A systematic review and meta-analysis of randomized controlled trials investigating the effects of supplementation with Nigella sativa (black seed) on blood pressure

The Role of Diet in the Prevention of Hypertension and Management of Blood Pressure: An Umbrella Review of Meta-Analyses of Interventional and Observational Studies

High blood pressure (BP) is a major pathological risk factor for the development of several cardiovascular diseases. Diet is a key modifier of BP, but the underlying relationships are not clearly demonstrated. This is an umbrella review of published meta-analyses to critically evaluate the wide range of dietary evidence from bioactive compounds to dietary patterns on BP and risk of hypertension. PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials were searched from inception until October 31, 2021, for relevant meta-analyses of randomized controlled trials or meta-analyses of observational studies. A total of 175 publications reporting 341 meta-analyses of randomized controlled trials (145 publications) and 70 meta-analyses of observational studies (30 publications) were included in the review. The methodological quality of the included publications was assessed using Assessment of Multiple Systematic Reviews 2 and the evidence quality of each selected meta-analysis was assessed using NutriGrade. This umbrella review supports recommended public health guidelines for prevention and control of hypertension. Dietary patterns including the Dietary Approaches to Stop Hypertension and the Mediterranean-type diets that further restrict sodium, and moderate alcohol intake are advised. To produce high-quality evidence and substantiate strong recommendations, future research should address areas where the low quality of evidence was observed (for example, intake of dietary fiber, fish, egg, meat, dairy products, fruit juice, and nuts) and emphasize focus on dietary factors not yet conclusively investigated.

A Scoping Review of the Clinical Evidence for the Health Benefits of Culinary Doses of Herbs and Spices for the Prevention and Treatment of Metabolic Syndrome

Metabolic syndrome (MetS) is a growing global health problem. Evidence suggests that diets rich in phytochemical-containing herbs and spices can contribute to reducing the risk of chronic diseases. This review assesses the scope of evidence supporting the use of herbs and spices in the diet for the prevention or treatment of MetS and its associated health conditions. A search of the PubMed, Scopus and Google Scholar databases was carried out to assess the available clinical evidence for culinary doses of commonly used herbs and spices. Trials that were measuring health factors related to metabolic disorders in healthy individuals, or the health of individuals with MetS or associated diseases, were included. Out of a total of 1738 papers identified, there were 142 relevant studies on black pepper, chilli, cardamom, cinnamon, coriander, cumin, fennel, fenugreek, garlic, ginger, nigella seed, rosemary, sage and turmeric. No relevant research was found for cloves, mint, oregano, parsley or thyme. Cinnamon, fenugreek and ginger were the herbs/spices with the most published trials on them and that showed promise for glycaemic control. Cardamom appears to have potential to reduce inflammatory markers, and cinnamon, ginger and turmeric to reduce blood lipids. Patients with type 2 diabetes were the population most likely to be included in studies, but the preventative benefits of herbs/spices in healthy populations were also investigated, particularly for chilli, ginger and cinnamon. There is evidence for the beneficial effect of culinary doses of many common herbs/spices in the prevention and treatment of MetS and associated disorders.

Antihypertensive effects of Nigella sativa supplementation: An updated systematic review and meta-analysis of randomized controlled trials

Clinical studies have suggested that Nigella Sativa (N. sativa) supplementation may effectively reduce blood pressure, but the findings are controversial. Therefore, this study aimed to examine the effects of N. sativa on blood pressure in adults. PubMed, Cochrane Library, Web of Science, Scopus, Embase databases, and Google Scholar were searched till August 2022. To analyze weighted mean differences (WMDs), a random-effects model was utilized. Nonlinear dose-response analysis and a meta-regression were conducted. N. sativa supplementation was effective in reducing both systolic (WMD: -3.06 mmHg; 95% CI: -3.89 to -2.22, p < 0.001; I2  = 84.7%, p < 0.001) and diastolic blood pressure (WMD = -2.69 mmHg; 95% CI: -3.72, -1.66, p < 0.001; I2  = 97.3%, p < 0.001). The current meta-analysis suggests that N. sativa supplementation can improve blood pressure and claims that N. sativa could be used as an effective approach to blood pressure management.

Nigella sativa and health outcomes: An overview of systematic reviews and meta-analyses

Background

Nigella sativa (N. sativa) consumption has been associated with various health outcomes; however, the results are not completely consistent.

