Anti-hyperglycemic effect of aqueous extract of Juglans regia L. leaf (walnut leaf) on type 2 diabetic patients: A randomized controlled trial

The hypoglycemic effects of Juglans regia L. internal septum in type 2 diabetic patients: A double-blind, randomized, placebo-controlled clinical trial

Introduction

The internal septum of J.regia is traditionally used to control diabetes, and its effectiveness has been shown in animal studies. Accordingly, human clinical trials are needed to confirm its effectiveness on hemoglobin A1c (HbA1c), fasting blood sugar (FBS), blood insulin level, and insulin resistance as a complementary for better control of type 2 diabetes.

Methods

This study was a randomized, double-blinded, controlled trial. The lyophilized powder of extract of the internal septum of J.regia was used to fill the capsules. Sixty type 2 diabetic patients were randomly divided into two groups. 500 mg capsules three times daily before meal was added to their routine drug regimen, and HbA1c, FBS, and blood insulin level were checked at the baseline and after three months.

Results

Sixty patients completed the study. The mean(±SD) age of patients was 49.1(10.2) and 50.9(12.7) years in the placebo and J.regia groups, respectively. We observed that J.regia internal septum increases the level of HbA1c by about 0.02 units, but this effect was not significant (MD=0.02,95%CI=-0.36 to 0.40, P=0.93). Regarding the impact of capsules on insulin level, it seems that J.regia-containing capsules can raise insulin level by one unit. However, it was not significant (MD=1.01,95%CI=-0.86 to 2.88, P=0.28). As for FBS, it can cause a decrease of four units, but this effect is also not significant (MD=-3.98,95%CI=-18.33 to 10.37, P=0.58).

Conclusion

Based on our study, the internal septum of J.regia has no significant effect on HbA1c, FBS, and insulin resistance. Moreover, no specific adverse reaction was observed in any of the patients.

Effectiveness and Safety of Ayurvedic Medicines in Type 2 Diabetes Mellitus Management: A Systematic Review and Meta-Analysis

Introduction: Many Ayurvedic medicines have the potential for managing type 2 diabetes mellitus (T2DM), with previous systematic reviews demonstrating effectiveness and safety for specific Ayurvedic medicines. However, many of the reviews need updating and none provide a comprehensive summary of all the Ayurvedic medicines evaluated for managing T2DM.

Objective: The objective of this systematic review was to evaluate and synthesize evidence on the effectiveness and safety of Ayurvedic medicines for managing T2DM.

Inclusion criteria: Published and unpublished RCTs assessing the effectiveness and safety of Ayurvedic medicines for managing T2DM in adults.

Methods: The JBI systematic review methodology was followed. A comprehensive search of sources (including 18 electronic databases) from inception to 16 January 2021 was made. No language restrictions were applied. Data synthesis was conducted using narrative synthesis and random effects meta-analyses, where appropriate. Pooled results are reported as mean differences (MD) with 95% confidence intervals (CI).

Results: Out of 32,519 records identified from the searches, 219 articles were included in the systematic review representing 199 RCTs (21,191 participants) of 98 Ayurvedic medicines. Overall, in the studies reviewed the methodology was not adequately reported, resulting in poorer methodological quality scoring. Glycated hemoglobin (HbA1c) was reduced using Aegle marmelos (L.) Corrêa (MD -1.6%; 95% CI −3 to −0.3), Boswellia serrata Roxb. (−0.5; −0.7 to −0.4), Gynostemma pentaphyllum (Thunb.) Makino (−1; −1.5 to −0.6), Momordica charantia L. (−0.3; −0.4 to −0.1), Nigella sativa L. (−0.4; −0.6 to −0.1), Plantago ovata Forssk. (−0.9; −1.4 to −0.3), Tinospora cordifolia (Willd.) Hook.f. and Thomson (−0.5; −0.6 to −0.5), Trigonella foenum-graecum L. (−0.6; −0.9 to −0.4), and Urtica dioica L. (−1.3; −2.4 to −0.2) compared to control. Similarly, fasting blood glucose (FBG) was reduced by 4–56 mg/dl for a range of Ayurvedic medicines. Very few studies assessed health-related quality of life (HRQoL). Adverse events were not reported in many studies, and if reported, these were mostly none to mild and predominately related to the gastrointestinal tract.

