Effect of Nigella sativa supplementation over a one-year period on lipid levels, blood pressure and heart rate in type-2 diabetic patients receiving oral hypoglycemic agents: nonrandomized clinical trial

Nigella sativa L. and its bioactive and nutraceutical components in the management of diabetic peripheral neuropathy

Diabetes-induced hyperglycemia leads to excessive production of oxygen free radicals, inflammatory cytokines, and oxidative stress, which initiates diabetic peripheral neuropathy (DPN). Currently, this condition affects 20% of adults with diabetes. Despite significant advances in the treatment of diabetes, the incidence of its complications, including DPN, is still high. Thus, there is a growing research interest in developing more effective and treatment approaches with less side effects for diabetes and its complications. Nigella sativa L. (NS) has received much research attention as an antioxidant, anti-yperglycemic factor, and anti-inflammatory agent. This natural compound demonstrates its antidiabetic neuropathy effect through various pathways, including the reduction of lipid peroxidation, the enhancement of catalase and superoxide dismutase enzyme activity, and the decrease in inflammatory cytokine levels. The present review focuses on the bioactive and nutraceutical components of black cumin (Nigella sativa L.) and their effects on DPN. In addition, we have also summarized the findings obtained from several experimental and clinical studies regarding the antidiabetic neuropathy effect of NS in animal models and human subjects.

Therapeutic Effects of Nigella sativa Oil and Whole Seeds on STZ-Induced Diabetic Rats: A Biochemical and Immunohistochemical Study

Background

Type II diabetes mellitus (DM) is an increasing health problem that has negative impacts on patients and healthcare systems, worldwide. The development of new therapies with better efficacy, fewer side effects, and lower prices are urgently needed to treat this disease.

Aim

To evaluate and compare the therapeutic effects of Nigella sativa (N. sativa) seed and oil on the biochemical parameters and regeneration of pancreatic islets (or islets of Langerhans) of streptozotocin (STZ)-induced diabetic rats.

Materials and Methods

The diabetic rat model was prepared by administering a single dose of STZ (35 mg/kg body weight). The whole seed or the oil of N. sativa was administered to the diabetic and control groups for a period of 28 days, but not to the negative and STZ controls. Serum blood glucose, liver enzymes, lipid profile, and renal function tests (uric acid, albumin, total protein, urea, and creatinine) were measured in all groups. After the rats were euthanized, their pancreases were extracted, and then sectioned and fixed on slides in preparation before staining with H&E stain and immunohistochemical study.

Results

Treatment of STZ-diabetic rats with N. sativa seeds or oil significantly improved their serum glucose levels, lipid profiles, and liver and renal functions as well as preserved the integrity of pancreatic β cells.

Conclusion

N. sativa seeds and oil demonstrate significant therapeutic improvement effects on DM and its related complications including effective protection of islets of Langerhans. The therapeutic benefits of N. sativa seeds and oil on DM and its related complications are comparable.

Effects of Nigella sativa supplementation on lipid profiles in adults: An updated systematic review and meta-analysis of randomized controlled trials

BACKGROUND AND AIM

Several experiments have suggested that Nigella sativa (N. sativa) supplementation may have a beneficial effect on the lipid profile. However, the results from these trials have been inconclusive. Therefore, this study aimed to explore the impact of N. sativa supplementation on the lipid profile of adult participants.

METHODS

We searched Scopus, Web of Science, PubMed, Cochrane, and Web of Science databases until December 2022. Random effects models were used, and pooled data were determined as standardized mean differences with a 95% confidence interval.

RESULTS

The findings of 34 studies with 2278 participants revealed that N. sativa supplementation significantly reduced total cholesterol (TC) (SMD: -1.78; 95% CI: -2.20, -1.37, p < 0.001), triglycerides (TG) (SMD: -1.2725; 95% CI: -1.67, -0.83, p < 0.001), and low-density lipoprotein cholesterol (LDL-C) (SMD: -2.45; 95% CI: -3.06, -1.85; p < 0.001) compared to control groups. However, a significant increase was found in high-density lipoprotein cholesterol (HDL-C) (SMD: 0.79; 95% CI: 0.38, 1.20, p < 0.001).

CONCLUSION

N. sativa has improved effects on TG, LDL-C, TC, and HDL-C levels. Overall, N. sativa may be suggested as an adjuvant anti-hyperlipidemic agent.

