Effects of dietary polyphenol curcumin supplementation on metabolic, inflammatory, and oxidative stress indices in patients with metabolic syndrome: a systematic review and meta-analysis of randomized controlled trials

The PI3K/Akt pathway: a target for curcumin's therapeutic effects

Purpose

The purpose of this review study is to investigate the effect of curcumin on the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt) signaling pathway in various diseases. Curcumin, the main compound found in turmeric, has attracted a lot of attention for its diverse pharmacological properties. These properties have increased the therapeutic potential of curcumin in chronic diseases such as cardiovascular disease, Type 2 diabetes, obesity, non-alcoholic fatty liver disease, kidney disease, and neurodegenerative diseases. One of the main mechanisms of the effect of curcumin on health is its ability to modulate the PI3K/Akt signaling pathway. This pathway plays an important role in regulating vital cellular processes such as growth, cell survival, metabolism, and apoptosis. Disruption of the PI3K/Akt signaling pathway is associated with the incidence of several diseases.

Methods

Electronic databases including PubMed, Google Scholar, and Scopus were searched with the keywords "phosphoinositide 3-kinase" AND "protein kinase B "AND "curcumin" in the title/abstract. Also, following keywords "non-alcoholic fatty liver disease" AND "diabetes" AND "obesity" AND "kidney disease" and "neurodegenerative diseases" was searched in the whole text.

Results

Research indicates that curcumin offers potential benefits for several health conditions. Studies have shown it can help regulate blood sugar, reduce inflammation, and protect the heart, kidneys, and brain.

Conclusion

This protective effect is partially achieved by regulating the PI3K-Akt survival pathway, which helps improve metabolic disorders and oxidative stress. By examining how curcumin affects this vital cell pathway, researchers can discover new treatment strategies for a range of diseases.

Effects of Nanocurcumin Supplementation on Metabolic Syndrome: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Metabolic syndrome (MetS) encompasses metabolic risk factors like elevated blood glucose, abnormal lipid levels, and hypertension. Nanocurcumin, a nanoscale formulation of curcumin, may offer therapeutic benefits for MetS management. This systematic review and meta-analysis evaluates the impact of nanocurcumin supplementation on key MetS parameters.

METHODS

A systematic literature search identified 20 randomized controlled trials (RCTs) with 1,394 participants. Data were pooled using a random-effects model, and standardized mean differences (SMDs) were calculated for key outcomes.

RESULTS

Nanocurcumin supplementation significantly improved waist circumference (WC) (standardized mean difference (SMD): -0.30cm), fasting blood sugar (FBS) (SMD: -0.34mg/dL), HbA1c (SMD: -0.33%), and quantitative insulin sensitivity check index (QUICKI) score (SMD: 0.73). Lipid profile parameters, including total cholesterol (SMD: -0.18mg/dL), LDL-C (SMD: -0.16mg/dL), and HDL-C (SMD: 0.32mg/dL), also reduced significantly. Improvement in diastolic blood pressure (DBP) (SMD: -0.32mmHg), total antioxidant capacity (TAC) (SMD: 0.44mmol/L), malondialdehyde (MDA) (SMD: -0.37mmol/L), tumor necrosis factor-α (TNF-α) (SMD: -2.30ng/L), interleukin-6 (IL-6) (SMD: -1.07ng/L), and high-sensitivity C-reactive protein (hs-CRP) (SMD: -0.34mg/L) were observed.

CONCLUSION

Nanocurcumin supplementation significantly improves multiple MetS-related parameters, including anthropometric measures, glycemic control, lipid profile, blood pressure, oxidative stress markers, and inflammatory biomarkers. These findings highlight nanocurcumin's potential as an effective adjunctive therapy for managing MetS. However, the variability in study participant ages, treatment durations, and sample sizes suggests the need for further well-designed RCTs to establish optimal usage guidelines.

