Recovery Of Bone And Muscle Mass In Patients With Chronic Kidney Disease And Iron Overload On Hemodialysis And Taking Combined Supplementation With Curcumin And Resveratrol

The Role of Antioxidant Transcription Factor Nrf2 and Its Activating Compounds in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a complex autoimmune disease in which kidney involvement, so-called lupus nephritis (LN), is common and one of the most severe manifestations. Oxidative stress (OS) may play a role in the pathogenesis of LN through the exacerbation of inflammation and immune cell dysfunction/dysregulation. Nuclear factor erythroid 2-related factor 2 (Nrf2), also known as nuclear factor erythroid-derived 2-like 2, is a transcription factor that in humans is encoded by the NFE2L2 gene and is regarded as a central regulator of the antioxidative response. Nrf2-activating compounds have been shown to alleviate oxidative stress in cells and tissues of lupus-prone mice. Although the precise mechanisms of Nrf2 activation on the immune system in SLE remain to be elucidated, Nrf2-activating compounds are considered novel therapeutical options to suppress OS and thereby might alleviate disease activity in SLE, especially in LN. This review therefore summarizes the role of the Nrf2 signaling pathway in the pathogenesis of SLE with LN and describes compounds modulating this pathway as potential additional clinical interventions.

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

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

Innovative Delivery Systems for Curcumin: Exploring Nanosized and Conventional Formulations

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

Chronic Kidney Disease Diets for Kidney Failure Prevention: Insights from the IL-11 Paradigm

Nearly every fifth adult in the United States and many older adults worldwide are affected by chronic kidney disease (CKD), which can progress to kidney failure requiring invasive kidney replacement therapy. In this review, we briefly examine the pathophysiology of CKD and discuss emerging mechanisms involving the physiological resolution of kidney injury by transforming growth factor beta 1 (TGFβ1) and interleukin-11 (IL-11), as well as the pathological consequences of IL-11 overproduction, which misguides repair processes, ultimately culminating in CKD. Taking these mechanisms into account, we offer an overview of the efficacy of plant-dominant dietary patterns in preventing and managing CKD, while also addressing their limitations in terms of restoring kidney function or preventing kidney failure. In conclusion, this paper outlines novel regeneration strategies aimed at developing a reno-regenerative diet to inhibit IL-11 and promote repair mechanisms in kidneys affected by CKD.

Enhancing the Bioavailability of Resveratrol: Combine It, Derivatize It, or Encapsulate It?

Overcoming the limited bioavailability and extensive metabolism of effective in vitro drugs remains a challenge that limits the translation of promising drugs into clinical trials. Resveratrol, despite its well-reported therapeutic benefits, is not metabolically stable and thus has not been utilized as an effective clinical drug. This is because it needs to be consumed in large amounts to overcome the burdens of bioavailability and conversion into less effective metabolites. Herein, we summarize the more relevant approaches to modify resveratrol, aiming to increase its biological and therapeutic efficacy. We discuss combination therapies, derivatization, and the use of resveratrol nanoparticles. Interestingly, the combination of resveratrol with established chemotherapeutic drugs has shown promising therapeutic effects on colon cancer (with oxaliplatin), liver cancer (with cisplatin, 5-FU), and gastric cancer (with doxorubicin). On the other hand, derivatizing resveratrol, including hydroxylation, amination, amidation, imidation, methoxylation, prenylation, halogenation, glycosylation, and oligomerization, differentially modifies its bioavailability and could be used for preferential therapeutic outcomes. Moreover, the encapsulation of resveratrol allows its trapping within different forms of shells for targeted therapy. Depending on the nanoparticle used, it can enhance its solubility and absorption, increasing its bioavailability and efficacy. These include polymers, metals, solid lipids, and other nanoparticles that have shown promising preclinical results, adding more "hype" to the research on resveratrol. This review provides a platform to compare the different approaches to allow directed research into better treatment options with resveratrol.

Curcumin/turmeric supplementation could improve blood pressure and endothelial function: A grade-assessed systematic review and dose-response meta-analysis of randomized controlled trials

BACKGROUND AND PURPOSE

A number of studies have examined the impact of curcumin/turmeric on blood pressure and the factors allegedly responsible for hypertension. In this systematic review and meta-analysis, we tried to sum up the existing literature on randomized controlled trials (RCTs) investigating this hypothesis.

METHODS

Online databases (PubMed, Scopus, Web of Science Core Collection, Cochrane Library, and Google Scholar) were searched from inception up to October 2022. We used the cochrane quality assessment tool to evaluate the risk of bias. Outcomes of interest included systolic blood pressure (SBP), diastolic blood pressure (DBP), blood levels of vascular cell adhesion molecule-1 (VCAM-1) and intracellular adhesion molecule-1 (ICAM-1), flow-mediated vasodilation (FMD), and pulse-wave velocity (PWV). Weighted mean differences (WMDs) were derived and reported. In case of significant between-study heterogeneity, subgroup analyses were carried out. Significance level was considered as P-values<0.05.

RESULTS

Finally, 35 RCTs out of 4182 studies were included. Our findings suggested that curcumin/turmeric supplementation significantly improved SBP (WMD: -2.02 mmHg; 95 % CI: -2.85, -1.18), DBP (WMD: -0.82 mmHg; 95 % CI: -1.46, -0.18), VCAM-1 (WMD: -39.19 ng/mL; 95 % CI: -66.15, -12.23), and FMD (WMD: 2.00 %; 95 % CI: 1.07, 2.94). However, it did not significantly change levels of ICAM-1 (WMD: -17.05 ng/ml; 95 % CI: -80.79, 46.70), or PWV (WMD: -79.53 cm/s; 95 % CI: -210.38, 51.33).

CONCLUSION

It seems that curcumin/turmeric supplementation could be regarded as a complementary method to improve blood pressure and endothelial function. However, further research is needed to clarify its impact on inflammatory adhesion molecules in the circulation.

