Search Results (122)

Ensuring food safety and consumer health are crucial elements of sustainable food safety management, requiring the use of substances that inhibit the growth of undesirable microorganisms at various stages of production. The negative impact of many of these on human health and the environment has led to increased interest in alternative solutions, such as plant extracts. The aim of this study was to determine the biological activity of extracts obtained from Nigella sativa seeds using various methods, including Soxhlet and ultrasound-assisted extraction (UAE) using hexane and methanol and supercritical CO₂ extraction (SFE) assisted with methanol. The content of polyphenolic compounds, their composition, and biological activity depended on the extraction method and solvent type. All extracts exhibited antimicrobial activity against Gram-positive bacteria (Listeria monocytogenes, Priestia megaterium, and Staphylococcus aureus), Gram-negative bacteria (Salmonella Enteritidis, Pseudomonas aeruginosa, and Escherichia coli), yeasts (Candida albicans and Rhodotorula mucilaginosa), and filamentous fungi (Alternaria brassicicola, Pythium sp., Fusarium culmorum, and F. graminearum). The MIC values were in the range of <0.125 to 2 mg/mL for bacteria and 1 to 8 mg/mL for fungi, depending on the extract. Microscopic observations performed using optical and fluorescence microscopy showed changes in the viability and morphology of the fungal cells. TPC values ranged from 9.877 mg/g in hexane extract obtained by ultrasound-assisted extraction to 39.064 mg/g in extract obtained by Soxhlet method with methanol. No negative effects of the extracts on wheat seed germination were observed. Analysis of the composition of polyphenolic compounds revealed the presence of vanillic acid, hydroxybenzoic acid, syringic acid, protocatechuic acid, and p-coumaric, catechin, and epicatechin acids in all extracts. The extracts obtained with methanol, both by the Soxhlet method and by ultrasound-assisted extraction, also contained gallic acid, myricetin, luteolin, apigenin, and sinapic acid. In all extracts, thymoquinone ranged from 8.344 mg/g to 63.125 mg/g of extract, which was detected with the highest concentration in hexane extracts. Full article

This study aimed to evaluate the effects of different pretreatment methods on the yield and chemical composition of Nigella sativa L. (i.e., black cumin) cold-pressed oil. Different pretreatment methods used included convection heating, microwave, ultrasound and pulsed electric fields (i.e., PEF); we investigated their effects on key parameters, including oil yield, fatty acid composition, total phenol and flavonoid content, peroxide value, acidity and antioxidant activity. However, no single pretreatment method was found to be better than all others. Instead, ultrasonication and pulsed electric fields (PEF) showed significant advantages. Ultrasonication showed the highest total phenolic content and improved oxidative stability, while PEF improved flavonoid content and antioxidant activity. Therefore, these findings suggest that a combination of several pretreatment options should be considered depending on specific industrial goals related to quality improvement and sustainability. This research also contributes to the existing knowledge on Nigella sativa L. oil processing and provides additional insights for optimizing extraction technique. Full article

Celtis africana, a rare plant native to southwestern Saudi Arabia, was explored for the first time as a source for the green synthesis of silver nanoparticles (AgNPs). Catechol-bearing phenolic amides in the aqueous leaf extract acted as both reducing and capping agents, enabling eco-friendly AgNP fabrication. The synthesized AgNPs were characterized using SEM, TEM, XRD, UV-Vis, and FTIR, revealing predominantly spherical nanoparticles with an average size of 9.28 ± 0.11 nm, a face-centered cubic crystalline structure, and a pronounced surface plasmon resonance at 424 nm. HPLC analysis confirmed the presence of caffeoyltryamine in the extract, while UV-Vis and FTIR indicated its attachment to the AgNP surface. The AgNPs exhibited broad-spectrum antimicrobial activity against Gram-positive bacteria (S. aureus, MRSA and E. faecalis) and Gram-negative bacteria (E. coli, K. pneumoniae, S. typhimurium, and P. aeruginosa), as well as pathogenic fungi such as C. albicans, C. glabrata, C. parapsilosis, and C. krusei with performance comparable to or exceeding that of AgNPs from Artemisia vulgaris, Moringa oleifera, and Nigella sativa. The MIC and MBC values for S. aureus, MRSA, E. coli, and S. typhimurium were consistently 6.25 µg/mL and 25 µg/mL, respectively, reflecting strong inhibitory and bactericidal effects at low concentrations. MTT assays demonstrated selective cytotoxicity, showing higher viability in normal human skin fibroblasts (HSF) than in MCF-7 breast cancer cells. The AgNPs also displayed strong antioxidant activity (IC₅₀ = 5.41 µg/mL, DPPH assay) and efficient catalytic reduction of 4-nitrophenol (4-NP) and methylene blue (MB), with rate constants of 0.0165 s⁻¹ and 0.0047 s⁻¹, respectively, exceeding most reported values. These findings identify Celtis africana as a promising source for eco-friendly AgNPs with strong antimicrobial, antioxidant, and catalytic properties for broad biological and environmental applications. Full article

