Effect of Nigella sativa L. supplementation on inflammatory and oxidative stress indicators: A systematic review and meta-analysis of controlled clinical trials.

AIMS: The objective of the present study was to perform a systematic review and meta-analysis on randomized controlled trials (RCTs) assessing the effects of Nigella sativa L. supplementation on the circulating inflammatory and oxidative stress markers, including C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), total antioxidant capacity (TAC) and malondialdehyde (MDA). METHODS: Systematic search was performed up to March 2020 using PubMed, Scopus, and ISI web of science databases. Two reviewers independently assessed study eligibility, extracted data, and evaluated methodological quality of included primary studies. Statistical heterogeneity was assessed using I-square (I2) statistic. Data were pooled by using the random-effect model and standardized mean difference (SMD) was considered as the summary effect size. RESULTS: Twelve trials were identified to be suitable for our meta-analysis. The pooled results using random effects model indicated that Nigella sativa supplementation significantly reduced CRP (SMD: -0.35; 95% CI: -0.59, -0.12, P < 0.001, I2 = 10.5%) and MDA concentrations (SMD: -0.56; 95% CI: -0.98, -0.15, P < 0.001, I2 = 64.7%). Moreover, Nigella sativa supplementation increased TAC (SMD: 0.48; 95% CI: 0.09, 0.87, P = 0.01, I2 = 65.6%) levels; however, it did not affect TNF-α (SMD: -0.35; 95% CI: -0.70, 0.01, P = 0.05, I2 = 58.2%). CONCLUSION: Nigella sativa supplementation is associated with improved inflammation and oxidative status. Additional prospective studies are recommended using higher supplementation doses and longer intervention period.

Barberry (Berberis vulgaris L.) is a safe approach for management of lipid parameters: A systematic review and meta-analysis of randomized controlled trials.

OBJECTIVE: We performed a meta-analysis to evaluate the efficacy of barberry supplementation on plasma lipid concentration in adult population. METHODS: The search included PubMed, Scopus, ISI Web of Science, Cochrane library, and Google Scholar (up to October 2018) to identify randomized controlled trials (RCTs) investigating the effects of barberry supplementation on serum lipid parameters. Mean Difference (MD) was pooled using a random-effects model. RESULTS: Meta-analysis on 5 RCTs with 339 participants indicated that barberry supplementation significantly decreased the levels of total cholesterol (MD: -23.58 mg/dl, 95% CI: -31.00 to -16.16, P ≤ 0.001), triglyceride (MD: -29.16 mg/dl, 95% CI: -42.91 to -15.41, P ≤ 0.001), and low-density lipoprotein cholesterol (MD: -13.75 mg/dl, 95% CI: -19.31 to -8.20, P ≤ 0.001) whereas changes in high-density lipoprotein cholesterol (MD: 3.40 mg/dl, 95% CI: -0.06-6.87, P = 0.054) was not statistically significant. CONCLUSION: This systematic review and meta-analysis suggested the efficacy of barberry supplementation on lipid parameters. However, further large-scale studies are needed to confirm these results.

Effects of Melatonin Supplementation On Blood Pressure: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Melatonin is a physiological indoleamine secreted from the pineal gland into the bloodstream. This hormone has antioxidant effects in cardiovascular disease, but the evidence regarding its effects on blood pressure (BP) has not been conclusive. Therefore, we assessed the impact of melatonin supplementation on systolic BP (SBP) and diastolic BP (DBP) through a systematic review and meta-analysis of available randomized controlled trials (RCTs). Medline, Scopus, Web of Science, Cochrane library, and Google scholar (until May 2018) were searched to identify potential RCTs with information on melatonin supplementation and BP. Mean Differences (MD) were pooled using a random-effects model. Standard methods were used for assessment of heterogeneity, sensitivity analysis, and publication bias. Pooling 5 RCTs (6 treatment arms) together identified significant reduction for SBP (MD: -3.43 mmHg, 95% confidence interval (CI): -5.76 to -1.09, p=0.004) and DBP (MD: -3.33 mmHg, 95% CI: -4.57 to -2.08, p<0.001) after supplementation with melatonin compared with control treatment. The sensitivity analysis indicated that the results were robust. We did not observe any evidence regarding publication bias. The findings of this meta-analysis support the overall favorable effect of melatonin supplementation on BP regulation.