The Protective Effects of Curcumin against Renal Toxicity

Curcumin is a naturally polyphenolic compound used for hepatoprotective, thrombosuppressive, neuroprotective, cardioprotective, antineoplastic, antiproliferative, hypoglycemic, and antiarthritic effects. Kidney disease is a major public health problem associated with severe clinical complications worldwide. The protective effects of curcumin against nephrotoxicity have been evaluated in several experimental models. In this review, we discussed how curcumin exerts its protective effect against renal toxicity and also illustrated the mechanisms of action such as anti-inflammatory, antioxidant, regulating cell death, and anti-fibrotic. This provides new perspectives and directions for the clinical guidance and molecular mechanisms for the treatment of renal diseases by curcumin.

Antioxidants for adults with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) is a significant risk factor for cardiovascular disease (CVD) and death. Increased oxidative stress in people with CKD has been implicated as a potential causative factor. Antioxidant therapy decreases oxidative stress and may consequently reduce cardiovascular morbidity and death in people with CKD. This is an update of a Cochrane review first published in 2012.

OBJECTIVES

To examine the benefits and harms of antioxidant therapy on death and cardiovascular and kidney endpoints in adults with CKD stages 3 to 5, patients undergoing dialysis, and kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies until 15 November 2022 using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Registry Platform (ICTRP) Search Portal, and ClinicalTrials.gov.

SELECTION CRITERIA

We included all randomised controlled trials investigating the use of antioxidants, compared with placebo, usual or standard care, no treatment, or other antioxidants, for adults with CKD on cardiovascular and kidney endpoints.

DATA COLLECTION AND ANALYSIS

Titles and abstracts were screened independently by two authors who also performed data extraction using standardised forms. Results were pooled using random effects models and expressed as risk ratios (RR) or mean difference (MD) with 95% confidence intervals (CI). Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 95 studies (10,468 randomised patients) that evaluated antioxidant therapy in adults with non-dialysis-dependent CKD (31 studies, 5342 patients), dialysis-dependent CKD (41 studies, 3444 patients) and kidney transplant recipients (21 studies, 1529 patients). Two studies enrolled dialysis and non-dialysis patients (153 patients). Twenty-one studies assessed the effects of vitamin antioxidants, and 74 assessed the effects of non-vitamin antioxidants. Overall, the quality of included studies was moderate to low or very low due to unclear or high risk of bias for randomisation, allocation concealment, blinding, and loss to follow-up. Compared with placebo, usual care, or no treatment, antioxidant therapy may have little or no effect on cardiovascular death (8 studies, 3813 patients: RR 0.94, 95% CI 0.64 to 1.40; I² = 33%; low certainty of evidence) and probably has little to no effect on death (any cause) (45 studies, 7530 patients: RR 0.95, 95% CI 0.82 to 1.11; I² = 0%; moderate certainty of evidence), CVD (16 studies, 4768 patients: RR 0.79, 95% CI 0.63 to 0.99; I² = 23%; moderate certainty of evidence), or loss of kidney transplant (graft loss) (11 studies, 1053 patients: RR 0.88, 95% CI 0.67 to 1.17; I² = 0%; moderate certainty of evidence). Compared with placebo, usual care, or no treatment, antioxidants had little to no effect on the slope of urinary albumin/creatinine ratio (change in UACR) (7 studies, 1286 patients: MD -0.04 mg/mmol, 95% CI -0.55 to 0.47; I² = 37%; very low certainty of evidence) but the evidence is very uncertain. Antioxidants probably reduced the progression to kidney failure (10 studies, 3201 patients: RR 0.65, 95% CI 0.41 to 1.02; I² = 41%; moderate certainty of evidence), may improve the slope of estimated glomerular filtration rate (change in eGFR) (28 studies, 4128 patients: MD 3.65 mL/min/1.73 m², 95% CI 2.81 to 4.50; I² = 99%; low certainty of evidence), but had uncertain effects on the slope of serum creatinine (change in SCr) (16 studies, 3180 patients: MD -13.35 µmol/L, 95% CI -23.49 to -3.23; I² = 98%; very low certainty of evidence). Possible safety concerns are an observed increase in the risk of infection (14 studies, 3697 patients: RR 1.30, 95% CI 1.14 to 1.50; I² = 3%; moderate certainty of evidence) and heart failure (6 studies, 3733 patients: RR 1.40, 95% CI 1.11 to 1.75; I² = 0; moderate certainty of evidence) among antioxidant users. Results of studies with a low risk of bias or longer follow-ups generally were comparable to the main analyses.

AUTHORS' CONCLUSIONS

We found no evidence that antioxidants reduced death or improved kidney transplant outcomes or proteinuria in patients with CKD. Antioxidants likely reduce cardiovascular events and progression to kidney failure and may improve kidney function. Possible concerns are an increased risk of infections and heart failure among antioxidant users. However, most studies were of suboptimal quality and had limited follow-up, and few included people undergoing dialysis or kidney transplant recipients. Furthermore, the large heterogeneity in interventions hampers drawing conclusions on the efficacy and safety of individual agents.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Effects of turmeric extract supplementation on the lipid and lipoprotein subfraction profile in hemodialysis patients: A randomised, double-blind, crossover and controlled trial

Dyslipidemia is common in patients with chronic kidney disease. Curcumin, a bioactive polyphenol from Curcuma longa, can improve lipid profile. This study aims to analyze the effects of Curcuma Longa extract supplementation on lipid profile and lipoprotein subfractions in hemodialysis (HD) patients. This is a longitudinal, double-blind, washout-period randomized clinical trial. The patients were randomized into two groups: the curcumin group (n = 10) (orange and carrot juice with 2.5 g of Curcuma Longa extract) and the control group (n = 11) (juice without curcumin) 3x/w during HD sessions for 3 months. After the washout period, patients continued the supplementation as a crossover for the same period. The lipid profile was measured using enzymatic assays. The high-density lipoprotein and low-density lipoprotein subfractions analyses were performed using LipoprintTM. In the curcumin group, the triglyceride values tended to decrease with a different triglyceride variation between the pre and post-intervention for the control and curcumin groups of 38.5 (19.8) mg/dL (p = 0.06). There was no statistical difference in the others parameters. In conclusion, Curcuma longa extract may be a good nutritional strategy to reduce triglyceride plasma levels in hemodialysis patients, but it seems ineffective for the other parameter.

