Identification, validation and quantification of thymoquinone in conjunction with assessment of bioactive possessions and GC-MS profiling of pharmaceutically valuable crop Nigella (Nigella sativa L.) varieties.

Background: Plants have been pivotal in traditional and modern medicine globally, with historical evidence supporting their therapeutic applications. Nigella (Nigella sativa L.) is an annual herbaceous plant of the Ranunculaceae family and is cultivated in the Middle East, Eastern Europe, and Western and Central Asia. The medicinal use of plants dates back thousands of years, documented in ancient writings from various civilizations. Alkaloids, phenolics, saponins, flavonoids, terpenoids, anthraquinones, and tannins found in plants exhibit antioxidant, immunomodulatory, anti-inflammatory, anticancer, antibacterial, and antidiabetic activities. Methodology: This study specifically examines the pharmacological potential of Nigella sativa L., emphasizing thymoquinone-a compound with diverse nutraceutical benefits. The extraction, characterization, and quantification of thymoquinone, alongside other physicochemical parameters, were carried out using ethanol through Soxhlet extraction procedures on five nigella varieties. HPLC analysis was performed to determine the maximum accumulation of thymoquinone in the released variety of the plant and the chemical composition of the seed oil isolated from Nigella sativa L., varieties utilized in the study was determined through GC-MS analysis. Results: The research revealed that the Ajmer nigella-20 variety stands out, exhibiting elevated levels of thymoquinone (0.20 ± 0.07%), antioxidants (76.18 ± 1.78%), and substantial quantities of total phenols (31.85 ± 0.97 mg GAEg-1 seed) and flavonoids (8.150 ± 0.360 mg QE 100 g-1 seed) compared to other varieties. The GC-MS profiling showed the presence of 11 major compounds in the studied varieties, with p-cymene, longifolene, and myristic acid identified as the major chemical compounds present in the oil. Conclusion: The observed variations among Nigella varieties indicate the Ajmer nigella-20 variety as particularly promising for thymoquinone and bioactive compound extraction. This study underscores Nigella's potential as a source of pharmacologically active compounds, highlighting the need for further exploration in therapeutic applications.

Long-range electron proton coupling in respiratory complex I - insights from molecular simulations of the quinone chamber and antiporter-like subunits.

Respiratory complex I is a redox-driven proton pump. Several high-resolution structures of complex I have been determined providing important information about the putative proton transfer paths and conformational transitions that may occur during catalysis. However, how redox energy is coupled to the pumping of protons remains unclear. In this article, we review biochemical, structural and molecular simulation data on complex I and discuss several coupling models, including the key unresolved mechanistic questions. Focusing both on the quinone-reductase domain as well as the proton-pumping membrane-bound domain of complex I, we discuss a molecular mechanism of proton pumping that satisfies most experimental and theoretical constraints. We suggest that protonation reactions play an important role not only in catalysis, but also in the physiologically-relevant active/deactive transition of complex I.

Relationship of Cytotoxic and Antimicrobial Effects of Triphenylphosphonium Conjugates with Various Quinone Derivatives.

Quinone derivatives of triphenylphosphonium have proven themselves to be effective geroprotectors and antioxidants that prevent oxidation of cell components with participation of active free radicals - peroxide (RO2·), alkoxy (RO·), and alkyl (R·) radicals, as well as reactive oxygen species (superoxide anion, singlet oxygen). Their most studied representatives are derivatives of plastoquinone (SkQ1) and ubiquinone (MitoQ), which in addition to antioxidant properties also have a strong antibacterial effect. In this study, we investigated antibacterial properties of other quinone derivatives based on decyltriphenylphosphonium (SkQ3, SkQT, and SkQThy). We have shown that they, just like SkQ1, inhibit growth of various Gram-positive bacteria at micromolar concentrations, while being less effective against Gram-negative bacteria, which is associated with recognition of the triphenylphosphonium derivatives by the main multidrug resistance (MDR) pump of Gram-negative bacteria, AcrAB-TolC. Antibacterial action of SkQ1 itself was found to be dependent on the number of bacterial cells. It is important to note that the cytotoxic effect of SkQ1 on mammalian cells was observed at higher concentrations than the antibacterial action, which can be explained by (i) the presence of a large number of membrane organelles, (ii) lower membrane potential, (iii) spatial separation of the processes of energy generation and transport, and (iv) differences in the composition of MDR pumps. Differences in the cytotoxic effects on different types of eukaryotic cells may be associated with the degree of membrane organelle development, energy status of the cell, and level of the MDR pump expression.

