The effects of curcumin on the metabolic parameters of non-alcoholic fatty liver disease: a meta-analysis of randomized controlled trials

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.

Curcumin effects on glycaemic indices, lipid profile, blood pressure, inflammatory markers and anthropometric measurements of non-alcoholic fatty liver disease patients: A systematic review and meta-analysis of randomized clinical trials

OBJECTIVES

Curcumin has antioxidant properties and has been proposed as a potential treatment for NAFLD. The aim of current systematic review and meta-analysis was to evaluate previous findings for the effect of curcumin supplementation on glycaemic indices, lipid profile, blood pressure, inflammatory markers, and anthropometric measurements of NAFLD patients.

METHODS

Relevant studies published up to January 2024 were searched systematically using the following databases: PubMed, SCOPUS, WOS, Science Direct, Ovid and Cochrane. The systematic review and meta-analysis were conducted according to the 2020 PRISMA guidelines. The quality of the papers was assessed the using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist. Pooled effect sizes were calculated using a random-effects model and reported as the WMD and 95% CI. Also, subgroup analyses were done to find probable sources of heterogeneity among studies.

RESULTS

Out of 21010 records initially identified, 21 eligible RCTs were selected for inclusion in a meta-analysis. Overall, 1191 participants of both genders, 600 in the intervention and 591 in the control group with NAFLD were included. There are several limitations in the studies that were included, for instance, the results are weakened substantially by potential bias or failure to account for potential adulteration (with pharmaceuticals) or contamination (with other herbs) of the curcumin supplements that were tested. However, previous studies have reported curcumin to be a safe complementary therapy for several conditions. Our study indicated that curcumin supplementation in doses of 50-3000 mg/day was associated with significant change in FBG [WMD: -2.83; 95% CI: -4.61, -1.06), I2 = 51.3%], HOMA-IR [WMD: -0.52; 95% CI: -0.84, -0.20), I2= 82.8%], TG [WMD: -10.31; 95% CI: -20.00, -0.61), I2 = 84.5%], TC [WMD: -11.81; 95% CI: -19.65, -3.96), I2 = 94.6%], LDL [WMD: -8.01; 95% CI: -15.79, -0.24), I2 = 96.1%], weight [WMD: -0.81; 95% CI: -1.28, -0.35), I2= 0.0%] and BMI [WMD: -0.35; 95% CI: -0.57, -0.13), I2= 0.0%] in adults with NAFLD. There was no significant change in HbA1C, plasma insulin, QUICKI, HDL, SBP, DBP, CRP, TNF-α and WC after curcumin therapy. Subgroup analysis suggested a significant changes in serum FBG, TG, SBP, WC in RCTs for intervention durations of ≥ 8 weeks, and SBP, TG, LDL, HDL, BMI, WC in RCTs with sample size > 55 participants.

CONCLUSION

Curcumin supplementation in doses of 50-3000 mg/day over 8-12 weeks was associated with significant reductions in levels of FBG, HOMA-IR, TG, TC, LDL, weight and BMI in patients with NAFLD. Previous studies have reported curcumin as a safe complementary therapy for several diseases. We would suggest that should curcumin supplements be used clinically in specific conditions, it should be used with caution. Also, difference in grades of NAFLD may effect the evaluated outcomes, so it is suggested that future studies be conducted with an analyses on subgroups according to their NAFLD grade. Furthermore, because of the failure to conduct independent biochemical assessment of the turmeric/curcumin product used in most studies as well as potential sources of bias, results should be interpreted with caution.

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

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

An updated meta-analysis of effects of curcumin on metabolic dysfunction-associated fatty liver disease based on available evidence from Iran and Thailand

Metabolic dysfunction-associated fatty liver disease (MAFLD) is a common cause of chronic liver disease and can progress to nonalcoholic steatohepatitis and cirrhosis. This study aims to summarize the evidence for the effects of curcumin on MAFLD progression. Studies were identified from Medline and Scopus databases until April 2022. Systematic reviews and meta-analyses (SRMA) and randomized controlled trials (RCT) were selected based on pre-specified criteria. Three reviewers independently extracted data and assessed quality of included studies. Of the 427 identified records, 6 SRMAs and 16 RCTs were included in the analysis. Very high overlap was observed among SRMAs with corrected covered area of 21.9%. From an updated meta-analysis, curcumin demonstrated significant improvement in aspartate and alanine aminotransferase with pooled mean difference [95% confidence interval (CI)] of -3.90 (-5.97, -1.82) and -5.61 (-9.37, -1.85) units/L, respectively. Resolution and improvement of hepatic steatosis was higher in curcumin than control group with pooled relative risk (95% CI) of 3.53 (2.01, 6.22) and 3.41 (1.36, 8.56), respectively. Curcumin supplementation also led to lower fasting blood sugar, body mass index, and total cholesterol. Further trials should be conducted to assess the effect of curcumin on liver histology, especially regarding non-invasive hepatic fibrosis and steatosis.

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).