Conclusion: The current evidence suggests the benefit of a range of Ayurvedic medicines in improving glycemic control in T2DM patients. Given the limitations of the available evidence and to strengthen the evidence base, high-quality RCTs should be conducted and reported.

The Effect of Walnut (Juglans regia) Leaf Extract on Glycemic Control and Lipid Profile in Patients With Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

Numerous clinical trials have examined the beneficial effects of Juglans regia leaf extract (JRLE) in patients with type 2 diabetes mellitus (T2DM); however, the results of these studies are inconsistent. Therefore, we conducted the current systematic review and meta-analysis to evaluate the effect of JRLE on glycemic control and lipid profile in T2DM patients. We searched online databases including PubMed, Scopus, EMBASE, and Web of Science for randomized controlled clinical trials that examined the effect of JRLE on glycemic and lipid indices in T2DM patients. Data were pooled using both fixed and random-effect models and weighted mean difference (WMD) was considered as the overall effect size. Of the total records, 4 eligible studies, with a total sample size of 195 subjects, were included. The meta-analysis revealed that JRLE supplementation significantly reduces fasting blood glucose (WMD, −18.04; 95% confidence interval [CI], −32.88 mg/dL, −3.21 mg/dL; p = 0.017) and significantly increases fasting insulin level (WMD, 1.93; 95% CI, 0.40 U/L, 3.45 U/L; p = 0.014). Although the overall effect of JRLE supplementation on hemoglobin A1c was not significant, a significant reduction was seen in studies with an intervention duration of > 8 weeks (WMD, −0.64; 95% CI, −1.16%, −0.11%; p = 0.018). Moreover, we also found no significant change in lipid parameters. Our findings revealed a beneficial effect of JRLE supplementation on glycemic indices in T2DM patients, but no significant improvement was found for lipid profile parameters.

Effect of tree nuts on glycemic outcomes in adults with type 2 diabetes mellitus: a systematic review

OBJECTIVE

The objective of this review was to synthesize the best available research evidence regarding the effectiveness of tree nuts on glycemic outcomes in adults with type 2 diabetes mellitus.

INTRODUCTION

There has been an increase in the use of complementary therapy, particularly botanical products, for management of type 2 diabetes mellitus. It has been reported that increasing mono- and polyunsaturated fatty acids in diet effectively lowers the risk of development of type 2 diabetes mellitus. Hence, it was hypothesized that consumption of nuts, which are high in polyunsaturated fatty acids and mono-unsaturated fatty acids, may aid in preventing diabetes and reducing levels of blood glucose by reducing glycemic load by displacing dietary carbohydrates present in diet.

INCLUSION CRITERIA

This systematic review included randomized controlled trials that compared the consumption of any type and form of tree nut with a placebo or any other intervention in adults with type 2 diabetes mellitus. Trials were included if they measured fasting blood glucose, postprandial blood glucose, and/or glycated hemoglobin. Trials that assessed triglyceride levels and weight postintervention were also considered for inclusion. Trials were restricted to the English language.

METHODS

A three step search of PubMed, CINAHL, Embase, Trip database, and Cochrane Central Register of Controlled Trials (CENTRAL) was done in July 2019. To find unpublished studies, ClinicalTrials.gov and Google Scholar were searched. Studies from the search were reviewed against the inclusion criteria by two reviewers. The JBI critical appraisal checklist for randomized controlled trials was used to assess the potential studies for methodological quality. A meta-analysis and subgroup analysis was conducted among trials with the same type of intervention and outcome measures. Results are presented in a narrative format where statistical pooling was not possible.

RESULTS

Fifteen trials were included with a total sample size of 667. Consumption of pistachios demonstrated a significant reduction in triglyceride levels (mmol/L) at three month or earlier follow-up (mean difference [MD] -0.28; confidence interval -0.33, -0.23; P <0.00001). The meta-analysis including all tree nuts combined showed reduction in both fasting blood glucose and glycated hemoglobin (MD -0.26 mmol/L and -0.11% respectively) at three month or earlier follow-up. The subgroup analysis demonstrated MD of -0.45, -0.16, and -0.90 mmol/L in fasting blood glucose following ingestion of walnuts, almonds, and hazelnuts, respectively, and -0.17% in glycated hemoglobin following ingestion of walnuts at three month or earlier follow-up. Although not clinically significant, these figures give an indication that further research with larger sample sizes and longer follow-up may show encouraging results.

