A crossover randomized controlled trial examining the effects of black seed (Nigella sativa) supplementation on IL-1ß, IL-6 and leptin, and insulin parameters in overweight and obese women.

BACKGROUND: Nigella sativa (NS) oil has been found to have advantageous benefits in the management of inflammation and obesity. This study investigated the effect of NS supplementation on blood mRNA expressions and serum levels of IL-1ß, IL-6, leptin, and insulin concentrations in overweight/obese women. METHODS: In a crossover design, participants were randomized to receive either NS supplements(2000 mg/day) or placebo for 2 durations(8 weeks). With between-subject and within-subject components and interactions, a repeated-measure ANOVA model was used considering the treatment, time, and the carryover effects. Cohen's d(d) was used to measure the magnitude of the effects. RESULTS: Forty-six eligible participants were included. NS supplementation significantly reduced the mRNA expressions(d=-0.68, P = 0.03) and serum levels of IL-1ß with medium-high effect sizes(d=-1.6, P < 0.001). Significant reductions with large effect sizes were observed in the gene expression and serum levels of IL-6(d=-1.8, d=-0.78, respectively; P < 0.01) and Leptin(d=-1.9, d=-0.89, respectively; P < 0.01, serum leptin P carryover < 0.001). Despite the meaningful carryover effect for serum leptin, results remained significant following the first intervention period analysis(P < 0.001). A significant but low effect size decrease in serum insulin was observed(d=-0.3, P = 0.02). CONCLUSIONS: The clinical significance of present findings regarding improvements in obesity-related pro-inflammatory markers must be interpreted with caution due to some observed medium-low effect sizes. TRIAL REGISTRATION: IRCT20180430039475N1 (Date:25/6/2018).

Exogenous application of selenium and nano-selenium alleviates salt stress and improves secondary metabolites in lemon verbena under salinity stress.

Salinity stress is one of the most serious abiotic factors that affects the growth, performance, and secondary compounds of medicinal plants. The aim of this study was to determine the effect of foliar application of selenium and nano-selenium separately on growth, essential oils, physiological parameters, and some secondary metabolites of Lemon verbena under salinity stress. The results showed that selenium and nano-selenium significantly increased growth parameters, photosynthetic pigments, and relative water content. Compared to the control, a higher accumulation of osmolytes (i.e., proline, soluble sugars, and total protein) and higher antioxidant activity were observed in the selenium-treated plants. In addition, selenium alleviated the adversary effect of oxidative stress, resulting from salinity, by reducing leaf electrolyte leakage, malondialdehyde, and H2O2 accumulation. Furthermore, selenium and nano-selenium enhanced the biosynthesis of secondary metabolites such as essential oils, total phenolic content, and flavonoid compounds under non-stress and salinity conditions. They also reduced Na+ accumulation in the root and shoot of the salinity-treated plants. Hence it can be concluded that exogenous application of selenium and nano-selenium separately can mitigate the negative effects of salinity by improving the quantitative and qualitative performance of lemon verbena plants under salinity stress.

The effect of Nigella sativa supplementation on cardiovascular risk factors in obese and overweight women: a crossover, double-blind, placebo-controlled randomized clinical trial.

PURPOSE: To assess the effect of Nigella sativa (N.S) oil supplements on CVD risk factors in a crossover design for the first time. METHODS: Obese and overweight healthy women were randomized to receive N.S oil (2000 mg/day) and placebo. This intervention period lasted for 8 weeks and separated by a 4-week washout period. An iso-caloric diet was given to every individual throughout the study. Blood pressure, lipid profile, atherogenic indices and liver enzymes were measured. Pkcross procedure was performed for statistical analyses using Stata software. Cohen's d was estimated as effect size for all outcomes to measure the magnitude of the effects. RESULTS: Thirty-nine participants completed the study. Capsules of N.S increased serum high-density lipoprotein cholesterol (Cohen's d = 0.47, P = 0.009), reduced low-density lipoprotein cholesterol (Cohen's d = - 0.33, P = 0.031), reduced TC/HDL-C ratio (as an atherogenic index, Cohen's d = - 0.9, P < 0.001), reduced serum glutamic-oxaloacetic transaminase (Cohen's d = 0- 0.5, P = 0.038) and reduced systolic blood pressure (Cohen's d = - 0.4, P < 0.001). There was no effect on diastolic blood pressure measures (P = 0.96). CONCLUSION: The overall improvements in cardiovascular disease (CVD) risk factors showed beneficial effects of N.S supplements among adults with obesity to prevent possible cardiovascular diseases. More studies with different designs and in other populations are suggested to clarify the exact effects of N.S as a complementary therapy for modulating CVD risk factors in individuals with overweight and obesity. TRIAL REGISTRATION: Iranian Registry of Clinical Trials, IRCT20180528039884N1, Registered on February 15th, 2019.

The effect of Nigella sativa on appetite, anthropometric and body composition indices among overweight and obese women: A crossover, double-blind, placebo-controlled, randomized clinical trial.

