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

A thorough analysis of data on the correlation between COL9A1 polymorphisms and the susceptibility to congenital talipes equinovarus: a meta-analysis

BACKGROUND

Congenital talipes equinovarus (CTEV) is a prevalent pediatric deformity with a multifactorial etiology. The objective of this meta-analysis was to explore the association between genetic variations in COL9A1 and the susceptibility to CTEV.

METHODS

A comprehensive analysis of pertinent literature released before November 15, 2023, in electronic bibliographic databases was carried out. The importance of the connection was clarified through odds ratios (ORs) with 95% confidence intervals (CIs), utilizing random or fixed-effects models depending on study heterogeneity. Statistical analysis was executed using Comprehensive Meta-Analysis software (Version 4.0).

RESULTS

A total of eight case-control studies involving 833 CTEV patients and 1280 healthy individuals were included in the analysis. Among these, four studies investigated the rs1135056 variant, encompassing 432 CTEV cases and 603 controls; two studies examined the rs35470562 variant, with 189 CTEV cases and 378 controls; and two studies explored the rs592121 variant, including 212 CTEV cases and 299 controls. The results revealed a significant association between the rs1135056 and rs35470562 polymorphisms in the COL9A1 gene, suggesting an increased risk of CTEV in the overall population. Conversely, no such association was found for the rs592121 variant.

CONCLUSION

Our findings reveal a substantial association between the genetic variants COL9A1 rs1135056 and rs35470562 and susceptibility to CTEV. Conversely, the variant rs592121 did not exhibit any corresponding link. However, the limitations imposed by the small study population have compromised the statistical reliability and generalizability of the results.

A Comprehensive Integration of Data Regarding the Correlation of TNF-α rs1800629 Polymorphism with Susceptibility to Cervical Cancer

BACKGROUND

Cervical cancer, globally, ranks as the runner-up among the most prevalent forms of cancer affecting women. The role of the tumor necrosis factor alpha (TNF-α) polymorphism in the susceptibility to cervical cancer has been a subject of interest. However, the current evidence regarding this association remains inconclusive.

METHODS

To address this uncertainty, eligible studies were systematically searched and retrieved from various databases including Cochrane Library, EMBASE, PubMed, Web of Science, CNKI, and Wanfang database. The search was conducted until September 01, 2023. The collected literature was then subjected to independent analysis by two authors. The pooled odds ratio along with the corresponding 95% confidence interval was calculated using different genetic models. Additionally, sensitivity and cumulative analyses were performed to assess the stability of the obtained results.

RESULTS

A total of 29 case-control studies involving 8850 cases and 9286 controls were included in the present analysis. The findings revealed that the TNF-α rs1800629 polymorphism increased the risk of cervical cancer under the allele genetic model (A vs. G: OR = 1.277, 95% CI = 1.104-1.477, P = 0.001) in the general population. Subgroup analysis based on ethnicity demonstrated that this polymorphism was associated with an increased risk of cervical cancer in Caucasian and African women, but not in Asians. Furthermore, subgroup analysis based on country of origin indicated a significant correlation between the TNF-α rs1800629 polymorphism and an increased risk of cervical cancer in American and Chinese women, but not in Iranian women.

CONCLUSIONS

The findings from this meta-analysis suggest that the TNF-α rs1800629 polymorphism is a risk factor for cervical cancer in the general population, particularly in Caucasian and African women. However, further well-designed studies are warranted to validate these findings.

Association between XRCC2 Arg188His Polymorphism and Breast Cancer Susceptibility: A Systematic Review and Meta-Analysis

Breast cancer is one of the most common cancers in the world and leading cause of cancer-related death among women. Several studies indicated that Arg188His (rs3218536) polymorphism of X-ray repair cross-complementing 2 (XRCC2) may be associated with breast cancer risk. However, this association remains ambiguous. Thus, we performed a meta-analysis to provide more precise conclusion on this issue. A comprehensive search in PubMed, Google Scholar and ISI Web of Science was performed to select all relevant studies. Odds ratios (OR) with corresponding 95% confidence intervals (CI) were applied to assess the strength of the relationships. A total of 17 studies with 5694 breast cancer cases and 6450 healthy subjects were identified. The pooled data revealed that XRCC2 Arg188His polymorphism was marginally with susceptibility to breast cancer globally under the heterozygote contrast (OR = 0.929, 95% CI = 0.873-0.987, p=0.018). Moreover, subgroup analysis by ethnicity revealed that this polymorphism was associated with breast cancer risk among Caucasians. On the whole, the present study demonstrates that the XRCC2 Arg188His polymorphism may contribute to an increased risk of breast cancer.

