Curcumin and long-chain Omega-3 polyunsaturated fatty acids for Prevention of type 2 Diabetes (COP-D): study protocol for a randomised controlled trial

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.

Anti-Neuroinflammatory Properties of n-3 Fatty Acids and Nano- Curcumin on Migraine Patients from Cellular to Clinical Insight: A Randomized, Double-Blind and Placebo-Controlled Trial

BACKGROUND AND OBJECTIVES

Migraine is an exhausting neuro-inflammatory disorder recognized as recurrent headache attacks. Evidence has shown that Interleukin (IL)-1β plays a substantial role in the neuro-immunity pathogenicity of migraine. n-3 fatty acids and curcumin revealed neuromodulatory and anti-inflammatory effects through several pathways, of which the suppression of IL-1β gene expression is an important inflammatory pathway. The aim of this study was the investigation of synergistic relation of n -3 fatty acids and nano-curcumin on IL-1β gene expression and serum levels in migraine patients.

METHODS

This study was performed as a randomized, double-blind, placebo-controlled trial in a period of two months. A total of 80 episodic migraines were assigned into 4 groups of 1) n-3 fatty acids and curcumin combination; 2) n -3 fatty acids; 3) nano-curcumin; and 4) n-3 fatty acids and curcumin placebo. The gene expression and serum level of IL-1β were measured by real-time PCR and ELISA methods respectively, at the beginning and the end of the interventions.

RESULTS

Results showed the n-3 fatty acids and nano-curcumin combination significantly reduced the attack frequency in a synergistic status (P < 0.001). A significantly greater reduction in the serum level of IL-1β was observed in the combination group, and the differences in the other groups were not statistically significant. The IL-1β gene expression in the combination group showed a significant reduction for other treatment groups (P < 0.05), but these significant differences were absent after multiple testing Bonferroni corrections.

CONCLUSION

Present findings revealed that n -3 fatty acids and curcumin co-supplementation can be suggested as a promising new approach in migraine headache management, but further studies are needed to confirm these findings.

Dietary Supplementation with Curcumin Reduce Circulating Levels of Glycogen Synthase Kinase-3β and Islet Amyloid Polypeptide in Adults with High Risk of Type 2 Diabetes and Alzheimer's Disease

Dietary supplementation with curcumin has been previously reported to have beneficial effects in people with insulin resistance, type 2 diabetes (T2D) and Alzheimer’s disease (AD). This study investigated the effects of dietary supplementation with curcumin on key peptides implicated in insulin resistance in individuals with high risk of developing T2D. Plasma samples from participants recruited for a randomised controlled trial with curcumin (180 mg/day) for 12 weeks were analysed for circulating glycogen synthase kinase-3 β (GSK-3β) and islet amyloid polypeptide (IAPP). Outcome measures were determined using ELISA kits. The homeostasis model for assessment of insulin resistance (HOMA-IR) was measured as parameters of glycaemic control. Curcumin supplementation significantly reduced circulating GSK-3β (−2.4 ± 0.4 ng/mL vs. −0.3 ± 0.6, p = 0.0068) and IAPP (−2.0 ± 0.7 ng/mL vs. 0.4 ± 0.6, p = 0.0163) levels compared with the placebo group. Curcumin supplementation significantly reduced insulin resistance (−0.3 ± 0.1 vs. 0.01 ± 0.05, p = 0.0142) compared with placebo group. Dietary supplementation with curcumin reduced circulating levels of IAPP and GSK-3β, thus suggesting a novel mechanism through which curcumin could potentially be used for alleviating insulin resistance related markers for reducing the risk of T2D and AD.

The effect of omega-3 and vitamin D co-supplementation on glycemic control and lipid profiles in reproductive-aged women with pre-diabetes and hypovitaminosis D: a randomized controlled trial

BACKGROUND

Prediabetes can predispose the individual to type 2 diabetes in the long-term. The present study was conducted to determine the effectiveness of vitamin D and omega-3 co-supplementation on glycemic control and serum lipid profiles in women of reproductive age with prediabetes and hypovitaminosis D.

METHODS

The present factorial, triple-blind, clinical trial was conducted on 168 women of reproductive age with prediabetes and hypovitaminosis D. The participants were assigned to four groups based on block randomization method: the placebo group received omega-3 and vitamin D placebos; the omega-3 group took omega-3 supplements and vitamin D placebos; the vitamin D group received omega-3 placebos and vitamin D supplements and the co-supplementation group. The groups received every 2 weeks 50,000 IU pearls of vitamin D and twice-daily doses of 1000-mg omega-3 tablets or placebos for 8 weeks. Dietary intake, physical activity, anthropometric indices and blood biochemical tests were measured at the beginning and end of the study. Analysis was performed using two-way mixed ANOVA.