Nutraceutical approaches to non-alcoholic fatty liver disease (NAFLD): A position paper from the International Lipid Expert Panel (ILEP)

Non-Alcoholic Fatty Liver Disease (NAFLD) is a common condition affecting around 10-25% of the general adult population, 15% of children, and even > 50% of individuals who have type 2 diabetes mellitus. It is a major cause of liver-related morbidity, and cardiovascular (CV) mortality is a common cause of death. In addition to being the initial step of irreversible alterations of the liver parenchyma causing cirrhosis, about 1/6 of those who develop NASH are at risk also developing CV disease (CVD). More recently the acronym MAFLD (Metabolic Associated Fatty Liver Disease) has been preferred by many European and US specialists, providing a clearer message on the metabolic etiology of the disease. The suggestions for the management of NAFLD are like those recommended by guidelines for CVD prevention. In this context, the general approach is to prescribe physical activity and dietary changes the effect weight loss. Lifestyle change in the NAFLD patient has been supplemented in some by the use of nutraceuticals, but the evidence based for these remains uncertain. The aim of this Position Paper was to summarize the clinical evidence relating to the effect of nutraceuticals on NAFLD-related parameters. Our reading of the data is that whilst many nutraceuticals have been studied in relation to NAFLD, none have sufficient evidence to recommend their routine use; robust trials are required to appropriately address efficacy and safety.

Meta-Analysis of Exploring the Effect of Curcumin Supplementation with or without Other Advice on Biochemical and Anthropometric Parameters in Patients with Metabolic-Associated Fatty Liver Disease (MAFLD)

Metabolic (dysfunction)-associated fatty liver disease (MAFLD), previously known as non-alcoholic fatty liver disease (NAFLD), is the most common chronic liver disease. MAFLD is characterized by the excessive presence of lipids in liver cells and metabolic diseases/dysfunctions, e.g., obesity, diabetes, pre-diabetes, or hypertension. Due to the current lack of effective drug therapy, the potential for non-pharmacological treatments such as diet, supplementation, physical activity, or lifestyle changes is being explored. For the mentioned reason, we reviewed databases to identify studies that used curcumin supplementation or curcumin supplementation together with the use of the aforementioned non-pharmacological therapies. Fourteen papers were included in this meta-analysis. The results indicate that the use of curcumin supplementation or curcumin supplementation together with changes in diet, lifestyle, and/or physical activity led to statistically significant positive changes in alanine aminotransferase (ALT), aspartate aminotransferase (AST), fasting blood insulin (FBI), homeostasis model assessment of insulin resistance (HOMA-IR), total triglycerides (TG), total cholesterol (TC), and waist circumference (WC). It appears that these therapeutic approaches may be effective in alleviating MAFLD, but more thorough, better designed studies are needed to confirm this.

Curcumin-piperine co-supplementation and human health: A comprehensive review of preclinical and clinical studies

Curcumin is extracted from the rhizomes Curcuma longa L. It is known for its anti-inflammatory and anti-oxidant activities. Despite its safety and potential for use against various diseases, curcumin's utility is restricted due to its low oral bioavailability. Co-administration of curcumin along with piperine could potentially improve the bioavailability of curcumin. The present review aimed to provide an overview of the efficacy and safety of curcumin-piperine co-supplementation in human health. The findings of this comprehensive review show the beneficial effects of curcumin-piperine in improving glycemic indices, lipid profile and antioxidant status in diabetes, improving the inflammatory status caused by obesity and metabolic syndrome, reducing oxidative stress and depression in chronic stress and neurological disorders, also improving chronic respiratory diseases, asthma and COVID-19. Further high-quality clinical trial studies are needed to firmly establish the clinical efficacy of the curcumin-piperine supplement.

Curcumin as a novel approach in improving lipid profile: An umbrella meta-analysis

AIMS

Several meta-analyses exist supporting the beneficial effects of curcumin supplementation on lipid profile parameters; however, some studies' findings are inconsistent. Therefore, the current umbrella of meta-analysis of clinical trials was performed to evaluate the findings of multiple meta-analyses on the efficacy of curcumin on lipid profiles in adults.

DATA SYNTHESIS

A comprehensive systematic search of PubMed/Medline, Scopus, Embase, Web of Science and Google Scholar were carried out up to May 2022 (in English only). Random-effects model was employed to conduct meta-analysis. The quality assessment of the selected meta-analyses was measured using a measurement tool to assess multiple systematic reviews (AMSTAR). From 101 articles returned in the literature search, 19 articles were met the qualified for inclusion in the umbrella meta-analysis. The results revealed that the curcumin supplementation was effective on reduction of total cholesterol (TC) (ES = -0.81 mg/dl; 95% CI: 1.39, -0.24, p = 0.006; I² = 68.8%, p < 0.001), triglycerides (TG) (ES: 0.84 mg/dl, 95% CI: 1.42, -0.27, p = 0.004; I² = 84.2%, p < 0.001), and low-density lipoprotein cholesterol (LDL-C) levels (ES: 0.49 mg/dl, 95%CI: 0.85, -0.13, p = 0.007; I² = 51.9%, p = 0.004). Beyond that, Curcumin intake significantly increased high-density lipoprotein cholesterol (HDL-C) levels (ES: 1.34 mg/dl, 95% CI: 0.37, 2.31, p = 0.007; I² = 97.8%, p < 0.001).

