidence to promote the clinical application of natural polyphenols in the management of obesity and T2DM.

The role of selected nutraceuticals in management of prediabetes and diabetes: An updated review of the literature

Dysglycemia is a disease state preceding the onset of diabetes and includes impaired fasting glycemia and impaired glucose tolerance. This review aimed to collect and analyze the literature reporting the results of clinical trials evaluating the effects of selected nutraceuticals on glycemia in humans. The results of the analyzed trials, generally, showed the positive effects of the nutraceuticals studied alone or in association with other supplements on fasting plasma glucose and post-prandial plasma glucose as primary outcomes, and their efficacy in improving insulin resistance as a secondary outcome. Some evidences, obtained from clinical trials, suggest a role for some nutraceuticals, and in particular Berberis, Banaba, Curcumin, and Guar gum, in the management of prediabetes and diabetes. However, contradictory results were found on the hypoglycemic effects of Morus, Ilex paraguariensis, Omega-3, Allium cepa, and Trigonella faenum graecum, whereby rigorous long-term clinical trials are needed to confirm these data. More studies are also needed for Eugenia jambolana, as well as for Ascophyllum nodosum and Fucus vesiculosus which glucose-lowering effects were observed when administered in combination, but not alone. Further trials are also needed for quercetin.

Study protocol to determine the effects of highly absorbable oral curcumin on the indicators of cognitive functioning: a double-blind randomised controlled trial

INTRODUCTION

Mild cognitive impairment (MCI) refers to a state in which cognitive functions, such as memory, have diminished but daily activities are largely unhampered. MCI is often overlooked but carries the risk of leading to development of dementia later. Curcumin is the main component of the natural herbal medicine turmeric. Curcumin is widely used as a health food and is an antioxidant that has anti-inflammatory and anti-amyloid actions. The current trial was designed to determine the effects of curcumin on indicators of cognitive functioning.

METHODS AND ANALYSIS

The current trial will be a single-centre randomised placebo-controlled double-blind parallel group trial. The participants will be 60 members of the general public with potential MCI, based on dementia screening using the Japanese version of the Mini Mental State Examination (MMSE-J). The investigational health food used in this trial will be a recently developed preparation for highly absorbable oral curcumin. This trial will determine the effects of the highly absorbable oral curcumin (brand name: curcuRouge) on the indicators of cognitive functioning, including the scores obtained with the MMSE-J, which is an interview-based measure of cognitive functioning, and the blood biomarkers that have been reported to be associated with dementia.

ETHICS AND DISSEMINATION

Informed written consent will be obtained from all the participants. The Ethical Review Board of the National Hospital Organization Kyoto Medical Center approved the study protocol.

TRIAL REGISTRATION NUMBER

University Hospital Medical Information Network (UMIN000042471).

Effects of high-absorption curcumin for the prevention of hypertensive heart disease: a double-blind, placebo-controlled, randomized clinical study

Aims

Hypertension is a strong risk factor for heart failure with preserved ejection fraction. Curcumin has p300-specific histone acetyltransferase inhibitory activity, suppresses cardiomyocyte hypertrophy and fibrosis, and significantly reduces myocardial brain natriuretic peptide (BNP) expression without altering blood pressure in a rat model of hypertensive heart disease. This double-blind, placebo-controlled, randomized study, for the first time, aimed to examine the efficacy of a high-absorption curcumin for the prevention of hypertensive heart disease in humans.

Methods and results

Patients exhibiting initial signs of hypertensive heart disease with left ventricular ejection fraction ≥60% and stable blood pressure <140/90 mmHg orally took a double-blinded capsule (either a 90 mg curcumin capsule or placebo) twice daily for 24 weeks. The primary endpoint was per cent changes in left ventricular diastolic function (E/E′) from baseline to 6 months after administration. The secondary endpoint was the per cent change in plasma BNP levels. The E/E′ ratio per cent change from baseline to 6 months after administration was similar between the placebo (n = 69) and the curcumin (n = 73) groups. The per cent change in plasma BNP levels was significantly lower in the curcumin group than in the placebo group. In patients <65 years, BNP per cent changes were significantly lower in the curcumin group than in the placebo group, but similar between groups in ≥65 years (<65 vs. ≥65 years: P for interaction = 0.011).

Conclusions

A high-absorption curcumin agent did not affect the E/E′ ratio, rather it significantly inhibited the increase in plasma BNP levels in patients with initial signs of hypertensive heart disease.

