Ancient nigella seeds from Boyali Höyük in north-central Turkey

The Immunomodulatory Effect of Nigella sativa

BACKGROUND

For thousands of years till nowadays, Nigella sativa (NS) has served as a common spice and food preservative. Its seed extracts, seed oil, and essential oil in traditional medicine have been used to remedy many ailments such as headaches, fever, gastric complaints, and even rheumatism. In addition, the antibacterial, virucidal, fungicidal, and antiparasitic properties of NS are well known. However, studies on the possible immunomodulatory effects of black cumin are relatively scarce. This article discusses in vitro and in vivo research supporting the immunomodulatory role of NS.

METHODS

The review is based on articles, books, and conference papers printed until September 2022, found in the Web of Science, PubMed, Wiley Online Library, and Google Scholar databases.

RESULTS

Experimental findings were reported concerning the ability of NS to modulate inflammation and immune responses or cytotoxic activity.

CONCLUSIONS

All results suggest that NS can potentially be employed in developing effective therapeutic agents for regulating immune reactions.

Delineating the potential targets of thymoquinone in ESKAPE pathogens using a computational approach

The present study was designed to identify and analyze the targets of thymoquinone on drug resistant pathogens employing in silico tools. The target identification was performed using STITCH tool, followed by the functional analysis of protein targets by VICMPred. Further, VirulentPred was used to determine the nature of virulence of target proteins. The putative epitopes present on the virulent proteins were identified using BepiPred tool. The subcellular location of the virulent proteins was assessed using PSORTb. The results showed multiple targets of the pathogens being targeted. The nitric-oxide synthase-like protein of Staphylococcus aureus and acetyltransferase family protein, histone acetyltransferase HPA2, GNAT family acetyltransferase of Acinetobacter baumannii was found to be the virulent proteins interacting with thymoquinone. Molinspiration assessments showed zero violations suggesting the druggability of TQ. The study unveils the molecular mechanisms underlying the antimicrobial effect of thymoquinone as demonstrated by in silico procedures.

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.

In-vitro evaluation of Nigella sativa and Punica granatum effect on protoscolices of hydatid cysts

Cystic echinococcosis (CE) are commonly found in the liver and lungs of affected hosts. The treatment approach is usually surgical, or giving drugs in conjunction before surgery to kill protoscolices, to avoid anaphylactic shock from leakage of hydatid fluid into the peritoneum and to decrease opportunities for recurrences. The present study was to evaluate the in vitro scolicidal efficacy of hydroalcoholic extract of Punica granatum peel and Nigella sativa, on the protoscolices of CE that collected from the lungs of infected camels. Different concentrations of extracts with different exposure times were used and a viability assay was applied to measure the scolicidal effect. N. sativa showed its highest scolicidal efficacy at 100 mg/mL and 10 mg/mL concentrations after 30 and 60 min. P. granatum peel extract showed its maximum scolicidal efficacy at 100 mg/mL concentration after 120 min. All experiments of the current study revealed that the extracts of both N. sativa and P. granatum had a scolicidal effects on the protoscolices of camel hydatid cysts. It could be concluded that N. sativa extract is more potent than P. granatum peel extract regarding scolicidal effect, but the efficacies of both extracts were of moderate significant correlation to exposure time and concentrations.

Ameliorative effects of thymoquinone on titanium dioxide nanoparticles induced acute toxicity in rats

Although the nanoparticles had a beneficial activity, it had also adverse effects as a result of generation of oxidative stress. The current study aimed to assess the ameliorative effect of thymoquinone (TQ) on titanium dioxide nanoparticles (TiO₂ NPs) induced acute toxicity in male rats. Forty-eight male rats were distributed into four equal groups (12 rats each). Group (1) received single oral dose of TiO₂ NPs (300 mg/kg), Group (2) received TiO₂ NPs and TQ (20 mg/kg), Group (3) received TQ and group (4) received only the vehicle and served as control group. TiO₂ NPs intoxicated group showed increased the level of lipid peroxidation product (LPO), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) and decreased the level of antioxidants and testosterone. Vascular and degenerative changes in the liver and testes were observed by light microscopy as well as presence of TiO₂ NPs in the lysosomes by electron microscopy. Treatment with TQ revealed improvement of the biochemical parameters, histology and ultrastructure of the liver and testes. It was concluded that acute intoxication of rats with TiO₂ NPs induced adverse effect in the liver and testes. Administration of TQ has an ameliorative effect against oxidative stress induced by TiO₂ NPs intoxication.