Nutraceuticals and the Network of Obesity Modulators

Obesity is considered an increasingly widespread disease in the world population, regardless of age and gender. Genetic but also lifestyle-dependent causes have been identified. Nutrition and physical exercise play an important role, especially in non-genetic obesity. In a three-compartment model, the body is divided into fat mass, fat-free mass and water, and obesity can be considered a condition in which the percentage of total fat mass is in excess. People with a high BMI index or overweight use self-medications, such as food supplements or teas, with the aim to prevent or treat their problem. Unfortunately, there are several obesity modulators that act both on the pathways that promote adipogenesis and those that inhibit lipolysis. Moreover, these pathways involve different tissues and organs, so it is very difficult to identify anti-obesity substances. A network of factors and cells contributes to the accumulation of fat in completely different body districts. The identification of natural anti-obesity agents should consider this network, which we would like to call "obesosome". The nutrigenomic, nutrigenetic and epigenetic contribute to making the identification of active compounds very difficult. This narrative review aims to highlight nutraceuticals that, in vitro or in vivo, showed an anti-obesity activity or were found to be useful in the control of dysfunctions which are secondary to obesity. The results suggest that it is not possible to use a single compound to treat obesity, but that the studies have to be addressed towards the identification of mixtures of nutraceuticals.

Is Nigella sativa an Effective Bodyweight Lowering Agent and a Mitigator of Obesity Risk? A Literature Review

Obesity is one of the major health-threatening conditions nowadays. Nigella sativa (NS) is a medicinal plant that demonstrates multiple therapeutic effects. In the current review, we aim to evaluate the weight lowering effect of NS in both clinical trials and experimental studies and to explore the possible reported mechanisms of this effect. We searched PubMed and Web of science and retrieved 14 clinical trials and 5 experimental studies that justify our inclusion criteria. After the analysis of these articles, we can conclude that long-term administration of NS for 6–12 weeks can significantly lower bodyweight and other anthropometric indices. NS-oil is more potent than NS-powder in lowering bodyweight probably due to the higher concentration of fatty acids and thymoquinone. The weight lowering effect of NS is not a toxic effect, it conversely and preferably lowers the elevated liver enzymes in condition of fatty liver. It is also frequently accompanied by positive metabolic modifications, such as enhancement of lipid profile, lowering blood glucose and improving insulin resistance. Possible mechanisms for NS-bodyweight lowering effect might include an appetite-suppression effect, lowering caloric-intake and inhibition of intestinal glucose absorption. However, further experimental evidence is required to support these mechanisms or unveil new ones.

Effects of Nigella sativa supplementation on blood concentration and mRNA expression of TNF-α, PPAR-γ and adiponectin, as major adipogenesis-related markers, in obese and overweight women: a crossover, randomised-controlled trial

Adipocyte expansion through adipogenesis can offset the adverse metabolic effects of obesity. Nigella sativa (NS) (black seed) oil is shown to have therapeutic features in the management of obesity. NS oil might have beneficial changes in obese populations through mediating serum levels of adipogenesis-related parameters and relative transcriptional gene-diet interactions (nutrigenomics), though no previous studies assessed this mechanism in overweight/obese participants. This study assessed the effects of NS oil supplements on blood concentration and mRNA expression levels of TNF-α, PPAR-γ and serum adiponectin and expression of AdipoR1, as major adipogenesis and obesity-related parameters, in overweight/obese women using a cross-over design. Eligible women were randomised to receive either NS oil supplements (2000 mg/d) or placebo. Two periods of interventions (8 weeks in each) were cross-changed by a 4-week washout period. An individualised diet plan without calorie deficits was given to participants to match their energy/macronutrient intakes. The Pkcross procedure and intention-to-treat analysis were performed using Stata. Cohen's d(d) was estimated to measure the magnitude of the effects. Forty-six participants were included. NS oil capsules reduced transcription levels ((d = -2·31), P < 0·001) and blood concentrations of TNF-α ((d = -0·29), P < 0·001). AdipoR1 expression (d = 2·24, P < 0·001) and serum adiponectin (d = 0·88, P < 0·001) showed a significant augmentation with a medium-high effect size, as did gene expression (d = 0·69, P < 0·001) and serum levels of PPAR-γ (d = 0·97, P < 0·001). There was a moderate but significant decrease in body weight (d = 0·6, P < 0·001). The present beneficial findings would provide strong information for future nutrigenomics/clinical trial studies assessing the role of NS in the management of obesity and other comorbidities.

