Comparison of nutritional supplements for glycemic control in type 2 diabetes: A systematic review and network meta-analysis of randomized trials.

AIMS: Direct and indirect evidence were combined in this systematic-review and network meta-analysis (NMA) to assess and compare the effect of nutritional supplements on glycemic control, and rank the supplements accordingly. METHODS: PubMed, Scopus, and Web of Science were searched up to April 2021. We included randomized controlled trials that investigated the effect of vitamins D, C, and E, magnesium, zinc, calcium, selenium, and omega-3 on at least one glycemic marker, including glycated hemoglobin (HbA1c), fasting blood sugar (FBS), homeostasis model assessment-estimated insulin resistance (HOMA-IR), HOMA-B, and insulin, in adults with type 2 diabetes. To estimate effectiveness of supplements, a random-effects NMA in the Bayesian framework was applied. To assess risk of bias, Cochrane Collaboration Tool was used. RESULTS: Analysis of 178 studies indicated that zinc, vitamin D, omega-3, vitamin C, and vitamin E were effective in reducing HbA1c with low certainty. For reduction of FBS, zinc, vitamin D, and vitamin C, and for HOMA-IR, vitamin D were effective with low certainty. None of the supplements were effective in the reduction of insulin and HOMA-B with low certainty. After excluding poor-quality studies, only vitamin D was significantly effective in reducing all of the markers. Consistently, when the analysis was restricted to studies with a duration of ≥12-weeks, vitamin D reduced HbA1c, FBS, and HOMA-IR. CONCLUSIONS: Vitamin D supplementation was more effective compared to other supplements in improving HbA1c, FBS, and HOMA-IR, albeit with low certainty of evidence. This result was confirmed by low-risk of bias studies. REGISTRATION: CRD42021240691.

Medicinal plant compounds as promising inhibitors of coronavirus (COVID-19) main protease: an in silico study.

The novel Coronavirus (COVID-19) has spread rapidly across the globe and has involved more than 215 countries and territories. Due to a lack of effective therapy or vaccine, urgent and concerted efforts are needed to identify therapeutic targets and medications. COVID-19 main protease represents a major target for drug treatment to inhibit viral function. The present study sought to evaluate medicinal plant compounds as potential inhibitors of the COVID-19 main protease using molecular docking and molecular dynamic analysis. The PDB files of COVID-19 main protease and some medicinal plant compounds were retrieved from the Protein Data Bank (http://www.rcsb.org) and Pubchem server, respectively. The Gromacs software was used for simulation studies, and molecular docking analysis was done using Autodock 4.2. The COVID-19 main protease simulation, compared with some phytochemicals docked to the COVID-19 main protease, were analyzed. Glabridin, catechin, and fisetin had the greatest tendency to interact with the COVID-19 main protease by hydrogen and hydrophobic interactions. Docking of these phytochemicals to COVID-19 main protease led to an increase in the radius of gyration (Rg), decrease in the Root mean square fluctuation (RMSF), and induced variation in COVID-19 main protease secondary structure. The high tendency interaction of glabridin, catechin, and fisetin to COVID-19 main protease induced conformational changes on this enzyme. These interactions can lead to enzyme inhibition. This simulated study indicates that these phytochemicals may be considered as potent inhibitors of the viral protease; however, more investigations are required to explore their potential medicinal use.Communicated by Ramaswamy H. Sarma.

The effect of cinnamon supplementation on lipid profiles in patients with type 2 diabetes: A systematic review and meta-analysis of clinical trials.

OBJECTIVE: The present systematic review and meta-analysis was performed to evaluate the effect of cinnamon supplementation on blood lipid profiles in patients with type 2 diabetes. METHODS: A systematic search (with no language restrictions) was performed in PubMed, Embase, Scopus, Web of Science, and Cochrane Library to identify relevant clinical trials up to 8th March 2020. Weighted mean differences (WMDs) and 95 % confidence intervals (CI) were pooled based on the random-effects model. Heterogeneity, publication bias, and sensitivity analyses were performed based on standard methods. RESULTS: Sixteen studies, involving 1025 participants, were included in the meta-analysis. This study found a significant decrease in triglycerides (TG) (WMD: -26.27 mg/dl, 95 % CI: [-38.93, -13.61], P < 0.001), total cholesterol (TC) (WMD: -13.93 mg/dl, 95 % CI: [-25.64, -2.22], P = 0.020), and low-density lipoprotein cholesterol (LDL-C) levels (WMD: -6.13 mg/dl, 95 % CI: [-10.72, -1.53], P = 0.009), while no change was observed on high-density lipoprotein cholesterol (HDL) concentration (WMD: 0.64 mg/dl, 95 % CI: [-0.18, 1.46], P = 0.128), in patients with type 2 diabetes. The reduction in TG, TC, and LDL-C was greater in; Eastern compared to Western countries, and studies with a duration of < 2 compared to ≥ 2 months. The increase in HDL was greater in; participants with a BMI ≥ 30 compared to <30, Western compared to Eastern countries, and intervention durations of ≥ 2 compared to < 2 months. CONCLUSIONS: Cinnamon supplementation significantly decreased serum TG, TC, and LDL-C concentrations, but did not change HDL-C levels, in patients with type 2 diabetes.

Effect of cinnamon supplementation on blood pressure and anthropometric parameters in patients with type 2 diabetes: A systematic review and meta-analysis of clinical trials.

BACKGROUND AND AIMS: The present systematic review and meta-analysis was conducted to investigate the effect of cinnamon supplementation on blood pressure and anthropometric indices in patients with type 2 diabetes. METHODS: PubMed, Embase, Scopus, Web of Science and Cochrane Library were systematically searched to find relevant records up to 22 August 2019. Standard mean difference (SMD) and 95% confidence interval (CI) were used to evaluate the effect of cinnamon supplementation on the outcomes of this study. In the case of heterogeneity, fixed and random effect models were used. The obtained data were analyzed by Stata 13. After excluding irrelevant records, 9 eligible articles were included. RESULTS: This meta-analysis found a significant reduction in systolic blood pressure (SBP) (SMD: -0.532, 95% CI: [-1.032, -0.033], P = 0.037) and diastolic blood pressure (DBP) (SMD: -0.681, 95% CI: [-1.297, -0.065], P = 0.030) of patients with type 2 diabetes following cinnamon supplementation. Based on the results of the present study, cinnamon supplementation had no significant effect on the body weight (BW) (SMD: -0.309, 95% CI: [-0.793, 0.175], P = 0.211), body mass index (BMI) (SMD: -0.550, 95% CI: [-1.244, 0.144], P = 0.120). and waist circumference (WC) (SMD: -0.235, 95% CI: [-0.518, 0.047], P = 0.103). CONCLUSIONS: Cinnamon supplementation significantly decreased SBP and DBP of patients with type 2 diabetes. Although cinnamon intake caused changes in anthropometric parameters, the observed changes were not statistically significant.