Effects of curcumin/turmeric supplementation on lipid profile: A GRADE-assessed systematic review and dose-response meta-analysis of randomized controlled trials

INTRODUCTION

Numerous approaches have been assigned to treat dyslipidemia (DLP). Turmeric/curcumin have been widely investigated with this regard. In the current study, we explored the effect of curcumin/turmeric supplementation on lipid profile.

METHODS

Online databases were searched up to October 2022. The outcomes included triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), apolipoprotein B (Apo-B), and apolipoprotein A (Apo-A). We used the Cochrane quality assessment tool to evaluate the risk of bias. The effect sizes were estimated as weighted mean difference (WMD) and 95% confidence intervals (CIs).

RESULTS

Out of 4182 articles retrieved from the initial search, 64 randomized clinical trials (RCTs) were included in the study. Between-study heterogeneity was significant. Meta-analysis showed that turmeric/curcumin supplementation exerts statistically significant improvements on blood levels of TC (WMD = -3.99mg/dL; 95% CI = -5.33, -2.65), TG (WMD = -6.69mg/dL; 95% CI = -7.93, -5.45), LDL-c (WMD = -4.89mg/dL; 95% CI = -5.92, -3.87), and HDL-c (WMD = 1.80mg/dL; 95% CI = 1.43, 2.17). However, turmeric/curcumin supplementation was not associated with improvements in blood levels of Apo-A or Apo-B. The studies did not thoroughly address the issues of potency, purity, or consumption with other foods.

CONCLUSION

Turmeric/curcumin supplementation seems to be effective in improving blood levels of TC, TG, LDL-c, and HDL-c; but may not be capable of improving their pertinent apolipoproteins. Since the evidence was assessed to be low and very low concerning the outcomes, these findings should be dealt with caution.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Ferroptosis: A new mechanism of traditional Chinese medicine compounds for treating acute kidney injury

Acute kidney injury (AKI) is a major health concern owing to its high morbidity and mortality rates, to which there are no drugs or treatment methods, except for renal replacement therapy. Therefore, identifying novel therapeutic targets and drugs for treating AKI is urgent. Ferroptosis is an iron-dependent and lipid-peroxidation-driven regulatory form of cell death and is closely associated with the occurrence and development of AKI. Traditional Chinese medicine (TCM) has unique advantages in treating AKI due to its natural origin and efficacy. In this review, we summarize the mechanisms underlying ferroptosis and its role in AKI, and TCM compounds that play essential roles in the prevention and treatment of AKI by inhibiting ferroptosis. This review suggests ferroptosis as a potential therapeutic target for AKI, and that TCM compounds show broad prospects in the treatment of AKI by targeting ferroptosis.

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

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

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

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

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

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

The effects of phytochemicals on serum triglycerides in subjects with hypertriglyceridemia: A systematic review of randomized controlled trials

This systematic review aimed to evaluate the efficacy of phytochemicals on lipid parameters in patients with hypertriglyceridemia (HTG). A comprehensive search was performed in PubMed/Medline, Scopus, ISI Web of Science, and Google Scholar from inception up to October 2021 to recognize randomized controlled trials (RCTs) assessing the effects of phytochemicals on lipid profiles in patients with HTG. Forty-eight RCTs including 53 arms and comprising 3,478 HTG patients met the eligibility criteria. Phytochemicals significantly reduced the serum levels of triglycerides in 32 out 53 arms, total cholesterol in 22 out of 51, low-density lipoprotein cholesterol in 21 out of 48, very low-density lipoprotein cholesterol in 1 out of 5, apolipoprotein B in 2 out of 4, and lipoprotein(a) levels in 2 out of 4 arms. Furthermore, phytochemicals supplementation increased the levels of high-density lipoprotein cholesterol in 15 out of 48 arms. In brief, phytochemicals supplementation might have beneficial effects on HTG. In most of the studies, phytochemicals had a favorable effect on at least one of the lipid parameters.

The Journey of Resveratrol from Vineyards to Clinics

With rising technological advancements, several factors influence the lifestyle of people and stimulate chronic inflammation that severely affects the human body. Chronic inflammation leads to a broad range of physical and pathophysiological distress. For many years, non-steroidal drugs and corticosteroids were most frequently used in treating inflammation and related ailments. However, long-term usage of these drugs aggravates the conditions of chronic diseases and is presented with morbid side effects, especially in old age. Hence, the quest for safe and less toxic anti-inflammatory compounds of high therapeutic potential with least adverse side effects has shifted researchers' attention to ancient medicinal system. Resveratrol (RSV) - 3,4,5^' trihydroxystilbene is one such naturally available polyphenolic stilbene derivative obtained from various plant sources. For over 2000 years, these plants have been used in Asian medicinal system for curing inflammation-associated disorders. There is a wealth of in vitro, in vivo and clinical evidence that shows RSV could induce anti-aging health benefits including, anti-cancer, anti-inflammatory, anti-oxidant, phytoesterogenic, and cardio protective properties. However, the issue of rapid elimination of RSV through the metabolic system and its low bio-availability is of paramount importance which is being studied extensively. Therefore, in this article, we scientifically reviewed the molecular targets, biological activities, beneficial and contradicting effects of RSV as evinced by clinical studies for the prevention and treatment of inflammation-mediated chronic disorders.

Caloric restriction induced epigenetic effects on aging

Aging is the subject of many studies, facilitating the discovery of many interventions. Epigenetic influences numerous life processes by regulating gene expression and also plays a crucial role in aging regulation. Increasing data suggests that dietary changes can alter epigenetic marks associated with aging. Caloric restriction (CR)is considered an intervention to regulate aging and prolong life span. At present, CR has made some progress by regulating signaling pathways associated with aging as well as the mechanism of action of intercellular signaling molecules against aging. In this review, we will focus on autophagy and epigenetic modifications to elaborate the molecular mechanisms by which CR delays aging by triggering autophagy, epigenetic modifications, and the interaction between the two in caloric restriction. In order to provide new ideas for the study of the mechanism of aging and delaying aging.