Exploring the role of curcumin in mitigating oxidative stress to alleviate lipid metabolism disorders

Lipid metabolism plays a crucial role in maintaining homeostasis and overall health, as lipids are essential molecules involved in bioenergetic processes. An increasing body of research indicates that disorders of lipid metabolism can contribute to the development and progression of various diseases, including hyperlipidemia, obesity, non-alcoholic fatty liver disease (NAFLD), diabetes mellitus, atherosclerosis, and cancer, potentially leading to poor prognoses. The activation of the oxidative stress pathway disrupts lipid metabolism and induces cellular stress, significantly contributing to metabolic disorders. A well-documented crosstalk and interconnection between these metabolic disorders exists. Consequently, researchers have sought to identify antioxidant-rich substances in readily accessible everyday foods for potential use as complementary therapies. Curcumin, known for its anti-inflammatory and antioxidant properties, has been shown to enhance cellular antioxidant activity, mitigate oxidative stress, and alleviate lipid metabolism disorders by reducing reactive oxygen species (ROS) accumulation. These effects include decreasing fat deposition, increasing fatty acid uptake, and improving insulin sensitivity. A review of the existing literature reveals numerous studies emphasizing the role of curcumin in the prevention and management of metabolic diseases. Curcumin influences metabolic disorders through multiple mechanisms of action, with the oxidative stress pathway playing a central role in various lipid metabolism disorders. Thus, we aimed to elucidate the role of curcumin in various metabolic disorders through a unified mechanism of action, offering new insights into the prevention and treatment of metabolic diseases. Firstly, this article provides a brief overview of the basic pathophysiological processes of oxidative stress and lipid metabolism, as well as the role of oxidative stress in the pathogenesis of lipid metabolism disorders. Notably, the article reviews the role of curcumin in mitigating oxidative stress and in preventing and treating diseases associated with lipid metabolism disorders, including hyperlipidemia, non-alcoholic fatty liver disease (NAFLD), atherosclerosis, obesity, and diabetes, thereby highlighting the therapeutic potential of curcumin in lipid metabolism-related diseases.

Plant Polyphenols as Heart's Best Friends: From Health Properties, to Cellular Effects, to Molecular Mechanisms of Action

Polyphenols are micronutrients found in fruits, vegetables, tea, coffee, cocoa, medicinal herbs, fish, crustaceans, and algae. They can also be synthesized using recombinant microorganisms. Interest in plant-derived natural compounds has grown due to their potential therapeutic effects with minimal side effects. This is particularly important as the aging population faces increasing rates of chronic diseases such as cancer, diabetes, arthritis, cardiovascular, and neurological disorders. Studies have highlighted polyphenols' capacity to reduce risk factors linked to the onset of chronic illnesses. This narrative review discusses polyphenol families and their metabolism, and the cardioprotective effects of polyphenols evidenced from in vitro studies, as well as from in vivo studies, on different animal models of cardiac disease. This study also explores the molecular mechanisms underlying these benefits. Current research suggests that polyphenols may protect against ischemia, hypertension, cardiac hypertrophy, heart failure, and myocardial injury through complex mechanisms, including epigenetic and genomic modulation. However, further studies under nutritionally and physiologically relevant conditions, using untargeted multigenomic approaches, are needed to more comprehensively elucidate these mechanisms and firmly prove the cardioprotective effects of polyphenols.

Natural Products in the Clinical Management of Metabolic Syndrome

Metabolic syndrome (MetS) is a prevalent health condition that requires significant attention and intervention due to its multifaceted nature. It encompasses a variety of ailments such as diabetes mellitus, hypertension, obesity, and dyslipidemia. Despite extensive research, the underlying pathophysiology of MetS is not entirely understood, and current synthetic drugs used to treat it have adverse effects and can be expensive. Therefore, natural products are being investigated as a potential alternative treatment for MetS. This chapter provides an overview of studies on natural products as a treatment for MetS. The available evidence suggests that bioactive phytochemicals and herbal medicines, such as curcumin, resveratrol, Nigella sativa, Hibiscus sabdariffa, and Theobroma cacao, have the potential to treat MetS effectively. Furthermore, natural products can be explored as a novel drug discovery approach for MetS. However, it is imperative to conduct well-designed randomized controlled trials with large sample sizes to confirm these findings. Based on our review, we conclude that natural products could be a promising alternative for treating MetS. Further research is warranted to explore this potential fully. The use of natural products for MetS treatment could reduce the reliance on synthetic drugs, many of which have harmful side effects and are costly. The development of natural products as a treatment for MetS could have significant implications for public health, and we encourage further research in this area.