Polyphenols and atherosclerosis: A critical review of clinical effects on LDL oxidation

Atherosclerosis is a major etiology of cardiovascular disease that causes considerable mortality. Oxidized low-density lipoprotein (oxLDL) is a fundamental attributor to atherosclerosis. Therefore, there seems to be an essential place for antioxidant therapy besides the current treatment protocols for coronary heart disease. Polyphenols are a class of compounds with substantial antioxidant properties that have shown the ability to reduce LDL oxidation in preclinical studies. However, clinical evidence has not been as conclusive although offering many promising signs. This review aims to examine the trials that have evaluated how dietary intake of polyphenols in different forms might influence the oxidation of LDL. Lowering the circulating cholesterol, incorporation into LDL particles, and enhancing systemic antioxidant activity are among the main mechanisms of action for polyphenols for lowering oxLDL. On the other hand, the population under study significantly affects the impact on oxLDL, as the type of the supplement and phenolic content. To conclude, although the polyphenols might decrease inflammation and enhance endothelial function via lowering oxLDL, there are still many gaps in our knowledge that need to be filled with further high-quality studies.

Effects of curcumin on low-density lipoprotein oxidation: From experimental studies to clinical practice

Atherosclerosis is the most frequent cause of death globally. Oxidized low-density lipoprotein (ox-LDL) has an essential role in the formation of atherosclerotic plaques and foamy macrophages. Ox-LDL increases the uptake of cholesterol by macrophages and is the major cause of blood flow disruption. Ox-LDL is produced during oxidative stress and treatment with antioxidants could inhibit the production and function of ox-LDL. Curcumin is a potent antioxidant and has a strong track record in the treatment of numerous diseases. Recent studies indicate that Curcumin exerts a lipid-lowering effect, and can modulate the formation of atherosclerotic plaque. The current review focuses upon the role of Curcumin in oxidation of LDL and foam cell formation in atherosclerotic lesions.

Pyrazole-Curcumin Suppresses Cardiomyocyte Hypertrophy by Disrupting the CDK9/CyclinT1 Complex

The intrinsic histone acetyltransferase (HAT), p300, has an important role in the development and progression of heart failure. Curcumin (CUR), a natural p300-specific HAT inhibitor, suppresses hypertrophic responses and prevents deterioration of left-ventricular systolic function in heart-failure models. However, few structure–activity relationship studies on cardiomyocyte hypertrophy using CUR have been conducted. To evaluate if prenylated pyrazolo curcumin (PPC) and curcumin pyrazole (PyrC) can suppress cardiomyocyte hypertrophy, cultured cardiomyocytes were treated with CUR, PPC, or PyrC and then stimulated with phenylephrine (PE). PE-induced cardiomyocyte hypertrophy was inhibited by PyrC but not PPC at a lower concentration than CUR. Western blotting showed that PyrC suppressed PE-induced histone acetylation. However, an in vitro HAT assay showed that PyrC did not directly inhibit p300-HAT activity. As Cdk9 phosphorylates both RNA polymerase II and p300 and increases p300-HAT activity, the effects of CUR and PyrC on the kinase activity of Cdk9 were examined. Phosphorylation of p300 by Cdk9 was suppressed by PyrC. Immunoprecipitation-WB showed that PyrC inhibits Cdk9 binding to CyclinT1 in cultured cardiomyocytes. PyrC may prevent cardiomyocyte hypertrophic responses by indirectly suppressing both p300-HAT activity and RNA polymerase II transcription elongation activity via inhibition of Cdk9 kinase activity.

Curcumin - The Nutraceutical With Pleiotropic Effects? Which Cardiometabolic Subjects Might Benefit the Most?