CONCLUSION

Curcumin have ameliorating effects on TC, TG, LDL-c, and HDL-c levels. Overall, Curcumin could be recommended as an adjuvant anti-hyperlipidemic agent.

REGISTRATION NUMBER

PROSPERO, CRD42021289500.

The effect of curcumin on hepatic fat content in individuals with obesity

AIM

To evaluate the effect of curcumin treatment on hepatic fat content in obese individuals.

MATERIALS AND METHODS

In a double-blind, parallel-group trial, 37 obese, non-diabetic individuals were randomized to placebo or curcumin treatment for 6 weeks. Curcumin was dosed as lecithin-formulated tablet; 200 mg twice daily. The primary endpoint was hepatic fat content as assessed by magnetic resonance spectroscopy (MRS). Other endpoints included anthropometric measurements, hepatic biomarkers including FibroScan measurements, metabolic variables, inflammation markers, appetite measures and ad libitum food intake.

RESULTS

Baseline characteristics (mean ± SD) were age 46 ± 14 years, hepatic fat content 12.2% ± 8.8% points, body mass index 38.8 ± 6.1 kg/m² and waist circumference 125.8 ± 12.3 cm. After 6 weeks of treatment with curcumin, hepatic fat content was changed by -0.86% points (95% CI -3.65; 1.94) compared with 0.71% points (95% CI - 2.08; 3.51) with placebo, thus resulting in a non-significant estimated treatment difference of -1.57% points (95% CI -5.36; 2.22, P = .412). Compared with placebo, curcumin treatment caused small reductions in fasting plasma glucose (estimated treatment difference [ETD] - 0.24 mmol/L [95% CI -0.45; -0.03]), triglycerides (ETD [percentage change] -20.22% [95% CI -33.21; -6.03]) and gamma glutamyltransferase (ETD [percentage change] -15.70% [95% CI -23.32; -7.32]), but except for gamma glutamyltransferase, none of these differences remained statistically significant after adjusting for multiple testing. Treatment was well tolerated.

CONCLUSIONS

Compared with placebo, curcumin treatment for 6 weeks had no significant effect on MRS-assessed hepatic fat content in obese individuals with primarily mild steatosis. Curcumin was well tolerated.

The effects of curcumin supplementation on metabolic biomarkers and body mass index in patients with nonalcoholic fatty liver disease, a systematic review and meta-analysis of randomized controlled trials

Background and Aims:

Curcumin is one of the most commonly used indigenous molecules endowed with various shielding functionalities that protect the liver. In the present research, we aimed to investigate the effects of curcumin on metabolic factors and body mass index (BMI) in patients with non-alcoholic fatty liver disease (NAFLD), using a meta-analysis of randomized, controlled trials.

Methods::

Online databases PubMed, Embase, Web of Science, and Science Direct were searched until April 2021 to identify eligible articles. Fourteen trials were included. Results: The results showed that curcumin consumption could significantly reduce AST (-0.35, (-0.57 to -0.14)), total cholesterol (-0.81, (-1.34 to -0.27)), TG (-0.49, (-0.71 to -0.27)), and FBS (-0.28, (-0.46 to -0.09)) in patients with NAFLD. However, the improvements in ALT (-0.29, (-0.58 to 0.00)), LDL (-0.48, (-0.97 to 0.01)), HDL (0.03, (-0.38 to 0.44)), and BMI (-0.13, (-0.29 to 0.02)) were not statistically significant. Furthermore, the findings revealed that the optimal dose and duration of curcumin consumption for patients with NAFLD is <500 mg/d for less than 10 weeks.

Conclusions:

The present study suggests that consuming curcumin can improve liver enzymes, lipid profile, FBS, and BMI in patients with NAFLD. Moreover, curcumin supplementation may provide beneficial effects on metabolic biomarkers and body weight if used at the appropriate dose and duration. Further RCTs are required to confirm our findings.

Curcumin and Piperine Combination for the Treatment of Patients with Non-alcoholic Fatty Liver Disease: A Double-Blind Randomized Placebo-Controlled Trial

BACKGROUND

Experimental and clinical studies have revealed that curcumin may be an effective therapy for non-alcoholic fatty liver disease (NAFLD). Hence, the aim of this study was to assess the effect of curcumin plus piperine administration on NAFLD.

METHODS

Adults 18-65 years-old diagnosed with NAFLD by liver sonography were randomly allocated to curcumin (500 mg/day) or placebo groups for 2 months. All participants received both dietary and exercise advice. Anthropometric and biochemical measurements as well as hepatic ultrasound were performed at baseline and final conditions.