N-methyl-D-aspartate receptors and thymoquinone induce apoptosis and alteration in mitochondria in colorectal cancer cells.

Colon cancer is on the rise in both men and women. In addition to traditional treatment methods, herbal treatments from complementary and alternative medicine are actively followed. Naturally derived from plants, thymoquinone (TQ) has drawn a lot of attention in the field of cancer treatment. MK-801, an N-methyl-D-aspartate agonist, is used to improve memory and plasticity, but it has also lately been explored as a potential cancer treatment. This study aimed to determine the roles of N-Methyl-D-Aspartate agonists and Thymoquinone on mitochondria and apoptosis. HT-29 cells were treated with different TQ and MK-801 concentrations. We analyzed cell viability, apoptosis, and alteration of mitochondria. Cell viability significantly decreased depending on doses of TQ and MK-801. Apoptosis and mitochondrial dysfunctions induced by low and high doses of TQ and MK-801. Our study emphasizes the need for further safety evaluation of MK-801 due to the potential toxicity risk of TQ and MK-801. Optimal and toxic doses of TQ and MK-801 were determined for the treatment of colon cancer. It should be considered as a possibility that colon cancer can be treated with TQ and MK-801.

Self-micellizing solid dispersion of thymoquinone with enhanced biopharmaceutical and nephroprotective effects.

The present study was designed to develop a self-micellizing solid dispersion (SMSD) containing Thymoquinone (TQM), a phytonutrient obtained from Nigella sativa seeds, aiming to improve its biopharmaceutical and nephroprotective functions. The apparent solubility of TQM in polymer solutions was used to choose an appropriate amphiphilic polymer that could be used to make an SMSD system. Based on the apparent solubility, Soluplus® was selected as an appropriate carrier, and mixing with TQM, SMSD-TQM with different loadings of TQM (5-15%) was made by solvent evaporation and freeze-drying techniques, respectively, and the formulations were optimized. The optimized SMSD-TQM was evaluated in terms of particle size distribution, morphology, release characteristics, pharmacokinetic behavior, and nephroprotective effects in a rat model of acute kidney injury. SMSD-TQM significantly improved the dissolution characteristics (97.8%) of TQM in water within 60 min. Oral administration of SMSD-TQM in rats exhibited a 4.9-fold higher systemic exposure than crystalline TQM. In a cisplatin-induced (6 mg/kg, i.p.) acute kidney-damaged rat model, oral SMSD-TQM (10 mg/kg) improved the nephroprotective effects of TQM based on the results of kidney biomarkers and histological abnormalities. These findings suggest that SMSD-TQM might be efficacious in enhancing the nephroprotective effect of TQM by overcoming biopharmaceutical limitations.

Effects of 5-fluorouracil, thymoquinone, and mammary stem cells' exosomes on in vitro cultured breast cancer cells.