Objectives

This overview of systematic reviews and meta-analyses aimed to evaluate the reporting and methodological quality, and to grade the available evidence of associations between N. sativa and health outcomes.

Methods

PubMed, Cochrane Library, Embase, and Scopus databases were searched from their inception to September 30, 2022. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 statement, Assessment of Multiple Systematic Reviews (AMSTAR) 2 checklist, and Grades of Recommendations, Assessment, Development and Evaluations (GRADE) systems were used to assess the reporting, methodological, and evidence quality for each meta-analysis, respectively. The results were synthesized in a narrative form.

Results

This overview included 20 eligible meta-analyses published in peer-reviewed journals between 2013 and 2021. The overall methodological quality was relatively poor, with only one moderate quality, four low quality, and 15 critically low quality studies. For reporting quality, items two, five, eight, nine, 15, and 24 need to improve. Among the 110 outcome indicators of the quality of evidence, five were graded as moderate, 17 as low, and 88 as very low. Risk of bias, inconsistency, and imprecision were the main downgrading factors.

Conclusion

This overview suggests that N. sativa is beneficial for various clinical outcomes. However, there are certain limitations to reporting and methodological quality. The clinical efficacy of N. sativa requires confirmation in high-quality, large-sample, randomized controlled trials.

The effect of nigella supplementation on blood pressure: A systematic review and dose-response meta-analysis

This study was performed to assess the effect of nigella supplementation on blood pressure levels among the adult population. A comprehensive search was carried out through PubMed, Scopus, Web of Science, and Cochrane Library by using relevant keywords to find out the randomized clinical trials evaluating the effect of nigella administration on systolic blood pressure (SBP) and diastolic blood pressure (DBP). A random-effect model was applied to achieve the overall effect size. Subgroup analysis and meta-regression were used to explore the source of heterogeneity and the effects of the possible moderators. Of the twenty-two trials that were eligible for the present study, seventeen studies consisting of 1048 participants were included in the meta-analysis. The results indicated that nigella administration could significantly reduce both SBP (-4.58 mmHg; 95%CI: -6.22, -2.94) and DBP (-3.08 mmHg; 95%CI: -4.62, -1.55). Subgroup analysis did not show any superiority between subgroups of variables. Dose-response analysis detected a nonlinear association between dose and duration of administration and change in blood pressure outcomes, highlighting that maximum SBP and DBP reduction was experienced at 2000 mg/day and 8 weeks of nigella administration, respectively. The present study suggests that nigella supplementation can be beneficial for managing blood pressure.

Identification of SARS-CoV-2 RNA-dependent RNA polymerase inhibitors from the major phytochemicals of Nigella sativa: An in silico approach

The coronavirus disease 2019 (COVID-19), which emerged in December 2019, continues to be a serious health concern worldwide. There is an urgent need to develop effective drugs and vaccines to control the spread of this disease. In the current study, the main phytochemical compounds of Nigella sativa were screened for their binding affinity for the active site of the RNA-dependent RNA polymerase (RdRp) enzyme of the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). The binding affinity was investigated using molecular docking methods, and the interaction of phytochemicals with the RdRp active site was analyzed and visualized using suitable software. Out of the nine phytochemicals of N. sativa screened in this study, a significant docking score was observed for four compounds, namely α-hederin, dithymoquinone, nigellicine, and nigellidine. Based on the findings of our study, we report that α-hederin, which was found to possess the lowest binding energy (–8.6 kcal/mol) and hence the best binding affinity, is the best inhibitor of RdRp of SARS-CoV-2, among all the compounds screened here. Our results prove that the top four potential phytochemical molecules of N. sativa, especially α-hederin, could be considered for ongoing drug development strategies against SARS-CoV-2. However, further in vitro and in vivo testing are required to confirm the findings of this study.