RESULTS

Seventy-nine participants were recruited and randomly allocated into the curcumin (n = 39) or placebo (n = 40) groups. There were no significant differences between placebo and curcumin groups for demographic and clinical characteristics and NAFLD grade at baseline. After the treatment period, the curcumin group exhibited lower alkaline phosphatase (-16.2 ± 22.8 versus -6.0 ± 22.5 mg/dL, p = 0.04) concentrations and severity of NAFLD compared with the placebo group (p = 0.04).

CONCLUSION

Results of this clinical trial suggest that short-term treatment with curcumin plus piperine administration improves NAFLD severity.

Effect of Curcumin on Diabetic Kidney Disease: A Systematic Review and Meta-Analysis of Randomized, Double-Blind, Placebo-Controlled Clinical Trials

Background

Curcumin, a polyphenolic constituent from Curcuma longa, possesses antioxidant, hypolipidemic, and antidiabetic properties and has been reported to protect against diabetic kidney disease (DKD); however, the effect is inconsistent.

Objective

This systematic review and meta-analysis aimed to investigate the effect of curcumin supplementation on renal function, lipid profile, blood pressure, and glycemic control in DKD.

Methods

A systematic and comprehensive literature search of interrelated randomized controlled trials (RCTs) was conducted in PubMed, Embase, Cochrane Library, Web of Science, Scopus, and ClinicalTrials.gov from inception to July 30, 2021. Two investigators independently extracted data and assessed the risk of bias. Weighted mean differences (WMDs) with 95% confidence intervals (CIs) were calculated to describe the effect sizes using a fixed-effect model. Statistical analysis was performed using STATA 14.0 and RevMan 5.3.

Results

Five RCTs involving 290 participants with DKD were included. Curcumin supplementation significantly improved the serum creatinine (WMD: −0.16 mg/dL, 95% CI: −0.3 to −0.02, P = 0.029, I² = 0%, moderate certainty), total cholesterol (WMD: −10.13 mg/dL, 95% CI: −17.84 to −2.14, P = 0.01, I² = 0%, moderate certainty), systolic blood pressure (WMD: 3.94 mmHg, 95% CI: 1.86 to 6.01, P < 0.01, I² = 33.5%, moderate certainty), and fasting blood glucose (WMD: −8.29 mg/dL, 95% CI: −15.19 to −1.39, P = 0.019, I² = 43.7%, moderate certainty) levels; however, it had no significant effects on blood urea nitrogen, proteinuria, triglyceride, low-density lipoprotein-cholesterol, high-density lipoprotein-cholesterol, and diastolic blood pressure levels.

Conclusions

Curcumin may provide great potential effects against DKD. More large-scale and high-quality RCTs are required to confirm these findings.

The effect of turmeric on lipid profile, malondialdehyde, liver echogenicity and enzymes among patients with nonalcoholic fatty liver disease: a randomized double blind clinical trial

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is one of the most common causes of liver transaminases elevation and a global health concern.

PURPOSE

This study designed to evaluate the effects of turmeric rhizomes (Curcumalonga Linn.) on liver enzymes, Lipid profiles and Malondialdehyde (MDA) in patients with NAFLD.

STUDY DESIGN

Randomized double-blind placebo controlled trial.

METHODS

64 cases of NAFLD randomly assigned to receive either turmeric (2 gr/day) or placebo for 8 weeks. The changes of liver transaminases, lipid profiles and MDA were measured before and after study period and compared between two groups (IRCT 2015092924262N1).

RESULTS

At the end of the study, the Turmeric group showed a significant reduction in liver enzymes (AST before 26.81 ± 10.54 after 21.19 ± 5.67, P = 0.044, ALT before 39.56 ± 22.41, after 30.51 ± 12.61, P = 0.043 and GGT before33.81 ± 17.50, after 25.62 ± 9.88, P = 0.046) compared with the placebo group. The serum levels of triglycerides, LDL, HDL and MDA had also a significant decrease among turmeric group as compared to baseline while there was no significant change in placebo group (P < 0.05). The serum cholesterol, VLDL level and sonographic grades of NAFLD had not any significant change in both groups.

CONCLUSION

In conclusion this study suggests that daily consumption of turmeric (and its active phenolic ingredients as curcumin) supplementation could be effective in management of NAFLD and decreasing serum level of liver transaminases.

Effect of Curcumin on Glycemic Control in Patients with Type 2 Diabetes: A Systematic Review of Randomized Clinical Trials

Type 2 diabetes mellitus (T2DM) is a chronic metabolic condition, which carries considerable morbidity and mortality. There is growing evidence that curcumin could modulate glucose homeostasis and improve vascular risk in patients with T2DM. The aim of this systematic review was to study the effect of curcumin on glycemic indices in patients with diabetes. A comprehensive search was conducted in PubMed, Scopus, Embase, and Google Scholar up to March 5, 2020, to identify randomized control trials investigating the effect of curcumin supplementation on glycemic indices including fasting blood glucose (FBS), hemoglobin A1c (HbA1C), and the homeostatic model assessment for insulin resistance (HOMA-IR). Eleven articles comprising 1131 individuals with T2DM were included in the study. Treatment with curcumin significantly reduced the level of FBS and HbA1c in 8 and 7 studies, respectively. HOMA-IR was evaluated in five studies, and this was reduced significantly by curcumin supplementation in three of those studies. Patients who took curcumin supplementation over longer periods (≥12 weeks) showed a significant reduction in glycemic indices. The current systematic review showed that curcumin can improve glycemic control in patients with T2DM. However, further studies are required to determine the optimum conditions for these effects of curcumin, particularly regarding readouts of insulin resistance.