Effects of resveratrol on renal ischemia-reperfusion injury: A systematic review and meta-analysis

Renal ischemia-reperfusion (I/R) injury may lead to acute kidney injury, which is characterized by high morbidity and mortality rates. Resveratrol (RSV) can be extracted from Chinese herbs, and multiple animal experiments have demonstrated its potential for renal protection. This systematic review evaluates the protective effect of RSV against renal I/R injury in animal models. The PubMed, Embase, Web of Science, and Science Direct databases were searched for animal experiments related to RSV in renal I/R injury from their establishment to June 2022. In total, 19 studies were included with 249 animals (129 treated with RSV and 120 as controls). The pooled analysis revealed that RSV administration significantly decreased serum creatinine (SCr) levels (16 studies, n = 243, WMD = -58.13, 95% CI = -79.26 to -37.00, p < 0.00001) and blood urea nitrogen (BUN) levels (12 studies, n = 163, WMD = -34.37, 95% CI = -46.70 to -22.03, p < 0.00001) in the renal I/R injury model. The level of malondialdehyde (MDA), an oxidative stress index, was alleviated [7 studies, n = 106, standardized mean difference (SMD) = -6.05, 95% CI = -8.90 to -3.21, p < 0.0001] and antioxidant enzymes such as glutathione (GSH) (7 studies, n = 115, SMD = 9.25, 95% CI = 5.51-13.00, p < 0.00001) and catalase (CAT) (4 studies, n = 59, SMD = 8.69, 95% CI = 4.35-13.03, p < 0.0001) were increased after treatment of RSV. The subgroup analysis suggested that 5-10 mg/kg of RSV optimally protects against renal I/R injury as both the BUN and SCr levels were significantly decreased at this dosage. The protective effects of RSV against renal I/R injury might be attributed to multiple mechanisms, such as inhibiting oxidative stress, apoptosis, inflammation, fibrillation, and promoting autophagy. For a deeper understanding of the protective effects of RSV, experimental studies on animal models and large randomized controlled trials in humans are needed.

Resveratrol in disease prevention and health promotion: A role of the gut microbiome

Resveratrol is a bioactive polyphenolic compound mainly present in grapes and red wine. It is known to exert beneficial effects in various experimental settings, such as antioxidant, anti-inflammatory, anti-proliferative, and immunoregulatory. Accumulating evidence suggests these health benefits might be, at least partially, attributed to resveratrol's role in protecting the intestinal barrier, regulating the gut microbiome, and inhibiting intestinal inflammation. The purpose of this review is to examine the bioactivities of resveratrol in disease prevention and health promotion from the standpoint of regulating the gut microbiome. The article aims to provide additional insight into the potential applications of resveratrol in the food and nutraceutical industry.

The effects of curcumin-containing supplements on inflammatory biomarkers in hemodialysis patients: A systematic review and meta-analysis

In the past decade, the effect of curcumin or turmeric supplementation on many aspects of health status in different populations has been evaluated. In the present study, a systematic review and meta-analysis were conducted to estimate the effect of curcumin administration on inflammatory markers in hemodialysis (HD) patients. A systematic search was performed in MEDLINE, EMBASE, Scopus, and Clarivate Analytics Web of Science databases from 1997 until June2022 for terms related to curcumin/turmeric and hemodialysis (HD). Randomized, double-blind/single-blind studies examining the effects of curcumin/turmeric on the inflammation of HD participants older than 18 years were considered eligible for inclusion. Data were pooled using the weighted mean difference (WMD) and 95% CI as the summary statistic, considering a random-effects analysis model. The data that were pooled from nine studies with 472 patients indicated that curcumin-containing supplement had significant effect on serum C-reactive protein (CRP) levels (WMD = -3.3 mg/L; 95% CI: -5.4 to -1.3; p < 0.001, I²  = 76.7%, 8 studies, 467 participants), and interlukine-6 (IL-6) levels (SMD: -0.4; 95% CI: -0.8 to -0.07; p = 0.02, I²  = 31.6%, 3 studies, 153 participants) compared control group. Although curcumin intervention could not change tumor neurosis factor-α (TNF-α) concentration (SMD = -0.3; 95% CI: -0.7 to 0.04; p = 0.08, I²  = 25.3%, 3 studies, 153 participants), when compared with the placebo group. Our study's main limitations were small number of studies, overall high risk of bias in the included trials, and high heterogeneity in some results. The present meta-analysis suggested that intervention with curcumin-containing supplements was associated with a significant reduction in serum hs-CRP and IL-6 concentrations in HD patients. The curcumin intervention in the reduction of hs-CRP levels was greater than the minimal clinically important difference (MCID) for CRP (0.5 mg/L), which can be helpful in physicians' clinical decisions.

Physiotherapeutic Protocol and ZnO Nanoparticles: A Combined Novel Treatment Program against Bacterial Pyomyositis

Myositis tropicans or pyomyositis is a muscle inflammation resulting from a bacterial infection of skeletal muscle (commonly caused by Staphylococcus aureus) that usually leads to hematogenous muscle seeding. The present study was designed to estimate the role of ZnO-NPs and a physiotherapeutic program in the management of induced biceps femoris atrophy in rats through histological, biochemical, and radiological examinations at different time intervals. At the beginning, several bacterial strains were evaluated through a proteolytic enzyme activity assay and the highest activity was recorded with the Staphylococcus aureus strain. ZnO-NPs were synthesized with the arc discharge method with an average size of 19.4 nm. The antibacterial activity of ZnO-NPs was investigated and it was revealed that the prepared ZnO-NPs showed a minimum inhibitory concentration of 8 µg/mL against the tested bacterium. The cytotoxicity of the prepared ZnO-NPs was tested in C2C12 myoblast cells, and it was elaborated that CC50 was 344.16 µg/mL. Biceps femoris pyomyositis was induced with a potent strain (Staphylococcus aureus); then, a physiotherapeutic program combined with the prepared ZnO-NPs treatment protocol was applied and evaluated. The combined program claimed antibacterial properties, preventing muscle atrophy, and resulted in the most comparable value of muscle mass.

