The Effects of Nigella sativa Supplementation on Liver Enzymes Levels: a Systematic Review and Meta-analysis of Randomized Controlled Trials

Effects of black seed (Nigella sativa L.) on cardiometabolic indices in type 2 diabetic patients: A systematic review and meta-analysis of RCTs

BACKGROUND

Black seed is known for its health benefits in traditional medicine. While recent studies suggest it may improve cardiometabolic health, its impact on type 2 diabetes mellitus (T2DM) remains unclear. This study aims to meta-analysis randomized controlled trials (RCTs) to assess the effects of black seed supplementation on cardiometabolic indices in T2DM patients.

METHODS

Following PRISMA guidelines, a comprehensive database search was conducted up to January 2025, and data were extracted from relevant RCTs. Mean differences (MD) and standard deviations (SD) were analyzed using a random-effects model, heterogeneity was assessed, and publication bias was evaluated.

RESULTS

The pooled meta-analysis of 16 RCTs showed that black seed supplementation significantly reduced fasting blood glucose (FBG) (MD: -21.43 mg/dL; p = 0.005), hemoglobin A1c (HbA1c) (MD: -0.44; p = 0.01), total cholesterol (TC) (MD: -18.80 mg/dL; p = 0.04) and low-density lipoprotein (LDL) (MD: -19.53 mg/dL; p = 0.003). No significant effects were observed for 2-hour postprandial glucose (2-hpp), fasting insulin, homeostatic model assessment (HOMA), triglycerides (TG), high-density lipoprotein (HDL), aspartate aminotransferase (AST), alanine aminotransferase (ALT), creatinine, and body weight, or body mass index (BMI). Subgroup analyses revealed that black seed supplementation effectively reduced FBG for longer than 8 weeks; additionally, HbA1c, HOMA, and LDL in higher doses (>1 g/day), shorter durations (≤8 weeks), and use of the oil form.

CONCLUSION

Black seed supplementation appears to significantly improve FBG, HbA1c, TC, and LDL levels in patients with T2DM. However, no significant effects were observed on other metabolic parameters, including insulin, TG, liver enzymes, kidney function, or body weight. These findings suggest that black seed may be a beneficial adjunct therapy for glycemic and lipid control in T2DM patients but require further research to confirm its broader metabolic effects.

The protective effect of various forms of Nigella sativa against hepatorenal dysfunction: underlying mechanisms comprise antioxidation, anti- inflammation, and anti-apoptosis

Introduction

The liver and kidney are vital organs that are interconnected, dealing with detoxifying and excreting xenobiotics. They are constantly exposed to oxidative stress, which can cause hepatorenal dysfunction. This study compares two forms of Nigella sativa (NS), NS oil (NSO), and NS seeds (NSS), for the first time, in their ability to mitigate hepatorenal injury induced by azathioprine (AZA), exploring potential underlying mechanisms.

Methods

Group (1): negative control; Group (2): positive control received 15 mg/kg AZA orally. Groups (3, 4, and 5) received 100 mg/kg silymarin (standard reference), 500 mg/kg NSO, and 250 mg/kg NSS, respectively, and were subjected to the same dose of AZA. A one-way analysis of variance was conducted, followed by Mann-Whitney post-hoc analysis.

Results

Administration of AZA induced hepatorenal dysfunction, evidenced by dyslipidemia, elevations in serum liver enzymes, creatinine, urea, pro-inflammatory cytokines, and cytokeratin-18. Antioxidant enzymes in liver and kidney tissues were reduced, with an elevation in caspase-3 and caspase-9. Both forms of NS significantly balanced serum pro- inflammatory cytokines (14.33 ± 2.33, 15.15 ± 1.64 vs. 24.87 ± 1.87) pg/ml, interleukin-4 (16.72 ± 1.14, 15.95 ± 1.03 vs. 10.64 ± 1.04) pg/ml, and interleukin-10 (19.89 ± 0.69, 18.38 ± 0.38 vs. 15.52 ± 1.02) pg/ml, and downregulated cytokeratin-18 (210.43 ± 21.56, 195.86 ± 19.42 vs. 296.54 ± 13.94) pg/ml for NSO and NSS vs. the positive group, respectively. NSS enhanced liver antioxidant activity (P < 0.05), normalized liver enzymes (P < 0.05, P < 0.01) for alanine aminotransferase and aspartate aminotransferase, respectively, and significantly lessened dyslipidemia (P < 0.05). Liver caspase-3 and caspase-9 improved significantly with NSS, while kidney caspase-3 and caspase-9 improved with NSO. NSO increased kidney glutathione peroxidase and catalase (P < 0.01) and corrected creatinine and urea (P < 0.05). Histopathological observations confirmed the present data.