Clinical evidence on the effects of saffron (Crocus sativus L.) on cardiovascular risk factors: A systematic review meta-analysis.

Cardiovascular disease is a one of most common causes of mortality around the world. This meta-analysis aims to summarize and conclude the clinical evidence regarding the use of saffron and its constituents, in particular crocin, on cardiovascular risk factors. A systematic review was conducted with PubMed, Scopus, Web of Science, Cochrane library and Google Scholar up to 24 May 2018. Randomized controlled trials (RCTs) that assessed the clinical effects of saffron and/or its constituents on blood lipid profile, glycemic parameters, blood pressure and anthropometric indices in human subjects were included. Eleven publication from ten studies comprising 622 participants included in quantitative analysis. Pooling of results showed significant effect of saffron on diastolic blood pressure (-1.24 mmHg; 95% CI: -1.51 to -0.96; I2 = 0%), body weight (-1.29 kg; 95% CI: -2.14 to -0.44; I2 = 70%) and waist circumstance (-1.68 cm; 95% CI: -3.31 to -0.04; I2 = 51%). When subgroup analysis was performed based on quality of studies, a significant reduction in fasting plasma glucose levels was observed in subgroup with high quality studies (-10.14 mg/dl; 95% CI: -13.80 to -6.48; I2 = 0%). Meta-analysis did not reveal any significant change in lipid profile, fasting insulin, systolic blood pressure and body mass index following saffron consumption. Present meta-analysis suggests that saffron might be beneficial in several outcomes related with cardiovascular disease. However, further RCTs with long term intervention with different dose of administration are needed.

Effect of Vitamin D Supplementation on Weight Loss, Glycemic Indices, and Lipid Profile in Obese and Overweight Women: A Clinical Trial Study.

INTRODUCTION: Vitamin D (vit D) deficiency has defined as a health problem worldwide. World Health Organization (WHO) has declared that obesity is an epidemic of the 21st century. Previous studies have shown that obesity may increase the risk of Vit D deficiency. Furthermore, other studies have demonstrated that vit D insufficiency was accompanied with higher risk of type 2 diabetes, cardiovascular diseases, hypertension, and obesity. The aim of this study was to survey the effect of vit D supplementation on weight loss among overweight and obese women aged 20-40 years in Isfahan. METHODS: This double-blind clinical trial was done on 50 overweight and obese women who were divided into two groups, in which one group received vit D supplements and the other group received placebo. Intervention group received vit D with dozes 50,000 IU/w for 6 weeks. The levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-c), high-density lipoprotein cholesterol (HDL-c), fasting blood sugar (FBS), insulin (ins), homeostasis model assessment of ins resistance (IR), C-reactive protein (CRP), height, weight (WT), waist circumference (WC), hip circumference (HC), and blood pressure (BP) were measured before and after intervention. RESULTS: After using vit D supplementation for 6 weeks, WT, WC, and body mass index (BMI) were decreased significantly and serum vit D increased significantly compared to control group (P < 0.001). Other factors including TC, TG, LDL-c, HDL-c, FBS, CRP, ins, IR, and waist to hip ratio (WHR) did not change significantly (P > 0.05). CONCLUSIONS: After 6 weeks of intervention, the means of WT, BMI, WC, and HC decreased significantly. Previous studies have shown that vit D deficiency was more prevalence in obese people and there was an inverse association among vit D with BMI and WC. The relationship between vit D and lipid profiles such as glycemic indexes, anthropometric indexes, CRP, and BP is not clear and needs more study in the future.

Cumin (Cuminum cyminum L.) is a safe approach for management of lipid parameters: A systematic review and meta-analysis of randomized controlled trials.