The effects of curcumin-containing supplementations on inflammatory markers and lipid profiles in patients with chronic kidney diseases: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

An evaluation the effects of curcumin on inflammatory markers and lipid profiles among patients with chronic kidney diseases (CKD).

METHODS

The electronic databases such as PubMed, and Scopus were searched systematically up until 12 December 2021. To evaluate the quality of the included studies, the Cochrane risk-of-bias tool for randomized trials was utilized. Likewise, data pooling was performed using a random effects model, also called a variance components model. Also, the findings were calculated as weighted mean difference (WMD) with a 95% confidence interval (CI).

RESULTS

In the end, this meta-analysis comprised a total number of nine studies. Curcumin intake significantly reduced total cholesterol (TC) (WMD=-13.77 mg/dL; 95% CI, -26.77, -0.77; p=0.04) and tumor necrosis factor alpha (TNF-α) (WMD=-18.87 pg/mL; 95% CI, -28.36, -9.38; p<0.001) compared with controls. The results did not confirm the significant effect of curcumin intake on triglyceride (TG) (WMD=-6.37 mg/dL; 95% CI, -26.59, 13.85; p=0.54), low-density lipoproteins (LDL-C) (WMD=-5.65 mg/dL; 95% CI, -20.81, 9.50; p=0.46), high-density lipoprotein (HDL-C) (WMD=0.16 mg/dL; 95% CI, -2.55, 2.88; p=0.91), and C-reactive protein (CRP) (WMD=-0.13 mg/L; 95% CI, -3.25, 3.30; p=0.93).

CONCLUSIONS

Our study showed that curcumin significantly impacts TC and TNF levels in CKD patients.

Effects of Dietary Chlorogenic Acid Supplementation Derived from Lonicera macranthoides Hand-Mazz on Growth Performance, Free Amino Acid Profile, and Muscle Protein Synthesis in a Finishing Pig Model

Chlorogenic acid (CGA), as one of the richest polyphenol compounds in nature, has broad applications in many fields due to its various biological properties. However, initial data on the effects of dietary CGA on protein synthesis and related basal metabolic activity has rarely been reported. The current study is aimed at (1) determining whether dietary CGA supplementation improves the growth performance and carcass traits, (2) assessing whether dietary CGA alters the free amino acid profile, and (3) verifying whether dietary CGA promotes muscle protein synthesis in finishing pigs. Thirty-two (Large × White × Landrace) finishing barrows with an average initial body weight of $71.89\pm 0.92$  kg were randomly allotted to 4 groups and fed diets supplemented with 0, 0.02%, 0.04%, and 0.08% CGA, respectively. The results indicated that, compared with the control group, dietary supplementation with 0.04% CGA slightly stimulated the growth performance of pigs, whereas no significant correlation was noted between the dietary CGA levels and animal growth ( $P>0.05$ ). Furthermore, the carcass traits of pigs were improved by 0.04% dietary CGA ( $P<0.01$ ). In addition, dietary CGA significantly improved the serum free amino acid profiles of pigs ( $P<0.01$ ), while 0.04% dietary CGA promoted more amino acids to translocate to skeletal muscles ( $P<0.05$ ). The relative mRNA expression levels of SNAT2 in both longissimus dorsi (LD) and biceps femoris (BF) muscles were augmented in the 0.02% and 0.04% groups ( $P<0.05$ ), and the LAT1 mRNA expression in the BF muscle was elevated in the 0.02% group ( $P<0.05$ ). We also found that dietary CGA supplementation at the levels of 0.04% or 0.08% promoted the expression of p-Akt and activated the mTOR-S6K1-4EBP1 axis in the LD muscle ( $P<0.05$ ). Besides, the MAFbx mRNA abundance in the 0.02% and 0.04% groups was significantly lower ( $P<0.05$ ). Our results revealed that dietary supplementation with CGA of 0.04% improved the free amino acid profile and enhanced muscle protein biosynthesis in the LD muscle in finishing pigs.

Oxidative Stress, Inflammation and Connexin Hemichannels in Muscular Dystrophies

Muscular dystrophies (MDs) are a heterogeneous group of congenital neuromuscular disorders whose clinical signs include myalgia, skeletal muscle weakness, hypotonia, and atrophy that leads to progressive muscle disability and loss of ambulation. MDs can also affect cardiac and respiratory muscles, impairing life-expectancy. MDs in clude Duchenne muscular dystrophy, Emery-Dreifuss muscular dystrophy, facioscapulohumeral muscular dystrophy and limb-girdle muscular dystrophy. These and other MDs are caused by mutations in genes that encode proteins responsible for the structure and function of skeletal muscles, such as components of the dystrophin-glycoprotein-complex that connect the sarcomeric-actin with the extracellular matrix, allowing contractile force transmission and providing stability during muscle contraction. Consequently, in dystrophic conditions in which such proteins are affected, muscle integrity is disrupted, leading to local inflammatory responses, oxidative stress, Ca²⁺-dyshomeostasis and muscle degeneration. In this scenario, dysregulation of connexin hemichannels seem to be an early disruptor of the homeostasis that further plays a relevant role in these processes. The interaction between all these elements constitutes a positive feedback loop that contributes to the worsening of the diseases. Thus, we discuss here the interplay between inflammation, oxidative stress and connexin hemichannels in the progression of MDs and their potential as therapeutic targets.

