Search Results (45)

This study compares the nutritional and metabolic properties of unconventional cold-pressed vegetable oils available on the Polish market. Twelve oils—milk thistle, evening primrose, flaxseed, camelina sativa, black cumin, pumpkin seed, sesame, mustard seed, sea buckthorn, blue poppy seed, borage, and safflower—were examined. The chosen oils were investigated based on their fatty acids profiles, total phenolic compounds (TPC), tocopherols, and pigment contents. Despite the high polyunsaturated fatty acids (PUFAs) content raising concerns about oxidative stability, the significant tocopherol levels and polyphenols content contribute to antioxidative protection. These oils’ favorable hypocholesterolemic, antiatherogenic, and antithrombogenic properties were highlighted by key nutritional indices, showing potential benefits for cardiovascular health. These results suggest that these oils are a promising dietary supplement for promoting both cardiovascular health and sustainability, owing to their rich content of essential fatty acids and bioactive compounds. Moreover, high correlations were found between theoretical and experimental established oxidative stability of the tested oils at the ending stage of the thermostat test. Full article

Thymoquinone (TQ), a bioactive compound derived from black cumin seeds, is renowned for its potent anti-obesity and anti-diabetic properties. Due to the stability challenges of TQ, it has predominantly been utilized in oil formulations. This study aimed to enhance the stability of TQ and investigated the impact of consuming insoluble fiber from black cumin seeds on restoring antioxidant function compromised by diabetes and improving hyperglycemia management. We evaluated the restorative effects of a 35-day administration of black cumin seed extract (BCS) on antioxidant function impaired by streptozotocin (STZ)-induced diabetes, alongside structural and functional alterations in the pancreas, liver, and kidneys. The results demonstrated significant improvements in organ weight, particularly in pancreatic tissue. Moreover, BCS administration markedly suppressed the expression of key genes associated with pancreatic dysfunction and damage, including caspase-3, transforming growth factor-beta 1 (TGF-β1), and interleukin-1 beta (IL-1β). Through oral glucose tolerance tests (OGTTs), BCS was found to effectively regulate chronic hyperglycemia and exhibit potential for managing acute hyperglycemia. These findings suggest that BCS not only addresses both glycemic and non-glycemic complications of diabetes but also offers a safe, long-term solution. Consequently, BCS emerges as a promising therapeutic agent for hyperglycemia management, including in prediabetic stages. 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

This study aimed to evaluate the oxidative stability and surface properties of cold-pressed vegetable oils using the Langmuir monolayer technique. Six oils—milk thistle, evening primrose, flaxseed, camelina sativa, black cumin, and pumpkin seed—were analyzed to investigate their molecular organization and behavior at the air/water interface, particularly after undergoing oxidation. The results showed that oils rich in polyunsaturated fatty acids (PUFAs), such as flaxseed and evening primrose oils, formed monolayers with larger molecular areas and lower stability, which led to faster oxidative degradation, especially under thermal conditions. In contrast, pumpkin seed oil, with a higher content of saturated fatty acids (SFAs), formed more condensed and stable monolayers, enhancing its resistance to oxidation. Black cumin oil, with a balanced profile of SFAs and monounsaturated fatty acids (MUFAs), demonstrated similar stability. The Langmuir technique facilitated a detailed analysis of monolayer phase transitions: PUFA-rich oils transitioned more readily to less stable phases, while SFA-rich oils maintained durable, condensed structures. These findings underscore the utility of this method for assessing the oxidative stability of vegetable oils and highlight key parameters—such as surface pressure, molecular area, and elasticity modulus—that can support the optimization of oil storage and quality in the food industry and related sectors. 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

