Efficacy and Safety of Resveratrol Supplements on Blood Lipid and Blood Glucose Control in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Combination of plant metabolites hinders starch digestion and glucose absorption while facilitating insulin sensitivity to diabetes

Introduction

Diabetes mellitus (DM) is a common endocrine disease resulting from interactions between genetic and environmental factors. Type II DM (T2DM) accounts for approximately 90% of all DM cases. Current medicines used in the treatment of DM have some adverse or undesirable effects on patients, necessitating the use of alternative medications.

Methods

To overcome the low bioavailability of plant metabolites, all entities were first screened through pharmacokinetic, network pharmacology, and molecular docking predictions. Experiments were further conducted on a combination of antidiabetic phytoactive molecules (rosmarinic acid, RA; luteolin, Lut; resveratrol, RS), along with in vitro evaluation (α-amylase inhibition assay) and diabetic mice tests (oral glucose tolerance test, OGTT; oral starch tolerance test, OSTT) for maximal responses to validate starch digestion and glucose absorption while facilitating insulin sensitivity.

Results

The results revealed that the combination of metabolites achieved all required criteria, including ADMET, drug likeness, and Lipinski rule. To determine the mechanisms underlying diabetic hyperglycemia and T2DM treatments, network pharmacology was used for regulatory network, PPI network, GO, and KEGG enrichment analyses. Furthermore, the combined metabolites showed adequate in silico predictions (α-amylase, α-glucosidase, and pancreatic lipase for improving starch digestion; SGLT-2, AMPK, glucokinase, aldose reductase, acetylcholinesterase, and acetylcholine M2 receptor for mediating glucose absorption; GLP-1R, DPP-IV, and PPAR-γ for regulating insulin sensitivity), in vitro α-amylase inhibition, and in vivo efficacy (OSTT versus acarbose; OGTT versus metformin and insulin) as nutraceuticals against T2DM.

Discussion

The results demonstrate that the combination of RA, Lut, and RS could be exploited for multitarget therapy as prospective antihyperglycemic phytopharmaceuticals that hinder starch digestion and glucose absorption while facilitating insulin sensitivity.

Novel insights into the role of mitochondria in diabetic cardiomyopathy: molecular mechanisms and potential treatments

Diabetic cardiomyopathy describes decreased myocardial function in diabetic patients in the absence of other heart diseases such as myocardial ischemia and hypertension. Recent studies have defined numerous molecular interactions and signaling events that may account for deleterious changes in mitochondrial dynamics and functions influenced by hyperglycemic stress. A metabolic switch from glucose to fatty acid oxidation to fuel ATP synthesis, mitochondrial oxidative injury resulting from increased mitochondrial ROS production and decreased antioxidant capacity, enhanced mitochondrial fission and defective mitochondrial fusion, impaired mitophagy, and blunted mitochondrial biogenesis are major signatures of mitochondrial pathologies during diabetic cardiomyopathy. This review describes the molecular alterations underlying mitochondrial abnormalities associated with hyperglycemia and discusses their influence on cardiomyocyte viability and function. Based on basic research findings and clinical evidence, diabetic treatment standards and their impact on mitochondrial function, as well as mitochondria-targeted therapies of potential benefit for diabetic cardiomyopathy patients, are also summarized.

Mechanism of rhubarb in the treatment of hyperlipidemia: A recent review

Hyperlipidemia is a metabolic disorder, which is a major risk factor for atherosclerosis, stroke, and coronary heart disease. Although lipid-lowering treatments have been extensively studied, safer treatments with fewer adverse effects are needed. Rhubarb is a traditional Chinese medicine that has lipid-lowering, anti-inflammatory, and antioxidant properties. Disturbance in lipid metabolism is the basis of tissue damage caused by hyperlipidemia and plays a key role in the development of hyperlipidemia; however, the molecular mechanisms by which rhubarb regulates lipid metabolism to lower lipid levels are yet to be elucidated. We conducted this study to summarize the phytochemical constituents of Rheum officinale and provide a comprehensive review of the molecular mechanisms underlying the regulation of lipid metabolism during hyperlipidemia treatment. It was found that rhubarb extracts, including emodin, rhubarb acid, and rhubarb phenol, regulate total cholesterol, triglyceride, TNF-α, and IL-1β levels through signaling pathways such as C/EBP α, 3T3-L1, PPAR α, and AMPK, thereby improving the hyperlipidemic state. This suggests that rhubarb is a natural drug with lipid-lowering potential, and an in-depth exploration of its lipid-lowering mechanism can provide new ideas for the prevention and treatment of hyperlipidemia.