Polydatin Attenuates Cisplatin-Induced Acute Kidney Injury by Inhibiting Ferroptosis

Cisplatin is widely used in the treatment of solid tumors, but its application is greatly limited due to its nephrotoxicity; thus, there is still no effective medicine for the treatment of cisplatin-induced acute kidney injury (Cis-AKI). We previously identified that polydatin (PD) exerts nephroprotective effects by antioxidative stress in AKI models. Recent evidence suggests that oxidative stress-induced molecular events overlap with the process of ferroptosis and that there are common molecular targets, such as glutathione (GSH) depletion and lipid peroxidation. Nevertheless, whether the nephroprotective effect of PD is related to anti-ferroptosis remains unclear. In this study, the inhibitory effect of PD on ferroptosis was observed in both cisplatin-treated HK-2 cells (20 μM) in vitro and a Cis-AKI mouse model (20 mg/kg, intraperitoneally) in vivo, characterized by the reversion of excessive intracellular free iron accumulation and reactive oxygen species (ROS) generation, a decrease in malondialdehyde (MDA) content and GSH depletion, and an increase in glutathione peroxidase-4 (GPx4) activity. Remarkably, PD dose-dependently alleviated cell death induced by the system Xc⁻ inhibitor erastin (10 μM), and the effect of the 40 μM dose of PD was more obvious than that of ferrostatin-1 (1 μM) and deferoxamine (DFO, 100 μM), classical ferroptosis inhibitors. Our results provide insight into nephroprotection with PD in Cis-AKI by inhibiting ferroptosis via maintenance of the system Xc⁻-GSH-GPx4 axis and iron metabolism.

The JAK/STAT signaling pathway: from bench to clinic

The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway was discovered more than a quarter-century ago. As a fulcrum of many vital cellular processes, the JAK/STAT pathway constitutes a rapid membrane-to-nucleus signaling module and induces the expression of various critical mediators of cancer and inflammation. Growing evidence suggests that dysregulation of the JAK/STAT pathway is associated with various cancers and autoimmune diseases. In this review, we discuss the current knowledge about the composition, activation, and regulation of the JAK/STAT pathway. Moreover, we highlight the role of the JAK/STAT pathway and its inhibitors in various diseases.

The JAK/STAT signaling pathway: from bench to clinic

The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway was discovered more than a quarter-century ago. As a fulcrum of many vital cellular processes, the JAK/STAT pathway constitutes a rapid membrane-to-nucleus signaling module and induces the expression of various critical mediators of cancer and inflammation. Growing evidence suggests that dysregulation of the JAK/STAT pathway is associated with various cancers and autoimmune diseases. In this review, we discuss the current knowledge about the composition, activation, and regulation of the JAK/STAT pathway. Moreover, we highlight the role of the JAK/STAT pathway and its inhibitors in various diseases.

Resveratrol Protects against Cerebral Ischemic Injury via Restraining Lipid Peroxidation, Transition Elements, and Toxic Metal Levels, but Enhancing Anti-Oxidant Activity

Cerebral ischemia is related to increased oxidative stress. Resveratrol displays anti-oxidant and anti-inflammatory properties. The transition elements iron (Fe) and copper (Cu) are indispensable for the brain but overload is deleterious to brain function. Aluminum (Al) and arsenic (As) are toxic metals that seriously threaten brain health. This study was conducted to elucidate the correlation of the neuroprotective mechanism of resveratrol to protect cerebral ischemic damage with modulation of the levels of lipid peroxidation, anti-oxidants, transition elements, and toxic metals. Experimentally, 20 mg/kg of resveratrol was given once daily for 10 days. The cerebral ischemic operation was performed via occlusion of the right common carotid artery together with the right middle cerebral artery for 60 min followed by homogenization of the brain cortex and collection of supernatants for biochemical analysis. In the ligation group, levels of malondialdehyde, Fe, Cu, Al, and As increased but those of the anti-oxidants superoxide dismutase and catalase decreased. Pretreating rats with resveratrol before ischemia significantly reversed these effects. Our findings highlight the association of overload of Fe, Cu, As, and Al with the pathophysiology of cerebral ischemia. In conclusion, resveratrol protects against cerebral ischemic injury via restraining lipid peroxidation, transition elements, and toxic metals, but increasing anti-oxidant activity.

Frailty in CKD and Transplantation

The population is aging. Although older adults have higher rates of comorbidities and adverse health events, they represent a heterogeneous group with different health trajectories. Frailty, a clinical syndrome of decreased physiological reserve and increased susceptibility to illness and death, has emerged as a potential risk stratification tool in older patients with chronic kidney disease (CKD). Frailty is commonly observed in patients with CKD and associated with numerous adverse outcomes, including falls, decreased quality of life, hospitalizations, and death. Multiple pathologic factors contribute to the development of frailty in patients with CKD, including biological mechanisms of aging and physiological dysregulation. Current interventions to reduce frailty are promising, but additional investigations are needed to determine whether optimizing frailty measures improves renal and overall health outcomes. This review of frailty in CKD examines frailty definitions, the impact of frailty on health outcomes across the CKD spectrum, mechanisms of frailty, and antifrailty interventions (e.g., exercise or senescent cell clearance) tested in CKD patients. In addition, existing knowledge gaps, limitations of current frailty definitions in CKD, and challenges surrounding effective antifrailty strategies in CKD are considered.

Effects of resveratrol supplementation on bone quality: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The results from clinical trials have revealed that the effects of resveratrol supplementation on bone mineral density (BMD) and bone biomarkers are inconsistent. Our objective was to determine the effects of resveratrol supplementation on BMD and serum bone biomarkers.

METHODS

PubMed, Cochrane library, EMBASE, Web of science and Scopus were searched up to August 24, 2020. Two reviewers independently performed the articles search and screen according to defined selection criteria. The study quality of the randomized controlled trials (RCTs) was evaluated with the Cochrane scoring system. Heterogeneity among studies was examined by Cochrane Q test. Retrieved data were pooled after mean differences (MD) were computed between two groups for BMD and serum biomarkers. Subgroup analyses were performed to evaluate a potential difference in terms of dose of resveratrol and intervention duration. Sensitivity analysis was executed by omitting studies with imputed values in order to evaluate the influence of these studies on the overall results.