Synthetic anthelmintic drugs not only contribute to the development of pathogen resistance and environmental pollution but also to the development of pathogen resistance. Therefore, identifying the anthelmintic properties of widely used medicinal plants could be of great practical interest to veterinary and human medicine. In our experiment, we evaluated the in vitro survivability of the noninvasive and invasive (L_1–2 and L_3, respectively) larvae of Strongyloides papillosus and Haemonchus contortus subject to aqueous solutions of ethanolic tinctures of traditional medicinal plants (46 species). Most of the plant species we studied belonged to the families Asteraceae (Achillea millefolium, Arctium lappa, Artemisia absinthium, Bidens tripartita, Calendula officinalis, Cynara cardunculus var. scolymus, Echinacea purpurea, Helichrysum arenarium, Inula helenium, Matricaria chamomilla, Silybum marianum, Tanacetum vulgare, Taraxacum officinale, Tragopogon porrifolius), Rosaceae (Agrimonia eupatoria, Fragaria vesca, Sanguisorba officinalis), and Lamiaceae (Leonurus cardiaca, Mentha × piperita, Origanum vulgare, Salvia officinalis, Thymus vulgaris). Other plant families were represented by 1–3 species: Fabaceae (Glycyrrhiza glabra, Hedysarum alpinum, Trifolium pratense), Salicaceae (Populus nigra, P. tremula, Salix alba), Fagaceae (Quercus robur), Betulaceae (Betula pendula), Juglandaceae (Juglans regia), Rhamnaceae (Frangula alnus), Acoraceae (Acorus calamus), Apiaceae (Foeniculum vulgare), Caprifoliaceae (Valeriana officinalis), Cucurbitaceae (Cucurbita pepo), Equisetaceae (Equisetum arvense), Ericaceae (Vaccinium vitis-idaea), Gentianaceae (Centaurium erythraea), Hypericaceae (Hypericum perforatum), Malvaceae (Althaea officinalis), Plantaginaceae (Linaria vulgaris, Plantago major), Poaceae (Zea mays), Polygonaceae (Polygonum aviculare), and Ranunculaceae (Nigella sativa). We determined Artemisia absinthium, Inula helenium, Matricaria chamomilla, Salvia officinalis, and Populus nigra, whose aqueous solutions of alcohol tinctures demonstrated nematocidal properties. The other plants we studied did not affect the viability of parasitic nematode larvae. Full article