Discussion

Conclusively, NSO and NSS mitigated hepatorenal dysfunction responses to AZA through antioxidant, anti-inflammatory, and anti-apoptosis properties that underlie their protective performance. Interestingly, NSO surpassed NSS in restoring renal oxidative damage, while NSS provided better hepatic protection than NSO, suggesting NSO for patients with kidney dysfunction and NSS for those with liver problems.

The effect of plant growth regulators, FeO3-CTs nanoparticles and LEDs light on the growth and biochemical compounds of black seed (Nigella sativa L.) callus in vitro

BACKGROUND

black seed (Nigella sativa L.) has long been utilized in traditional medicine and as a food ingredient due to its potential therapeutic properties including its effectiveness against cancer, coronaviruses, and bacterial infections. Recently, it has garnered significant attention for its rich reservoir of beneficial secondary metabolites. In vitro culture of black seeds presents an efficient and modern approach for the large-scale production of these valuable compounds, offering advantages such as space efficiency, reduced time, and lower costs. This study aimed to develop and optimize a protocol for callus induction and the identification of key secondary metabolites, including thymoquinone (TQ), phenolic compounds, and flavonoids. To induce callus formation in seed explants, two plant growth regulators (PGRs) were applied individually or in combination and incorporated into Murashige and Skoog (MS) culture medium.

RESULTS

The combination of Auxin, 2,4-dichlorophenoxyacetic acid (2,4-D) and cytokinin, 6-benzylaminopurine (BAP), effectively induced callus formation in most explants, with the response varying based on concentration. The highest callus fresh weight (7.02 g) was obtained on Red(R) LED lighting with FeO3-CTs nanoparticles (100 mg/L- 1), which also resulted in the highest dry weight (1.307 g) after 40 days of cultivation. Similarly, the highest levels of phenols, flavonoids and amino acids were observed under R LED with FeO3-CTs nanoparticles (100 mg L- 1), while FeO3-CTs nanoparticles at 100 and 200 mg/L- 1) exhibited significant effects on metabolite production. In contrast, the antioxidant activity against DPPH free radicals and total carbohydrate accumulation were enhanced in callus cultures treated with FeO3-CTs nanoparticles (200 mg/L- 1) under dark conditions. Additionally, GC-MS analysis revealed that FeO3-CTs nanoparticles (100 mg/L- 1) yielded the most effective enhancement of secondary metabolites under blue (B) LED light at a concentration of 295 mg/L- 1.

CONCLUSION

The finding of this study highlights the potential of the proposed method for the large-scale production of secondary metabolites, total carbohydrates, amino acids, phenolic compounds, and flavonoids from black seed callus cultures in a controlled environment. This optimized approach offers a cost-effective and space-efficient strategy for enhancing bioactive compound synthesis, with potential applications in pharmaceutical and nutraceutical industries.

Immune stimulatory effect of Nigella sativa in healthy animal models: A systematic review and meta-analysis

The immune-modulatory effects of black seeds (Nigella sativa seeds, NSS) are well documented, but the overall in vivo impact of this important natural medicinal product on immune system function has yet to be established. Here we systematically reviewed and meta-analyzed the effects of NSS on humoral [serum titers of immunoglobulins including IgG, IgM, anti-Newcastle virus disease (anti-NDV), and sheep red blood cell antigen (anti-SRBC)] and cellular immunity [total white blood cell (WBC) count and percentages of monocytes, lymphocytes, basophils, neutrophils, and eosinophils] in healthy animals. The PubMed, ScienceDirect, Web of Science, and Scopus databases were searched according to predefined eligibility criteria. Meta-analyses were performed to estimate the final effect size using RevMan software. Seventeen animal studies were eligible for analysis. For humoral immunity, the overall pooled effect size (ES) of NSS on serum titers of IgM and anti-NVD antibodies was not significantly different [mean difference (MD) 75.27, 95% CI: -44.76 to 195.30, p = 0.22 (I2 = 89%, p = 0.003), and -0.01, 95% CI: -0.27 to 0.25, p = 0.94 (I2 = 74%, p = 0.02), respectively]. However, NSS significantly increased serum titers of IgG and anti-SRBC antibodies [MD 3.30, 95% CI: 2.27 to 4.32, p = 0.00001 (I2 = 0%, p = 0.97), and 1.15, 95% CI: 0.74 to 1.56, p = 0.00001 (I2 = 0%, p = 0.43), respectively]. For cellular immunity, the ES of NSS on WBCs, monocytes, and lymphocytes were not significantly different [MD 0.29, 95% CI: -0.55 to 1.13, p = 0.50, (I2 = 14%, p = 0.32), - 0.01, 95% CI: -0.45 to 0.44, p = 0.97 (I2 = 0%, p = 0.77), and 4.73, 95% CI: -7.13 to 16.59, p = 0.43, (I2 = 99%, p = 0.00001), respectively]. In conclusion, black seeds enhance humoral immunity in healthy animals but do not affect cellular immunity.