RESULTS

Ten eligible studies involving 698 subjects were included in this meta-analysis with 401 participants receiving resveratrol and 297 receiving placebo. Supplementation of resveratrol had no statistically significant effects on areal bone mineral density (aBMD) at lumbar spine (MD: -0.02, 95% CI: - 0.05, 0.01, p = 0.26, I² = 6%), total hip BMD (MD: -0.01, 95% CI: - 0.04, 0.02, p = 0.65, I² = 0%), and whole body BMD (MD: 0.00, 95% CI: - 0.02, 0.02, p = 0.74, I² = 0%). Supplementation of resveratrol also did not result in significant change in bone serum markers, including serum alkaline phosphatase (ALP), bone alkaline phosphatase (BAP), osteocalcin (OCN), procollagen I N-terminal propeptide (PINP), C-terminal telopeptide of type I collagen (CTX) and parathyroid hormone (PTH). Subgroup analysis showed the effect of resveratrol supplementation on BMD and serum bone markers were similar in trails of different doses, intervention duration, and pathological conditions of the participants.

CONCLUSION

Resveratrol supplementation did not show any significant effect on BMD or serum bone markers with the current evidence. Further investigation with more well-organized multicentre randomized trial is warranted.

Curcumin and Resveratrol Improve Muscle Function and Structure through Attenuation of Proteolytic Markers in Experimental Cancer-Induced Cachexia

Muscle wasting and cachexia are prominent comorbidities in cancer. Treatment with polyphenolic compounds may partly revert muscle wasting. We hypothesized that treatment with curcumin or resveratrol in cancer cachectic mice may improve muscle phenotype and total body weight through attenuation of several proteolytic and signaling mechanisms in limb muscles. In gastrocnemius and soleus muscles of cancer cachectic mice (LP07 adenocarcinoma cells, N = 10/group): (1) LC-induced cachexia, (2) LC-cachexia+curcumin, and (3) LC-cachexia + resveratrol, muscle structure and damage (including blood troponin I), sirtuin-1, proteolytic markers, and signaling pathways (NF-κB and FoxO3) were explored (immunohistochemistry and immunoblotting). Compared to nontreated cachectic mice, in LC-cachexia + curcumin and LC-cachexia + resveratrol groups, body and muscle weights (gastrocnemius), limb muscle strength, muscle damage, and myofiber cross-sectional area improved, and in both muscles, sirtuin-1 increased, while proteolysis (troponin I), proteolytic markers, and signaling pathways were attenuated. Curcumin and resveratrol elicited beneficial effects on fast- and slow-twitch limb muscle phenotypes in cachectic mice through sirtuin-1 activation, attenuation of atrophy signaling pathways, and proteolysis in cancer cachectic mice. These findings have future therapeutic implications as these natural compounds, separately or in combination, may be used in clinical settings of muscle mass loss and dysfunction including cancer cachexia.

Effects of dietary polyphenol supplementation on iron status and erythropoiesis: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The iron-chelating activities of polyphenols raise concern whether there is a risk of iron deficiency or anemia induced by polyphenol supplementation. Results from clinical trials regarding the effects of polyphenol supplementation on iron status and erythropoiesis are inconclusive.

OBJECTIVE

We performed a systematic review and meta-analysis of randomized controlled trials to determine the effects of polyphenol supplementation on iron status and erythropoiesis.

METHODS

Published articles were searched between May 1988 and 7 December, 2020. Finally, we identified 34 randomized controlled trials. Random-effects meta-analyses were performed to obtain the weighted mean difference of serum iron (SI), transferrin saturation (TS), ferritin, and hemoglobin concentration. Funnel plots and Egger's test were used to determine the risk of bias. The robustness of the effect sizes was examined by sensitivity analysis.

RESULTS

Polyphenol supplementation had an inhibitory effect on the SI concentration (-13.72 μg/dL; 95% CI: -20.74, -6.71) and TS (-3.10%; 95% CI: -4.93, -1.27), with no effect on ferritin (-9.34 ng/mL; 95% CI: -28.55, 9.87). Polyphenols increased the hemoglobin concentration (8.53 g/L; 95% CI: 3.33, 13.73). In healthy participants, polyphenol reduced the TS (-3.83%; 95% CI: -7.47, -0.19) and increased the hemoglobin concentration (12.87 g/L; 95% CI: 1.61, 24.14). Similarly, polyphenol reduced the SI concentration (-8.60 μg/dL; 95% CI: -16.10, -1.10) and increased the hemoglobin concentration (8.50 g/L; 95% CI: 0.86, 16.15) in patients with metabolic diseases. In patients with β-thalassemia, polyphenol decreased the SI concentration (-23.19 μg/dL; 95% CI: -35.84, -10.55), TS (-3.23%; 95% CI: -5.54, -0.91), and ferritin concentration (-223.62 ng/mL; 95% CI: -359.32, -87.91), but had no effect on the hemoglobin concentration.

CONCLUSION

Healthy individuals and patients with metabolic diseases may benefit from the positive impact of polyphenols on erythropoiesis. Patients with β-thalassemia may benefit from the effect of polyphenols on reducing SI. This trial was registered at PROSPERO (International prospective register of systematic reviews) as CRD42020161983.

Herbal antioxidants in dialysis patients: a review of potential mechanisms and medical implications

The consumption of exogenous antioxidants isolated from herbal extracts has shown beneficial effects on ameliorating dialysis-related complications through debilitating oxidative stress and inflammatory process. Many clinical studies available in public databases have reported the improved consequences of dialysis in patients supplemented with herbal antioxidants. Exploration of such data offers great possibilities for gaining insights into the potential mechanisms and medical implications of herbal antioxidants. In this work, the mechanisms and implications of some famous bioactive substances including silymarin, curcumin, resveratrol, emodin, and quercetin on the consequences of dialysis in chronic kidney disease (CKD) patients were explored. The protective features of silymarin are due to the flavonoid complex silybin. Curcumin is an active element from the root of curcuma longa with extensive beneficial properties, including antioxidant, anti-inflammatory activity, and inhibitory effects on cell apoptosis. Resveratrol can reduce the oxidative stress by neutralization of free radicals. Emodin is known as a natural anthraquinone derivative isolated from Chinese herbs. Finally, quercetin has been reported to exhibit several properties including antioxidant, anti-diabetic, analgesic, antihistaminic, antiviral, cholesterol reducer, and renal hemodynamic modulator. However, potential mechanisms and medical implications of the aforementioned herbal antioxidants seem to be more complicated, that is, more studies are required in this field.