The effect of Nigella sativa on TAC and MDA in obese and overweight women: secondary analysis of a crossover, double blind, randomized clinical trial

Purpose

Since obesity is a risk factor for various diseases and is associated with increased oxidative stress conditions, some herbs are considered to be effective in reducing obesity and its complications.

Methods

This secondary analysis investigates the effect of Nigella sativa (N.S) oil supplement on total antioxidant capacity (TAC) and malondialdehyde (MDA) levels in obese/overweight women. Obese and overweight healthy women were randomized to receive 2,000 mg/d of N.S supplement and placebo. The intervention periods lasted 8 weeks and were separated by a 4-week washout period. Also, each participant was given an iso-calorie diet. Baseline characteristics and TAC and MDA levels were measured. Pkcross analysis was performed for statistical analysis using Stata software. Also, Cohen's d was estimated as effect size for all results to assess the magnitude of the effects.

Results

39 women completed the study. N.S oil supplementation at a dose of 2000 mg/d significantly increased serum TAC (P effect = 0.017, Cohen's d = 1.81) and reduced serum MDA (P effect < 0/001, Cohen's d =  - 0.32).

Conclusion

Based on our findings taking N.S supplementation for 8 weeks can improve antioxidant conditions in obese and overweight adults. However, more studies with a larger population and the presence of both genders need to be done to confirm the results.Registration number: IRCT20180430039475N1.

Effects of Nigella sativa, Camellia sinensis, and Allium sativum as Food Additives on Metabolic Disorders, a Literature Review

Objective: Metabolic disorders (MD) can disturb intracellular metabolic processes. A metabolic disorder can be resulted from enzyme deficits or disturbances in function of various organs including the liver, kidneys, pancreas, cardiovascular system, and endocrine system. Some herbs were used traditionally for spices, food additives, dietary, and medicinal purposes. Medicinal plants possess biological active compounds that enhance human health. We aimed to provide evidence about therapeutic effects of some medicinal herbs on MD.

Data Sources: PubMed, Scopus, and Google Scholar were explored for publications linked to MD until February 2021. The most literature reports that were published in the last 10 years were used. All types of studies such as animal studies, clinical trials, and in vitro studies were included. The keywords included “Metabolic disorders,” “Nigella sativa L.,” “Thymoquinone,” “White tea”OR “Camellia sinensis L.” “catechin,” and “Allium sativum L.” OR “garlic” were searched.

Results: Based on the results of scientific studies, the considered medicinal plants and their active components in this review have been able to exert the beneficial therapeutic effects on obesity, diabetes mellitus and non-alcoholic fatty liver disease.

Conclusions: These effects are obvious by inhibition of lipid peroxidation, suppression of inflammatory reactions, adjustment of lipid profile, reduction of adipogenesis and regulation of blood glucose level.

Association of ACE I/D and PAI-1 4G/5G polymorphisms with susceptibility to type 2 diabetes mellitus

BACKGROUND

A number of studies were carried out to assess the association of angiotensin I converting enzyme (ACE) I/D and plasminogen activator inhibitor-1 (PAI-1-1) 4G/5G polymorphisms with susceptibility to type 2 diabetes mellitus (T2DM). However, there are a few studies in Iranian patients with T2DM. Here, we tested for an association of ACE I/D and PAI-1 4G/5G polymorphisms with T2DM risk.

METHODS

One hundred-eighteen patients with T2DM and 125 healthy subjects were participates in this study. The ACE I/D (rs4340) and PAI-1 4G/5G (rs1799889) polymorphisms was genotyped by conventional and PCR-RFLP assays, receptively. The associations was evaluated by calculating the odds ratio (OR) and 95% confidence interval (95% CI).