Efficacy and safety of dietary polyphenol administration as assessed by hormonal, glycolipid metabolism, inflammation and oxidative stress parameters in patients with PCOS: a meta-analysis and systematic review

BACKGROUND

The current knowledge about the efficacy and safety of dietary polyphenol administration in patients with polycystic ovarian syndrome (PCOS) is divergent.

OBJECTIVE

To evaluate the pooled efficacy and safety of dietary polyphenol administration in the treatment of patients with PCOS.

METHODS

The pubmed, Embase, Scopus, Cochrane Library, and Web of Science databases were searched for randomized controlled trials (RCTs) of dietary polyphenol administration for the treatment of PCOS. English-language RCTs involving adults with PCOS were thoroughly searched in electronic databases from the time of their establishment to May 2024. Random-effects models were used because heterogeneity was derived from differences in intervention materials and study duration, among other confounding factors. The effect sizes of the outcomes in the pooled analysis are expressed as weighted mean differences (WMDs) and 95% confidence intervals (CIs).

RESULTS

A total of 15 RCTs involving 934 patients were finally included. Compared with control treatments, dietary polyphenol administration significantly reduced luteinizing hormone (LH) (WMD: -0.85, 95% CI [-1.32 to -0.38], p = 0.00), and prolactin levels (WMD: -3.73, 95% CI [-6.73 to -0.74], p = 0.01). Dietary polyphenol administration significantly reduced insulin levels (WMD: -0.85, 95% CI [-1.32 to -0.38], p = 0.00). Regarding lipid metabolism, dietary polyphenol administration only reduced triglyceride levels (WMD: -8.96, 95% CI [-16.44 to -1.49], p = 0.02). Malondialdehyde (MDA) (WMD: -0.65, 95% CI [-0.68 to -0.62], p = 0.00), tumor necrosis factor (TNF-α) (WMD: -1.39, 95% CI [-2.41 to -0.37], p = 0.01) concentrations were significantly reduced by dietary polyphenol administration. None of the interventions significantly affected weight, body mass index (BMI), waist circumference (WC), homeostatic model-insulin resistance (HOMA-IR), fasting blood sugar (FBS), glycated hemoglobin (HBA1c), follicle-stimulating hormone (FSH), testosterone (T), dehydroepiandrosterone (DHEA), estradiol (E2), anti-Müllerian hormone (AMH), quantitative insulin-sensitivity check index (QUICKI), sex hormone-binding globulin (SHBG), total antioxidant capacity (TAC), C-peptide, C-reactive protein (CRP), high-density lipoprotein (HDL), low-density lipoprotein (LDL), cholesterol, cholesterol/HDL, acne score, thyroid-stimulating hormone (TSH), aspartate aminotransferase (AST), alanine aminotransferase (ALT) or alkaline phosphatase (ALP).

CONCLUSION

Dietary polyphenol administration was efficacious in patients with PCOS in our study. This review might provide new insight into the treatment of patients with PCOS and the potential of daily polyphenol supplementation in patients with PCOS. Nevertheless, these results must be interpreted carefully as a result of the heterogeneity and risk of bias among the studies and we expect that more high-quality RCTs evaluating the efficacy and safety of dietary polyphenol adnimistration in patients with PCOS will be conducted in the future.

SYSTEMATIC REVIEW REGISTRATION

CRD42024498494.

The effect of curcumin supplementation on glycemic indices in adults: A meta-analysis of meta-analyses