SIRT1, a promising regulator of bone homeostasis

Sirtuin 1 (SIRT1), a nicotinamide adenine dinucleotide-dependent deacetylase, epigenetically regulates various cell metabolisms, including inflammation, tumorigenesis, and bone metabolism. Many clinical studies have found the potential of SIRT1 in predicting and treating bone-related disorders, such as osteoporosis and osteonecrosis, suggesting that SIRT1 might be a regulator of bone homeostasis. In order to identify the mechanisms that underlie the pivotal role of SIRT1 in bone homeostasis, many studies revealed that SIRT1 could maintain the balance between bone formation and absorption via regulating the ratio of osteoblasts to osteoclasts. SIRT1 controls the differentiation of mesenchymal stem cells (MSCs) and bone marrow-derived macrophages, increasing osteogenesis and reducing osteoclastogenesis. Besides, SIRT1 can enhance bone-forming cells' viability, including MSCs and osteoblasts under adverse conditions by resisting senescence, suppressing apoptosis, and promoting autophagy in favor of osteogenesis. Furthermore, the effect on bone vasculature homeostasis enables SIRT1 to become a valuable strategy for ischemic osteonecrosis and senile osteoporosis. The review systemically discusses SIRT1 pathways and the critical role in bone homeostasis and assesses whether SIRT1 is a potential target for manipulation and therapy, to lay a solid foundation for further researches in the future.

The Discovery of Druggable Anti-aging Agents

Caloric restriction (CR) has been shown to extend the lifespan of many species. Research to identify compounds that imitate the results of CR has shown extensions of both lifespan and healthspan via different mechanisms. For example, mechanistic target of rapamycin (mTOR) inhibitors such as rapamycin, phenols, and flavonoids show antioxidant characteristics, while spermidine induces autophagy. Herein, we summarize research progress and proposed mechanisms for the most well-known compounds showing lifespan-extending potential for anti-aging characteristics.

The Use of Curcumin for the Treatment of Renal Disorders: A Systematic Review of Randomized Controlled Trials

Chronic kidney disease (CKD) is one of the significant causes of morbidity and mortality worldwide, which could develop and progress to end-stage renal disease. Increased inflammation and reduced antioxidant capacity commonly occur in CKD and hemodialysis patients. Curcumin is a natural bioactive compound with antioxidant and anti-inflammatory properties. This systematic review was undertaken with the main aim of assessing the effects of curcumin/turmeric supplementation on renal diseases based on clinical trials. A comprehensive search was performed in PubMed/MEDLINE, Scopus, ISI Web of Science, and Google Scholar from inception up to April 6, 2020 to identify clinical trials assessing the effects of curcumin or turmeric alone, or in combination with other herbs or nutrients on renal diseases. Twelve studies met the eligibility criteria. These randomized controlled trials (RCTs) comprised 631 patients with either chronic kidney diseases (CKD), hemodialysis, diabetic proteinuria and nephropathy, and lupus nephritis. Curcumin/turmeric supplementation had favorable effects on renal diseases, particularly in terms of inflammation and oxidative stress. However, with the exception for proteinuria, their impact on clinical parameters, such as blood urea nitrogen, creatinine, glomerular filtration rate (GFR), and serum albumin, was weak and not significant. No serious adverse effects were reported following curcumin/turmeric supplementation. Within the limitations of this review, it can be concluded that curcumin/turmeric supplementation might have some beneficial effects on inflammatory and oxidative stress parameters of patients but no considerable positive impact on clinical outcomes of kidney diseases, apart from proteinuria.

Bioactive Compounds for the Management of Hypertriglyceridemia: Evidence From Clinical Trials and Putative Action Targets

Hypertriglyceridemia refers to the presence of elevated concentrations of triglycerides (TG) in the bloodstream (TG >200 mg/dL). This lipid alteration is known to be associated with an increased risk of atherosclerosis, contributing overall to the onset of atherosclerotic cardiovascular disease (CVD). Guidelines for the management of hypertriglyceridemia are based on both lifestyle intervention and pharmacological treatment, but poor adherence, medication-related costs and side effects can limit the success of these interventions. For this reason, the search for natural alternative approaches to reduce plasma TG levels currently represents a hot research field. This review article summarizes the most relevant clinical trials reporting the TG-reducing effect of different food-derived bioactive compounds. Furthermore, based on the evidence obtained from in vitro studies, we provide a description and classification of putative targets of action through which several bioactive compounds can exert a TG-lowering effect. Future research may lead to investigations of the efficacy of novel nutraceutical formulations consisting in a combination of bioactive compounds which contribute to the management of plasma TG levels through different action targets.

Corylifol A from Psoralea corylifolia L. Enhances Myogenesis and Alleviates Muscle Atrophy

Inflammatory conditions caused by cancer, chronic diseases or aging can lead to skeletal muscle atrophy. We identified myogenic compounds from Psoralea corylifolia (PC), a medicinal plant that has been used for the treatment of inflammatory and skin diseases. C2C12 mouse skeletal myoblasts were differentiated in the presence of eight compounds isolated from PC to evaluate their myogenic potential. Among them, corylifol A showed the strongest transactivation of MyoD and increased expression of myogenic markers, such as MyoD, myogenin and myosin heavy chain (MHC). Corylifol A increased the number of multinucleated and MHC-expressing myotubes. We also found that the p38 MAPK signaling pathway is essential for the myogenic action of corylifol A. Atrophic condition was induced by treatment with dexamethasone. Corylifol A protected against dexamethasone-induced myotube loss by increasing the proportion of multinucleated MHC-expressing myotubes compared with dexamethasone-damaged myotubes. Corylifol A reduced the expression of muscle-specific ubiquitin-E3 ligases (MAFbx and MuRF1) and myostatin, while activating Akt. These dual effects of corylifol A, inhibition of catabolic and activation of anabolic pathways, protect myotubes against dexamethasone damage. In summary, corylifol A isolated from P. corylifolia alleviates muscle atrophic condition through activating myoblast differentiation and suppressing muscle degradation in atrophic conditions.