We performed a meta-analysis to evaluate the efficacy of cumin supplementation on plasma lipid concentration in adult population. The search included PubMed, Scopus, ISI Web of Science, Google Scholar, and the Cochrane library (up to January 2018) to identify randomized controlled trials (RCTs) investigating the effects of cumin supplementation on serum lipid parameters. Mean difference (MD) was pooled using a random-effects model. Meta-analysis of data from six eligible RCTs with 376 participants showed a significant reduction in plasma concentration of total cholesterol (MD [95% CI] -10.90 [-21.39, -0.42] mg/dl, p = 0.042) and low-density lipoprotein cholesterol (MD [95% CI] -6.94 [-11.53, -2.35] mg/dl, p = 0.003) after supplementation with cumin compared with control treatment, and plasma concentration of high-density lipoprotein cholesterol (MD [95% CI] 3.35 [1.58, 5.12] mg/dl, p˂0.001) were found to be increased. Although our analysis indicated that cumin supplementation cannot change triglyceride (TG) concentration (MD [95% CI] -20.48 [-41.23, -0.26] mg/dl, p = 0.053), but after stratified the RCTs based on the primary level of TG (hypertriglyceridemia versus nonhypertriglyceridemia subjects), there was a significant decrease in nonhypertriglyceridemia subset. This systematic review and meta-analysis suggested the efficacy of cumin supplementation on lipid parameters.

The effects of ethanol extract of Berberis vulgaris fruit on histopathological changes and biochemical markers of the liver damage in diabetic rats.

OBJECTIVES: Various studies have shown that the diabetes is associated with liver failure. The objective of this study was determining the effects of Berberis vulgaris fruit on histopathological and biochemical markers of liver in diabetic rats. MATERIALS AND METHODS: In this experimental study, 60 male Wistar rats weighing 200-250 g with free access to water and ad libitum were randomly divided to five twelve-membered groups including healthy control (group 1), diabetic control (group 2, this two groups received distilled water), treated diabetic positive control (group 3) using dose 150 mg/kg/day metformin, and two groups treated with doses 200 (group 4) and 600 (group 5) mg/kg/BW of B. vulgaris extracts via gavage feeding for 8 weeks. Diabetes mellitus was experimentally induced by one dose injection of alloxan 120 mg/kg. This pre-clinical study was performed on 120 mg/kg alloxan induced diabetic rats. RESULTS: The hepatic steatosis status, liver cholestasis and fibrosis were not changed in group 4 and 5. Glycogen deposition changed mildly and polymorphonuclear neutrophils infiltration changed moderately at group 5. Liver hepatitis changed mildly and severely at group 3 as well as group 5, respectively. Glucose, serum glutamic-oxaloacetic transaminase, serum glutamic pyruvic transaminase, and alkaline phosphatase were lower in high dose group compared to other groups. CONCLUSION: Results suggested that B. vulgaris extract can decrease liver damage by influencing hepatic histopathological and biochemical markers in diabetic rats.

The Effect of Green Tea and Sour Tea (Hibiscus sabdariffa L.) Supplementation on Oxidative Stress and Muscle Damage in Athletes.

OBJECTIVE: Additional oxygen consumption during intense exercises may lead to oxidative stress and contribute to muscular fatigue. Green tea and sour tea (Hibiscus sabdariffa L.), which contain various flavonoids and polyphenols, have many healthful properties such as anticarcinogenic, anti-inflammatory, and heart protecting effects. The aim of the present study was to assess the effects of green tea and sour tea supplementation on oxidative stress and muscle damage in soccer athletes. METHODS: This randomized, double-blind control trial was conducted on 54 male soccer players. Participants were randomly assigned to three groups to receive: 450 mg/d green tea extract (GTE) in the first group (n = 18), 450 mg/d sour tea extract (STE) in the second group (n = 18) and 450 mg/d maltodextrin in the control group (n = 18). Fasting whole blood samples were taken under resting conditions at the beginning and the end of the study to quantify the serum levels of muscle damage indices, aspartate aminotransferase (AST), creatine kinase (CK), lactate dehydrogenase (LDH), and oxidative stress biomarkers, malondialdehyde (MDA), and total antioxidant capacity (TAC). RESULTS: After six weeks intervention, athletes who received GTE and STE supplements compared with the placebo had a significantly decreased MDA level (P = 0.008). Furthermore, STE supplementation resulted in a significant increase in TAC level compared with GTE and placebo groups (P = 0.01). However, supplementation with GTE and STE had no significant effects on muscle damage indices. CONCLUSION: GTE and STE supplementation have beneficial effects on oxidative stress status in male athletes. However, both kinds of tea extract did not affect muscle damage status.