Curcumin, an inherent polyphenolic compound, has the potential to influence glycemic indices. Nevertheless, the conclusions drawn from extant meta-analyses remain contentious. To determine the impact of curcumin supplementation on these indices, the current umbrella meta-analysis included existing systematic reviews and meta-analyses. A thorough systematic search was conducted using databases Embase, PubMed, WOS, Scopus, and the Cochrane Library to acquire peer-reviewed literature published before January 2024. The random-effects model was employed to conduct a meta-analysis. The present analysis incorporated a total of 22 meta-analytic studies. The findings of our study indicate that the administration of curcumin supplements leads to a significant decrease in fasting blood sugar levels (FBS) (ES: -1.63; 95 % CI: -2.36, -0.89, P<0.001; I2=88.4 %, P<0.001), homeostasis model assessment-estimated insulin resistance (HOMA-IR) (ES: -0.38; 95 % CI: -0.48, -0.28, P<0.001; I2=35.9 %, P=0.142), hemoglobin A1c (HbA1c) (ES: -0.44; 95 % CI: -0.67, -0.21, P<0.001; I2=65.0 %, P=0.014), and insulin (ES: -0.86; 95 % CI: -1.52, -0.21, P=0.010; I2=92.5 %, P<0.001). The results of this study suggest that the administration of curcumin supplements may be a beneficial intervention for enhancing glycemic indices.

The effect of curcumin supplementation on endothelial function and blood pressure in patients with metabolic disorders: A meta-analysis of meta-analyses

Several interventional studies have revealed the beneficial impact of curcumin supplementation on blood pressure and endothelial function, but the findings are conflicting. Therefore, this study was conducted to investigate the effects of curcumin supplementation on blood pressure and endothelial function. A meta-analyses of randomized clinical trials were performed by searching PubMed, Embase, Scopus, and Web of Science were searched up to March 31, 2024. Random effects models were used to calculate weighted mean differences (WMD). Pooled estimates of 10 studies revealed that curcumin decreased diastolic blood pressure (DBP) [WMD = -0.94, 95 % CI: -1.59, -0.30; p = 0.004], pulse wave velocity (PWV) [WMD = -45.60, 95 % CI: -88.16, -3.04; p = 0.03, I2 = 0.0 %, p = 0.59], and vascular cell adhesion molecule-1 (VCAM-1) [WMD = -39.19; 95 % CI: -66.15, -12.23, p =0.004; I2=73.0 %, p = 0.005] significantly, and increased flow-mediated dilation (FMD) [WMD = 1.64, 95 % CI: 1.06, 2.22; p < 0.001, I2 = 0.0 %, p = 0.61. However, curcumin did not significantly change systolic blood pressure (SBP) [WMD = -0.64, 95 % CI: -1.96, 0.67; p =0.34, I2 = 83.5 %, p <0.001], and Intercellular Adhesion Molecule 1 (ICAM1) [WMD = -17.05; 95 % CI: -80.79, 46.70, p =0.601; I2=94.1 %, p < 0.001]. These results suggest that curcumin has a beneficial effect on DBP, PWV, VCAM-1 and FMD levels and may be an effective adjunctive therapy for improving blood pressure and endothelial function.

Curcumin on Human Health: A Comprehensive Systematic Review and Meta-Analysis of 103 Randomized Controlled Trials

The aim of this meta-analysis was to determine the effect of curcumin on a range of health outcomes. PubMed, EMBASE, Scopus, and Web of Science were searched from inception until September 2023. Randomized clinical trials (RCTs) that compared the effect of Curcuma longa L. with placebo were considered eligible. The risk of bias and overall certainty of evidence were assessed using the Newcastle-Ottawa Scale and Grading of Recommendations Assessment, Development, and Evaluation (GRADE), respectively. We meta-analyzed the effect sizes across eligible studies using the random-effects model. In total, 103 RCTs on 42 outcomes were included, incorporating a total population of 7216 participants. Overall, 23 out of 42 (55%) outcomes reported statistically significant effect sizes. The credibility of the evidence was rated as high for fasting blood sugar (FBS), C-reactive protein (CRP), high-density lipoprotein (HDL), and weight. The remaining outcomes presented moderate (waist circumference [WC], hip circumference [HC], body mass index [BMI], insulin, Homeostatic Model Assessment for Insulin Resistance [HOMA-IR], quantitative insulin-sensitivity check index [QUICKI], leptin, gamma-glutamyl transferase [GGT], glutathione [GSH], and superoxide dismutase [SOD]), low (14 outcomes), or very low (14 outcomes) evidence. In conclusion, curcumin supplementation can modify FBS and some glycemic indices, lipid parameters, as well as inflammatory and oxidative parameters. This updated summary of the accumulated evidence may help inform clinicians and future guidelines regarding medical and scientific interest in curcumin. However, due to limitations in the methodological quality of the included studies, well-designed and long-term RCTs with large sample sizes are needed. Trial registration: PROSPERO: CRD42021251969.