Targeting dyslipidemia by herbal medicines: A systematic review of meta-analyses

ETHNOPHARMACOLOGICAL RELEVANCE

The worldwide increasing prevalence of dyslipidemia has become a global health concern. Various herbal remedies have been claimed to be effective for the treatment of dyslipidemia in traditional and folkloric medicine of different regions clinical trials have been conducted to investigate their efficacy. The aim of the current systematic review is to critically assess the meta-analyses of controlled trials (CT) evaluated herb medicines for dyslipidemia.

MATERIALS AND METHODS

Relevant studies from Web of Science, PubMed, Scopus, and Cochrane Library databases based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist until January 2021 have been searched. All meta-analyses which pooled studies on the effect of herbal medicines on lipid profile including total cholesterol (TC), triglyceride (TG), and low- or high-density lipoprotein cholesterol (LDL-C, HDL-C) were also included. Meta-analyses of in vitro, animal or observational studies were excluded.

RESULTS

The overall of 141 meta-analyses were revealed. Vegetable oils, phytosterols, tea, soy protein, nuts, and curcumin have been studied frequently among the herbal medicines. Among 13 meta-analyses on vegetable oils, the greater reduce of TC (18.95 mg/dl), LDL-C (16.24 mg/dl) and TG (13.69 mg/dl) were exhibited from sunflower oil. Furthermore, rice bran oil (6.65 mg/dl) increased HDL-C significantly. Phytosterols in 12 meta-analyses demonstrated significant improvements in reducing TC, LDL-C and TG as 16.4, 23.7, and 8.85 mg/dl, respectively, and rise in HDL-C as 10.6 mg/dl. The highest reduction in serum level of TC, LDL-C and TG was reported while intake Green tea; 27.57, 24.75, and 31.87 mg/dl, accordingly within 9 meta-analyses. Average improvement of lipid profiles by 6 meta-analyses on plant proteins were 23.2, 21.7, 15.06, and 1.55 mg/dl for TC, LDL-C, TG, and HDL-C, respectively. Among 11 meta-analyses on nuts, almond showed better and significant alleviations in TC (10.69 mg/dl), walnut in LDL-C (9.23 mg/dl), pistachio in TG (22.14 mg/dl), and peanut in HDL-C (2.72 mg/dl). Overall, Curcumin, Curcuminoid, and Turmeric have resulted in the reduction of TC (25.13 mg/dl), LDL-C (39.83 mg/dl), TG (33.65 mg/dl), and an increase in the HDL-C (4.31 mg/dl).

CONCLUSION

The current systematic review shed light on the use of herbal medicines for the management of dyslipidemia. However, more well-conducted CTs are required to determine effective doses of herbal medicines.

Pleiotropic nature of curcumin in targeting multiple apoptotic-mediated factors and related strategies to treat gastric cancer: A review

Gastric cancer (GC) is one of the major reasons for cancer-associated death and exhibits the second-highest mortality rate worldwide. Several advanced approaches have been designed to treat GC; however, these strategies possess many innate complications. In view of this, the upcoming research relying on natural products could result in designing potential anticancer agents with fewer side effects. Curcumin, isolated from the rhizomes of Curcuma longa L. has several medicinal properties like antiinflammatory, antioxidant, antiapoptotic, antitumor, and antimetastatic. Such pleiotropic nature of curcumin impedes the invasion and proliferation of GC by targeting several oncogenic factors like p23, human epidermal factor receptor2 including Helicobacter pylori. The side effect of chemotherapy, that is, chemotherapeutic resistance and radiotherapy could be reduced combination therapy of curcumin. Moreover, the photodynamic therapy of curcumin destroys the cancer cells without affecting normal cells. However, further more potential studies are required to establish the potent efficacy of curcumin in the treatment of GC. The current review details the anticancer activities of curcumin and related strategies which could be employed to treat GC with additional focus on its inhibitory properties against viability, proliferation, and migration of GC cells through cell cycle arrest and stimulation by apoptosis-mediated factors.

Pharmacotherapy for Weight Loss in Cirrhosis and Liver Transplantation: Translating the Data and Underused Potential

BACKGROUND AND AIMS

Thirty percent of patients with cirrhosis are obese and the prevalence of obesity increases after transplant to >40% post-transplant. There are currently four weight loss medications approved by the FDA for treatment of obesity (orlistat, phentermine-topiramate, naltrexone-bupropion, and liraglutide). The aim of this review was to investigate the data on the use of these weight loss medications and alternative medicines in patients with cirrhosis and in liver transplant recipients (LTRs).