Nigella sativa L., which is commonly referred to as black cumin, is a globally recognized plant for the nutraceutical and pharmaceutical values of its seed oil. While numerous studies have investigated Nigella oil, there is a scarcity of information regarding the variation of key phytoconstituents in Nigella oil from diverse seed sources. It is also unclear whether the variation in phytoconstituents across different seed sources translates to variations in their respective oils, which is important for understanding their health benefits. Additionally, there is a gap in information on how specific phytochemicals transfer from seed to oil during the oil pressing. Therefore, this study investigated Nigella sourced from different genotypes and agricultural practices (planting densities and sowing times) to determine total phenolic content (TPC), antioxidant capacity (FRAP and CUPRAC), thymoquinone (TQ), and fatty acid composition. The results showed significant variation of TPC (87.4–144.1 mg gallic acid equivalents (GAE)/100 g), FRAP (454.1–560.9 mg Trolox equivalents (TE)/100 g), CUPRAC (356.3–482.5 mg TE/100 g), TQ (1493.5–2268.4 mg TQ/100 g), saturated fatty acid (SFA) (65.9–83.7 mg/g), monounsaturated fatty acid (MUFA) (42.5–67.8 mg/g), and polyunsaturated fatty acid (PUFA) (266.1–383.4 mg/g) in the oil derived from the seeds of different genotypes and agricultural practices. The total transfer of TPC, FRAP, and CUPRAC into the screw-pressed oil was relatively low, contributing only 2.3–3.7%, 7.1–11.7%, and 1.5–2.3%, respectively, of their total value in the respective seed. However, the transfer of TQ, SFA, MUFA, and PUFA was observed to be comparatively higher, contributing 32.8–48.5%, 60.8–84.2%, 45.6–74.4%, and 43.1–69.4%, respectively, of their total value in the respective seed. There was no strong correlation observed among TPC, FRAP, CUPRAC, and TQ, and none of the fatty acids showed a strong correlation with these variables. Full article

Nigella sativa L. seeds and their industrial process products, oils, cake, and meal, are valuable sources of bioactive compounds with antioxidant properties. In this work, the effect of technological processes on the antioxidant capacity (AC) and total phenolic content (TPC) in the black cumin oils obtained by cold pressing and solvent extraction, as well as the by-products, were evaluated. The AC values of black cumin seeds (BCS), cold-pressed black cumin oil (BCCPO), black cumin oil extracted from seeds (BCEO-S), black cumin oil extracted from cake (BCEO-C), black cumin cake (BCC), and black cumin meal (BCM) were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and cupric reducing antioxidant capacity (CUPRAC) assays, whereas TPC in these samples was analyzed by the Folin–Ciocalteu (FC) method. Two applied conventional oil extraction methods, screw pressing and solvent extraction, significantly affected the AC and TPC in the obtained black cumin oils and by-products. The solvent-extracted black cumin oils revealed higher antioxidant properties (DPPH = 4041–16,500 μmol TE/100 g, CUPRAC = 1275–4827 μmol TE/100 g) than the cold-pressed black cumin oil (DPPH = 3451 μmol TE/100 g and CUPRAC = 3475 μmol TE/100 g). In addition, the oil yield (20.92–48.86%) and antioxidant properties of BCCPO (DPPH = 2933–5894 μmol TE/100 g and TPC = 135–199 mg GAE/100 g) and BCC (DPPH = 1890–2265 μmol TE/100 g and TPC = 284–341 mg GAE/100 g) closely depended on the nozzle diameters (5, 8, and 10 mm) mounted in a screw press. Although both by-products were a rich source of antioxidants, BCM had significantly lower CUPRAC (1514 μmol TE/100 g) and TPC (92 mg GAE/100 g) values than BCC (CUPRAC = 3397 μmol TE/100 g and TPC = 426 mg GAE/100 g). Nevertheless, acid hydrolysis and alkaline hydrolysis of BCM extracts significantly increased their antioxidant potential. However, the DPPH (35,629 μmol TE/100 g), CUPRAC (12,601 μmol TE/100 g), and TPC (691 mg GAE/100 g) results were higher for the BCM extract after acid hydrolysis than those for alkaline hydrolysate (DPPH = 2539 μmol TE/100 g, CUPRAC = 5959 μmol TE/100 g, and TPC = 613 mg GAE/100 g). Finally, the generated AGREEprep metrics highlighted the sustainability and the greenness of the cold pressing of oil from BCS. Full article