Systematic Review and Meta-Analysis of Sclerocarya birrea on Metabolic Disorders: Evidence from Preclinical Studies

BACKGROUND/OBJECTIVES

Metabolic disorders, including diabetes, obesity, and cardiovascular diseases, are significant global health issues. Nutraceuticals, such as Sclerocarya birrea (SB), known for its high polyphenol content, are increasingly explored for managing these conditions. This study aims to evaluate the antihyperglycemic, hypolipidemic, and antihypertensive effects of SB in animal models to understand its potential as a natural intervention for metabolic diseases.

METHODS

A systematic review and meta-analysis were conducted according to PRISMA guidelines. Searches across databases like PubMed, Web of Science, Embase, and Scopus identified studies using SB in animal models of metabolic disorders. Inclusion criteria were studies with SB intervention, control groups, and quantitative measures of metabolic parameters. The study was registered with INPLASY (INPLASY2024100031).

RESULTS

The meta-analysis revealed that SB significantly reduces blood glucose levels in diabetic animal models. Acute administration of SB showed a pooled standardized mean difference (SMD) of -7.13 (95% CI: -11.44 to -2.83) at 1 h and -9.75 (95% CI: -15.92 to -3.59) at 2-4 h post-administration. Chronic administration indicated a non-significant reduction in glucose levels (SMD: -5.69, 95% CI: -16.38 to 5.01).

CONCLUSIONS

SB appears to have the potential for reducing blood glucose levels and may offer benefits for other cardiometabolic risk factors, including lipid profiles and oxidative stress. However, variability in the results underscores the need for further research, including standardized animal studies and clinical trials, to confirm these effects and clarify the mechanisms by which SB may impact metabolic disorders.

The effects of curcumin supplementation on biomarkers of inflammation, oxidative stress, and endothelial function: A meta-analysis of meta-analyses

Numerous interventional studies have revealed the beneficial impact of curcumin supplementation on inflammation, oxidative stress, and endothelial function biomarkers, but the findings are still inconsistent. Thus, this study was conducted to investigate the effects of curcumin supplementation on inflammation, oxidative stress, and endothelial function biomarkers. A meta-analyses of randomized clinical trials was performed by searching PubMed, Embase, Scopus, and Web of Science up to March 31, 2024. Pooled estimates of 21 meta-analyses revealed that curcumin significantly reduced CRP (weighted mean difference (WMD) = -0.87; 95 % CI: - 1.14, - 0.59, P< 0.001), tumor-necrosis factor-alpha (TNF-α) (WMD = -2.72; 95 % CI: -4.05, -1.38; P< 0.001), interleukin-6 (IL-6) (WMD = -0.97, 95 % CI: -1.40, -0.54; P< 0.001), malondialdehyde (MDA) (Effect size (ES) = -0.81; 95 % CI: -1.39, -0.23, P = 0.006) and pulse wave velocity (PWV) (WMD = -45.60; 95 % CI: -88.16, -3.04, P = 0.036), and increased flow-mediated dilation (FMD) (WMD = 1.64, 95 % CI: 1.06, 2.22, P < 0.001), catalase (CAT) (WMD = 10.26; 95 % CI: 0.92, 19.61, P= 0.03), glutathione peroxidase (GPx) (WMD = 8.90; 95 % CI: 6.62, 11.19, P <0.001), and superoxide dismutase (SOD) levels (WMD = 20.51; 95 % CI: 7.35, 33.67, P= 0.002 and SMD = 0.82; 95 % CI: 0.27, 1.38, P= 0.004). However, curcumin did not significantly change total antioxidant capacity (TAC) (ES = 0.29; 95 % CI: -0.09, 0.66, P= 0.059). These results suggest that curcumin has a beneficial effect on CRP, IL-6, TNF-α, SOD, GPx, CAT, MDA, PWV, and FMD levels and may be an effective adjunctive therapy for improving inflammation, oxidative stress, and endothelial function. Registration number: PROSPERO, CRD42024539018.