Background: Oral infections such as dental caries and candidiasis are mediated by resilient biofilms, which are increasingly tolerant to conventional antimicrobials. This study investigated the antimicrobial and antibiofilm effects of Salvia officinalis and Nigella sativa CO₂ extracts against Streptococcus mutans and Candida albicans, with emphasis on synergistic interactions. Methods: Extracts were analyzed using gas chromatography–mass spectrometry analysis (GC–MS) and evaluated through planktonic MIC/MBC assays, time–kill kinetics, and biofilm models (MBIC/MBEC, biomass, metabolic activity). A novel three-dimensional checkerboard (3D-CB) and fractional inhibitory concentration index (FICI) approach was applied to optimize extract ratios, concentrations, and exposure times. Results: S. officinalis extract showed greater activity against S. mutans (MIC 256 mg/L; MBC 512 mg/L), while N. sativa was more effective against C. albicans (MIC 256 mg/L; MFC 512 mg/L). Both extracts reduced biofilm biomass and metabolic activity by over 70% at higher doses. Synergy was confirmed at ratios of 70:30 (S. officinalis: N. sativa) for S. mutans (FICI 0.38) and 40:60 for C. albicans (FICI 0.42). The achieved synergistic effect further decreased MBEC values fourfold and prolonged post-antibiotic effects. Conclusions: Synergistic S. officinalis–N. sativa formulations enhanced antimicrobial activity against oral pathogens in both planktonic and biofilm states, supporting their potential as next-generation dental antimicrobials. Full article

Nigella sativa L. is a species of the Ranunculaceae family and belongs to the genus Nigella, which comprises 14 species native to the regions of the Eastern Mediterranean, North Africa, and subcontinental India. Several significant groups of bioactive compounds, with pharmacological activities, have been isolated from the Nigella sativa L. species. Numerous beneficial effects have been demonstrated for these compounds. This review provides a comprehensive summary of the chemical constituents, bioactive compounds, modern administration methods, studies on the antidiabetic potential, evidence in commonly associated type 2 diabetes mellitus (T2DM) conditions, and evidence of T2DM complications. Research shows that Nigella sativa L. can be successfully included in complementary and alternative therapy for T2DM pathology, having multiple benefits both in diseases associated with and in complications of T2DM. Full article

Thymoquinone (TMQ) is the main therapeutic constituent in black cumin (Nigella sativa L.) seeds. Conventional quantification by high-performance liquid chromatography (HPLC) is accurate but unsuitable for large-scale screening. This study evaluated the potential of near-infrared reflectance spectroscopy (NIRS) as a rapid and non-destructive alternative. A multi-year dataset of 780 seed samples was analyzed, and robust calibration models were developed using modified partial least squares regression. Independent validation of a two-year calibration equation using samples from a third year yielded a high predictive performance (r² = 0.85; SEP = 1.18 mg g⁻¹). Adding part of the samples from the third year to the calibration contributed to further improvement in the prediction of the remaining samples, demonstrating the benefits of continuous equation updates. The calibration equation proved effective for selecting genotypes with high TMQ content, particularly when expanded with samples from the third year. Spectral analysis identified key wavelengths associated with TMQ content, with wavelengths around 2106 nm and 2254 nm being the most relevant. This work demonstrates the applicability of NIRS for rapid phenotyping of TMQ content in black cumin seeds. Full article

A plant breeding program needs helpful markers, especially morphological ones, which can allow breeders to dispense with other markers, including cytological traits and flow cytometry. These markers can assist plant breeders in distinguishing diploid and tetraploid plants during the seedling stage. Therefore, the present study aimed to investigate and validate effective methodologies for the early identification of artificially induced polyploids in black cumin. Thus, we established an extensional program for black cumin breeding including producing seeds, active compounds, and flowers as ornamental plants. Field experiments on tetraploids and diploids were carried out to evaluate the morphological and yield traits of both plants. Also, some cytological studies and Gas Chromatography (GC) analysis were conducted to achieve these goals. The results showed the possibility of realizing diploid and tetraploid plants in early growing black seeds in the field (mainly after the first cotyledon leaves). This crucial outcome can support plant breeders in identifying polyploidy during the seedling stage without referring to biochemical markers, flow cytometry, and cytological traits. All morphological and yield-related traits were superior in diploid plants compared to tetraploids. The results showed that diploid and tetraploid plants exhibited plant heights of 116 cm and 95 cm, numbers of secondary branches of 112 and 22, numbers of flowers of 111.7 and 24.75, and shoot fresh weights of 610 g and 147.5 g, respectively. Furthermore, the number of seeds per capsule, seed yield per plant, and oil percentage in diploids were 97.5 seeds, 24 g, and 22.94%, compared with 35.25 seeds, 4.62 g, and 17.76% in tetraploids, respectively. This work used the cotyledon leaf shape as a morphological marker to distinguish the tetraploid and diploid plants, as diploids are typically taller with pointed cotyledons, whereas tetraploids are shorter with rounded cotyledon tips. This study will create great opportunities for plant breeders to save time and costs during their programs. Further studies on such suggested black cumin breeding programs are needed on diploids, triploids, and tetraploids. Full article

