Sumac fruit supplementation improve glycemic parameters in patients with metabolic syndrome and related disorders: A systematic review and meta-analysis

Natural products and dietary interventions on liver enzymes: an umbrella review and evidence map

Background

The association between natural products and dietary interventions on liver enzymes is unclear; therefore, this study aimed to examine their effects on liver enzymes in adults.

Methods

PubMed, Embase, and Cochrane Library of Systematic Reviews databases were searched from inception until March 2023. The Assessment of Multiple Systematic Reviews-2 (AMSTAR-2) and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) systems were used to assess the methodological and evidence quality, and the therapeutic effects were summarized in a narrative form.

Results

A total of 40 meta-analyses on natural products (n = 25), dietary supplements (n = 10), and dietary patterns (n = 5) were evaluated, and results were presented in a narrative form. The overall methodological quality of the included studies was relatively poor. The results indicated that positive effects were observed for nigella sativa, garlic, artichoke, curcumin, silymarin, vitamin E, vitamin D, L-carnitine, propolis, and polyunsaturated fatty acids on certain liver enzymes. The dietary patterns, including high-protein, Mediterranean, and calorie-restriction diets and evening snacks, may reduce liver enzymes; however, other supplements and herbs did not reduce liver enzyme levels or have minimal effects. The evidence quality was generally weak given the risk of bias, heterogeneity, and imprecision.

Conclusion

This umbrella review suggests that natural products and dietary interventions have beneficial therapeutic effects on liver enzymes levels. Further clinical trials are necessary to establish the effectiveness of supplements that reduce liver enzymes.

Gualou-Xiebai-Banxia-Tang regulates liver-gut axis to ameliorate Metabolic Syndrome in HFD-fed mice

BACKGROUND

Metabolic syndrome (MetS), characterized by obesity, hyperglycemia, and abnormal blood lipid levels, is the pathological basis of many cardiovascular diseases. Gualou-Xiebai-Banxia-Tang decoction (GT) was first described in the Synopsis of the Golden Chamber, the earliest traditional Chinese medicine (TCM) monograph on diagnosis and treatment of miscellaneous diseases in China. According to TCM precepts, based on its ability to activate yang to release stagnation, activate qi to reduce depression, remove phlegm, and broaden the chest, GT has been used for more than 2,000 years to treat cardiovascular ailments. However, the molecular bases of its therapeutic mechanisms remain unclear.

PURPOSE

The aim of this study was to identify lipid- and glucose-related hepatic genes differentially regulated by GT, and to assess GT impact on gut microbiota composition, in mice with high-fat diet (HFD)-induced MetS.

STUDY DESIGN AND METHODS

ApoE-/- mice were fed with an HFD for 24 weeks, with or without concurrent GT supplementation, to induce MetS. At the study's end, body weight, visceral fat weight, blood lipid levels, and insulin sensitivity were measured, and histopathological staining was used to evaluate hepatosteatosis and intestinal barrier integrity. Liver transcriptomics was used for analysis of differentially expressed genes in liver and prediction of relevant regulatory pathways. Hepatic lipid/glucose metabolism-related genes and proteins were detected by RT-qPCR and western blotting. Gut microbial composition was determined by 16S rRNA gene sequencing.

RESULTS

GT administration reduced MetS-related liver steatosis and weight gain, promoted insulin sensitivity and lipid metabolism, and beneficially modulated gut microbiota composition by decreasing the relative abundance of g_Lachnospiraceae_NK4A136_group and increasing the relative abundance of g_Alistipes. Liver transcriptomics revealed that GT regulated the expression of genes related to lipid and glucose metabolism (Pparγ, Igf1, Gpnmb, and Trem2) and of genes encoding chemokines/chemokine receptors (e.g. Cxcl9 and Cx3cr1). Significant, positive correlations were found for Ccr2, Ccl4, Ccr1, and Cx3cr1 and the g_Lachnospiraceae_NK4A136_group, and between Cxcl9, Ccr2, Ccl4, and Cx3cr1 and g_Desulfovibrio. GT treatment downregulated the protein expressions of SCD1 and CX3CR1 and upregulated the expression of PCK1 protein.

CONCLUSION

GT supplementation alleviates HFD-induced MetS in mice by improving hepatic lipid and glucose metabolism. The anti-metabolic syndrome effects of GT may be related to the regulation of the gut-liver axis.

Association between Metabolic Syndrome and Leukocytes: Systematic Review and Meta-Analysis

Background: Metabolic syndrome (MetS) is a group of metabolic abnormalities characterised by central obesity, hypertension, dyslipidaemia, and dysregulation of blood glucose, which is associated with the risk of diabetes, cardiovascular disease, and overall mortality. White blood cell count is a selective marker of acute infection and inflammation, which could provide information on the metabolic status of subjects. This study aims to provide the best evidence on the association between MetS and white blood cell count by determining the effect size of this biomarker. Methods: A systematic review and meta-analysis of studies indexed in the PubMed and Scopus databases were performed. Methodological quality was assessed using the STROBE tool, overall risk of bias using RevMan (Cochrane Collaboration), and quality of evidence using Grade Pro. Results: We included 14 articles comparing leukocyte concentrations in 21,005 subjects with MetS and 66,339 controls. Subjects with MetS had a higher mean leukocyte count, 0.64 cells ×109/L; CI95% 0.55-0.72; p < 0.00001; I2 = 93%. Conclusions: An in-depth evaluation of the relationship of leukocytes in the pathophysiological process of MetS could lead to new insights into early diagnosis.