Despite continuous advances in pharmacotherapy, atherosclerotic cardiovascular disease remains the world's leading killer. Atherosclerosis relates not only to an increased level of cholesterol, but involves the development of atherosclerotic plaques, which are formed as a result of processes including inflammation and oxidative stress. Therefore, in addition to the classical risk factors for ASCVD (such as type 2 diabetes, overweight, obesity, hypertension and metabolic syndrome), residual risk factors such as inflammation and oxidative stress should also be reduced. The most important intervention in ASCVD is prevention, which includes promoting a healthy diet based on products of natural origin. Curcumin, which is often present in the diet, has been demonstrate to confer several benefits to health. It has been shown in numerous clinical trials that curcumin exhibited anti-diabetic, lipid-lowering, antihypertensive, antioxidant and anti-inflammatory effects, as well as promoting weight loss. All this means that curcumin has a comprehensive impact on the most important risk factors of ASCVD and may be a beneficial support in the treatment of these diseases. Recently, it has also been shown that curcumin may have a beneficial effect on the course of SARS-CoV-2 infection and might be helpful in the prevention of long-COVID complications. The aim of this review is to summarize the current knowledge regarding the safety and efficacy of curcumin in the prevention and treatment of cardiometabolic diseases.

The effects of curcumin on anthropometric and cardiometabolic parameters of patients with metabolic related diseases: a systematic review and dose-effect meta-analysis of randomized controlled trials

Objective:To perform a meta-analysis of published randomized controlled trials (RCTs) to assess the effects of curcumin supplementation with different formulations on anthropometric and cardiometabolic indices in patients with metabolism-related diseases (MRDs). Methods: Six databases, including PubMed, Embase, Web of Science, China national knowledge internet (CNKI), Wanfang and China Biology Medicine (CBM), were systematically searched to find relevant articles from 2011 to July 2021. The effect sizes were expressed as weighted mean difference (WMD) with 95% confidence intervals (CI). Between-study heterogeneity was assessed using I2. Subgroup analysis was conducted to find possible sources of heterogeneity. Curcumin formulations in this study were divided as low bioavailability, high bioavailability and nanocurcumin. Results: Of the retrieved 1585 articles, 31 were included in the final analysis. Combined effect sizes suggested a significant effect of curcumin supplementation on reduced body weight (BW) (WMD: -0.94 kg, 95% CI: -1.40, -0.47) and body mass index (BMI) (WMD: -0.40 kg/m2, 95% CI: -0.60, -0.19), respectively. The results also showed significant improvements of fasting plasma glucose (FPG) (WMD: -0.50 mg/dL, 95% CI: -0.72, -0.28), glycosylated hemoglobin (Hb1Ac) (WMD: -0.42%, 95% CI: -0.57, -0.26), insulin (INS) (WMD: -1.70 μIU/mL, 95%CI: -2.03, -1.38), homeostasis model assessment-insulin resistance (HOMA-IR) (WMD: -0.71, 95%CI: -1.11, -0.31), high-density lipoprotein cholesterol (HDL-C) (WMD: 1.73 mg/dL, 95%CI: 0.78, 2.68) and high sensitivity C-reactive protein (Hs-CRP) (WMD: -1.11, 95%CI: -2.16, -0.05). Nanocurcumin showed a greater reduction in FPG (WMD: -1.78 mg/dL, 95% CI: -2.49, -1.07), INS (WMD: -1.66 μIU/mL, 95% CI: -3.21, -0.11), TC (WMD: -12.64 mg/dL (95% CI: -23.72, -1.57) and LDL-C (WMD: -8.95 mg/dL, 95% CI: -16.51, -1.38). The dose-effect analysis showed that there were trends of first rising and then falling between the supplemented curcumin dose and BW, BMI, LDL-C, Hb1Ac, which were clearly distinguished at 80 mg/d due to the strong effect of nanocurcumin on outcomes. A slow upward trend between the dose of curcumin supplementation and HDL-C. No relationships between dose and outcomes were found for FPG and insulin, except for nanocurcumin at 80 mg/d. Conclusions: Our study showed some significant beneficial effects of curcumin supplementation on improving BW, BMI, and the levels of FPG, Hb1Ac, HOMA-IR, HDL-C and Hs-CRP in patients with MRDs. Nanocurcumin may have a greater effect on the reduction of FPG, INS, TC and LDL-C than other curcumin formulations. Considering the potential bias and limitations of studies included, further quality studies with larger sample sizes are needed to confirm these results.