CONCLUSIONS

The authors found that pistachio consumption for three months or less significantly reduced triglyceride levels. Other tree nuts (walnuts, almonds, and hazelnuts) reduced fasting blood glucose and glycated hemoglobin levels by varying degrees. Further robust randomized controlled trials with power calculation-based sample size, comparing same type, dose, and method of nut intervention, will provide more evidence. For now, clinical decisions should be based on standard practice local guidelines.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42019133558.

Identifying potential active components of walnut leaf that action diabetes mellitus through integration of UHPLC-Q-Orbitrap HRMS and network pharmacology analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Walnut leaf (WL) is a hypoglycemic herbal medication with blood glucose-lowering activity that can affect diabetes mellitus (DM). However, the active components of WL and the mechanisms by which these compounds affect DM are unclear.

AIM OF STUDY

This study aimed to determine these effective ingredients and elucidate the potential mechanisms by which they affect DM via ultra-high performance liquid chromatography-hybrid quadrupole-Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap HRMS) coupled with network pharmacology analysis.

MATERIALS AND METHODS

First, UHPLC-Q-Orbitrap HRMS was utilized to identify components of WL. Second, the putative targets of the components were identified and predicted based on chemical similarity and online databases. Third, the key candidate targets and potential active components were identified through topological analysis of a component-disease target interaction network. Finally, interactions between active components and therapeutic targets were confirmed by molecular docking analysis.

RESULTS

One hundred and thirty components were identified in WL, among which 38 were considered potentially bioactive, as they showed hypoglycemic effects. Among these 38, 8 key active components possessed high similarities and shared 4 targets with approved drugs. These findings were confirmed by molecular docking analysis.

CONCLUSION

The approach combining UHPLC-Q-Orbitrap HRMS with network pharmacology analysis is a rapid and effective tool to identify potentially bioactive constituents in medicinal plants and prescriptions.

Effects of a hydroalcoholic extract of Juglans regia (walnut) leaves on blood glucose and major cardiovascular risk factors in type 2 diabetic patients: a double-blind, placebo-controlled clinical trial

Background

We aimed to evaluate the effects of a hydroalcoholic extract of Juglans regia L. leaves on blood glucose level and cardiovascular risk factors in type 2 diabetic patients.

Methods

In this randomized, double-blind, placebo-controlled, parallel-group (2 arms) clinical trial, 50 diabetic patients were divided into two groups: treatment group (receive the capsules containing 100 mg J. regia leaf extract) and control group (receive the capsules containing placebo, microcrystallin cellulose). Baseline participant data were matched between the two arms of the study. We administered the prepared capsules to the patients twice daily for 8 weeks. Blood glucose level, glycosylated hemoglobin (HbA1c) level, body weight, body mass index, blood pressure, lipid profile, serum insulin, and insulin resistance were compared between the two groups before and after the intervention. P < 0.05 was considered significant.

Results

After excluding eleven patients, 20 received J. regia leaf extract and 20 patients received placebo. The J. regia leaf extract did not significantly change the blood glucose and insulin resistance condition. However, in this group, body weight, body mass index, and systolic blood pressure significantly decreased compared with the baseline measurements (P = 0.028, P = 0.030, and P = 0.005, respectively). The lipid profile did not change significantly compared with the baseline measurements. In the control group, postprandial glucose and HbA1c levels significantly decreased after the intervention (P = 0.030 and P = 0.028, respectively). The other variables were not significantly different in this group. At the end of the study, the variables were not significantly different between the two groups.

Conclusion

In this double-blind study, 200 mg/d of J. regia leaf extract had no significant effect on blood glucose level and HOMA-IR score in patients with type 2 diabetes. However, the J. regia leaf extract was effective in reducing body weight and blood pressure. An accidental finding of our study was that microcrystalline cellulose, a widely used placebo in clinical trials, led to a reduction in blood glucose level.

Trial registration

Iranian Registry of Clinical Trials (IRCT: 138901203180 N2, 2010/6/6); retrospectively registered.