The therapeutic effect and possible mechanisms of alginate oligosaccharide on metabolic syndrome by regulating gut microbiota

Metabolic syndrome (MetS) is a disease condition incorporating the abnormal accumulation of various metabolic components, including overweight or abdominal obesity, insulin resistance and abnormal glucose tolerance, hypertension, atherosclerosis, or dyslipidemia. It has been proved that the gut microbiota and microbial-derived products play an important role in regulating lipid metabolism and thus the onset and development of MetS. Previous studies have demonstrated that oligosaccharides with prebiotic effects, such as chitosan oligosaccharides, can regulate the structure of the microbial community and its derived products to control weight and reduce MetS associated with obesity. Alginate oligosaccharides (AOS), natural products extracted from degraded alginate salts with high solubility and extensive biological activity, have also been found to modulate gut microbiota. This review aims to summarize experimental evidence on the positive effects of AOS on different types of MetS while providing insights into mechanisms through which AOS regulates gut microbiota for preventing and treating MetS.

Effects of Curcumin on Radiation/Chemotherapy-Induced Oral Mucositis: Combined Meta-Analysis, Network Pharmacology, Molecular Docking, and Molecular Dynamics Simulation

The study aims to investigate the effects of curcumin on radiation/chemotherapy-induced oral mucositis (R/CIOM) and preliminarily explore its mechanism. Randomized controlled trials were identified from the PubMed, Embase, Web of Science, Cochrane Library, Medline, and Google Scholar databases. RevMan 5.4 was used for statistical analysis to calculate the combined risk ratios (RRs). The mechanism was analyzed through network pharmacology, molecular docking, and a molecular dynamics simulation. The targets of curcumin were collected in HERB, PharmMapper, Targetnet, Swiss Target Prediction, and SuperPred. OMIM, GeneCards, and Disgenet were used to collect relevant targets for R/CIOM. Cytoscape software 3.8.0 was used to construct the component-target-pathway network. Protein-Protein Interaction (PPI) networks were constructed using the STRING database. GO and KEGG enrichment analyses were performed by Metascape. AutoDock Vina 4.2 software was used for molecular docking. The molecular dynamics simulation was performed by Gromacs v2022.03. It is found that 12 studies involving 565 patients were included. Meta-analyses showed that curcumin reduced the incidence of severe R/CIOM (RR 0.42 [0.24, 0.75]) and the mean severity of R/CIOM (MD -0.93 [-1.34, -0.52]). Eleven core target genes were identified in the treatment of R/CIOM with curcumin. The results of molecular docking and the molecular dynamics simulation showed that curcumin had strong binding energy and stability with target proteins including MAPK3, SRC, and TNF. Overall, these findings suggest curcumin can effectively improve severe R/CIOM, perhaps by affecting MAPK3, SRC, and TNF.

Maternal Polyphenols and Offspring Cardiovascular-Kidney-Metabolic Health

BACKGROUND

The convergence of cardiovascular, kidney, and metabolic disorders at the pathophysiological level has led to the recognition of cardiovascular-kidney-metabolic (CKM) syndrome, which represents a significant global health challenge. Polyphenols, a group of phytochemicals, have demonstrated potential health-promoting effects.

METHODS

This review highlights the impact of maternal polyphenol supplementation on the CKM health of offspring.

RESULTS

Initially, we summarize the interconnections between polyphenols and each aspect of CKM syndrome. We then discuss in vivo studies that have investigated the use of polyphenols during pregnancy and breastfeeding, focusing on their role in preventing CKM syndrome in offspring. Additionally, we explore the common mechanisms underlying the protective effects of maternal polyphenol supplementation.

CONCLUSIONS

Overall, this review underscores the potential of early-life polyphenol interventions in safeguarding against CKM syndrome in offspring. It emphasizes the importance of continued research to advance our understanding and facilitate the clinical translation of these interventions.