The Role of Natural Products on Diabetes Mellitus Treatment: A Systematic Review of Randomized Controlled Trials

The present study was carried out to relate the role of natural products in the metabolism of an increasingly prevalent disease, type 2 diabetes mellitus. At present, in addition to the pharmacological resources, an attempt is being made to treat diabetes mellitus with natural products. We carried out a systematic review of studies focusing on the role of natural products on diabetes mellitus treatment. The bibliographic search was done through Medline (Pubmed) and Web of Science. From 193 records, the title and summary of each were examined according to the criteria and whether they met the selection criteria. A total of 15 articles were included; after reviewing the literature, it is apparent that the concept of natural products is ambiguous as no clear boundary has been established between what is natural and what is synthetic, therefore we feel that a more explicit definition of the concept of "natural product" is needed. Gut microbiota is a promising therapeutic target in the treatment of diabetes. Therefore, it would be necessary to work on the relationship between the microbiome and the benefits in the treatment of diabetes mellitus. Treatment based solely on these natural products is not currently recommended as more studies are needed.

Improving Curcumin Bioavailability: Current Strategies and Future Perspectives

Curcumin possesses a plethora of interesting pharmacological effects. Unfortunately, it is also characterized by problematic drug delivery and scarce bioavailability, representing the main problem related to the use of this compound. Poor absorption, fast metabolism, and rapid systemic clearance are the most important factors contributing to low curcumin levels in plasma and tissues. Accordingly, to overcome these issues, numerous strategies have been proposed and are investigated in this article. Due to advances in the drug delivery field, we describe here the most promising strategies for increasing curcumin bioavailability, including the use of adjuvant, complexed/encapsulated curcumin, specific curcumin formulations, and curcumin nanoparticles. We analyze current strategies, already available in the market, and the most advanced technologies that can offer a future perspective for effective curcumin formulations. We focus the attention on the effectiveness of curcumin-based formulations in clinical trials, providing a comprehensive summary. Clinical trial results, employing various delivery methods for curcumin, showed that improved bioavailability corresponds to increased therapeutic efficacy. Furthermore, advances in the field of nanoparticles hold great promise for developing curcumin-based complexes as effective therapeutic agents. Summarizing, suitable delivery methods for this polyphenol will ensure the possibility of using curcumin-derived formulations in clinical practice as preventive and disease-modifying therapeutics.

Effect of curcumin on C-reactive protein as a biomarker of systemic inflammation: An updated meta-analysis of randomized controlled trials

It has been suggested that curcumin is a potential agent for lowering the levels of C-reactive protein (CRP) and high-sensitivity CRP (hs-CRP), as markers of inflammation. In the current meta-analysis, we attempted to clarify the efficacy of curcumin supplementation in lowering the concentrations of CRP and hs-CRP in patients with autoinflammatory conditions. Nine studies were found evaluating the effect of curcumin on CRP levels, while 23 studies were identified for hs-CRP. CRP concentration was decreased significantly compared to the placebo (WMD = -3.67 mg/L, 95% CI = -6.96 to -0.38, p = 0.02). There was a significant effect of curcumin at dose ≤1,000 mg/day on the CRP concentration. CRP concentration significantly decreased after >10-week intervention compared with placebo.hs-CRP concentration in the intervention group was significantly lower than that of placebo group. A significant effect of curcumin consumption was detected on the serum level of hs-CRP in studies with prescribing ≤1,000 mg/day, and those with ≤10-week duration of intervention. Curcumin consumption resulted in a reduction of hs-CRP in a non-linear fashion with stronger effects with less than 2000 mg curcumin per day. Curcumin seems to be beneficial in decreasing the hs-CRP and CRP levels in proinflammatory settings.

Efficacy and Safety of Curcumin Supplement on Improvement of Insulin Resistance in People with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background

Diabetes is a major public health concern. In addition, there is some evidence to support curcumin as part of a diabetes treatment program.

Methods

Data from randomized controlled trials were obtained to assess the effects of curcumin versus placebo or western medicine in patients with type 2 diabetes mellitus (T2DM). The study's registration number is CRD42018089528. The primary outcomes included homeostasis model assessment-insulin resistance (HOMA-IR), glycosylated hemoglobin (HbAlc), total cholesterol (TC), and triglyceride (TG).

Results

Four trials involving 453 patients were included. The HOMA-IR of curcumin group is lower in Asia (WMD: -2.41, 95% CI: -4.44 to -0.39, P=0.02) and the Middle East subgroups (WMD: -0.60, 95% CI: -0.74 to -0.46, P < 0.00001). The HbAlc in the curcumin group is lower than that in the control group (WMD: -0.69; 95% CI: -0.91, -0.48; P < 0.0001). The TC and TG levels of the curcumin group are lower in the Asia subgroup (TC: WMD: -23.45, 95% CI: -40.04 to -6.84, P=0.006; TG: WMD: -54.14, 95% CI: -95.71 to -12.57, P=0.01), while in the Middle East the difference was of not statistically significant (TC: WMD: 22.91, 95% CI: -16.94 to 62.75, P=0.26; TG: WMD: -4.56, 95% CI: -19.28 to 10.16, P=0.54).