Threshing and cleaning are crucial for efficient harvest procedures that are carried out to separate the grains from the biomass and eliminate any potential contaminants or foreign debris. This study examines the cleaning capabilities of the grain cleaning equipment Kimseed Cleaner MK3, a vibratory sieve and air-screen device, for tiny oilseed crops, particularly kalonji (Nigella sativa) and sesame (Sesamum indicum L.), which are valued for their industrial, medicinal, and nutritional properties. These crops frequently provide post-harvest cleaning issues because of their tiny size and vulnerability to contamination from weed seeds, plant residues, and immature or damaged conditions. In order to determine the ideal operating parameters, 0.5 kg of threshed seed samples with 10% moisture content were utilised in the experiment. A variety of shaker frequencies (0.1–10 Hz) and airflow speeds (0.1–10 m/s) were assessed. A two-stage cleaning method was applied for sesame: the first stage targeted larger contaminants (6.5–7.0 Hz and 1.25–1.5 m/s), while the second stage targeted finer impurities (5.25–5.5 Hz and 1.75–2.0 m/s). With a single-stage procedure (5.5–6.0 Hz and 1.0–1.5 m/s), kalonji was successfully cleaned. The findings demonstrated that sesame attained 98.5% purity at the output rate of 200.6 g/min (12.03 kg/h) while kalonji reached 97.6% seed purity at an output rate of 370.2 g/min (22.2 kg/h). These results demonstrate how important carefully regulated shaker frequency and airflow speed are for improving output quality and cleaning effectiveness. The study shows that the Kimseed MK3 is a suitable low-cost, scalable option for research operations and smallholder farmers, providing better seed quality and processing efficiency for underutilised yet economically valuable oilseed crops. Full article

The aim of this study was to examine cold-pressed oils available on the Polish market derived from different plants and manufacturers in the context of their biological activity, including micro- and macroelements, antioxidant properties, antimicrobial activity, and selected effects on eukaryotic cells. In total, 76 oil samples of 34 selected oil types from nine Polish companies (five commercial and four amateur) were tested. The content of macro- and micronutrients was assessed using ICP-OES, the level of fatty acid unsaturation was examined using Fourier transform infrared spectroscopy (FTIR), and total antioxidant potential (TAP) was assessed using the DPPH method. The antimicrobial activity of the selected oils against Gram-positive and Gram-negative bacteria, as well as fungi, representing both pathogens and human microbiota, was tested using the broth microdilution method. The MTT reduction assay was used to exclude the cytotoxic effect of the oils on the human fibroblast line HFF-1. It has been concluded that the composition of cold-pressed oils varied significantly depending on the plant used and the manufacturer. The total content of the elements tested ranged from 172.91 mg/kg in Helianthus annuus oil to 1580.73 mg/kg in Silybum marianum oil. The iron concentration limits were exceeded in 10 oils, the copper concentration limits were exceeded in 34 oils, and the lead concentration limits were exceeded in 18 oils. At least one of these elements was exceeded in 40 oils (53% of the tested samples), which is why testing the concentration of elements should be a standard procedure for assessing the quality of cold-pressed oils. There was no statistically significant correlation between the content of any macro- and microelements and TAP. While TAP was strongly correlated with the spectral unsaturation index of the oils, this relationship can be used to develop a simple and rapid assessment of oils quality. The strongest antioxidant activity (over 90%) was observed for Nigella sativa oils. Interestingly, among all the tested oils, only these from Nigella sativa L., whatever the producer, possessed also strong antimicrobial activity. None of the tested oils showed cytotoxicity against eukaryotic cells, so the cold-pressed oils can be considered safe. Full article