Background: 5-fluorouracil (5-FU) is an antimetabolic agent used for treating slowly growing solid tumors like breast and ovarian carcinoma. Thymoquinone (TQ) is the main biologically active constituent of Nigella sativa, it has been found to demonstrate anticancerous effects in several preclinical studies, and this is because TQ possesses multitarget nature. Stem cells-derived exosomes are in the spotlight of research and are promising tissue regenerative and anticancer cell-derived nanovesicles. Aim: Herein, we studied the antineoplastic effects of Exosomes derived from mammary stem cells (MaSCs-Exo) on breast cancer cells, alone or combined with TQ when compared to a breast cancer chemotherapeutic agent; 5-FU. Methods: Our approach included performing viability test and measuring the expression of pro-apoptotic gene (Bax), anti-apoptotic gene (BCL-2) and angiogenic gene (VEGF) on Human MCF-7 cells (breast adenocarcinoma cells), the MCF-7 cells were cultured and incubated with medium containing 5-FU (25 µg/ml), TQ (200 µg/ml), MaSCs-Exo (100 µg protein equivalent), a combination of TQ (200 µg/ml) and MaSCs-Exo (100 µg). Results: Our obtained results show that TQ and MaSCs-Exo each can effectively inhibit breast cancer cell line (MCF-7) proliferation and growth. Also, the results show that the combination of TQ and MaSCs-Exo had higher cytotoxic effects on MCF-7 breast cancer cells than TQ or 5-FU, alone. Conclusion: The present study shows a promising anticancer potential of exosomes isolated from mammary stem cells; this effect was potentiated by adding TQ with MaSCs-derived exosomes.

Thymoquinone is a natural antibiofilm and pathogenicity attenuating agent in Pseudomonas aeruginosa.

Pseudomonas aeruginosa belongs to the critical pathogens that represent a global public health problem due to their high rate of resistance as listed by WHO. P. aeruginosa can result in many nosocomial infections especially in individuals with compromised immune systems. Attenuating virulence factors by interference with quorum sensing (QS) systems is a promising approach to treat P. aeruginosa-resistant infections. Thymoquinone is a natural compound isolated from Nigella sativa (black seed) essential oil. In this study, the minimum inhibitory concentration of thymoquinone was detected followed by investigating the antibiofilm and antivirulence activities of the subinhibitory concentration of thymoquinone against P. aeruginosa PAO1. The effect of thymoquinone on the expression of QS genes was assessed by quantitative real-time PCR, and the protective effect of thymoquinone against the pathogenesis of PAO1 in mice was detected by the mouse survival test. Thymoquinone significantly inhibited biofilm, pyocyanin, protease activity, and swarming motility. At the molecular level, thymoquinone markedly downregulated QS genes lasI, lasR, rhlI, and rhlR. Moreover, thymoquinone could protect mice from the pathologic effects of P. aeruginosa increasing mouse survival from 20% to 100%. In conclusion, thymoquinone is a promising natural agent that can be used as an adjunct therapeutic agent with antibiotics to attenuate the pathogenicity of P. aeruginosa.

Tumoricidal properties of thymoquinone on human colorectal adenocarcinoma cells via the modulation of autophagy.

Colorectal cancer (CRC) is deadly anaplastic changes in the gastrointestinal tract with high-rate mortality. In recent years, the application of phytocompounds has been extended along with different therapeutic protocols. Here, we monitored the effects of Thymoquinone (TQ) on autophagy via mitochondrial function after modulation of the Wnt/ß-catenin signaling pathway.Human colorectal adenocarcinoma HT-29 cells were treated with TQ (60 µM) and 15 µM Wnt3a inhibitor (LGK974) for 48 h. The survival rate was evaluated using an MTT assay. The expression of Wnt-related factors (c-Myc, and Axin), angiogenesis (VE-Cadherin), and mitophagy-related factors (PINK1, OPTN) was assessed using real-time PCR assay. Protein levels of autophagy factors (Beclin-1, LC3, and P62) were monitored using western blotting. Using flow cytometry analysis, the intracellular accumulation of Rhodamine 123 was evaluated. The migration properties were analyzed using a scratch wound healing assay.Data indicated that TQ can reduce the viability of HT-29 cells compared to the control cells (p < 0.05). The expression of VE-Cadherin was inhibited while the expression of PINK1 was induced in treated cells (p < 0.05). Both LGK974 and TQ-treated cells exhibited activation of autophagy flux (Beclin-1↑, LC3II/I↑, and p62↓) compared to the control group (p < 0.05). TQ can increase intracellular accumulation of Rhodamine 123, indicating the inhibition of efflux mechanisms in cancer cells. Along with these changes, the migration of cells was also reduced (p < 0.05).TQ is a potential phytocompound to alter the dynamic growth of human colorectal HT-29 cells via the modulation of autophagy, and mitophagy-related mechanisms.