Designing novel industrial and functional foods using the bioactive compounds from Nigella sativa L. (black cumin): Biochemical and biological prospects toward health implications

Nigella sativa is one of the nutraceuticals that has gained popularity and studied extensively in recent decades as it is considered a safe medicinal plant for use as a dietary supplement. N. sativa contains a wide variety of bioactive substances, which include polyphenols, volatile oils (thymoquinone and p-cymene), proteins, and peptides. The biological attributes of N. sativa include antioxidant, antimicrobial, antifungal, anti-inflammatory, anticancer, antidiabetic, antihypertensive, hypolipidemic, and antioxidant activities, which have potential applications for the prevention of a variety of chronic diseases. In the food industry, N. sativa improves the sensory qualities, shelf life, strength, and freshness of foods, such as bread, pizza, biscuits, cookies, and cakes. This review discusses the industrial use of N. sativa, which includes processing technologies to enhance its health-promoting properties as well as the isolation of nutraceutical components.

Thymoquinone: A comprehensive review of its potential role as a monotherapy for metabolic syndrome

Metabolic syndrome (MetS) is a widespread global epidemic that affects individuals across all age groups and presents a significant public health challenge. Comprising various cardio-metabolic risk factors, MetS contributes to morbidity and, when inadequately addressed, can lead to mortality. Current therapeutic approaches involve lifestyle changes and the prolonged use of pharmacological agents targeting the individual components of MetS, posing challenges related to cost, compliance with medications, and cumulative side effects. To overcome the challenges associated with these conventional treatments, herbal medicines and phytochemicals have been explored and proven to be holistic complements/alternatives in the management of MetS. Thymoquinone (TQ), a prominent bicyclic aromatic compound derived from Nigella sativa emerges as a promising candidate that has demonstrated beneficial effects in the treatment of the different components of MetS, with a good safety profile. For methodology, literature searches were conducted using PubMed and Google Scholar for relevant studies until December 2023. Using Boolean Operators, TQ and the individual components of MetS were queried against the databases. The retrieved articles were screened for eligibility. As a result, we provide a comprehensive overview of the anti-obesity, anti-dyslipidaemic, anti-hypertensive, and anti-diabetic effects of TQ including some underlying mechanisms of action such as modulating the expression of several metabolic target genes to promote metabolic health. The review advocates for a paradigm shift in MetS management, it contributes valuable insights into the multifaceted aspects of the application of TQ, fostering an understanding of its role in mitigating the global burden of MetS.

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.

Potential Pharmacological Applications of Nigella Seeds with a Focus on Nigella sativa and Its Constituents against Chronic Inflammatory Diseases: Progress and Future Opportunities

The leading cause of death worldwide has been identified as chronic illnesses, according to the World Health Organization (WHO). Chronic inflammatory conditions such as asthma, cancer, diabetes, heart disease, and obesity account for three out of every five deaths. Although many people benefit from using nonsteroidal anti-inflammatory medicines (NSAIDs) for pain and inflammation relief, there are significant adverse effects to using these medications. Medicinal plants possess anti-inflammatory properties with minimal or no side effects. Nigella sativa (NS), also known as black cumin, is one of the plants used in traditional medicine the most. Many studies on the NS have shown that their therapeutic properties are attributed to the seed, oil, and secondary metabolites. This plant has been studied extensively and has many medical uses, such as anti-inflammatory. NS or its phytochemical compounds, such as thymoquinone, can cause cell apoptosis via oxidative stress, block efflux pumps, enhance membrane permeability, and exert potent biocidal effects. Notwithstanding the extensively documented anti-inflammatory effectiveness observed in the experimental model, the precise mechanisms underlying its anti-inflammatory effects in diverse chronic inflammatory diseases and its multi-targeting characteristics remain largely unexplored. This review examines NS or its secondary metabolites, a valuable source for the therapeutic development of chronic inflammatory diseases. Most clinical studies were done for diabetes and cardiovascular disease; therefore, more studies are required to examine the NS extracts and phytoconstituents to treat cancer, obesity, diabetes, asthma, neurological disorders, and COVID-19. This study will be a significant resource for clinicians and biologists seeking a pharmaceutical solution for inflammatory diseases.

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.

The effect of moderate-intensity exercises on physical fitness, adiposity, and cardiovascular risk factors in Saudi males university students

Physical inactivity has been linked to several non-communicable diseases. This cross-sectional study investigated the impact of moderate-intensity exercise on physical fitness, adiposity, and cardiovascular risk factors in 284 Saudi male university students in the Eastern Province of Saudi Arabia between 2017 and 2019. The physical activity (PA) intervention comprised three (120 minutes each) sessions of moderate intensity on non-consecutive days each week, delivering a total of 360 minutes of PA per week for ten weeks. We measured physical fitness using VO₂ max calculations and assessed adiposity and cardiovascular risk factors using a range of parameters, such as systolic/diastolic blood pressure, heart rate, mean arterial pressure, body mass index, waist circumference, waist-to-height ratio, waist-to-hip ratio, body adiposity index, and body fat percentage. Our study found a significant increase in VO₂ max after ten weeks of moderate-intensity exercise (<0.001). Additionally, body adiposity indices were significantly reduced before and after the intervention (p<0.001), as were cardiovascular risk factors. Our findings suggest that regular moderate-intensity exercise effectively improves physical fitness, decreases adiposity, and lowers cardiovascular risk factors in Saudi male adults. We recommend that policymakers and public health practitioners increase physical activity among university students by launching a campaign on social media and through.