RESULTS

The genotype distribution of ACE I/D and PAI-1 4G/5G polymorphisms were not deviated from the Hardy-Weinberg equilibrium in healthy controls. The ACE II, ID, and DD genotype frequencies were 18.6%, 48.3%, and 33.1% in the T2DM patients versus 24.0%, 45.6% and 30.4% in healthy subjects, respectively. The PAI-1 4G/4G, 4G/5G, and 5G/5G genotype frequencies were 16.9%, 51.7%, and 31.4% in cases versus 24.8%, 57.6% and 17.6% in controls, respectively. There is a significant distribution in genotype/allele of PAI-1 4G/4G between cases with T2DM and healthy control, but not for ACE I/D. Moreover, the 5G/5G genotype is significantly (OR = 2.139, CI 95% 1.171-3.907, p = 0.013) increased the risk of T2DM by two folds in the cases than healthy controls.

CONCLUSIONS

Our findings suggest that PAI-1 4G/5G may be likelihood risk factor for the development of T2DM in the Iranian patients. The higher frequency of PAI-1 5G/5G genotype in patients with T2DM revealed that individuals with the 5G allele may be at higher risk of T2DM development than those with 4G. However, there was no significant association between ACE I/D polymorphism and T2DM in our population. Future rigorous, well-designed studies with larger sample should replicate this study to confirm our findings in Iranian T2DM patients.

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.

Effects of Nigella sativa oil and thymoquinone against bisphenol A-induced metabolic disorder in rats

The underlying mechanisms of bisphenol A (BPA)-induced metabolic disorder and the protective impact of Nigella sativa oil (NSO) and thymoquinone (TQ) against BPA-induced metabolic disorder were investigated. Rats were treated as follows: Control, BPA (10 mg/kg), TQ (2 mg/kg), NSO (84 μL/kg), BPA + TQ (0.5, 1, 2 mg/kg), and BPA + NSO (21, 42, 84 μL/kg). BPA was administered by gavage, while, TQ and NSO were injected intraperitoneally (daily, 54 days). The weight, blood pressure, serum parameters [glucose, lipid profile, hepatic enzymes, insulin, interlukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), leptin, adiponectin], malondialdehyde (MDA), glutathione (GSH) and insulin signaling pathways [insulin receptor substrate (p-IRS,IRS); kinase (p-Akt,Akt); glycogen synthase kinase (p-GS3K,GS3K)] were measured. BPA increased the blood pressure, MDA, lipid profile, hepatic enzymes, insulin, IL-6, TNF-α, and leptin, and decreased the GSH and phosphorylated forms of IRS, Akt, GS3K but did not alter weight, glucose, IRS, AKT, and GS3K in the liver. Administration of NSO or TQ with BPA reduced the blood pressure, liver level of MDA, lipid profile, hepatic enzymes, insulin, IL-6, TNF-α, leptin, and increased the liver level of GSH and p-IRS, p-AKT, p-GS3K. TQ and NSO are thought to be effective in controlling metabolic disorders induced by BPA.

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.

Therapeutic effects of black seed oil supplementation on chronic obstructive pulmonary disease patients: A randomized controlled double blind clinical trial

This study sought to examine whether supplementation of Black Seed Oil (BSO) can improve pulmonary function tests (PFTs), inflammation, and oxidant-antioxidant markers in COPD patients. The study involved 100 patients of mild to moderate COPD divided randomly into 2 groups who were appointed to receive standard medication only (control group) or with additional Black Seed Oil (BSO group). They were assessed initially and after 3 months, 44 patients responded in control group and 47 patients in BSO group. BSO group evidenced a significant decreasing in oxidant and inflammatory markers; thiobarbituric acid reactive-substances (TBARS), protein carbonyl (PC) content, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), a significant increase in antioxidants; superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH), glutathione peroxidase (GPx), vitamin C, and E, and a significant improvement in PFTs versus control group and baseline levels. Supplementation of Black Seed Oil may be an effective adjunct therapy to improve pulmonary functions, inflammation, and oxidant-antioxidant imbalance in COPD patients.

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.