APPROACH AND RESULTS

While there is paucity of data for these medications in patients with cirrhosis and LTRs, Liraglutide appears to be generally safe in view of its pharmacokinetic properties. Phentermine-topiramate seems to have the highest weight loss potential but special consideration should be given to neuropsychiatric disorders, cardiovascular comorbidities, and drug interactions. There are emerging data on use of alternative medicines for weight loss but more data are needed.

CONCLUSIONS

The use of weight loss medications is feasible in this patient population but the decision of which medication to prescribe should be individualized based on the degree of renal and hepatic impairment, other co-morbidities, and concomitant medications.

The efficacy of novel metabolic targeted agents and natural plant drugs for nonalcoholic fatty liver disease treatment: A PRISMA-compliant network meta-analysis of randomized controlled trials

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent chronic liver disease characterized by excess accumulation of fat in hepatocytes. Because no drug has been approved for NAFLD treatment, this work analyzed the effects of agents resulting from 2 research hotspots, metabolic target agents, and natural plant drugs, on NAFLD with network meta-analysis.

METHODS

Public databases were searched through August 14, 2020. Randomized controlled trials that compared obeticholic acid, elafibranor, cenicriviroc, selonsertib, curcumin, silymarin, and resveratrol to placebo were included. Liver pathology improvement, hepatic biochemical indicators, and lipid metabolism indicators were analyzed.

RESULTS

Thirty-five studies were included in the meta-analysis. Obeticholic acid was found to significantly increase the frequency of liver biopsy improvement compared to placebo (OR: 2.10; 95% CI: 1.60, 2.77). The ranking results among the hepatic biochemical indicators showed that obeticholic acid (94.9%) and elafibranor (86.3%) have a relative advantage in reducing alanine aminotransferase (ALT) levels, and obeticholic acid also had an advantage (95.4%) in reducing aspartate aminotransferase (AST) levels. Considering lipid metabolic indicators, elafibranor (expSMD: 0.01; 95% CI: 0.00, 0.05; SUCRA: 100%), and obeticholic acid (expSMD: 0.48; 95% CI: 0.28,0.84; SUCRA: 75.6%) significantly reduced triglyceride (TG) levels compared with placebo; moreover, obeticholic acid, but not elafibranor, caused a serious increase in total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) levels and a decrease in high-density lipoprotein cholesterol (HDL-C) levels.

CONCLUSIONS

Novel metabolic targeted agents generally have better effects than natural plant drugs, especially obeticholic acid, and elafibranor. However, obeticholic acid showed serious adverse effects such as increasing LDL-C levels and decreasing HDL-C levels. Curcumin showed potential advantages for NAFLD but lacked statistical significance.

Effect of Nigella sativa in the treatment of nonalcoholic fatty liver disease: A systematic review and meta-analysis of randomized controlled trials

The effectiveness of Nigella sativa (NS) treatment for nonalcoholic fatty liver disease (NAFLD) remains controversial. This systematic review, and meta-analysis, was conducted to evaluate potential benefits of NS for NAFLD. Up to June 11, 2020, randomized controlled trials (RCTs) evaluating NS for the treatment of NAFLD were searched and included from PubMed, Embase, Cochrane Library, and Web of science. Mean differences (MD) or risk ratio (RR) and 95% confidence intervals (CI) were calculated. Six articles from five trails with a total of 358 participants were included. Although NS has no beneficial effect on the levels of total cholesterol (TC) and low-density lipoprotein cholesterol (LDL), triglyceride (TG), insulin, and tumor necrosis factor α (TNF-α), its supplementation did improve the levels of alanine transaminase (ALT), aspartate transaminase (AST), fasting blood sugar (FBS), high-density lipoprotein cholesterol (HDL), high-sensitivity C reactive protein (hs-CRP), and grade of fatty liver compared with placebo. In summary, this study showed that NS supplementation was effective in the treatment of NAFLD and could improve the levels of ALT, AST, FBS, HDL, and hs-CRP in patients with NAFLD, as well as the severity of NAFLD. High-quality large sample RCTs are necessary to confirm the benefit of NS supplementation for NAFLD.

Beneficial Effects of Plant-Derived Natural Products on Non-alcoholic Fatty Liver Disease

Non-alcoholic fatty liver disease is becoming in one of the most prevalent liver diseases that leads to liver transplantation. This health problem is a multisystem disease with a complex pathogenesis that involves liver, adipose tissue, gut, and muscle. Although several pharmacological agents have been investigated to prevent or treat non-alcoholic fatty liver disease, currently there is no effective treatment for the management of this chronic liver disease. Nonetheless, the use of natural products has emerged as a alternative therapeutic for the treatment of hepatic diseases, including non-alcoholic fatty liver disease, due to its anti-inflammatory, antioxidant, antidiabetic, insulin-sensitizing, antiobesity, hypolipidemic, and hepatoprotective properties. In the present review, we have discussed the evidence from experimental and clinical studies regarding the potential beneficial effects of plant-derived natural products (quercetin, resveratrol, berberine, pomegranate, curcumin, cinnamon, green tea, coffee, garlic, ginger, ginseng, and gingko biloba) for the treatment or prevention of non-alcoholic fatty liver disease.