Curcumin Supplementation and Vascular and Cognitive Function in Chronic Kidney Disease: A Randomized Controlled Trial

Chronic kidney disease (CKD) increases the risk of cardiovascular disease and cognitive impairment. Curcumin is a polyphenol that improves vascular and cognitive function in older adults; however, its effects on vascular and cognitive function in patients with CKD are unknown. We hypothesized that curcumin supplementation would improve vascular and cognitive function in patients with CKD. Eighty-eight adults diagnosed with stage 3b or 4 CKD (aged 66 ± 8 years, 75% male) participated in a 12-month, randomized, double-blind, placebo-controlled study to test the effects of curcumin (Longvida®, 2000 mg/day) on vascular and cognitive function. Our primary outcome was brachial artery flow-mediated dilation (FMD). Our secondary outcomes were nitroglycerin-mediated dilation, carotid-femoral pulse wave velocity (cfPWV), and cognitive function assessed via the NIH Toolbox Cognition Battery. At baseline, the mean estimated glomerular filtration rate was 34.7 ± 10.8, and the median albumin/creatinine ratio was 81.9 (9.7, 417.3). A total of 44% of participants had diabetes. Compared with placebo, 12 months of curcumin did not improve FMD (median change from baseline was -0.7 (-2.1, 1.1) and -0.1 (-1.5, 1.5) for curcumin and placebo, respectively, with p = 0.69). Similarly, there were no changes in nitroglycerin-mediated dilation, cfPWV, or cognitive outcomes. These results do not support chronic curcumin supplementation to improve vascular and cognitive function in patients with CKD.

Biomaterials Designed to Modulate Reactive Oxygen Species for Enhanced Bone Regeneration in Diabetic Conditions

Diabetes mellitus, characterized by enduring hyperglycemia, precipitates oxidative stress, engendering a spectrum of complications, notably increased bone vulnerability. The genesis of reactive oxygen species (ROS), a byproduct of oxygen metabolism, instigates oxidative detriment and impairs bone metabolism in diabetic conditions. This review delves into the mechanisms of ROS generation and its impact on bone homeostasis within the context of diabetes. Furthermore, the review summarizes the cutting-edge progress in the development of ROS-neutralizing biomaterials tailored for the amelioration of diabetic osteopathy. These biomaterials are engineered to modulate ROS dynamics, thereby mitigating inflammatory responses and facilitating bone repair. Additionally, the challenges and therapeutic prospects of ROS-targeted biomaterials in clinical application of diabetic bone disease treatment is addressed.

Potential Benefit of Spices for Glycemic Control

The prevalence of hyperglycemia is increasing worldwide in large part due to the escalating prevalence of obesity. It can occur along with other disorders and diseases, contributing to escalating health costs and accumulating disabilities. Besides dietary approaches and availability of antidiabetic medications, other complementary approaches and adjunct therapies using biologically active botanical phytochemicals have received growing attention for managing type 2 diabetes mellitus. Spices are one source of these bioactive plant constituents, and considerable preclinical studies have investigated their possible health benefits. There also are an increasing number of human clinical trials assessing the ability of spices and their individual plant constituents to improve glucose homeostasis in those with type 2 diabetes mellitus and other dysglycemic conditions. This narrative review provides a summary of the human studies evaluating the effects of select spices on glucose homeostasis and highlights areas for future research.

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.

Regulatory effects of curcumin on nitric oxide signaling in the cardiovascular system

The continuously rising prevalence of cardiovascular disease (CVD) globally substantially impacts the economic growth of developing countries. Indeed, one of the leading causes of death worldwide is unfavorable cardiovascular events. Reduced nitric oxide (NO) generation is the pathogenic foundation of endothelial dysfunction, which is regarded as the first stage in the development of a number of CVDs. Nitric oxide exerts an array of biological effects, including vasodilation, the suppression of vascular smooth muscle cell proliferation and the functional control of cardiac cells. Numerous treatment strategies aim to increase NO synthesis or upregulate downstream NO signaling pathways. The major component of Curcuma longa, curcumin, has long been utilized in traditional medicine to treat various illnesses, especially CVDs. Curcumin improves CV function as well as having important pleiotropic effects, such as anti-inflammatory and antioxidant, through its ability to increase the bioavailability of NO and to positively impact NO-related signaling pathways. In this review, we discuss the scientific literature relating to curcumin's positive effects on NO signaling and vascular endothelial function.