The effects of Capsicum annuum supplementation on lipid profiles in adults with metabolic syndrome and related disorders: A systematic review and meta-analysis of randomized controlled trials

The electiveness of Capsicum annuum supplementation in controlling dyslipidemia in adults has been unclear. Therefore, this meta-analysis focuses on the relationship between C. annuum supplementation and lipid profile in adults with metabolic syndrome (MetS) and related disorders. PubMed, Scopus, ISI Web of Science, and the Cochrane Library were searched up to March 2021. Only randomized controlled trials (RCTs) studying the administration of C. annuum compared to control on lipid markers in adults with MetS and related disorders were examined. Pooled effect sizes were reported as weighted mean differences (WMDs) and 95% confidence intervals (CIs). The results of four eligible RCTs showed that C. annuum supplementation could significantly reduce total cholesterol (TC) (WMD: -4.98 mg/dL, 95% CI: -7.08 to -2.88, p ≤ 0.001) levels, but did not regulate triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol concentrations. In summary, the present findings suggest the beneficial effects of C. annuum supplementation on the reduction of plasma levels of TC. However, to draw a firm link between C. annuum supplementation and lipid profile, more trials with adequate sample sizes, specifically in subjects with dyslipidemia are warranted.

The effect of sumac supplementation on insulin resistance, inflammation, oxidative stress, and antioxidant capacity in adults with metabolic syndrome: A randomized crossover clinical trial

The impact of sumac supplementation was not previously examined in patients with metabolic syndrome (MetS). So, we investigated the influence of sumac supplementation on insulin resistance, inflammation, oxidative stress, and antioxidant markers in adults with MetS. The current study was a single-center, triple-blind, randomized, placebo-controlled crossover clinical trial that was conducted on 47 patients with MetS. Participants were randomly divided into two groups of intervention and control in the first phase. They received capsules containing 500 mg sumac or placebo (lactose) twice a day, after lunch and dinner, for 6 weeks. After a 2-week washout period, the subjects crossed over to the alternate arm. In both arms, fasting venous blood samples were obtained at baseline and at the sixth week of the intervention to determine glycemic status, high-sensitivity C-reactive protein (hs-CRP), malondialdehyde (MDA), total antioxidant capacity (TAC), and antioxidant enzymes activity. The mean (±SD) age, weight, and body mass index of participants were respectively 58.7 ± 5.83 years, 79.9 ± 14.35 kg, and 31.6 ± 4.6 kg/m² ; 80.9% of subjects were females (n = 38). Based on per-protocol analyses, the serum fasting insulin concentration was unexpectedly decreased in the placebo group (change in sumac vs. control: 0.95 ± 3.9 vs. -1.17 ± 3.9 mU/L; p = 0.04). Sumac supplementation, compared to control, has marginally enhanced catalase activity (change in sumac vs. control: 2.91 ± 9.5 vs. -1.07 ± 9.1 nmol/min/ml; p = 0.06). This supplementation has also increased serum TAC and the activity of superoxide dismutase, but these changes were not significant. This intervention did not affect other insulin resistance, inflammatory, or oxidative stress markers. We found that 1 g/day sumac consumption for 6 weeks, as adjuvant therapy, could improve the antioxidant defense system in adults with MetS but did not affect insulin resistance, inflammation, or oxidative stress.

The effects of dietary supplements and natural products targeting glucose levels: an overview

Identifying effective dietary supplements and medicinal herbs has attracted the attention of clinicians and researchers to complement the standard treatment in controlling diabetes mellitus. In the present overview, we aimed to collect studies with the highest level of evidence to shed light on detecting the most effective dietary supplements and medicinal herbs for controlling glycemic status. For the current overview, four electronic databases, including PubMed, Scopus, Web of Science, and Cochrane Library, were systematically searched from inception to 31 December 2020 and then updated until 1 October 2021 to obtain eligible meta-analyses on either dietary supplements or medicinal herbs and their effects on glycemic status. Fasting blood sugar (FBS) and Hemoglobin A1C (HbA1C) were considered as primary outcomes. Finally, ninety-one meta-analyses on dietary supplements (n = 55) and herbs (n = 36) were included. Evidence showed positive effects of chromium, zinc, propolis, aloe vera, milk thistle, fenugreek, cinnamon, ginger, and nettle on FBS and/or HbA1C. However, mostly the heterogeneity (I2) was high. Other supplements and herbs also showed no reduction in glucose levels or their effects were small. Although some dietary supplements and medicinal herbs showed a significant reduction in FBS and/or HbA1C, mostly their effects from the clinical point of view were not remarkable. In addition, due to high heterogeneity, publication bias, and a limited number of included studies in most cases further clinical trials are needed for making decision on anti-diabetic supplement efficacy.