Effect of Nigella sativa on Selected Gastrointestinal Diseases

Nigella sativa L. (family Ranunculaceae), also known as black cumin, has been used in cuisine around the world for many years. Due to its health-promoting properties, it can be used not only in the food industry but also in medicine. The main bioactive compound contained in the black cumin extract is thymoquinone (TQ), which has a special therapeutic role. The results of research in recent years confirmed its hypoglycemic, hypolipemic, and hepatoprotective effects, among others. In addition, the results of laboratory tests also indicate its immunomodulatory and anticancer effects, although there is still a lack of data on the mechanisms of how they are involved in the fight against cancer. Including this plant material in one’s diet can be both an element of prophylaxis and therapy supporting the treatment process, including pharmacological treatment. However, attention should be paid to its potential interactions with drugs used in the treatment of chronic diseases.

Synergistic Effects of Nigella sativa and Exercise on Diabetic Profiles: A Systematic Review

Individually, Nigella sativa (NS) and physical training interventions have been shown to be effective preventive and therapeutic strategies for diabetes mellitus. However, the effect of these in combination on bioindicators of diabetes has not yet been evaluated; there is little information available in the literature. A systematic review was therefore performed to assess any mutually potentiating impacts of NS and physical training interventions in diabetic subjects. A search was performed on this topic in the PubMed, CINAHL, Google Scholar and Web of Science databases for randomised, quasi-randomised or non-randomised controlled trials, studies with factorial or single-cohort pre-post designs, case series as well as case reports. The search terms encompassed various combinations of the following: "exercise", "training", "physical activity", "NS", "treadmill", "swimming", "Thymoquinone", "Nigellone", "caraway oil" and "black seeds". Two reviewers screened the abstracts of 202 identified publications according to predetermined inclusion criteria-i.e. papers published from 2009 onwards in the English language, studies on human or animal subjects, and the assessment of diabetic bioindicators following the combined administration of NS and exercise regimens in comparison with just one of these interventions or against controls. Despite the rich data available regarding the effect of both interventions separately, two human studies and two animal studies were ultimately included in the review. However, the benefit of combined administration of NS and exercise regimens on glycemic and lipidemic control was much more obvious compared to exercise alone. In conclusion, these findings suggested that combined administration of NS and exercise regimens could be used as an effective adjuvant for oral antidiabetic drugs in diabetes control.

The Effectiveness of Nigella sativa and Ginger as Appetite Suppressants: An Experimental Study on Healthy Wistar Rats

Background

Obesity is a global pandemic that is associated with high morbidity and mortality. Natural herbs are commonly used for weight reduction and appetite suppression. Therefore, we aim to investigate the role and mechanism of Nigella sativa (NS) and ginger on weight reduction and appetite regulation.

Methods

This experimental study was performed at Imam Abdulrahman Bin Faisal University. Twenty-five female rats were distributed into 5 groups: NS (oral 1000mg/kg), Ginger (500 mg/kg), NS-ginger (both interventions), a positive control (intraperitoneal 50 μg/kg Liraglutide), and a negative control. Each intervention was given for 9 weeks. Food intake and body weight were assessed weekly. Serum lipid profile and peptides involved in appetite control (cholecystokinin (CCK), glucagon-like peptide 1(GLP-1), gastric inhibitory polypeptide (GIP), ghrelin, peptide YY, and orexin) were assayed at the end of the experiment.

Results

None of the interventions showed a statistically significant difference regarding food consumption or weight gain (p > 0.05). However, the three interventions significantly reduced total cholesterol (TC), NS and NS-ginger significantly increased HDL, NS increased ghrelin and ginger increased orexin.

Conclusion

The present dose and duration of NS, ginger, or in combination did not demonstrate a significant change in body weight or food consumption in comparison to the negative or positive controls. However, NS or ginger has improved the lipid profile by reducing TC and increasing HDL. In addition, NS or ginger can influence some of the peptides involved in appetite regulation such as the increase in ghrelin induced by NS and the reduction of orexin induced by ginger. We believe that these latter effects are novel and might indicate a promising effect of these natural products on appetite regulation.