Thymoquinone, a major constituent in Nigella sativa seeds, is a potential preventative and treatment option for atherosclerosis

Atherosclerosis is a widespread and progressive chronic arterial disease that remains the leading cause of mortality and morbidity worldwide. It is generally accepted that atherosclerosis is a multifactorial disease characterized by dyslipidemia and inflammation in the vessel walls. Nonpharmacological interventions to treat chronic diseases like atherosclerosis have gained considerable attention in recent years. Thymoquinone (TQ), the major bioactive constituent of Nigella sativa seeds, presents one such example of a natural therapeutic agent that has captured the attention of many researchers due to its wide array of medicinal properties, including its potent anti-atherosclerotic effects. Various in vitro and in vivo studies support the potential of TQ in ameliorating hyperlipidemia, hypercholesterolemia, oxidative stress, and inflammation, all of which are key hallmarks of atherosclerosis. However, to date, no review has been conducted to substantiate the role of TQ in preventing and/or treating atherosclerosis. This comprehensive review aims to examine recent in vitro and in vivo experimental findings reported on the potential anti-atherosclerotic effects of TQ. The roles of TQ in combatting hyperlipidemia, oxidative stress, and inflammation in atherosclerosis are highlighted. We also shed light on the role of TQ in preventing foam cell formation by decreasing low-density lipoprotein (LDL) availability and oxidation. Moreover, recent findings on the protective role of TQ on early markers of atherosclerosis, including homocysteinemia and endothelial dysfunction, are also underscored. Experimental evidence suggests that TQ can potentially be employed as a natural therapeutic agent with minimal side effects against the development and/or progression of atherosclerosis and its associated complications.

Phytonutrient supplements and metabolic biomarkers of cardiovascular disease: An umbrella review of meta-analyses of clinical trials

Phytonutrients exert several pharmacological effects on humans. In this study, we performed an umbrella review of the association of phytonutrient supplements (PNSs) with biomarkers of cardiovascular disease. Relevant published systematic reviews and meta-analyses of clinical trials were identified by searching PubMed, Embase, and Cochrane Library until July 4, 2020. Weighted mean differences (WMDs) and 95% confidence intervals (CIs) for summarized effects and I2 statistics of heterogeneity were extracted from individual studies or reanalyzed using a random-effects model. Of the 50 included studies, pooled effects of PNSs on blood pressure, lipid profiles, and glycemic control were reported in 16, 25, and 14 articles, respectively. The findings appeared to be highly heterogeneous among individual trials of included systematic reviews and meta-analyses. Ginger (WMD = -6.36 mmHg, 95% CI = -11.27, -1.46) and Hibiscus sabdariffa (WMD = -7.58 mmHg, 95% CI = -9.69, -5.46) were associated with lowered systolic blood pressure, whereas Aloe vera, Nigella sativa, and spirulina were associated with beneficial effects on both lipid profiles and glycemic control. In summary, this umbrella review has provided up-to-date evidence for the effect of PNSs on biomarkers related to hypertension, dyslipidemia, and diabetes. The results must be interpreted with caution due to potential heterogeneity.

Effects of Nigella sativa oil supplementation on selected metabolic parameters and anthropometric indices in patients with coronary artery disease: A randomized, double-blind, placebo-controlled clinical trial

Various metabolic parameters are risk factors related to the amplified risk of atherosclerotic cardiovascular disease. A wide variety of data exist on Nigella sativa (NS) and metabolic parameters. The current study is designed to examine NS supplementation on lipid profile, blood pressure, glycemic control, anthropometric indices, and insulin resistance in individuals with coronary artery disease (CAD). In a randomized, double-blind, placebo-controlled clinical trial, 60 patients with CAD received either 2 g of NS oil or sunflower oil as a placebo for 8 weeks. Biochemical and anthropometric measurements were assessed. NS significantly reduced weight (-1.82 Kg; 95% C, [2.72, 4.13]), body mass index (-0.67 kg/m² ; 95% C, [0.33, 1.01]), waist circumference (-2.15 cm; 95% C, [1.06, 3.23]), hip circumference (-1.26 cm; 95% C, [0.61, 1.910]), waist-to-hip ratio (0.008; 95%C, [0.001, 0.01]), systolic (-9.52 mmHg; 95% C, [7.14, 11.9]), diastolic blood pressure (-8.26 mmHg; 95% C, [4.89, 11.62]), and fasting blood glucose (FBS) (-4.32 mg/dl; 95% C, [-0.51, 9.15]) as compared with the placebo group. The results indicate a potential beneficiary effect of NS on the metabolic parameters in CAD patients including improvements in anthropometric indices, blood pressure, and FBS.