Potential of resveratrol in the treatment of interstitial lung disease

Interstitial lung disease (ILD) is a heterogeneous group of diseases characterized by lung injury caused by lung fibroblast proliferation, interstitial inflammation, and fibrosis. Different cell signal transduction pathways are activated in response to various proinflammatory or fibrotic cytokines, such as IL-6, and these cytokines are increased in different ILDs. The overexpressed cytokines and growth factors in ILD can activate TGF-β/Smad2/3/4, NF-κB, and JAK/STAT signal transduction pathways, promote the activation of immune cells, increase the release of pro-inflammatory and pro-fibrotic factors, differentiate fibroblasts into myofibroblasts, and promote the occurrence and development of ILD. This finding suggests the importance of signal transduction pathways in patients with ILD. Recent evidence suggests that resveratrol (RSV) attenuates excessive inflammation and pulmonary fibrosis by inhibiting the TGF-β/Smad2/3/4, NF-κB, and JAK/STAT signal transduction pathways and overactivation of immune cells. In this review, advances in lung protection and the underlying mechanisms of RSV are summarized, and the potential efficacy of RSV as a promising treatment option for ILD is highlighted.

δ-Tocotrienol in Combination with Resveratrol Improves the Cardiometabolic Risk Factors and Biomarkers in Patients with Metabolic Syndrome: A Randomized Controlled Trial

Background: Metabolic syndrome (MetS) is a cluster of central obesity, hypertension, hyperglycemia, and dyslipidemia. It is a global health issue with an increased risk of cardiovascular disease. Recently, a few natural products have been reported with promising anti-inflammatory and antioxidative effects. We aimed to evaluate the impact of δ-tocotrienol and resveratrol mixture (TRM) supplementation on cardiometabolic risk factors and biomarkers in patients with MetS. Methods: A randomized controlled trial was conducted at the hospitals of National University of Medical Sciences Rawalpindi, Pakistan. A total of 82 patients with MetS aged 18-60 years were enrolled based on International Diabetes Federation-2005 diagnostic criteria and randomly grouped into TRM (n = 41) and placebo (n = 41). Patients in the TRM group were given a 400 mg capsule (δ-tocotrienol 250 mg; resveratrol 150 mg), and a placebo (cellulose 400 mg) twice daily for 24 weeks. The biochemical tests were analyzed on ADVIA 1800 Chemistry^® analyzer and inflammatory biomarkers by ELISA methods. Results: In the TRM group, a significant reduction in waist circumference, blood pressure, mean (95% confidence interval) of fasting plasma glucose -0.15 mmol/L (-0.22 to -0.08), serum triglyceride -0.32 mmol/L (-0.47 to -0.17), and increment in high-density lipoprotein cholesterol were observed as compared with placebo. TRM supplementation also improved biomarkers: high-sensitive C-reactive protein -0.61 mg/L (-0.89 to -0.33), interleukin-6-1.99 pg/mL (-2.50 to -1.48), tumor necrosis factor-α -2.19 pg/mL (-2.55 to -1.83), malondialdehyde -0.48 μmol/L (-0.65 to -0.30), and total antioxidant capacity 1.71 U/mL (1.29 to 2.13). Conclusion: TRM supplementations improved cardiometabolic risk factors and biomarkers of inflammation and oxidative stress without any significant side effects in the patients with MetS. Clinical Trials Registry: The clinical trial was registered in Sri Lanka Clinical Trials Registry (https://slctr.lk/trials/slctr-2019-021).