Saudi Arabian Plants: A Powerful Weapon against a Plethora of Diseases

The kingdom of Saudi Arabia (SA) ranks fifth in Asia in terms of area. It features broad biodiversity, including interesting flora, and was the historical origin of Islam. It is endowed with a large variety of plants, including many herbs, shrubs, and trees. Many of these plants have a long history of use in traditional medicine. The aim of this review is to evaluate the present knowledge on the plants growing in SA regarding their pharmacological and biological activities and the identification of their bioactive compounds to determine which plants could be of interest for further studies. A systematic summary of the plants' history, distribution, various pharmacological activities, bioactive compounds, and clinical trials are presented in this paper to facilitate future exploration of their therapeutic potential. The literature was obtained from several scientific search engines, including Sci-Finder, PubMed, Web of Science, Google Scholar, Scopus, MDPI, Wiley publications, and Springer Link. Plant names and their synonyms were validated by 'The Plant List' on 1 October 2021. SA is home to approximately 2247 plant species, including native and introduced plants that belong to 142 families and 837 genera. It shares the flora of three continents, with many unique features due to its extreme climate and geographical and geological conditions. As plants remain the leading supplier of new therapeutic agents to treat various ailments, Saudi Arabian plants may play a significant role in the fight against cancer, inflammation, and antibiotic-resistant bacteria. To date, 102 active compounds have been identified in plants from different sites in SA. Plants from the western and southwestern regions have been evaluated for various biological activities, including antioxidant, anti-cancer, antimicrobial, antimalarial, anti-inflammatory, anti-glycation, and cytotoxic activities. The aerial parts of the plants, especially the leaves, have yielded most of the bioactive compounds. Most bioactivity tests involve in vitro assessments for the inhibition of the growth of tumour cell lines, and several compounds with in vitro antitumour activity have been reported. More in-depth studies to evaluate the mode of action of the compounds are necessary to pave the way for clinical trials. Ecological and taxonomical studies are needed to evaluate the flora of SA, and a plan for the conservation of wild plants should be implemented, including the management of the protection of endemic plants.

Potential health benefits of Nigella sativa on diabetes mellitus and its complications: A review from laboratory studies to clinical trials

This review aims to gather and summarize up-to-date information on the potential health benefits of Nigella sativa (NS) on diabetes mellitus (DM) and its complications from different animal models, clinical trials and in vitro studies. DM is one of the most prevalent metabolic disorders resulting from chronic hyperglycaemia due to problems in insulin secretion, insulin action or both. It affects people regardless of age, gender and race. The main consequence of DM development is the metabolic dysregulation of glucose homeostasis. Current treatments for DM include pharmacological therapy, insulin and diabetic therapy targeting β cells. Some of these therapeutic approaches are promising; however, their safety and effectiveness remain elusive. Since ancient times, medicinal plants have been used and proven effective against diseases. These plants are believed to be effective and benefit physiological and pathological processes, as they can be used to prevent, reduce or treat multiple diseases. Nigella sativa Linn. is an annual indigenous herbaceous plant belonging to Ranunculaceae, the buttercup family. NS exhibits multifactorial activities; it could ameliorate oxidative, inflammatory, apoptotic and insulinotropic effects and inhibit carbohydrate digestive enzymes. Thus, this review demonstrates the therapeutic potential of NS that could be used as a complement or adjuvant for the management of DM and its complications. However, future research should be able to replicate and fill in the gaps of the study conducted to introduce NS safely to patients with DM.

Nigella sativa supplementation improves cardiometabolic indicators in population with prediabetes and type 2 diabetes mellitus: A systematic review and meta-analysis of randomized controlled trials

Objective

Nigella sativa (N. sativa) from the family Ranunculaceae has medicinal properties. Previous studies have reported promising findings showing that N. sativa may benefit cardiometabolic health; however, current evidence on its cardiometabolic effects on those with prediabetes and type 2 diabetes mellitus (T2DM) is still unclear. Hence, we conducted a systematic review and meta-analysis to assess the efficacy of N. sativa on cardiometabolic parameters in population with prediabetes and T2DM.

Methods

PubMed/Medline, ISI Web of Science, Scopus, and Cochrane library were systematically searched up to June 20, 2022. Meta-analyses using random-effects models were used.