Nigella sativa in controlling Type 2 diabetes, cardiovascular, and rheumatoid arthritis diseases: Molecular aspects

Oxidative stress is an important factor in the etiology of several chronic diseases that include cardiovascular disease (CVD), Type 2 diabetes (T2D), and rheumatoid arthritis (RA). Oxidative stress can lead to inflammation, and this can contribute to these chronic diseases. Reducing inflammation and oxidative stress may, therefore, be useful in the prevention and treatment of these conditions. One of the treatment options for chronic diseases is the use of traditional medicine and herbs, such as Nigella sativa. This is one of the herbs that have recently been assessed for its ability to reduce inflammation and oxidative stress. We have reviewed the reported effects of N. sativa on risk factors of chronic diseases (CVD, DM, and RA) with emphasis on molecular and cellular mechanisms in controlling inflammation and oxidative stress. Various mechanisms have been proposed to contribute to the beneficial properties of N. sativa, including a reduction of lipid peroxidation via its antioxidant properties; agonist of peroxisome proliferator-activated receptor gamma in adipose tissue; activation of AMP-activated protein kinase, increased antioxidants, inhibition of nuclear factor-kappa B pathway; increased in interleukin-10 expression, CD4+ T-cell percentage, T regulatory cell percentage (CD4+ CD25+ T-cell) in peripheral blood, and CD4+/CD8+ ratio, but to prove this claim, it is necessary to conduct experimental and well-designed clinical trial studies with a larger sample size on the effects of N. sativa on these chronic diseases.

Phytotherapy for Cardiovascular Disease: A Bench-to-Bedside Approach

At present, cardiovascular disease (CVD) remains the leading cause of morbidity and mortality worldwide, and global trends suggest that this panorama will persist or worsen in the near future. Thus, optimization of treatment strategies and the introduction of novel therapeutic alternatives for CVD represent key objectives in contemporary biomedical research. In recent years, phytotherapy-defined as the therapeutic use of whole or minimally modified plant components-has ignited large scientific interest, with a resurgence of abundant investigation on a wide array of medicinal herbs (MH) for CVD and other conditions. Numerous MH have been observed to intervene in the pathophysiology of CVD via a myriad of molecular mechanisms, including antiinflammatory, anti-oxidant, and other beneficial properties, which translate into the amelioration of three essential aspects of the pathogenesis of CVD: Dyslipidemia, atherosclerosis, and hypertension. Although the preclinical data in this scenario is very rich, the true clinical impact of MH and their purported mechanisms of action is less clear, as large-scale robust research in this regard is in relatively early stages and faces important methodological challenges. This review offers a comprehensive look at the most prominent preclinical and clinical evidence currently available concerning the use of MH in the treatment of CVD from a bench-to-bedside approach.

The effect of nigella sativa on biomarkers of inflammation and oxidative stress: A systematic review and meta-analysis of randomized controlled trials

Inflammation and oxidative stress are involved in the pathogenesis of a myriad of chronic disorders. This systematic review and meta-analysis was designed to determine the effects of Nigella Sativa (NS) seed and seed oil consumption on several biomarkers of inflammation and oxidative stress. The Scopus, Web of Science, and PubMed-MEDLINE databases were systematically searched until August 2019. The quality assessment and heterogeneity of the selected randomized clinical trials (RCTs) were measured using the Jadad checklist, and Q and I² tests, respectively. Finally, a total of 10 clinical RCTs were found to be eligible for this meta-analysis. The pooled findings showed that NS consumption significantly reduced serum high-sensitivity C-reactive protein (hs-CRP; WMD: -0.67, 95% CI: -1.29, -0.05, I²  = 95.7%), tumor necrosis factor-alpha (TNF-α; WMD: -2.29, 95% CI: -4.48, -0.11, I²  = 93%), and malondialdehyde (MDA; WMD: -1.18, 95% CI: -2.24, -0.12, I²  = 85.4%), and significantly increased total antioxidant capacity (TAC; WMD: 0.35, 95% CI: 0.10, 0.59, I²  = 77.1%), and superoxide dismutase (SOD; WMD: 66.30, 95% CI: 1.03, 131.57, I²  = 99.4%) levels. Overall, the results of this systematic review and meta-analysis imply that NS consumption may decrease inflammatory response and oxidative stress markers. PRACTICAL APPLICATIONS: Overall, the evidence supports the consumption of NS to reduce hs-CRP, TNF-α, and MDA, and to increase SOD and TAC levels. In addition, the subgroup analyses findings concluded that lower dosages of NS, longer durations of the intervention, and the use of NS seed oil may result in more effective action on inflammatory markers, but because of the limited number of trials, the results must be analyzed with caution, especially for the subgroup analysis. However, further prospective studies regarding the effect of NS consumption on biomarkers of inflammation and oxidative stress, with larger sample sizes, from various countries and longer follow-up periods, are required to confirm whether NS possesses veritable anti-inflammatory and antioxidant effects.