RESULTS

A significant reduction was observed in fasting glucose, insulin, homeostasis model assessment-beta cell function, weight and waist circumference in the co-supplementation group compared to the other three groups (P < 0.05). Moreover, high-density lipoprotein-cholesterol levels increased significantly in the co-supplementation group compared to the other three groups (P < 0.05). Despite the fact that homeostasis model assessment-insulin resistance, total cholesterol, triglyceride and low-density lipoprotein-cholesterol levels decreased after intervention in the co-supplementation group, there was no significant difference between the groups in these outcomes.

CONCLUSION

Vitamin D and omega-3 co-supplementation improved fasting serum glucose, insulin, high-density lipoprotein-cholesterol level, homeostasis model assessment-beta cell function, weight and waist circumference in women of reproductive age with prediabetes and hypovitaminosis D. This co-supplementation can therefore be recommended for glycemic control in these women.Trial registration Iranian Registry of Clinical Trials Code: IRCT20100130003226N17. Registered on 9 Feb. 2019.

The effect of co supplementation of omega-3 and vitamin D on cardio metabolic risk factors and psychological distress in reproductive-aged women with prediabetes and hypovitaminosis D: a study protocol for a randomized controlled trial

BACKGROUND

A prediabetic state is a risk factor for type 2 diabetes. There are no approved drugs to manage prediabetes. Among the supplements routinely used by individuals, vitamin D and omega-3 have been studied to reduce fasting blood sugar. However, their co-supplementation has not been studied in individuals with prediabetes. This randomized controlled trial is designed to determine the effects of these two supplements on fasting blood sugar, other cardio metabolic risk factors, and psychological distress in reproductive-aged women with prediabetes and hypovitaminosis D.

METHODS/DESIGN

This 2 × 2 factorial, triple-blind, randomized, placebo-controlled, clinical trial will be done on 168 women of reproductive age diagnosed with prediabetes and hypovitaminosis D. Participants will be randomly assigned equally to four groups: (1) 1000 mg omega-3 fatty acid twice a day + vitamin D placebo every two weeks; (2) omega-3 fatty acid placebo twice a day + 50,000 IU vitamin D every two weeks; (3) 1000 mg omega-3 fatty acid twice a day + 50,000 IU vitamin D every two weeks; (4) omega-3 fatty acid placebo twice a day + vitamin D placebo every two weeks for eight weeks. At the beginning, participants will provide a self-reported questionnaire on the sociodemographic characteristics. At baseline and post-intervention visits, physical activity, Depression Anxiety Stress Scale 21 and Pittsburgh Sleep Quality Index, and a three-day food record will be collected for each individual. Blood pressure, weight, height, and waist circumference will also be measured. At the beginning and at the end, a blood sample will be used for estimating serum glucose indices (fasting blood sugar and insulin, homeostasis model assessment-insulin resistance, homeostasis model assessment-beta cell function), lipids (triglyceride, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, total cholesterol), and vitamin D status. Data analysis using Kolmogorov-Smirnov test, paired t-test, one-way analysis of variance, and repeated measures analysis of variance will be conducted through SPSS-24 software.

DISCUSSION

The primary aim of the present trial is to determine the effect of vitamin D and/or omega-3 on glycemic indices, lipid profiles, psychological distress, blood pressure, and anthropometric indices in prediabetic women with hypovitaminosis D. The results from this trial will provide evidence on the efficacy of these two supplements for preventing or delaying the onset of type 2 diabetes in high-risk individuals.

TRIAL REGISTRATION

Iran Clinical Trials Registry, IRCT20100130003226N17. Registered on 9 February 2019.

The Neuromodulatory Effects of ω-3 Fatty Acids and Nano-Curcumin on the COX-2/ iNOS Network in Migraines: A Clinical Trial Study from Gene Expression to Clinical Symptoms

Background:

Migraine is a common neuroinflammatory disorder characterized by recurrent attacks of pain. Human and experimental models of migraine studies have demonstrated the role played by COX-2/ iNOS in migraine’s neuroinflammatory pathogenesis. COX-2 and iNOS are closely linked and both contribute to inflammation and neurogenic pain in the central nervous system. Omega- 3 fatty acids and curcumin, an active polyphenol of turmeric, have anti-inflammatory and neuroprotective effects through several mechanisms, including the suppression of COX-2 and iNOS gene expression, as well as their serum levels. The aim of the present study is to evaluate the nutrigenomic effects of ω-3 fatty acids, nano-curcumin, and a combination of the two, on neuroinflammation and clinical symptoms in migraine patients.