Nigella sativa (NS) is a promising medicinal plant with diverse therapeutic properties. This study aimed to investigate the impact of NS oil (NSO) on memory functions in rats with LPS (lipopolysaccharide)-induced neuroinflammation, as well as its effect on serum levels of inflammatory cytokines, neuropeptide Y (NPY) and brain-derived neurotrophic factor (BDNF). Male rats were divided into four groups: control, LPS-control, LPS+NSO 3 and 5 mL/kg. Neuroinflammation was induced by a single intraperitoneal LPS injection (2 mg/kg). The novel object recognition test (NORT) and Y-maze were used for the evaluation of memory processes. Recognition index (RI) and % spontaneous alteration (%SA) were registered, respectively. Blood samples for TNF-α, IL-1β, IL-10, BDNF, and NPY serum levels were taken. Thymoquinone, the active compound of the oil, was detected by high-performance liquid chromatography. NSO administration resulted in an improvement in spatial and episodic memory, as evidenced by increased % SA and RI compared to LPS-control. Treatment with NSO led to a significant reduction in pro-inflammatory cytokines and NPY, along with an increase in IL-10 and BDNF levels, when compared to LPS-control. In conclusion, NSO enhances BDNF production and regulates pro- and anti-inflammatory cytokines release, which probably contributes to the observed cognitive improvement in animals with experimental neuroinflammation. Full article

Nigella sativa L. (generally known as black cumin) is a medicinal plant prized for its therapeutic and nutritional benefits. Its seed oil is used extensively in pharmaceuticals, nutraceuticals, cosmetics, and cooking. However, extracting oil to satisfy the world’s needs leaves behind plenty of solid residues. The seeds of Nigella are loaded with health-benefiting phytoconstituents, but so might their extraction residues. While much research on seeds and oil has been carried out, there is relatively little information about solid residue, particularly regarding health-benefiting phytoconstituents. Additionally, there is a knowledge gap relating to how phytoconstituents transfer from seeds to solid residue during oil extraction and any loss of key phytoconstituents that may occur during this transfer. Understanding the health-benefiting phytoconstituents in Nigella solid residue is crucial for unlocking its full potential for value-added applications in health and nutrition. Moreover, understanding the dynamics of these phytoconstituent transfers is essential for optimizing extraction processes and preserving the nutritional and therapeutic value of the derived products. Therefore, this study investigated the composition of the screw-press solid residues of different Nigella genotypes grown under similar environmental conditions. The results showed moderate variation in the levels of potential health-benefitting phytoconstituents in Nigella solid residues regarding total phenolic content (TPC) (720.5–934.8 mg GAE/100 g), ferric reducing antioxidant capacity (FRAP) (853.1–1010.5 mg TE/100 g), cupric reducing antioxidant capacity (CUPRAC) (3863.1–4801.5 mg TE/100 g), thymoquinone (TQ) (156.0–260.1 mg/100 g), saturated fatty acid (SFA) (2.0–2.2 mg/g), monounsaturated fatty acid (MUFA) (2.0–3.6 mg/g), and polyunsaturated fatty acid (PUFA) (8.2–12.1 mg/g). Notably, TPC, FRAP, and CUPRAC had high transfer rates into the solid residue (78.1–85.9%, 65.4–75.7%, and 84.5–90.4%, respectively), whereas TQ, SFA, MUFA, and PUFA showed lower transfer rates (15.9–19.3%, 7.5–8.9%, 12.0–18.3%, and 6.5–7.5%, respectively). When summing the values of individual phytoconstituents transferred into oil and solid residue from their respective seeds during processing, it was found that only 80.6–88.3% of TPC, 74.2–84.4% of FRAP, 86.3–92.3% of CUPRAC, 54.4–64.9% of TQ, 68.5–92.4% of SFA, 76.2–90.6% of MUFA, and 51.6–76.6% of PUFA were transferred from the total value present in their respective seeds. Full article