Conclusion

Based on the current evidence, curcumin may assist in improving the insulin resistance, glycemic control, and decreased TG and TC in patients with T2DM.

The Effect of Curcumin in Improving Lipid Profile in Patients with Cardiovascular Risk Factors: A Systematic Review of Clinical Trials

Cardiovascular disease (CVD) is a major cause of death worldwide. Lipid abnormalities are one of the major risk factors for CVD. Curcumin is a natural polyphenol with lipid-lowering properties. Therefore, we carried out a systematic review to summarize the randomized controlled trials (RCTs) investigating the effect of curcumin on lipid profile in patients at risk of CVD. A comprehensive systematic search was conducted in PubMed, Scopus, Web of Science, and Google Scholar up to March 1, 2020, to identify controlled clinical trials assessing the effects of curcumin on lipid profile in patients at risk of CVD. From 1051 initially identified studies, 22 met the eligibility criteria. Curcumin supplementation significantly reduced at least one of the lipid profile indices (triglycerides, total cholesterol, low-density lipoprotein-cholesterol, and high-density lipoprotein-cholesterol) in 15 studies and improved more than one index in five studies. However, curcumin had no effect on any of lipid profile indices in seven studies. Overall, studies using a bioavailable formulation of curcumin had a better impact on the lipid profile. The findings of this systematic review showed that curcumin supplementation significantly reduced at least one of the lipid profile indices in more than two-thirds of the included studies. Curcumin might be used as an accessible, inexpensive, and safe agent to reduce risk of CVD. More randomized, clinical controlled trials are needed to verify these results.

Therapeutic potential of mitochondrial uncouplers for the treatment of metabolic associated fatty liver disease and NASH

Background

Mitochondrial uncouplers shuttle protons across the inner mitochondrial membrane via a pathway that is independent of adenosine triphosphate (ATP) synthase, thereby uncoupling nutrient oxidation from ATP production and dissipating the proton gradient as heat. While initial toxicity concerns hindered their therapeutic development in the early 1930s, there has been increased interest in exploring the therapeutic potential of mitochondrial uncouplers for the treatment of metabolic diseases.

Scope of review

In this review, we cover recent advances in the mechanisms by which mitochondrial uncouplers regulate biological processes and disease, with a particular focus on metabolic associated fatty liver disease (MAFLD), nonalcoholic hepatosteatosis (NASH), insulin resistance, and type 2 diabetes (T2D). We also discuss the challenges that remain to be addressed before synthetic and natural mitochondrial uncouplers can successfully enter the clinic.

Major conclusions

Rodent and non-human primate studies suggest that a myriad of small molecule mitochondrial uncouplers can safely reverse MAFLD/NASH with a wide therapeutic index. Despite this, further characterization of the tissue- and cell-specific effects of mitochondrial uncouplers is needed. We propose targeting the dosing of mitochondrial uncouplers to specific tissues such as the liver and/or developing molecules with self-limiting properties to induce a subtle and sustained increase in mitochondrial inefficiency, thereby avoiding systemic toxicity concerns.

The Effects of Curcumin on Diabetes Mellitus: A Systematic Review

Diabetes mellitus (DM) is an ensemble of metabolic conditions that have reached pandemic proportions worldwide. Pathology's multifactorial nature makes patient management, including lifelong drug therapy and lifestyle modification, extremely challenging. Currently, there is growing evidence about the effectiveness of using herbal supplements in preventing and controlling DM. Curcumin is a bioactive component found Curcuma longa, which exhibits several physiological and pharmacological properties such as antioxidant, anti-inflammatory, anticancer, neuroprotective, and anti-diabetic activities. For these reasons, our objective is to systematically review the effects of Curcuma longa or curcumin on DM. Databases such as PUBMED and EMBASE were searched, and the final selection included sixteen studies that fulfilled the inclusion criteria. The results showed that curcumin's anti-diabetic activity might be due to its capacity to suppress oxidative stress and inflammatory process. Also, it significantly reduces fasting blood glucose, glycated hemoglobin, and body mass index. Nanocurcumin is also associated with a significant reduction in triglycerides, VLDL-c, total cholesterol, LDL-c, HDL-c, serum C reactive protein, and plasma malonaldehyde. Therefore, it can be considered in the therapeutic approach of patients with DM.