Exercise Combined with a Chinese Medicine Herbal Tea for Patients with Type 2 Diabetes Mellitus: A Randomized Controlled Trial

Objectives: Exercise and Traditional Chinese Medicine (TCM) herbal tea may improve glucose metabolism through quite different mechanisms while sharing some common effects. The purpose of this study was to discover whether the intervention of exercise combined with TCM herbal tea intervention could produce advanced improvement in glucose metabolism than exercise alone in community patients with type 2 diabetes mellitus (T2DM). Materials and Methods: This was a 12-week, randomized controlled trial in which 75 community patients with T2DM were randomly assigned to the single group (n = 39) receiving intervention of aerobic and resistance exercise three times per week and the combined group (n = 36) receiving intervention of TCM herbal tea (consisted of six substances) taken once daily besides the exercise. The change of glycated hemoglobin A1 (HbA1c), tested before and after intervention, served as the primary outcome. Other measurements include fasting plasma glucose (FPG), glycated serum protein (GSP), lipid profile, and physical fitness profile. Results: HbA1c and FPG levels and their changes showed no group difference. The level of GSP was lower, and its decrease was also larger after exercise combined with TCM herbal tea than after single exercise intervention (p < 0.05). Lipid profile and physical fitness parameters were similar in the two groups except the larger six-minute walk test (6MWT) power after the combined intervention (p < 0.05). Patients showed good compliance with the intervention and had similar exercise days or amount in the two groups. No patient reported serious adverse events or significant changes in other lifestyles. Conclusions: A 12-week of exercise combined with TCM herbal tea could not enhance the hypoglycemic effects by exercise alone in community patients with type 2 diabetes. However, the lower GSP level and larger 6MWT work brought by combined intervention suggest its potential benefits, and further studies are needed to explore the effects of longer period and larger dosage of intervention. Clinical Trial Registration Number: Chinese Clinical Trial Registry: ChiCTR1800018721.

The Effect of Resveratrol on Blood Lipid Profile: A Dose-Response Meta-Analysis of Randomized Controlled Trials

(1) Background: The effects of resveratrol on blood lipids are controversial. Whether there is a dose-response of the lipid profile upon resveratrol supplementation is unknown. (2) Methods: This dose-response meta-analysis of randomized controlled trials (RCTs) was performed to explore the effects of resveratrol supplementation on lipid profile. A systematical and comprehensive search of several databases was conducted by 30 June 2022. (3) Results: The results indicated that the intake of resveratrol could significantly decrease the total cholesterol (TC) (mean difference = −10.28; 95%CI: −13.79, −6.76, p < 0.001), triglyceride (TG) (Mean difference = −856; 95%CI: −12.37, −4.75, p < 0.001) and low-density lipoprotein cholesterol (LDL-C) (mean difference = −5.69; 95%CI: −11.07, −0.31, p = 0.038) level, but did not alter the level of high-density lipoprotein cholesterol (HDL-C). In the non-linear dose−response analysis, we observed a significant effect of the supplementation dosage on the level of LDL-C (p-nonlinearity = 0.002). Results from the sub-group analysis showed that the reduction of LDL-C was more significant in the trials with a duration of ≥12 weeks and in subjects with type 2 diabetes mellitus. (4) Conclusion: Findings from this study suggest that resveratrol may be beneficial to reduce TC, TG, and LDL-C levels in the blood. The dosage of the resveratrol intervention is an essential factor that affects the level of LDL-C.

Influence of Age and Dose on the Effect of Resveratrol for Glycemic Control in Type 2 Diabetes Mellitus: Systematic Review and Meta-Analysis