Thymoquinone Inhibits the Migration and Invasive Characteristics of Cervical Cancer Cells SiHa and CaSki In Vitro by Targeting Epithelial to Mesenchymal Transition Associated Transcription Factors Twist1 and Zeb1

Cervical cancer is one of the most common gynecological malignant tumors worldwide, for which chemotherapeutic strategies are limited due to their non-specific cytotoxicity and drug resistance. The natural product thymoquinone (TQ) has been reported to target a vast number of signaling pathways in carcinogenesis in different cancers, and hence is regarded as a promising anticancer molecule. Inhibition of epithelial to mesenchymal transition (EMT) regulators is an important approach in anticancer research. In this study, TQ was used to treat the cervical cancer cell lines SiHa and CaSki to investigate its effects on EMT-regulatory proteins and cancer metastasis. Our results showed that TQ has time-dependent and dose-dependent cytotoxic effects, and it also inhibits the migration and invasion processes in different cervical cancer cells. At the molecular level, TQ treatment inhibited the expression of Twist1, Zeb1 expression, and increased E-Cadherin expression. Luciferase reporter assay showed that TQ decreases the Twist1 and Zeb1 promoter activities respectively, indicating that Twist1 and Zeb1 might be the direct target of TQ. TQ also increased cellular apoptosis in some extent, but apoptotic genes/proteins we tested were not significant affected. We conclude that TQ inhibits the migration and invasion of cervical cancer cells, probably via Twist1/E-Cadherin/EMT or/and Zeb1/E-Cadherin/EMT, among other signaling pathways.

Thymoquinone, as an anticancer molecule: from basic research to clinical investigation

Thymoquinone is an anticancer phytochemical commonly found in black cumin. In this review, we discuss the potential of thymoquinone as anticancer molecule, its mechanism of action and future usage in clinical applications. Thymoquinone exhibits anticancer activity via numerous mechanisms of action, specifically by showing selective antioxidant and oxidant activity, interfering with DNA structure, affecting carcinogenic signaling molecules/pathways and immunomodulation. In vitro activity of thymoquinone has been further implicated in animal models of cancer; however, no clinical application has been proven yet. This is the optimum time to focus on clinical trials for developing thymoquinone as a future drug in cancer therapeutics.

Thymoquinone inhibits cancer metastasis by downregulating TWIST1 expression to reduce epithelial to mesenchymal transition

Proteins that promote epithelial to mesenchymal transition (EMT) are associated with cancer metastasis. Inhibition of EMT regulators may be a promising approach in cancer therapy. In this study, Thymoquinone (TQ) was used to treat cancer cell lines to investigate its effects on EMT-regulatory proteins and cancer metastasis. We show that TQ inhibited cancer cell growth, migration and invasion in a dose-dependent manner. At the molecular level, TQ treatment decreased the transcriptional activity of the TWIST1 promoter and the mRNA expression of TWIST1, an EMT-promoting transcription factor. Accordingly, TQ treatment also decreased the expression of TWIST1-upregulated genes such as N-Cadherin and increased the expression of TWIST1-repressed genes such as E-Cadherin, resulting in a reduction of cell migration and invasion. TQ treatment also inhibited the growth and metastasis of cancer cell-derived xenograft tumors in mice but partially attenuated the migration and invasion in TWIST1-overexpressed cell lines. Furthermore, we found that TQ treatment enhanced the promoter DNA methylation of the TWIST1 gene in BT 549 cells. Together, these results demonstrate that TQ treatment inhibits TWIST1 promoter activity and decreases its expression, leading to the inhibition of cancer cell migration, invasion and metastasis. These findings suggest TQ as a potential small molecular inhibitor of cancer growth and metastasis.

Thymoquinone causes multiple effects, including cell death, on dividing plant cells

Thymoquinone (TQ) is a major constituent of Nigella sativa oil with reported anti-oxidative activity and anti-inflammatory activity in animal cells. It also inhibits proliferation and induces programmed cell death (apoptosis) in human skin cancer cells. The present study sought to detect the influence of TQ on dividing cells of three plant systems and on expression of Bcl2-associated athanogene-like (BAG-like) genes that might be involved during the process of cell death. BAG genes are known for the regulation of diverse physiological processes in animals, including apoptosis, tumorigenesis, stress responses, and cell division. Synthetic TQ at 0.1mg/mL greatly reduced wheat seed germination rate, whereas 0.2mg/mL completely inhibited germination. An Evans blue assay revealed moderate cell death in the meristematic zone of Glycine max roots after 1h of TQ treatment (0.2mg/mL), with severe cell death occurring in this zone after 2h of treatment. Light microscopy of TQ-treated (0.2mg/mL) onion hairy root tips for 1h revealed anti-mitotic activity and also cell death-associated changes, including nuclear membrane disruption and nuclear fragmentation. Transmission electron microscopy of TQ-treated cells (0.2mg/mL) for 1h revealed shrinkage of the plasma membrane, leakage of cell lysate, degradation of cell walls, enlargement of vacuoles and condensation of nuclei. Expression of one BAG-like gene, previously associated with cell death, was induced 20 min after TQ treatment in Glycine max root tip cells. Thus, TQ has multiple effects, including cell death, on dividing plant cells and plants may serve as a useful system to further investigate the mechanisms underlying the response of eukaryotic cells to TQ.