The Clinical Use of Curcumin for the Treatment of Rheumatoid Arthritis: A Systematic Review of Clinical Trials

Rheumatoid arthritis (RA) is a chronic inflammatory disease of the joints, which is prevalent in about 0.5-1.0% of the world population. Newer therapies for RA have only minimal efficacy in some cases and some adverse effects. Curcumin with anti-antioxidant, anti-inflammatory, and immunomodulatory properties might have beneficial effects on RA. We have carried out a systematic review with the main aim of estimating the effect of curcumin supplementation on RA. A systematic search of the medical databases, PubMed, Scopus, ISI, and Google Scholar was performed up to March 21, 2020 to identify clinical trials assessing the effect of turmeric or curcumin on RA. Six studies, comprising 259 patients with RA of 6-12 weeks duration, were included. Disease activity was assessed using 28 joints (DAS-28), visual analog scale (VAS), and American College of Rheumatology (ACR-20) scores. Treatment with curcumin significantly reduced DAS-28 scores in four out of five studies and VAS scores for pain in all three studies and significantly increased ACR-20 scores in all three studies in which it was measured. Erythrocyte sedimentation rate (ESR) and circulating C-reactive protein (CRP) were assessed in six and five studies, respectively, out of which four studies reported significant reductions in these parameters in response to curcumin treatment. Rheumatoid factor (RF) was significantly reduced after consumption of curcumin in all three relevant studies. None of the studies reported serious adverse effects with curcumin consumption. The present systematic review suggests that curcumin could be used as a safe agent to treat RA. Thus, further validation is justified.

Turmeric and Curcumin: From Traditional to Modern Medicine

The rhizome of turmeric (Curcuma longa L.) has been used as an herbal medicine, coloring agent, spice, and food additive for thousands of years in different parts of the world particularly in Asian countries. It has been used for a range of diseases in many traditional medical schools, including Islamic traditional medicine, Chinese traditional medicine, and Ayurveda. It has been used mainly for digestive problems, as a cardio-, hepato-, and neuroprotective agent as well as in many inflammatory conditions such as arthritis and for enhancing immune system. Curcumin, a diarylheptanoid derivative found in turmeric, has anti-inflammatory, antioxidant, and anticancer properties; controls obesity and metabolic problems; and improves memory and mood disorders. Therapeutically, curcumin exhibits promising potential in preclinical and clinical studies and is currently in human trials for a variety of conditions, including metabolic syndrome, nonalcoholic fatty liver disease, rheumatoid arthritis, migraine, premenstrual syndrome, ulcerative colitis, knee osteoarthritis, polycystic ovarian syndrome, atherosclerosis, liver cirrhosis, amyotrophic lateral sclerosis, depression, psoriasis, and Alzheimer's disease. Among all beneficial activities reported for curcumin, the research toward the obesity and metabolic-preventing/suppressing aspects of curcumin is growing. These findings emphasize that most of the traditional applications of turmeric is due to the presence of its key constituent, curcumin. According to the traditional background of turmeric use and clinical values of curcumin, further preclinical studies for unstudied properties and clinical studies with larger sample sizes for confirmed activities are expected.

Medicinal plants and bioactive natural compounds as inhibitors of HMG-CoA reductase: A literature review

Cardiovascular diseases (CVDs) are one of the most important causes for mortality worldwide. Elevated levels of total cholesterol, and particularly LDL-cholesterol (LDL-C) are the main risk factor for acute myocardial infarction (AMI) and ischemic heart disease. The risk of CVDs could be reduced by decreasing the elevated cholesterol levels. β-hydroxy β-methylglutaryl-CoA reductase (HMGCoAR) is the primary and rate-limiting enzyme in the cholesterol biosynthesis pathway. Recently, the crucial role of nutraceuticals in maintaining normal physiological function was established. Nutraceuticals play an important role in preventing several non-communicable diseases such as obesity, CVDs, cancer, diabetes, and reducing hyperlipidemia. Although the effect of nutraceuticals and herbal medicine on CVDs and dyslipidemia was previously investigated thoroughly, the effect of these natural products on HMGCoAR as one of the important enzymes involved in CVDs etiopathogenesis has not yet been investigated. Therefore, the major aim of this paper was to review the effects of nutraceuticals and medicinal plants on HMGCoAR. Results indicate that different types of natural foods, isolated nutrients, herbal products, and dietary supplements as nutraceuticals decrease the expression and activity of HMGCoAR. This review shows that medicinal plants and nutraceuticals could be used to decrease HMGCoAR activity as accessible and convenient and economical natural compounds to prevent dyslipidemia and CVDs.