A Whole Food Plant-Based Diet Is Effective for Weight Loss: The Evidence

What does the best available balance of scientific evidence show is the optimum way to lose weight? Calorie density, water content, protein source, and other components significantly influence the effectiveness of different dietary regimes for weight loss. By "walling off your calories," preferentially deriving your macronutrients from structurally intact plant foods, some calories remain trapped within indigestible cell walls, which then blunts the glycemic impact, activates the ileal brake, and delivers prebiotics to the gut microbiome. This may help explain why the current evidence indicates that a whole food, plant-based diet achieves greater weight loss compared with other dietary interventions that do not restrict calories or mandate exercise. So, the most effective diet for weight loss appears to be the only diet shown to reverse heart disease in the majority of patients. Plant-based diets have also been found to help treat, arrest, and reverse other leading chronic diseases such as type 2 diabetes and hypertension, whereas low-carbohydrate diets have been found to impair artery function and worsen heart disease, the leading killer of men and women in the United States. A diet centered on whole plant foods appears to be a safe, simple, sustainable solution to the obesity epidemic.

Nigella sativa L as a potential phytotherapy for coronavirus disease 2019: A mini review of in silico studies

Background

Coronaviruses are responsible for several human diseases, such as the infectious novel coronavirus disease 2019 (COVID-19), which is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Nigella sativa is a natural food supplement with a known safety profile that may provide a wealth of documented antiviral compounds.

Objective

To explore the studies supporting the N sativa potential for hitting SARS-CoV-2 targets.

Methods

A literature search for published or preprint in silico studies between 1990 and 2020 in electronic databases (PubMed, Science Direct, Scopus, and Google Scholar) was performed for the terms Nigella sativa, black seed, coronavirus, SARS-CoV-2, and COVID-19.

Results

At least 8 in silico studies have shown that some compounds of N sativa, including nigelledine, α-hederin, hederagenin, thymohydroquinone, and thymoquinone, had high to moderate affinity with SARS-CoV-2 enzymes and proteins. These compounds may potentially inhibit SARS-CoV-2 replication and attachment to host cell receptors.

Conclusions

These preliminary data of in silico studies propose N sativa as a potential phytotherapy candidate for COVID-19. Further preclinical experimental evidence is required followed by a Phase I clinical trial. (Curr Ther Res Clin Exp. 2020; 81:XXX-XXX).

Effects of Nigella sativa on glycemic control, lipid profiles, and biomarkers of inflammatory and oxidative stress: A systematic review and meta-analysis of randomized controlled clinical trials

The aim of this systematic review and meta-analysis was to evaluate the effects of Nigella sativa (N. sativa) on glycemic control, lipid profiles, and biomarkers of inflammatory and oxidative stress. Two independent authors systematically examined online databases consisting of, EMBASE, Scopus, PubMed, Cochrane Library, and Web of Science from inception until October 30, 2019. Cochrane Collaboration risk of bias tool was applied to assess the methodological quality of the studied trials. The heterogeneity among the included studies were assessed using the Cochrane's Q test and I-square (I² ) statistic. Data were pooled using a random-effects model and weighted mean difference (WMD) was considered as the overall effect size. A total of 50 trials were included in this meta-analysis. We found a significant reduction in total cholesterol (WMD: -16.80; 95% CI: -21.04, -12.55), triglycerides (WMD: -15.73; 95% CI: -20.77, -10.69), LDL-cholesterol (WMD: -18.45; 95% CI: -22.44, -14.94) and VLDL-cholesterol (WMD: -3.72; 95% CI: -7.27, -0.18) following supplementation with N. sativa. In addition, there was significant reductive effect observed with N. sativa on fasting glucose (WMD: -15.18; 95% CI: -19.82, -10.55) and HbA1C levels (WMD: -0.45; 95% CI: -0.66, -0.23). Effects of N. sativa on CRP (WMD: -3.61; 95% CI: -9.23, 2.01), TNF-α (WMD: -1.18; 95% CI: -3.23, 0.86), TAC (WMD: 0.31; 95% CI: 0.00, 0.63), and MDA levels (WMD: -0.95; 95% CI: -2.18, 0.27) were insignificant. This meta-analysis demonstrated the beneficial effects of N. sativa on fasting glucose, HbA1c, triglycerides, total-, VLDL-, LDL-cholesterol levels.