Methods:

This study reports the results of a clinical trial over a 2-month period, involving 74 episodic migraine patients who received ω-3 fatty acids, nano-curcumin, a combination of them, or a placebo. At the start and end of the study, the expression of COX-2/iNOS (in peripheral mononuclear blood cells isolated from patients) and COX-2/iNOS serum levels were measured, using real-time PCR and ELISA respectively. The frequency, severity and duration of pain attacks were also recorded.

Results:

The results of the present trial showed that ω-3 fatty acids and nano-curcumin can reinforce each other’s effects in the downregulation of COX-2/iNOS mRNA, as well as reduce their serum levels. In addition, the combination of ω-3 and nano-curcumin significantly reduced the frequency, severity and duration of headaches (P<0.05).

Conclusion:

These findings indicate that combination therapy of ω-3 fatty acids and nano-curcumin can be considered as a promising new approach in migraine prevention.

The effect of curcumin supplementation on circulating adiponectin: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

Our objective was to perform a systematic review and meta-analysis on randomized controlled trials (RCTs) assessing the effect of curcumin on serum adiponectin concentration.

METHODS

We searched PubMed/Medline, Scopus, ISI Web of Science, Cochrane Library, and Google scholar databases up to April 2019. RCTs conducted among human adults studied the effects of curcumin on serum adiponectin concentrations as an outcome variable was included. The weighted mean differences (WMD) and standard deviations (SD) of change in serum adiponectin levels were calculated. The random effects model was used for deriving a summary of mean estimates with their corresponding SDs.

RESULTS

Out of 313 records, 6 trials that enrolled 652 subjects were included. The pooled results showed that curcumin supplementation significantly increased adiponectin concentrations in comparison with placebo (WMD: 0.82 Hedges' g; 95% confidence interval (CI): 0.33 to 1.30, P˂0.001). Greater effects on adiponectin were observed in trials lasting ≤10 weeks (WMD: 1.05 Hedges' g; 95% CI: 0.64 to 1.45, P˂0.001).

CONCLUSION

Curcumin significantly improves adiponectin concentrations. However, due to some limitations in this study, further studies are needed to reach a definitive conclusion about the effect of curcumin on the levels of adiponectin.

Augmented cAMP Signaling by Co-Administration of Resveratrol and Curcumin: A Cellular Biosensor Kinetic Assessment

BACKGROUND

Curcumin and resveratrol are two polyphenolic compounds extensively investigated for their medicinal effects on inflammatory signaling. However, there is a paucity of information on the Adenosine-3', 5'-cyclic monophosphate (cAMP) kinetics following administration of curcumin and resveratrol in biological systems. In this study, kinetic modulation of cAMP as a target detection messenger in pro-inflammatory pathways was assessed by co-administration of curcumin and resveratrol using a cellular sensor model.

METHODS

To evaluate their putative activity, curcumin and resveratrol compounds were administered alone or in combination on the media culture of cAMP EPAC (exchange protein directly activated by cAMP) bioluminescence resonance energy transfer (BRET) biosensor. The study was performed at the following two centers at Tehran University of Medical Sciences (TUMS): 1- Biotechnology Research Center, and, 2- Endocrinology and Metabolism Research Institute (EMRI) in 2017. Time course kinetic of cAMP response signals were plotted. Forskolin and IBMX were used to stabilize the cAMP signals.

RESULTS

When we treated HEK-293T biosensor cells at 10uM concentration, curcumin and resveratrol upregulated cAMP signaling. Co-administration of resveratrol and curcumin revealed an augmented cAMP level, as compared to treatments with the compounds alone.

CONCLUSION

Co-administration of curcumin and resveratrol leverage cAMP kinetic response in a time-course manner. The presented methodology can be readily adopted for drug development and novel biopharmaceutical functional analyses.