Toward Regulatory Effects of Curcumin on Transforming Growth Factor-Beta Across Different Diseases: A Review

Immune response, proliferation, migration and angiogenesis are juts a few of cellular events that are regulated by transforming growth factor-β (TGF-β) in cells. A number of studies have documented that TGF-β undergoes abnormal expression in different diseases, e.g., diabetes, cancer, fibrosis, asthma, arthritis, among others. This has led to great fascination into this signaling pathway and developing agents with modulatory impact on TGF-β. Curcumin, a natural-based compound, is obtained from rhizome and roots of turmeric plant. It has a number of pharmacological activities including antioxidant, anti-inflammatory, anti-tumor, anti-diabetes and so on. Noteworthy, it has been demonstrated that curcumin affects different molecular signaling pathways such as Wnt/β-catenin, Nrf2, AMPK, mitogen-activated protein kinase and so on. In the present review, we evaluate the potential of curcumin in regulation of TGF-β signaling pathway to corelate it with therapeutic impacts of curcumin. By modulation of TGF-β (both upregulation and down-regulation), curcumin ameliorates fibrosis, neurological disorders, liver disease, diabetes and asthma. Besides, curcumin targets TGF-β signaling pathway which is capable of suppressing proliferation of tumor cells and invading cancer cells.

The effects of curcumin intake on wound healing and metabolic status in patients with diabetic foot ulcer: A randomized, double-blind, placebo-controlled trial

This study was conducted to determine the effects of curcumin intake on wound healing and metabolic status in patients with diabetic foot ulcer (DFU). The current randomized, double-blind, placebo-controlled trial was conducted among 60 patients with grade 3 DFU. Participants were randomly allocated into two groups (30 participants each group), received either 80 mg nanocurcumin daily for 12 weeks or placebo. Primary endpoints in this study were serum insulin levels and insulin resistance. Curcumin intake significantly decreased fasting plasma glucose (p = .02), insulin (p = .01), insulin resistance (p = .02), and significantly increased insulin sensitivity (p = .008) compared with the placebo. Moreover, curcumin intake led to a significant reduction in total- (p < .001), LDL-cholesterol (p < .001), and a significant increase in total antioxidant capacity (TAC) (p < .001) and total glutathione (GSH) (p = .01) compared with the placebo. However, there was no significant improvement in wound healing parameters. Overall, our study demonstrated that nanocurcumin intake in patients with DFU resulted in a significant improvement of glycemic control, total- and LDL-cholesterol, TAC, and GSH but did not affect the indicators of ulcer size.

Natural products and phytochemical nanoformulations targeting mitochondria in oncotherapy: an updated review on resveratrol

Mitochondria are intracellular organelles with two distinct membranes, known as an outer mitochondrial membrane and inner cell membrane. Originally, mitochondria have been derived from bacteria. The main function of mitochondria is the production of ATP. However, this important organelle indirectly protects cells by consuming oxygen in the route of energy generation. It has been found that mitochondria are actively involved in the induction of the intrinsic pathways of apoptosis. So, there have been efforts to sustain mitochondrial homeostasis and inhibit its dysfunction. Notably, due to the potential role of mitochondria in the stimulation of apoptosis, this organelle is a promising target in cancer therapy. Resveratrol is a non-flavonoid polyphenol that exhibits significant pharmacological effects such as antioxidant, anti-diabetic, anti-inflammatory and anti-tumor. The anti-tumor activity of resveratrol may be a consequence of its effect on mitochondria. Multiple studies have investigated the relationship between resveratrol and mitochondria, and it has been demonstrated that resveratrol is able to significantly enhance the concentration of reactive oxygen species, leading to the mitochondrial dysfunction and consequently, apoptosis induction. A number of signaling pathways such as sirtuin and NF-κB may contribute to the mitochondrial-mediated apoptosis by resveratrol. Besides, resveratrol shifts cellular metabolism from glycolysis into mitochondrial respiration to induce cellular death in cancer cells. In the present review, we discuss the possible interactions between resveratrol and mitochondria, and its potential application in cancer therapy.