Black cumin seeds (Nigella sativa) and black cumin seed oil (BCSO) exhibit various pharmacological activities, most of which are attributed to the presence of thymoquinone (TQ). TQ, however, is characterized by low stability at elevated temperatures and instability in aqueous environments. In this study, the spectroscopic properties of TQ were used to monitor changes in TQ content in BCSO subjected to thermal exposure. Simultaneously, the influence of the presence of TQ on the antioxidant properties of this oil was determined. The used spectrofluorimetric and chromatographic method quantified the presence of TQ. The antiradical properties of the oil in different stages of thermal oxidation degradation were determined by the DPPH method. The measured antiradical activity of the oil, depending on the exposure conditions used, revealed the difference correlated with the content of the TQ. However, the presence in BCSO of other bioactive components, like phenols, had a more significant influence on its total antioxidant capacity. Furthermore, our study, for the first time, focused on the rise in TQ content in the oil during thermal storage, indicating a new method to enhance the TQ content in BCSO. Full article

Endophytic microbes in medicinal plants often possess beneficial traits for plant health. This study focuses on the bacterial endophyte strain B.L.Ns.14, isolated from Nigella sativa leaves, which demonstrated multiple plant growth-promoting properties. In vitro tests showed that B.L.Ns.14 supports plant growth, colonization, and tolerance to abiotic stress. The strain also exhibited antifungal activity against phytopathogens such as Rhizoctonia solani, Colletotrichum acutatum, Verticillium dahliae, and Fusarium oxysporum f. sp. radicis-lycopersici. Whole-genome analysis, supported by ANI and dDDH values, identified B.L.Ns.14 as Bacillus halotolerans. Genome mining revealed 128 active carbohydrate enzymes (Cazymes) related to endophytism and biocontrol functions, along with genes involved in phosphate solubilization, siderophore and IAA production, biofilm formation, and motility. Furthermore, genes for osmolyte metabolism, Na+/H+ antiporters, and stress response proteins were also identified. The genome harbors 12 secondary metabolite biosynthetic gene clusters, including those for surfactin, plipastatin mojavensin, rhizocticin A, and bacilysin, known for their antagonistic effects against fungi. Additionally, B.L.Ns.14 promoted Arabidopsis thaliana growth under both normal and saline conditions, and enhanced Solanum lycopersicum growth via seed biopriming and root irrigation. These findings suggest that Bacillus halotolerans B.L.Ns.14 holds potential as a biocontrol and plant productivity agent, warranting further field testing. Full article

Thymoquinone (TQ), a bioactive compound from black cumin (Nigella sativa), has demonstrated a broad range of therapeutic effects. The aim of this study is to evaluate the antifungal efficacy of TQ by targeting key virulence factors in Candida albicans, specifically focusing on isocitrate lyase (ICL) activity, biofilm formation, and gene expression. This study explored TQ’s impact on ICL, a decisive enzyme in the glyoxylate cycle, along with its effect on hyphal formation, biofilm development, and the virulent gene expression of C. albicans through in silico and in vitro studies. Molecular docking revealed a binding energy of −6.4 kcal/mol between TQ and ICL, indicating moderate affinity. The stability of the ICL-TQ complex was validated through 50 ns molecular dynamics simulations, showing the root mean square deviation (RMSD) values of 0.35 nm for ICL and 0.38 nm for the complex. In vitro studies further validated these findings, showing a dose-dependent inhibition of ICL activity. TQ at 2 µg/mL reduced enzyme activity by 57%, and at 4 µg/mL, by 91.4%. Additionally, TQ disrupted the yeast-to-hyphae switch, a key virulence factor, with 1 and 2 µg/mL doses significantly inhibiting hyphal formation. The biofilm formation was similarly affected, with a 58% reduction at 2 µg/mL and an 83% reduction at 4 µg/mL. TQ also downregulated the ALS1 and HWP1 genes that are associated with adhesion and biofilm development, demonstrating its broad-spectrum antifungal activity. These findings suggest that TQ is a promising candidate for antifungal therapies, targeting multiple virulence factors in C. albicans and potentially overcoming biofilm-associated drug resistance. Future research should focus on in vivo validation, optimization for clinical applications, and expanding its spectrum against other drug-resistant fungal species. Full article