Results

Eleven randomized controlled trials (RCTs) were included in the meta-analysis. N. sativa intervention resulted in significant changes in fasting plasma glucose (FPG), hemoglobin A1c (HbA1c), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), c-reactive protein (CRP), and malondialdehyde (MDA), without overall changes in glucose levels after oral glucose tolerance test (OGTT), fasting insulin, homeostatic model assessment of insulin resistance (HOMA-IR), triglyceride, high-density lipoprotein cholesterol (HDL-C), and body mass index (BMI) when compared with the control group. In subgroup analyses, N. sativa supplementation enhanced serum levels of HDL-C in subjects with baseline HDL-C lower than 40 mg/dL. Furthermore, HOMA-IR and BMI values decreased in the N. sativa-supplemented group compared with the control group, when the length of follow-up was more than 8 weeks and the dose was more than 1 g/day for N. sativa supplementation, respectively.

Conclusion

Our findings indicate that N. sativa supplementation may effectively improve cardiometabolic profiles in individuals with prediabetes and T2DM.

Effect of Nigella sativa supplementation on kidney function, glycemic control, oxidative stress, inflammation, quality of life, and depression in diabetic hemodialysis patients: study protocol for a double-blind, randomized controlled trial

Background and objectives

The kidney is probably the most crucial target of microvascular damage in diabetes, which can ultimately eventuate end-stage renal disease (ESRD). Hemodialysis is the most usual way of renal replacement therapy in ESRD. Patients receiving hemodialysis are susceptible to many complications like hyperglycemia, inflammation, depression, anxiety, and poor quality of life. So, they are constrained to consume many drugs. Medicinal herbs are used in different cultures as a reliable source of natural remedies. This study aims to determine the efficacy of Nigella sativa (NS) oil supplementation on blood glucose, kidney function tests, inflammation, oxidative stress, quality of life, and depression in hemodialysis patients.

Methods and analysis

This double-blind, randomized controlled trial will enroll 46 patients with diabetes mellitus who give hemodialysis thrice a week. Patients who have an inflammatory or infectious disease and who are receiving nonsteroidal anti-inflammatory drugs will be excluded. Patients will be randomized to the treatment and control group, which will be recommended using two soft gels of NS and paraffin oil, respectively. Laboratory tests will be assessed at baseline and end of the study, including fasting blood sugar, glycated albumin, insulin, creatinine, blood urea nitrogen, urea, uric acid, superoxide dismutase, malondialdehyde, total antioxidant capacity, high sensitive C reactive protein, and 24-h urine volume. Also, the kidney disease and quality of life and hospital anxiety and depression scale questionnaires will be evaluated.

Discussion

Previous studies have reported a positive effect of Nigella sativa supplementation in chronic kidney disease, but there is no evidence that this plant is safe in hemodialysis patients. The results of this study can be helpful in better control of blood sugar and kidney function and reduce complications in diabetic hemodialysis patients.

Trial registration

Iranian Registry of Clinical Trials . Registered on 31 May 2020

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05917-y.

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.

Antidiabetic Activity of Nigella Sativa (Black Seeds) and Its Active Constituent (Thymoquinone): A Review of Human and Experimental Animal Studies

The use of herbal medicine to manage chronic conditions including diabetes has become a recent global trend. Diabetes mellitus (DM) is a group of metabolic disorders characterized by hyperglycemia. The present review is aimed to analyze the antidiabetic activity of N. sativa as many type 2 diabetic patients use it as a complementary therapy along with their modern allopathic medications or as an alternative therapy. The literature was reviewed in databases like Medline/PubMed Central/PubMed, Google Scholar, Science Direct, EBSCO, Scopus, Web of science, EMBASE, Directory of open access journals (DOAJ), and reference lists to identify relevant articles supporting the use of N. sativa in diabetes management. Numerous clinical and animal studies have demonstrated the antidiabetic efficacy of black seeds (N. sativa) and its major bioactive constituent thymoquinone. Based on these findings patients with diabetes may use N. sativa as an adjuvant therapy, which may help to reduce the dose and incidence of adverse effects of modern antidiabetic medicines.

Nigella sativa as a promising intervention for metabolic and inflammatory disorders in obese prediabetic subjects: A comparative study of Nigella sativa versus both lifestyle modification and metformin

AIM

This study aimed at evaluating the effect of Nigella sativa (NS) on anthropometric, metabolic and inflammatory parameters and examining its related molecular mechanisms in obese prediabetic individuals as compared to both lifestyle modification (LM) and Metformin (Met).

METHODS

This study included 117 obese prediabetic subjects who were randomized into LM group which followed controlled diet and exercise regimen, metformin group received metformin 500 mg tablets twice daily and NS group received NS oil soft gelatin capsules 450 mg twice daily. Anthropometric (weight, BMI), glycemic, lipid, inflammatory parameters and genetic expressions of Sirtuin-1 (SIRT1) and p53 genes were assessed before and six months after interventions.