Trends in use, pharmacology, and clinical applications of emerging herbal nutraceuticals

The nutraceuticals market is vast, encompassing many different products with inconsistent levels of evidence available to support their use. This overview represents a Western perspective of the nutraceuticals market, with a brief comparison with that in China, as an illustration of how individual health supplements increase and decrease in popularity in regional terms. Recent changes in sales patterns, mainly taken from the US market, are summarized and a selection of five newer products, which have not been subject to extensive recent review are profiled: astaxanthin, a carotenoid found in red algae, seafood, salmon and trout, as an antioxidant; cannabidiol, a non-euphoric marijuana ingredient used as mood enhancer and for painful/inflammatory conditions; modified extracts of ginseng used in new indications including dementia and space travel; monk fruit, a non-sugar high intensity sweetener and nigella seed, a popular food ingredient and Asian medicine, which has experienced an extraordinary rise in sales recently. LINKED ARTICLES: This article is part of a themed section on The Pharmacology of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.6/issuetoc.

Optimum Extraction Technology for the Seed Oil of Nigella sativa L

Seed oil of Nigella sativa L. is a popular edible oil in Egypt. How to improve the extraction efficiency of the oil will expand the use of the resource. In this paper, the four extraction factors, particle size of the seed, liquid-seed ratio, extraction time, and temperature, were optimized by the single-factor and orthogonal experiment to increase the extraction yield and linoleic acid concentration. The results showed that the twice extraction technology could increase the oil rate of 23.55% compared with the once extraction technology. The extraction rate of the once extraction could reach 33.51% under the conditions of liquid-seed ratio: 9 : 1 mL/g, extraction temperature: 35°C, extraction time: 1 h, and particle size: 60 meshes. The optimum twice extraction conditions with the extraction rate of 43.78% were 8 : 1 ml/g, 40°C, 1.5 h, and 60 meshes. Besides, the highest concentration of linoleic acid (58.09 mg/g) was twice extraction condition with 7 : 1 mL/g, 40°C, 2 h, and 60 meshes.

Nigella sativa L. seed regulated eNOS, VCAM-1 and LOX-1 genes expression and improved vasoreactivity in aorta of diabetic rat

ETHNOPHARMACOLOGICAL RELEVANCE

Nigella sativa L. seed has been widely used in traditional medicine for the treatment of diabetes. The major reason for vascular complications in diabetic patients is endothelial dysfunction. However, the impact of N. sativa seed on endothelial dysfunction in diabetes remains unclear.

AIM OF THE STUDY

This study was conducted to evaluate the effect of the hydroalcoholic extract of N. sativa seed on eNOS, VCAM-1, and LOX-1 genes expression and the vasoreactivity of aortic rings to acetylcholine (Ach) in streptozotocin (STZ)-induced diabetic rat.

MATERIALS AND METHODS

Treated rats received N. sativa seed extract (100, 200, and 400 mg/kg) daily by gavage for 6 weeks. The fasting blood glucose and lipids were measured and atherogenic index of plasma (AIP) was calculated. The endothelium-dependent vasoreactivity responses of isolated aortic rings were evaluated in the presence of cumulative concentrations of Ach (10^-8-10^-5 M). eNOS, VCAM-1, and LOX-1 genes expression in aortic tissue was assessed by using real time polymerase chain reaction (PCR).

RESULTS

Male diabetic Wistar rats treated with N. sativa seed extract for six weeks reduced serum glucose and lipids and improved AIP. The vasorelaxant responses of aortic rings to Ach were markedly improved. N. sativa seed significantly increased eNOS in mRNA expression level and function, while it decreased VCAM-1 and LOX-1 expressions in vascular cells of aortic tissue which assessed only in mRNA level.

CONCLUSIONS

The results of this study showed that N. sativa seed more likely, has antidiabetic and antihyperlipidemic properties and improved vasoreactivity, endothelial dysfunction, and vascular inflammation in diabetic rats' aorta.

PROTECTIVE EFFECT OF NIGELLA SATIVA OIL ON MYOCARDIUM IN STREPTOZOTOCIN-INDUCED DIABETIC RATS

Background

To evaluate the protective effect of Nigella sativa oil (NSO) on the myocardium in streptozotocin-induced diabetic rats.