Polycystic ovary syndrome and its management: In view of oxidative stress

In the past two decades, oxidative stress (OS) has drawn a lot of interest due to the revelation that individuals with many persistent disorders including diabetes, polycystic ovarian syndrome (PCOS), cardiovascular, and other disorders often have aberrant oxidation statuses. OS has a close interplay with PCOS features such as insulin resistance, hyperandrogenism, and chronic inflammation; there is a belief that OS might contribute to the development of PCOS. PCOS is currently recognized as not only one of the most prevalent endocrine disorders but also a significant contributor to female infertility, affecting a considerable proportion of women globally. Therefore, the understanding of the relationship between OS and PCOS is crucial to the development of therapeutic and preventive strategies for PCOS. Moreover, the mechanistic study of intracellular reactive oxygen species/ reactive nitrogen species formation and its possible interaction with women's reproductive health is required, which includes complex enzymatic and non-enzymatic antioxidant systems. Apart from that, our current review includes possible regulation of the pathogenesis of OS. A change in lifestyle, including physical activity, various supplements that boost antioxidant levels, particularly vitamins, and the usage of medicinal herbs, is thought to be the best way to combat this occurrence of OS and improve the pathophysiologic conditions associated with PCOS.

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.

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 nanomicelle curcumin supplementation and Nigella sativa oil on the expression level of miRNA-21, miRNA-422a, and miRNA-503 gene in postmenopausal women with low bone mass density: A randomized, triple-blind, placebo-controlled clinical trial with factorial design

This study aimed to investigate the effect of nanomicelle curcumin (CUR), Nigella sativa oil (NS), and CUR and NS on the plasma levels of miR-21, miR-422a, and miR-503 expression in postmenopausal women with low bone mass density (BMD). This randomized, triple-blind, placebo-controlled clinical trial with a factorial design was conducted on 120 postmenopausal women from the integrated healthcare system, Tabriz-Iran. The BMD was determined using dual-energy X-ray absorptiometry (DEXA). Women were randomly divided into four groups of 30 participants: (a) CUR (80 mg) and placebo of NS, (b) NS (1,000 mg) and placebo of CUR, (c) CUR (80 mg) and NS (1,000 mg), and (d) both placebos (containing microcrystalline cellulose). The plasma level of miRNA-21, miRNA-422a, and miRNA-503 was determined by qRT-PCR. The expression level of miRNAs at the baseline was similar. At the end of the intervention, only the expression level of miRNA-21 changed statistically significantly between the four groups (p = .037) and between the NS and placebo groups (p = .005). Also, its expression in the two groups receiving NS (p = .037) and NS-CUR (p = .043) was significantly increased. NS and NS-CUR supplementation can increase the expression level of miRNA-21 in postmenopausal women with low bone density, and bring perspective to further studies of the target.

Nutrition Strategy and Life Style in Polycystic Ovary Syndrome-Narrative Review

Here we present an extensive narrative review of the broadly understood modifications to the lifestyles of women with polycystic ovary syndrome (PCOS). The PubMed database was analyzed, combining PCOS entries with causes, diseases, diet supplementation, lifestyle, physical activity, and use of herbs. The metabolic pathways leading to disturbances in lipid, carbohydrate, and hormonal metabolism in targeted patients are described. The article refers to sleep disorders, changes in mental health parameters, and causes of oxidative stress and inflammation. These conditions consistently lead to the occurrence of severe diseases in patients suffering from diabetes, the fatty degeneration of internal organs, infertility, atherosclerosis, cardiovascular diseases, dysbiosis, and cancer. The modification of lifestyles, diet patterns and proper selection of nutrients, pharmacological and natural supplementation in the form of herbs, and physical activity have been proposed. The progress and consequences of PCOS are largely modifiable and depend on the patient’s approach, although we have to take into account also the genetic determinants.