Curcumin as a preventive or therapeutic measure for chemotherapy and radiotherapy induced adverse reaction: A comprehensive review

Curcumin has attracted much attention for medicinal purposes in wide range of illnesses including cancer. In some studies, its efficacy is evaluated against chemotherapy and radiotherapy induced adverse reaction and also as adjuvant to cancer treatment. Here we have tried to present a comprehensive review on protective and therapeutic effect of curcumin against these side effects. METHOD: The data were collected by searching Scopus, PubMed, Medline, and Cochrane database systematic reviews, using key words "nephrotoxicity", "cardiotoxicity", "genotoxicity", "ototoxicity", "hepatotoxicity", "reproductive toxicity", "myelosuppression", "pulmonary toxicity", "radiotherapy induced side effect" with "turmeric" and "curcumin". Although curcumin has low bioavailability, it has shown brilliant profile on prevention and management of chemotherapy and radiotherapy induced adverse reactions, particularly based on in vitro and in vivo studies and limited number of human studies on radiotherapy adverse reactions. Antioxidant and anti-inflammatory properties of the curcumin are the main proposed mechanism of action for management and prevention of adverse reactions. One of the major points regarding the protective effect of curcumin is its wide tolerable therapeutic range of dose with minimal side effects. Furthermore, new nano-formulations help to improve the bioavailability, increase in efficacy and lower the adverse effects. In conclusion, based on the present knowledge, curcumin has significant supportive potential in patients receiving chemotherapy or radiotherapy and may be suggested as adjutant with cancer treatments. Further well-designed human studies are recommended.

Does Turmeric/curcumin Supplementation Change Anthropometric Indices in Patients with Non-alcoholic Fatty Liver Disease? A Systematic Review and Meta-analysis of Randomized Controlled Trials

Curcumin is the principal polylphenol of turmeric that has been used to treat various disorders. However, its anti-obesity effects in patients with non-alcoholic fatty liver disease (NAFLD) remain controversial. Therefore, we aimed to perform a meta-analysis on the effects of supplementation with turmeric/curcumin on body weight, body mass index (BMI) and waist circumference (WC) in these patients. PubMed, Scopus, Cochrane Library, and ISI Web of Science were searched until January 2019, without any restrictions. Clinical trials that reported body weight, BMI and WC in patients with NAFLD were included. Weighted mean differences (WMDs) were pooled using a random-effects model. Eight studies (449 participants) fulfilled the eligibility criteria of the present meta-analysis. Overall, meta-analysis could not show any beneficial effect of turmeric/curcumin supplementation on body weight (WMD, -0.54 kg; 95% confidence interval [CI], -2.40, 1.31; p = 0.56; I2 = 0.0%), BMI (WMD, -0.21 kg/m2; 95% CI, -0.71, 0.28; p = 0.39; I2 = 0.0%) and WC (WMD, -0.88 cm; 95% CI, -3.76, 2.00; p = 0.54; I2 = 0.0%). Subgroup analysis based on participants' baseline BMI, type of intervention, and study duration did not show any significant association in all subgroups. The results showed that turmeric/curcumin supplementation had no significant effect on body weight, BMI and WC in patients with NAFLD. Further studies with large-scale are needed to find out possible anti-obesity effects of turmeric/curcumin.

The impact of turmeric or its curcumin extract on nonalcoholic fatty liver disease: a systematic review of clinical trials

Background:

Turmeric and its curcumin extract have been evaluated in patients with nonalcoholic fatty liver disease (NAFLD), a common ailment that can lead to irreparable liver damage.

Objective:

To identify the evidence supporting the use of turmeric or curcumin therapy in NAFLD.

Methods:

We searched PubMed, EMBASE, and Cochrane Central from the earliest possible date to 12/17/18 including terms for turmeric, curcumin, and NAFLD. We assessed the impact of turmeric or its curcumin extract on alanine transaminase (ALT), aspartate transaminase (AST), and NAFLD severity via ultrasound.

Results:

Five trials assessed the comparative efficacy of curcumin/turmeric in NAFLD. One trial was single armed with comparisons only versus baseline and another trial was only available in abstract form. All of the trials had small sample sizes, 4 of 5 trials had limited durations of follow-up, and all trials had methodological limitations that negatively impacted the strength and applicability of evidence. Clinical and methodological heterogeneity precluded statistical pooling. Three of the 4 trials with evaluable data for turmeric or curcumin versus their own baseline demonstrated significant reductions in ALT, AST, and NAFLD severity grade. Two of the 4 placebo controlled trials had significant mean difference reductions in ALT and AST for turmeric or curcumin versus placebo while 2 of 3 of these trials found significant reductions in NAFLD severity grade. Among these trials, only one used turmeric instead of a curcumin extract and this turmeric trial did not demonstrate any differences in ALT, AST, or NAFLD severity between the turmeric and placebo groups.

Conclusions:

Curcumin extract is a promising, but not proven, treatment for NAFLD while the role for turmeric is less clear. The general findings are that ALT, AST and NAFLD severity are reduced with the use of curcumin.