Background: The oils obtained from the seeds of Nigella sativa, also named black cumin, are rich in bioactive compounds that strengthen immunity and support human health. This study aimed to compare Nigella sativa oils pressed from Egyptian (Eg-NSSO), Ethiopian (Et-NSSO), and Syrian (Sy-NSSO) seeds. Methods: The analyzed oils were obtained from a local company. The content of phenolic compounds, tocochromanols, phytosterols, volatile compounds, triglycerides, and fatty acids composition was determined using chromatographic methods. The oxidative stability was determined by Rancimat technique as well as the determination of DPPH and ABTS scavenging activity. As an assessment of bioactivity, the antimicrobial and anti-aflatoxigenic properties of oils were evaluated. Results: Ethiopian oil had highest content of phenolic compounds, flavonoids, phytosterols, and tocochromanols and was characterized by the longest induction period (IP = 7.89 h). The share of thymoquinone was the highest in Ethiopian oil (34.84%), followed by Egyptian (27.36%), then Syrian (22.59%). Ethiopian oil recorded a high antibacterial activity, while Egyptian oil showed a unique antifungal activity against toxigenic fungi. Aflatoxins’ secretion into liquid medium containing NSSO was reduced, especially with Egyptian oil. Full article

Interest in natural extracts for managing oral biofilms is increasing, with black cumin seed oil (BCSO) demonstrating efficacy against Streptococcus mutans. The effectiveness of antibacterial agents should be evaluated using multi-species oral biofilm models that closely mimic actual conditions. This study aimed to compare the antibacterial effects of BCSO and chlorhexidine gluconate (CHX) on oral microcosm biofilms. Biofilms using human saliva as the inoculum were cultured for 2 days and subsequently treated with 0.5% dimethyl sulfoxide, 0.5% BCSO, or 0.12% CHX once daily for 6 days. Following treatment, the red fluorescence intensity (Ratio_R/G) of the oral biofilm; biomass, including extracellular polymeric substance (EPS) levels and live bacteria counts; and colony-forming units (CFUs) of aciduric bacteria were evaluated. Ratio_R/G after BCSO treatment (1.26 ± 0.03) was not significantly different from that after CHX treatment (p = 0.552). The EPS levels were also not significantly different between the two groups (p = 0.743). The live bacteria count was 0.55 times lower in the BCSO-treated group than in the CHX-treated group (p = 0.018). No significant between-group difference was observed in the CFUs of aciduric bacteria (p = 0.935). These results suggest that BCSO exhibits antibacterial effects similar to those of CHX, highlighting its potential as an effective alternative. Full article

Nigella sativa (N. sativa; Ranunculaceae), commonly referred to as black cumin, is one of the most widely used medicinal plants worldwide, with its seeds having numerous applications in the pharmaceutical and food industries. With the emergence of antibiotic resistance in pathogens as an important health challenge, the need for alternative microbe-inhibitory agents is on the rise, whereby black cumin has gained considerable attention from researchers for its strong antimicrobial characteristics owing to its high content in a wide range of bioactive compounds, including thymoquinone, nigellimine, nigellidine, quercetin, and O-cymene. Particularly, thymoquinone increases the levels of antioxidant enzymes that counter oxidative stress in the liver. Additionally, the essential oil in N. sativa seeds effectively inhibits intestinal parasites and shows moderate activity against some bacteria, including Bacillus subtilis and Staphylococcus aureus. Thymoquinone exhibits minimum inhibitory concentrations (MICs) of 8–16 μg/mL against methicillin-resistant Staphylococcus aureus (MRSA) and exhibits MIC 0.25 µg/mL against drug-resistant mycobacteria. Similarly, quercetin shows a MIC of 2 mg/mL against oral pathogens, such as Streptococcus mutans and Lactobacillus acidophilus. Furthermore, endophytic fungi isolated from N. sativa have demonstrated antibacterial activity. Therefore, N. sativa is a valuable medicinal plant with potential for medicinal and food-related applications. In-depth exploration of the corresponding therapeutic potential and scope of industrial application warrants further research. Full article