RESULTS

Post-intervention pairwise comparison revealed that, NS was statistically similar to metformin in improving anthropometric, glycemic parameters and SIRT1 gene expression. There was non-significant difference between LM and NS regarding their effects on anthropometric and most of glycemic parameters. Lifestyle modification group showed significantly higher HOMA-B and SIRT1 expression than NS and metformin. Nigella sativa improved lipid panel and significantly reduced TNF-α level and Castelli risk index-I as compared to other interventions.

CONCLUSION

Nigella sativa uniquely improved lipid panel and significantly suppressed inflammation. Therefore, Nigella sativa may represent a promising intervention for obese prediabetic subjects. Clinicaltrial.gov ID: NCT03925714.

Black Cumin (Nigella sativa L.): A Comprehensive Review on Phytochemistry, Health Benefits, Molecular Pharmacology, and Safety

Mounting evidence support the potential benefits of functional foods or nutraceuticals for human health and diseases. Black cumin (Nigella sativa L.), a highly valued nutraceutical herb with a wide array of health benefits, has attracted growing interest from health-conscious individuals, the scientific community, and pharmaceutical industries. The pleiotropic pharmacological effects of black cumin, and its main bioactive component thymoquinone (TQ), have been manifested by their ability to attenuate oxidative stress and inflammation, and to promote immunity, cell survival, and energy metabolism, which underlie diverse health benefits, including protection against metabolic, cardiovascular, digestive, hepatic, renal, respiratory, reproductive, and neurological disorders, cancer, and so on. Furthermore, black cumin acts as an antidote, mitigating various toxicities and drug-induced side effects. Despite significant advances in pharmacological benefits, this miracle herb and its active components are still far from their clinical application. This review begins with highlighting the research trends in black cumin and revisiting phytochemical profiles. Subsequently, pharmacological attributes and health benefits of black cumin and TQ are critically reviewed. We overview molecular pharmacology to gain insight into the underlying mechanism of health benefits. Issues related to pharmacokinetic herb-drug interactions, drug delivery, and safety are also addressed. Identifying knowledge gaps, our current effort will direct future research to advance potential applications of black cumin and TQ in health and diseases.

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.

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.

Evaluation of the Antioxidant Activity of Nigella sativa L. and Allium ursinum Extracts in a Cellular Model of Doxorubicin-Induced Cardiotoxicity

Natural products black cumin—Nigella sativa (N. sativa) and wild garlic—Allium ursinum (AU) are known for their potential role in reducing cardiovascular risk factors, including antracycline chemotherapy. Therefore, this study investigates the effect of N. sativa and AU water and methanolic extracts in a cellular model of doxorubicin (doxo)-induced cardiotoxicity. The extracts were characterized using Ultraviolet-visible (UV-VIS) spectroscopy, Fourier-transform infrared (FT-IR) spectroscopy, Liquid Chromatography coupled with Mass Spectrometry (LC-MS) and Gas Chromatography coupled with Mass Spectrometry (GC-MS) techniques. Antioxidant activity was evaluated on H9c2 cells. Cytosolic and mitochondrial reactive oxygen species (ROS) release was evaluated using 2′,7′-dichlorofluorescin-diacetate (DHCF-DA) and mitochondria-targeted superoxide indicator (MitoSOX red), respectively. Mitochondrial membrane depolarization was evaluated by flow cytometry. LC-MS analysis identified 12 and 10 phenolic compounds in NSS and AU extracts, respectively, with flavonols as predominant compounds. FT-IR analysis identified the presence of carbohydrates, amino acids and lipids in both plants. GC-MS identified the sulfur compounds in the AU water extract. N. sativa seeds (NSS) methanolic extract had the highest antioxidant activity reducing both intracellular and mitochondrial ROS release. All extracts (excepting AU methanolic extract) preserved H9c2 cells viability. None of the investigated plants affected the mitochondrial membrane depolarization. N. sativa and AU are important sources of bioactive compounds with increased antioxidant activities, requiring different extraction solvents to obtain the pharmacological effects.

Diabetes and plant-derived natural products: From ethnopharmacological approaches to their potential for modern drug discovery and development

Diabetes is a disease of serious concern faced by the health care industry today. Primary diabetes mellitus and its complications are still costly to manage with modern drugs. Extensive research on the screening of anti-diabetic agents in past decades established natural products as one of the major potential sources of drug discovery. However, only a few drugs of plant origin have been scientifically validated. Therefore, the development of new anti-diabetic drugs is of great demand. Hence, natural products could be explored as potential anti-diabetic drugs. Natural plants derived extracts and molecules like berberine, ginsenosides, curcumin, stevioside, gingerols, capsaicin, catechins, simple phenolic compounds, anthocyanins, resveratrol, genistein and hesperidin obtained from different species are used for curing diabetes and found to possess different action mechanisms. In this review, the importance of medicinal plants and their active constituents for anti-diabetic agents are described. The present study also emphasized the importance of diabetes control, reduction in its complications and use of the anti-diabetic agents. The detailed action mechanism of these extracts/compounds for their activities are also described. However, the anti-diabetic drugs from plant origin require scientific validation through animal and clinical studies to exploit in terms of modern commercial medicines.