Association of Dietary n3 and n6 Fatty Acids Intake with Hypertension: NHANES 2007-2014

We conducted this cross-sectional study in the American general population to explore the association of dietary n3 and n6 fatty acids intake and the risk of hypertension. We used data from the National Health and Nutrition Examination Survey (NHANES) 2007–2014 in this study. We obtained dietary n3 and n6 fatty acids data through two 24 h dietary recall interviews and n3, n6 fatty acids intake were adjusted by weight. We defined hypertension as now taking prescribed medicine for hypertension or blood pressure above 130/80 mmHg. We applied binary logistic regression, multinomial logistic regression, and restricted cubic spline to evaluate the associations of dietary n3 and n6 fatty acids intake with hypertension. A total of 18,434 participants were included in this study. In the multivariate-adjusted model 2, the odds ratios (ORs) with 95% confidence interval (CI) of hypertension were 0.58 (0.49–0.68), 0.53 (0.45–0.63), and 0.92 (0.80–1.06) for the highest versus the lowest tertile of dietary n3, n6 fatty acids intake and n6:n3 ratio, respectively. Further excluded participants with hypertension history, the ORs with 95% CI of newly diagnosed hypertension were 0.60 (0.50–0.73), 0.52 (0.43–0.62), and 0.95 (0.79–1.14) for the highest versus lowest tertile of dietary n3, n6 fatty acids intake and n6:n3 ratio, respectively. Dose-response analyses showed that the risk of hypertension was associated with dietary n3 and n6 fatty acids intake. Our study suggested that dietary n3 and n6 fatty acids intake were inversely associated with the risk of hypertension in US adults.

Efficacy and safety of Rhizoma curcumea longae with respect to improving the glucose metabolism of patients at risk for cardiovascular disease: a meta-analysis of randomised controlled trials

BACKGROUND

Clinical evidence suggests that curcuminoids, as a natural polyphenol, can provide support for cardioprotection and glucose metabolism. This meta-analysis assessed the efficacy and safety of curcumin with respect to improving glucose metabolism in patients with cardiovascular risk factors.

METHODS

Four databases (PubMed, Cochrane Library, Web of Science and Embase) were searched up to June 2018. The inclusion criteria included (i) randomised controlled trials (RCT) and (ii) subjects with risk factors for cardiovascular disease supplemented with curcumin and curcuminoids. A random-effects model and a standardised mean difference with a 95% confidence interval were used to perform quantitative data synthesis. Sensitivity and subgroup analyses were conducted to assess the effects.

RESULTS

Fourteen eligible RCT with 1277 subjects were included. In the overall analyses, curcumin led to significant decreases in fasting blood glucose (FBG), glycated haemoglobin (HbA1c) and homeostatic model assessment of insulin resistance (HOMA-IR). The subgroup analyses suggested that curcumin or combined curcuminoids were more effective at reducing FBG and HbA1c in type 2 diabetes patients than in individuals with metabolic syndrome. Supplementation with curcuminoids at doses ≥300 mg day^-1 showed significant decreases in FBG, HbA1c and HOMA-IR. The effects of supplementation on FBG, HbA1c and HOMA-IR were more significant over long periods (≥12 weeks) than short periods. Curcumin and curcuminoids were well tolerated, with no serious adverse events.

CONCLUSIONS

Curcumin or combined curcuminoids could exert cardioprotective effects in patients at risk for cardiovascular disease by improving glucose metabolism. However, further high-quality studies and larger sample sizes are required to confirm these results.

Curcumin reduces inflammation in knee osteoarthritis rats through blocking TLR4 /MyD88/NF-κB signal pathway

Preclinical Research & Development Curcumin has been shown to possess a series of beneficial effects, such as antiinflammatory, antioxidant, analgesic, and promoting healing. However, the effect and relative mechanism of curcumin on knee osteoarthritis (OA) have not been elucidated. The aim of this study is to explore the protective effect of curcumin on monosodium iodoacetate (MIA)-induced OA. Forty-eight rats were randomized into four experimental groups: control group, OA group, OA + PBS group, and OA + curcumin group, respectively. A single intraarticular injection of MIA was applied to establish the rat model of knee OA. Hematoxylin-eosin staining was used to evaluate histological changes of knee joint. The paw withdrawal threshold was collected and the expression of synovial fluid cytokine levels was measured by ELISA. The protein expression of TRL-4, MyD88, p-IκBα, NF-κB, TNF-α, IL-1β, and IL6 was measured by western blot. Treating with curcumin can significantly reduce joint diameter and Mankin's score, and increase the paw withdrawal threshold. The expression of synovial fluid inflammatory biomarkers, IL-6, IL-1β, and TNF-α in the OA + curcumin group were lower than that in OA and OA + PBS group. The protein expression of the TLR4 receptor was increased in the OA, OA + PBS, and OA + curcumin group compared to the control group. However, curcumin treatment can significantly decrease the expression of MyD88, p-IκBα, NF-κB, TNF-α, IL-1β, and IL6 in OA + curcumin group. These findings may indicate that curcumin could block TLR4/NF-κB signal pathway, and reduce inflammation level to prevent knee wound in OA rats. Curcumin may be a feasible kind of medicament in the treatment of knee OA.