Antibacterial activity of Thymoquinone, an active principle of Nigella sativa and its potency to prevent bacterial biofilm formation

Background

Thymoquinone is an active principle of Nigella sativa seed known as "Habbah Al-Sauda" in Arabic countries and "Sinouj" in Tunisia. Bacterial biofilms tend to exhibit significant tolerance to antimicrobials drugs during infections.

Methods

The antibacterial activity of Thymoquinone (TQ) and its biofilm inhibition potencies were investigated on 11 human pathogenic bacteria. The growth and development of the biofilm were assessed using the crystal violet (CV) and the 2, 3-bis [2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide (XTT) reduction assay.

Results

TQ exhibited a significant bactericidal activity against the majority of the tested bacteria (MICs values ranged from 8 to 32 μg/ml) especially Gram positive cocci (Staphylococcus aureus ATCC 25923 and Staphylococcus epidermidis CIP 106510). Crystal violet assay demonstrated that the minimum biofilm inhibition concentration (BIC50) was reached with 22 and 60 μg/ml for Staphylococcus aureus ATCC 25923 and Staphylococcus epidermidis CIP 106510 respectively. In addition our data revealed that cells oxidative activity was influenced by TQ supplementation. In the same way, TQ prevented cell adhesion to glass slides surface.

Conclusion

The ability of TQ to prevent biofilm formation warrants further investigation to explore its use as bioactive substances with antibiofilm potential.

Phytochemical and biological investigation of the extracts of Nigella sativa L. seed waste

Different extracts of Nigella sativa L. seed waste; aqueous (AE) 200 mg/kg, ethanol 70% (EE) 250 mg/kg and hexane (HE) 10 mg/kg, were evaluated for their hepatoprotective activities. They were administered orally, once daily, for 5 consecutive days. On day 5, liver injury was induced in animals by a single i.p. injection of carbon tetrachloride (10 mg/kg b. w. of 0.25% (v/v). Hepatoxicity produced, was evaluated by both biochemical and histopathological investigations. The aqueous extract attenuated the CCl(4) -induced liver damage likely due to the decrease of proinflammatory cytokines and T-cell proliferation. This was noticed by a significant decrease in both serum and tissue cytokines; tumor necrosis factor-alpha (TNF-α), interferon-gamma (INF-γ) and interlukin-beta (IL-1β), in the markers of liver functions; bilirubin and glutamic pyruvic transaminase (GPT) and in the oxidative stress markers; malondialdehyde (MDA) and glutathione content (GSH). Fractionation of this extract was performed and its component, protein, saponin, and polyphenol fractions were evaluated by appropriate analytical procedures. The crude protein of the seed waste reached 36.85% while protein fingerprint showed four bands ranging from 91.97 KD and 29.00 KD. The saponin content was evaluated through the determination of the haemolytic index and reached 15.56 mg/g dry powder. Finally, Folin Ciocalteu method was used for the determination of the total polyphenols. The same biochemical and histopathological studies were again performed on the different fractions of the aqueous extract; protein fraction (PF) 10 mg/kg, saponin fraction (SF) 5 mg/kg and polyphenol fraction (FF) 10 mg/kg. The biochemical changes were improved only by the protein fraction (PF) of the seed waste of Nigella sativa. This was manifested by a significant reduction in both serum and tissue cytokines in the liver markers and in the oxidative stress markers. Moreover, liver histopathology showed that (PF) reduced the incidence of liver lesions including hepatic cells cloudy swelling, lymphocytes infiltration, hepatic necrosis and fibrous connective tissue proliferation induced by CCl(4) in mice. From this study, it is concluded that the protein fraction of the aqueous extract of Nigella sativa seed waste exhibited a promising hepatoprotective effect in the management of different liver disorders.