OBJECTIVES: Obesity is a global concern which is associated with several complications and disease. DESIGN: Present study is the first crossover, double-blind, placebo-controlled, randomized clinical trial aimed to evaluate the effect of Nigella Sativa (N. sativa) intervention on anthropometric and body composition parameters as well as dietary intake and appetite in a crossover design. METHOD: Forty-five healthy women with obesity or overweight were randomized into two groups of intervention and placebo, and the study conducted in two 8-week periods of intervention separated by a 4-week washout period. Anthropometric and body composition indices and dietary intake were measured. Also, appetite sensation was evaluated via a standard visual analog scale (VAS) questionnaire. Pkcross procedure was performed for statistical analysis using STATA. Cohen's d effect size was estimated for all outcomes to determine the magnitude of the effects. RESULTS: Supplementation with 2000 mg of N. sativa oil found to have a considerable increment in the measures of body mass index (P < 0.001, Cohen's d = 0.5), body weight (P < 0.001, Cohen's d = 0.6) and waist circumference (P = 0.020, Cohen's d = 0.4) with a medium effect size measure, and a significant decrease in body fat mass (P = 0.019, Cohen's d = 0.2), body fat percent (P < 0.001, Cohen's d = 0.2) and visceral fat area (P = 0.011, Cohen's d = 0.2) with a small effect size measure. CONCLUSION: The overall improvements in anthropometric and body composition parameters and a significant decrease in appetite represents the beneficial effects of N. sativa supplements in the treatment of obesity. More studies with different dosages, a larger number of participants, and longer intervention duration are recommended to illustrate the exact effects of N. sativa as a complementary therapy for obesity.

The effect of Nigella sativa on the measures of liver and kidney parameters: A systematic review and meta-analysis of randomized-controlled trials.

The aim of this systematic review and dose-response meta-analysis was to determine the effect of Nigella sativa (N.S) supplementation on liver and kidney parameters. We searched PubMed, Scopus, ISI Web of Science, Cochrane central register for controlled trials and Google Scholar from database inception to April 2019 for relevant controlled trials. Mean differences and standard deviations for each outcome were pooled using a random-effects model and a dose-response analysis was performed using a fractional polynomial model. Quality of evidence was evaluated using Cochrane Collaboration Risk of Bias tool and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology. Nineteen trials (n = 1295 participants) were included in the meta-analysis. We observed that N.S supplements had significant reducing effects on alkaline-phosphatase (ALP) [9 trials, n = 710 participants, weighted mean difference (WMD)= -10.825; 95 %CI: -19.658, -1.992 U/L; P = 0.016; I2 = 75.7 %; P-heterogeneity = 0.000) and blood urea nitrogen (BUN) (12 trials, n = 821 participants, WMD= -1.016; 95 % CI: -1.760, -0.273 U/L; P = 0.007; I2 = 87.7 %; P-heterogeneity = 0.000) concentrations. Subgroup analysis showed that, an intervention of more than 12 weeks was found to have a reducing effect on aspartate- aminotransferase (AST) measures (2 trials, n = 201 participants, WMD= -11.317; 95 % CI: -15.007, -7.626; P = 0.000; I2 = 0.0 %; P-heterogeneity = 0.977). Creatinine levels increased significantly in studies that considered adjusted analysis based on covariates (3 trials, n = 152 participants, WMD = 0.070; 95 % CI: 0.027, 0.112 U/L; P = 0.001; I2 = 0.0 %; P-heterogeneity = 0.788). A daily dose of 1100-1500 mg of N.S supplements was observed to have a substantial reducing effect on ALP levels (5 trials, n = 340 participants, WMD= -11.323; 95 % CI: -21.418, -1.229 U/L; P = 0.028; I2 = 0.00 %; P-heterogeneity = 0.686), while a dosage of more than 2000 mg per day led to a significant increase in BUN concentrations (2 trials, n = 101 participants, WMD= -1.016; 95 % CI: -1.760, -0.273 U/L; P = 0.007; I2 = 87.7 %; P-heterogeneity = 0.000). Our data suggested that N.S supplementation had significant impacts on liver and kidney parameters leading to a decrease in ALP and BUN levels. Longer duration of intervention and normal daily dosages of N.S supplements led to significant reductions in ALP and AST concentrations, respectively, while higher daily dosages increased BUN levels. Hence, in spite of favorable impacts of N.S supplements on liver and kidney parameters, due to the herbal nature of N.S, more studies with high-quality, large-scale, long-term intervention and precise baseline characteristics are needed to assess the exact effective dose, duration and efficacy of N.S supplementation on kidney and liver parameters.

Effects of oral Nigella sativa oil on the expression levels and serum concentrations of adiponectin, PPAR-γ, and TNF-α in overweight and obese women: a study protocol for a crossover-designed, double-blind, placebo-controlled randomized clinical trial.

BACKGROUND: Obesity is a major public health problem in recent decades. The accumulation of excessive fat promotes inflammatory status. Meanwhile, herbal products are marketed for their weight-loss properties, such as Nigella sativa (N. Sativa) which has been used for centuries to treat rheumatoid arthritis, diabetes, and asthma; recently, the anti-obesity characteristics of N. sativa have also been indicated. However, the exact mechanisms and cellular-related pathways are still unclear. Thus, we will aim to assess the effects of oral N. sativa on the gene expression of inflammatory and adipogenesis-related factors, including TNF-α, PPAR-γ, and adiponectin as well as assessing their serum concentrations among obese and overweight individuals. METHODS: Obese and overweight women aged 25-55 years with a body mass index (BMI) of 25-35 kg/m2 will be recruited from the Obesity Clinic in Shahid Sadoughi University of Medical Sciences and will be assessed for eligibility against inclusion criteria. They will be randomly assigned into two groups to receive either two capsules of N. sativa or two capsules of placebo per day for eight weeks (each capsule contains 1000 mg of N. sativa or placebo). There will be a four-week wash-out period and then participants will receive the reverse supplements for another eight weeks. Biochemical assessments and gene expressions (using real-time polymerase chain reaction) will be conducted at the beginning and at the end of every intervention period. DISCUSSION: The present study will investigate the probable cellular pathways for the anti-obesity effects of N. sativa in overweight/obese women. TRIAL REGISTRATION: Iranian Registry of Clinical Trials, IRCT20180528039884N1 . Registered on 2nd of July, 2018.