Biochar derived from poultry manure increases nutrient availability and promotes plant growth. This study investigated the effect of biochar with mycorrhizal and/or plant growth-promoting rhizobacteria on soil fertility, chemical properties, oil, and seed yield of Black Cumin (Nigella sativa L.) plants. A split-plot design with three replicates was employed, with biochar derived from poultry litter (BC) applied at rates of 0, 5, and 10 t ha⁻¹, with beneficial microbes such as arbuscular mycorrhizal fungi (AMF) and plant growth-promoting rhizobacteria (PGPR) affecting the growth of Black Cumin plants, and some soil properties, such as pH, electrical conductivity (EC), soil organic matter (SOM) and fertility index (FI), showing significant differences (p ≤ 0.05) among biochar and/or bio-fertilizer treatments. All biochar treatments with or without bio-fertilizers significantly increased pH, EC, OM and FI in comparison to the control treatment. The results demonstrated that applying biochar at the highest rate (10 t ha⁻¹) increased fresh and dry capsule weights by 94.51% and 63.34%, respectively, compared to the control treatment (C). These values were significantly increased by 53.05 and 18.37%, compared to untreated plants when combined with AMF and PGPR. Furthermore, when biochar was applied in conjunction with both AMF and PGPR, fresh and dry capsule weights saw significant increases of 208.84% and 91.18%, respectively, compared to the untreated control treatment. The interaction between biochar, AMF, and PGPR significantly improved plant growth, yield, soil properties, and the fixed and volatile oil content of Black Cumin. These findings suggest that the combined application of biochar, AMF, and PGPR enhances nutrient availability and uptake, leading to improved growth and higher yields in Black Cumin plants, resulting in increased yield production. Full article

Turmeric rhizomes (Curcuma longa) and black cumin seeds (Nigella sativa) are polyherbal ingredients used for the management of cancer and other chronic inflammatory diseases in Nigerian ethnomedicine. Previous studies have shown the antioxidant, anti-inflammatory, and anticancer activities of the individual plant extracts. However, the two spices have not been biologically potentiated in their combined form. Therefore, this study obtained essential oils (EOs) from the combined spices and evaluated their inhibitory effects on free radicals, protein denaturation, and cancer proliferation. The EOs were extracted by hydro-distillation (HD) and characterized by gas chromatography-mass spectrometry (GC-MS). In vitro antioxidant assessment was conducted based on DPPH, hydrogen peroxide (H₂O₂), nitric oxide (NO), and ferric ion (Fe³⁺) radical scavenging assays. The cytotoxicity of the oil against non-tumorigenic (HEK293) and cancerous (HepG2 and HeLa) cell lines was determined following the MTT cell viability assay. An in silico molecular docking analysis of the oil constituents was also performed. Six batches of EOs I–VI were afforded, comprising twenty-two major constituents, with aromatic Ar-turmerone being the most prominent compound. There was a marked improvement in the bioactivity of the oils upon repeated HD and as a combination. The batch VI oil exhibited the best activity, with a cytotoxicity (CC₅₀) of 10.16 ± 1.69 µg/100 µL against the HepG2 cell line, which was comparable to 5-fluorouracil (standard, CC₅₀ = 8.59 ± 1.33 µg/100 µL). In silico molecular docking suggested δ-curcumene, Ar-curcumene, Ar-turmerol, and Ar-turmerone among the promising compounds based on their high binding energy scores with NOX2, NF-κB, and mdm2 proteins. In conclusion, the oils from the turmeric–black cumin combined possess a considerable inhibition ability against free radicals, protein denaturation, and cancer proliferation. This study’s findings further underscore the effectiveness of turmeric–black cumin as a polyherbal medicinal ingredient. Full article