Materials and methods

Thirty-two 7-8-week-old female Wistar albino rats (300-350 g) were equally divided into 4 groups: nondiabetic untreated animals (control), diabetes mellitus (DM), NSO, and DM+NSO groups. For the induction of diabetes, 45 mg/kg streptozotocin was applied to the rats in the DM and DM+NSO groups as a single intraperitoneal dose. NSO (400 mg/kg) was orally administered through an intragastric catheter once a day over 21 days. Formalin-fixed, paraffin-embedded tissue sections of the myocardium were evaluated histopathologically and immunohistochemically.

Results

Compared to the control, NSO, and DM+NSO groups, the myocardial tissue samples from the rats in the DM group had significantly higher myositis, hyaline degeneration, and Zenker's necrosis. Moreover, the Bcl-2 expressions were significantly higher in the control, NSO, and DM+NSO groups than in the DM group.

Conclusion

NSO has a protective effect on the myocardium of streptozotocin-induced diabetic rats, most likely via suppressing apoptosis.

Dietary Phytoestrogen Intake is Inversely Associated with Hypertension in a Cohort of Adults Living in the Mediterranean Area

Background: Dietary polyphenols, including phytoestrogens are abundantly present in a balanced diet. Evidence for their role in preventing non-communicable diseases is emerging. Methods: We examined the association between estimated habitual intakes of dietary phytoestrogens and hypertension in a cohort study. The baseline data included 1936 men and women aged 18 years and older. Intakes of total phytoestrogens, isoflavones, and lignans were calculated from validated food frequency questionnaire. Data on the polyphenols content in foods were retrieved from the Phenol-Explorer database. Results: Individuals in the highest quartile of dietary phytoestrogens intake were less likely to be hypertensive (OR: 0.66, 95% CI: 0.44–0.98); moreover, the association showed a significant decreasing trend. Isoflavones and lignans were not associated with lower odds of hypertension; however, some individual compounds, such as biochanin A and pinoresinol showed an independent inverse association with hypertension. Conclusions: Dietary phytoestrogens are associated with lower likelihood of hypertension in adults living in the Mediterranean area. Future studies are needed to confirm the present findings (i.e., prospective cohort studies) and to better understand the mechanisms underlying such associations.

Review on the Potential Therapeutic Roles of Nigella sativa in the Treatment of Patients with Cancer: Involvement of Apoptosis: - Black cumin and cancer

Nigella sativa (N. sativa, family Ranunculaceae) is a medicinal plant that has been widely used for centuries throughout the world as a natural remedy. A wide range of chemical compounds found in N. sativa expresses its vast therapeutic effects. Thymoquinone (TQ) is the main component (up to 50%) in the essential oil of N. sativa. Also, pinene (up to 15%), p-cymene (40%), thymohydroquinone (THQ), thymol (THY), and dithymoquinone (DTQ) are other pharmacologically active compounds of its oil. Other terpenoid compounds, such as carvacrol, carvone, 4-terpineol, limonenes, and citronellol, are also found in small quantities in its oil. The main pharmacological characteristics of this plant are immune system stimulatory, anti-inflammatory, hypotensive, hepatoprotective, antioxidant, anti-cancer, hypoglycemic, anti-tussive, milk production, uricosuric, choleretic, anti-fertility, and spasmolytic properties. In this regard, we have searched the scientific databases PubMed, Web of Science, and Google Scholar with keywords of N. sativa, anti-cancer, apoptotic effect, antitumor, antioxidant, and malignancy over the period from 2000 to 2017. The effectiveness of N. sativa against cancer in the blood system, kidneys, lungs, prostate, liver, and breast and on many malignant cell lines has been shown in many studies, but the molecular mechanisms behind that anti-cancer role are still not clearly understood. From among the many effects of N. sativa, including its anti-proliferative effect, cell cycle arrest, apoptosis induction, ROS generation, anti-metastasis/anti-angiogenesis effects, Akt pathway control, modulation of multiple molecular targets, including p53, p73, STAT-3, PTEN, and PPAR-γ, and activation of caspases, the main suggestive anti-cancer mechanisms of N. sativa are its free radical scavenger activity and the preservation of various anti-oxidant enzyme activities, such as glutathione peroxidase, catalase, and glutathione-S-transferase. In this review, we highlight the molecular mechanisms of apoptosis and the anti-cancer effects of N. sativa, with a focus on its molecular targets in apoptosis pathways.