Background: Several clinical trials have suggested that resveratrol has hypoglycemic properties; however, there are other studies in which such an effect has not been observed. Methods: We carried out a systematic search in several databases; seventeen studies were selected for the systematic review and fifteen were included in the meta-analysis. Results: Resveratrol decreases glucose levels in subjects aged 45−59 years at doses <250 mg/day (−8.64 mg/dL, p < 0.00001), 250−500 mg/day (−22.24 mg/dL, p = 0.0003), and 500−1000 mg/day (−28.40 mg/dL, p = 0.0008), while in subjects older than 60 years, it only decreases with doses of 250−500 mg/day. Likewise, HbA1c improved in subjects aged 45−59 years with doses of 250−500 mg (−0.60%, p < 0.00001), but not in subjects older than 60 years. Insulin levels improved in subjects aged 45−59 years with doses < 250 mg/day (−0.80 mIU/L, p = 0.0003) and doses of 250−500 mg/day (−5.0 mIU/L, p = 0.0003), although in subjects older than 60 years, they only improved with doses of 250−500 mg/day (−1.79 mIU/L, p = 0.01). On the other hand, HOMA-IR only improved in subjects older than 60 years with doses of 250−500 mg/day (−0.40, p = 0.01). Conclusions: Resveratrol has a statistically significant dose−response effect on glucose concentrations, HbA1c, and insulin levels; however, there is not enough scientific evidence to propose a therapeutic dose.

The Cost-Effectiveness of Supplemental Carnosine in Type 2 Diabetes

In this paper, we assess the cost-effectiveness of 1 g daily of carnosine (an over the counter supplement) in addition to standard care for the management of type 2 diabetes and compare it to standard care alone. Dynamic multistate life table models were constructed in order to estimate both clinical outcomes and costs of Australians aged 18 years and above with and without type 2 diabetes over a ten-year period, 2020 to 2029. The dynamic nature of the model allowed for population change over time (migration and deaths) and accounted for the development of new cases of diabetes. The three health states were 'Alive without type 2 diabetes', 'Alive with type 2 diabetes' and 'Dead'. Transition probabilities, costs, and utilities were obtained from published sources. The main outcome of interest was the incremental cost-effectiveness ratio (ICER) in terms of cost per year of life saved (YoLS) and cost per quality-adjusted life year (QALY) gained. Over the ten-year period, the addition of carnosine to standard care treatment resulted in ICERs (discounted) of AUD 34,836 per YoLS and AUD 43,270 per QALY gained. Assuming the commonly accepted willingness to pay threshold of AUD 50,000 per QALY gained, supplemental dietary carnosine may be a cost-effective treatment option for people with type 2 diabetes in Australia.

Correlation between TCM Syndromes and Type 2 Diabetic Comorbidities Based on Fully Connected Neural Network Prediction Model

Objective

To predict the major comorbidities of type 2 diabetes based on the distribution characteristics of syndromes, and to explore the relationship between TCM syndromes and comorbidities of type 2 diabetes.

Methods

Based on the electronic medical record data of 3413 outpatient visits from 995 type 2 diabetes patients with comorbidities, descriptive statistical methods were used to analyze the basic characteristics of the population, the distribution characteristics of comorbidities, and TCM syndromes. A neural network model for the prediction of type 2 diabetic comorbidities based on TCM syndromes was constructed.

Results

Patients with TCM syndrome of blood amassment in the lower jiao were diagnosed with renal insufficiency with 95% test sensitivity. The patients with spleen deficiency combined with ascending counterflow of stomach qi and cold-damp patterns were diagnosed with gastrointestinal lesions with 92% sensitivity. The patients with TCM syndrome group of spleen heat and exuberance of heart fire were diagnosed as type 2 diabetes complicated with hypertension with a sensitivity of 91%. In addition, the prediction accuracy of combined neuropathy, heart disease, liver disease, and lipid metabolism disorder reached 70∼90% in TCM syndrome groups.

Conclusion

The fully connected neural network model study showed that syndrome characteristics are highly correlated with type 2 diabetes comorbidities. Syndrome location is commonly in the heart, spleen, stomach, lower jiao, meridians, etc., while syndrome pattern manifests in states of deficiency, heat, phlegm, and blood stasis. The different combinations of disease location and disease pattern reflect the syndrome characteristics of different comorbidities forming the characteristic syndrome group of each comorbidity. Major comorbidities could be predicted with a high degree of accuracy through TCM syndromes. Findings from this study may have further implementations to assist with the diagnosis, treatment, and prevention of diabetic comorbidities at an early stage.