Nigella sativa, also known as black cumin, is esteemed for its rich reservoir of health-benefitting phytoconstituents nestled within its seeds. The composition of its seeds can be influenced by factors such as genotype diversity and agricultural practices. Understanding these dynamics is important for maximizing the nutritional and medicinal attributes of the seeds. This study investigated how different genotypes, growing densities, and sowing times affect oil yield and phytoconstituents of Nigella seeds in Northern Australia. The aim was to find the optimal combination of these factors to maximize desirable compounds. Our findings revealed variability in oil yield and phytoconstituents among different genotypes, growing densities, and sowing times. No single genotype stood out as having elevated levels of all desired compounds. For instance, genotype AVTKS#5 had high total phenolic content (TPC) and antioxidant capacity, while AVTKS#8 and AVTKS#7 excelled in thymoquinone (TQ) and polyunsaturated fatty acids (PUFAs) and monounsaturated fatty acids (MUFAs), respectively. Planting density had a nuanced impact, with no significant effect on oil yield and CUPRAC values, but higher densities decreased TPC, FRAP, and TQ. Interestingly, seeds cultivated at 20 and 30 plants/m² had higher ratios of MUFAs/SFAs, PUFAs/SFAs, and (MUFAs + PUFAs)/SFAs, indicating the importance of planting density in shaping fatty acid profiles. Sowing times also had a noticeable effect, with late sowing leading to a decrease in oil yield from 19% to 14%. May-sown seeds had higher TPC, FRAP, CUPRAC, and fatty acid ratios, while TQ levels peaked in June-sown seeds. Our study highlighted positive correlations among TPC, FRAP, CUPRAC, and TQ, emphasizing their collective contribution to the nutritional and medicinal potency of Nigella seeds. Fatty acids, on the other hand, showed no significant correlation with these parameters, indicating independent regulation. In summary, our comprehensive analysis provides insights into the factors (genotype and agronomic practice) that shape the phytochemical profile of Nigella seeds, and suggests better genotype, planting density, and time of sowing for the cultivation and quality production. Full article

Nigella sativa L. (black cumin) is one of the most investigated medicinal plants in recent years. Volatile compounds like thymoquinone and unsaponifiable lipid compounds are crucial functional components of this oil. Unfortunately, the composition of oils and their quality indicators are ambiguous both in terms of identified compounds and value ranges. Thirteen oils were extracted with hexane from black cumin seeds grown in India, Syria, Egypt, and Poland and analyzed for their fatty acid composition, unsaponifiable compound content and volatile compounds. Oils were also subjected to quality tests according to standard methods. The fatty acid composition and sterol content/composition were relatively stable among the tested oils. Tocol content varied in the range of 140–631 mg/kg, and among them, β-tocotrienol and γ-tocopherol prevailed. Oils’ volatile compounds were dominated by seven terpenes (p-cymene, α-thujene, α-pinene, β-pinene, thymoquinone, γ-terpinene, and sabinene). The highest contents of these volatiles were determined in samples from Poland and in two of six samples from India. High acid and peroxide values were typical features of N. sativa L. oils. To sum up, future research on the medicinal properties of black cumin oil should always be combined with the analysis of its chemical composition. Full article

The hydrophilic–lipophilic balance (HLB) is a valuable parameter used to determine the relative hydrophobicity of a compound based on its chemical structure. This semi-empirical parameter has been instrumental in formulating oil-in-water and water-in-oil emulsions using well-characterized ingredients with known HLB values. However, recent trends toward the use of minimally processed “virgin” oils of therapeutic or nutritional value may render the reported “required HLB” values inaccurate. Minimally processed oils can contain numerous compounds at varying or unknown concentrations, rendering the HLB value incalculable. Factors such as regional source, growing season, and processing method contribute to the variability in oil composition. Furthermore, the solubilization of lipophilic bioactives in oils can significantly alter the HLB of the oil phase in a concentration-dependent manner. This complicates the formulation of emulsions, as the HLB values of both the oil phase and emulsifiers must be closely matched to achieve stable formulations. This study presents a simple and efficient experimental method to determine an HLB value of a complex ingredient without resorting to lengthy Design-of-Experiment (DoE) matrices and trial-and-error approaches. The optimal HLB of a formulation can be determined from a series of experiments in which two well-characterized surfactants of known HLB values are mixed at varying proportions with an unknown oil phase, where the HLB of the oil is considered to match the HLB value of the surfactants combined at the proportion at which nanoemulsions with the smallest, most stable oil droplets are formed. Similarly, when the HLB values of the oil phase and other contributing components are precisely known, the unknown HLB of a complex natural surfactant can be calculated. These calculations assist in formulating emulsions efficiently and effectively by ensuring optimal compatibility among all the components. Full article