An investigation of the effects of curcumin on iron overload, hepcidin level, and liver function in β-thalassemia major patients: A double-blind randomized controlled clinical trial

This study investigated the effects of curcumin, the active polyphenol in turmeric, on iron overload, hepcidin level, and liver function in β-thalassemia major patients. This double-blind randomized controlled clinical trial was conducted on 68 β-thalassemia major patients. The subjects were randomly divided into 2 groups to receive either 500 mg curcumin capsules (total: 1,000 mg) twice daily or placebo for 12 weeks. Dietary intakes and biochemical variables including hemoglobin, transferrin saturation, total iron binding capacity, nontransferrin bound iron (NTBI), ferritin, hepcidin, alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were assessed at the beginning and end of the trial. Curcumin significantly reduced serum levels of NTBI (2.83 ± 1.08 compared with 2.22 ± 0.97 μmol/L, p = .001), ALT (42.86 ± 11.15 compared with 40.60 ± 9.89 U/L, p = .018), and AST (49.45 ± 12.39 compared with 46.30 ± 10.85 U/L, p = .002) at the end of the study. Based on analysis of covariance, a significant decrease was also observed in levels of NTBI (2.22 ± 0.97 vs. 2.55 ± 0.94 μmol/L, p = .026), ALT (40.60 ± 9.89 vs. 45.01 ± 10.42 U/L, p = .004), and AST (46.30 ± 10.85 vs. 50.99 ± 9.36 U/L, p = .009) in curcumin group in comparison with placebo group. There were no significant changes in hepcidin and other variables in any of the 2 groups. Curcumin administration alleviated iron burden and liver dysfunction by reducing NTBI, ALT, and AST levels in patients with β-thalassemia major.

Omega-3 fatty acids, membrane remodeling and cancer prevention

Proteins are often credited as the macromolecule responsible for performing critical cellular functions, however lipids have recently garnered more attention as our understanding of their role in cell function and human health becomes more apparent. Although cellular membranes are the lipid environment in which many proteins function, it is now apparent that protein and lipid assemblies can be organized to form distinct micro- or nanodomains that facilitate signaling events. Indeed, it is now appreciated that cellular function is partly regulated by the specific spatiotemporal lipid composition of the membrane, down to the nanosecond and nanometer scale. Furthermore, membrane composition is altered during human disease processes such as cancer and obesity. For example, an increased rate of lipid/cholesterol synthesis in cancerous tissues has long been recognized as an important aspect of the rewired metabolism of transformed cells. However, the contribution of lipids/cholesterol to cellular function in disease models is not yet fully understood. Furthermore, an important consideration in regard to human health is that diet is a major modulator of cell membrane composition. This can occur directly through incorporation of membrane substrates, such as fatty acids, e.g., n-3 polyunsaturated fatty acids (n-3 PUFA) and cholesterol. In this review, we describe scenarios in which changes in membrane composition impact human health. Particular focus is placed on the importance of intrinsic lipid/cholesterol biosynthesis and metabolism and extrinsic dietary modification in cancer and its effect on plasma membrane properties.

Curcumin and other dietary polyphenols: potential mechanisms of metabolic actions and therapy for diabetes and obesity

Recent controversy regarding the therapeutic potential of curcumin indicates the challenges to research in this field. Here, we highlight the investigations of curcumin and other plant-derived polyphenols that demonstrate their application to metabolic diseases, in particular, obesity and diabetes. Thus, a number of preclinical and clinical investigations have shown the beneficial effect of curcumin (and other dietary polyphenols) in attenuating body weight gain, improving insulin sensitivity, and preventing diabetes development in rodent models and prediabetic subjects. Other intervention studies with dietary polyphenols have also found improvements in insulin resistance. Recent studies suggest that the metabolic effects of curcumin/polyphenols are linked to changes in the gut microbiota. Thus, research into curcumin continues to provide novel insights into metabolic regulation that may ultimately translate into effective therapy.

Oxidative stress and inflammation as central mediators of atrial fibrillation in obesity and diabetes

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia in humans. Several risk factors promote AF, among which diabetes mellitus has emerged as one of the most important. The growing recognition that obesity, diabetes and AF are closely intertwined disorders has spurred major interest in uncovering their mechanistic links. In this article we provide an update on the growing evidence linking oxidative stress and inflammation to adverse atrial structural and electrical remodeling that leads to the onset and maintenance of AF in the diabetic heart. We then discuss several therapeutic strategies to improve atrial excitability by targeting pathways that control oxidative stress and inflammation.