Effect of Nigella sativa oil supplement on risk factors for cardiovascular diseases in patients with type 2 diabetes mellitus

This study aimed to evaluate the effects of Nigella sativa oil on serum level of systemic inflammation, oxidative stress, fasting blood glucose (FBG), and lipid profile in patients with type 2 diabetes mellitus (T2DM). This double-blind randomized clinical trial study was based on 50 patients with T2DM. Patients were allocated randomly to either N. sativa oil or placebo groups. The intervention group received 1,000 mg N. sativa oil as two capsules, daily for 8 weeks, whereas the placebo group received a corresponding placebo. At baseline and the end of the study, 5 ml blood was collected from each patient after 14-hour fasting for measuring serum C-reactive protein (hs-CRP), malondialdehyde (MDA), FBS, and lipid profile. Analyses covariance was performed to compare investigated parameters between two groups, controlled for relevant covariates. Using N. sativa supplement was significantly associated with decrease in FBS (p < .001), triglyceride (p < .001), total cholesterol (p < .001), low-density lipoprotein cholesterol (p < .001), serum hs-CRP, MDA (p < .001) and increase in serum level of high-density lipoprotein cholesterol (p < .001) in intervention group compared with placebo group. Nigella sativa oil supplement has cardiovascular protective effects in patients with T2DM, by improving the lipid profile and glycemia, by reducing the C-reactive protein level and the lipid peroxidation.

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.

An Evidence-based Review of Medicinal Plants used in Traditional Persian Medicine for Treatment of Osteoarthritis

Osteoarthritis (OA) is known to be the leading cause of pain and disability in the elderly. The prevalence of this disease in adults over 60 years was 9.6% in men and 18% in women. The therapeutic goals of this disease generally include pain relief with the least side effects, improvement of articular function and improvement of life, in which pharmacological and nonpharmacological treatments are performed in different protocols. Due to the common side effects of pain relievers and complaints after invasive joint surgeries, there is a growing interest in the use of Traditional and Complementary protocols in OA treatment. In this paper, different sources of Traditional Persian Medicine (TPM) were searched to obtain any evidence evaluating any medicinal plants in the management of OA. Over 250 effective medicinal plants for the treatment of OA have been introduced in these sources, and by searching electronic databases including PubMed and Scopus, we have found that of these plants, 39 have direct or indirect evidence in the treatment of this complication by different mechanism of actions such as effect on Body mass index (BMI), obesity and dyslipidemia, anti-inflammatory, anti-nociceptive and antioxidant activity. The most important medicinal plants with direct evidence in the management of OA are Allium sativum, Commiphora mukul, Linum usitatissimum, Matricaria chamomilla, Nigella sativa, Zingiber officinale, and Piper nigrum. Medicinal plants seem to be a valuable source for discovering and identifying new drugs for treatment of OA; however, since most of the studies are preclinical, further clinical trials are required to achieve more conclusive results.

Effect of Nigella Sativa oil versus metformin on glycemic control and biochemical parameters of newly diagnosed type 2 diabetes mellitus patients

PURPOSE

Nature is a phenomenal treasure of remedies. Numerous previous studies reported that Nigella sativa NS improved glycemic control, reduced insulin resistance, and improved lipid profile. NS was never investigated before as a monotherapy for newly diagnosed type 2 diabetes mellitus T2DM patients. Our aim was to investigate the potential metabolic benefits of NS monotherapy in newly diagnosed T2DM patients.

METHOD

Prospective, open-label randomized clinical trial at outpatient endocrinology clinic at Ain-Shams University hospital. Eligible patients were randomly assigned to either metformin tablets or NS oil capsules. Both groups received treatment for 3 months. Glycemic index (FBG, 2 h pp, A1C, insulin sensitivity %S, secretory function %B, insulin resistance IR), lipid profile (TC, LDL, HDL, TG), liver and kidney functions (AST, ALT, Sr cr), total antioxidant capacity TAC, weight, waist circumference WC and body mass index BMI were assessed at baseline and at the end of treatment period.

RESULTS

A concentration of 1350 mg/day NS in newly diagnosed T2DM patients was inferior to metformin in terms of lowering FBG, 2 h pp, and A1C or increasing %B. However, NS was comparable to metformin in lowering weight, WC, and BMI significantly. NS was comparable to metformin in regards of their effects on fasting insulin, %S, IR, ALT, TC, LDL, HDL, TG, and TAC. Metformin showed significant increase in AST and creatinine which was reserved in NS group.

CONCLUSION

NS administration in newly diagnosed T2DM was tolerable with no side effects as compared to metformin; however, it was inferior to metformin in terms of diabetes management.

The effects of black seed supplementation on cardiovascular risk factors in patients with nonalcoholic fatty liver disease: A randomized, double-blind, placebo-controlled clinical trial

Nonalcoholic fatty liver disease (NAFLD) is highly related to cardiovascular disorders risk factors. This study aimed to evaluate the effects of black seed (Nigella sativa) supplementation on cardiovascular disorders risk factors in patients with NAFLD. This randomized, double-blind, placebo-controlled clinical trial was conducted on 50 patients with NAFLD. Participants were assigned to receive a lifestyle modification plus 2 g/day of either N. sativa or placebo for 12 weeks. Compared with the placebo, N. sativa supplementation led to significant reductions in serum glucose (-7.95 vs. -1.22; p = .041), serum insulin (-3.87 vs. -1.07; p = .027), homeostatic model of assessment for insulin resistance (-1.02 vs. -0.28; p = .021), and a significant increase in quantitative insulin sensitivity check index (0.03 vs. 0.006; p = .002). All of these changes were remained significant after adjusting for known confounding variables; however, there was no significant difference in lipid profile changes between the two groups (p = .05). N. sativa supplementation significantly decreased hepatic steatosis percentage compared with the placebo after adjustment for confounding variables (p = .005). In conclusion, our results indicate that daily intake of 2-g N. sativa plus lifestyle modification is superior to lifestyle modification alone in amelioration of insulin resistance and hepatic steatosis in patients with NAFLD.

Nigella sativa L. (Black Cumin): A Promising Natural Remedy for Wide Range of Illnesses

The seed of Nigella sativa (N. sativa) has been used in different civilization around the world for centuries to treat various animal and human ailments. So far, numerous studies demonstrated the seed of Nigella sativa and its main active constituent, thymoquinone, to be medicinally very effective against various illnesses including different chronic illness: neurological and mental illness, cardiovascular disorders, cancer, diabetes, inflammatory conditions, and infertility as well as various infectious diseases due to bacterial, fungal, parasitic, and viral infections. In spite of limited studies conducted so far, the promising efficacy of N. sativa against HIV/AIDS can be explored as an alternative option for the treatment of this pandemic disease after substantiating its full therapeutic efficacy. Moreover, the strong antioxidant property of this valued seed has recently gained increasing attention with regard to its potential role as dietary supplement with minimal side effects. Besides, when combined with different conventional chemotherapeutic agents, it synergizes their effects resulting in reducing the dosage of concomitantly used drugs with optimized efficacy and least and/or no toxicity. A number of pharmaceutical and biological properties have been ascribed to seeds of N. sativa. The present review focuses on the profile of high-value components along with traditional medicinal and biological principles of N. sativa seed and its oil so as to explore functional food and nutraceutical potential of this valued herb.

The effects of Nigella sativa L. on obesity: A systematic review and meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Nigella sativa L. (N.sativa) is a traditional herbal medicine that has been used for centuries to treat rheumatoid arthritis, diabetes, asthma, and other metabolic disorders. Recently, anti-obesity characteristics of N.sativa have been indicated.

AIM OF THE STUDY

The effects of N. sativa as a complementary therapy in obesity management remains controversial. We aimed to perform a meta-analysis on the effects of supplementation with N. sativa on some anthropometric indices in adult subjects.

MATERIALS AND METHODS

We searched PubMed/Medline, Cochrane Library, ISI Web of Science, and Scopus databases until June 2017 to identify relevant placebo-controlled clinical trials. Data was reported as weighted mean differences and standard deviations to show the magnitude of effects for N. sativa on body weight, body mass index (BMI) and waist circumference (WC).

RESULTS

Findings of 11 studies revealed that N. sativa supplement reduced body weight (-2.11 kg, 95% CI: -3.61, -0.61, I²:72.4%), BMI (-1.16 kg/m²; 95%CI: -1.81, -0.51; I²: 40.1%) and WC (-3.52 cm, 95%CI: -4.10, -2.92, I² =0%) significantly compared to placebo groups.

CONCLUSION

Supplementation with N. sativa exerts a moderate effect on reduction in body weight, BMI and WC. However, due to the high heterogeneity for body weight and limited high quality studies, the findings should be declared by caution. No serious side effects were also reported following N. sativa supplementation. Further studies are needed to clarify the effects of N. sativa on other anthropometric indices.