Thymoquinone protects thioacetamide-induced chronic liver injury by inhibiting TGF-ß1/Smad3 axis in rats.

Chronic liver injury due to various etiological factors results in excess secretion and accumulation of extracellular matrix proteins, leading to scarring of liver tissue and ultimately to hepatic fibrosis. If left untreated, fibrosis might progress to cirrhosis and even hepatocellular carcinoma. Thymoquinone (TQ), an active compound of Nigella sativa, has been reported to exhibit antioxidant, anti-inflammatory and anticancer activities. Therefore, the effect of TQ against thioacetamide (TAA)-induced liver fibrosis was assessed in rats. Fibrosis was induced with intraperitoneal administration of TAA (250 mg/kg b.w.) twice a week for 5 weeks. TQ (20 mg/kg b.w.) and silymarin (50 mg/kg b.w.) were orally administered daily for 5 weeks separately in TAA administered groups. Liver dysfunction was reported by elevated liver enzymes, increased oxidative stress, inflammation and fibrosis upon TAA administration. Our study demonstrated that TQ inhibited the elevation of liver marker enzymes in serum. TQ administration significantly increased antioxidant markers, such as superoxide dismutase, catalase, glutathione, glutathione peroxidase and glutathione reductase in the liver tissue of rats. Further, TQ significantly attenuated liver fibrosis, as illustrated by the downregulation of TAA-induced interleukin-ß, tumour necrosis factor-α, inducible nitric oxide synthase and fibrosis markers like transforming growth factor-ß (TGF-ß), α-smooth muscle actin, collagen-1, Smad3 and 7. Therefore, these findings suggest that TQ has a promising hepatoprotective property, as indicated by its potential to effectively suppress TAA-induced liver fibrosis in rats by inhibiting oxidative stress and inflammation via TGF-ß/Smad signaling.

The Role of Sargahydroquinoic Acid and Sargachromenol in the Anti-Inflammatory Effect of Sargassum yezoense.

The anti-inflammatory effect of the ethanol extract of Sargassum yezoense and its fractions were investigated in this study. The ethanol extract exhibited a strong anti-inflammatory effect on lipopolysaccharide-stimulated RAW 264.7 macrophages and effectively suppressed the M1 polarization of murine bone-marrow-derived macrophages stimulated by lipopolysaccharides and IFN-γ (interferon-gamma). Through a liquid-liquid extraction process, five fractions (n-hexane, chloroform, ethyl acetate, butanol, and aqueous) were acquired. Among these fractions, the chloroform fraction (SYCF) was found to contain the highest concentration of phenolic compounds, along with two primary meroterpenoids, sargahydroquinoic acid (SHQA) and sargachromenol (SCM), and exhibit significant antioxidant capacity. It also demonstrated a robust anti-inflammatory effect. A direct comparison was conducted to assess the relative contribution of SHQA and SCM to the anti-inflammatory properties of SYCF. The concentrations of SHQA and SCM tested were determined based on their relative abundance in SYCF. SHQA contributed to a significant portion of the anti-inflammatory property of SYCF, while SCM played a limited role. These findings not only highlight the potential of the chloroform-ethanol fractionation approach for concentrating meroterpenoids in S. yezoense but also demonstrate that SHQA and other bioactive compounds work additively or synergistically to produce the potent anti-inflammatory effect of SYCF.

Electrochemical Analysis for Total Alkalinity of Water by the Measurement of Cathodic Prepeak of Quinone Caused by Surplus Acid.

In this study, an electrochemical analysis, coupled with the concept of back neutralization titration and the voltammetric determination of surplus acid, is proposed for determining the total alkalinity of water samples. When linear sweep voltammetry of 3,5-di-tert-butyl-1,2-benzoquinone (DBBQ) with H2SO4 in a water and ethanol (44 : 56, v/v) mixture was carried out using a bare glassy carbon working electrode, a cathodic prepeak of DBBQ caused by H2SO4 was observed on the voltammogram at a more positive potential than when compared with the original cathodic peak of DBBQ. When similar voltammetry was carried out in the presence of Na2CO3 and H2SO4, the cathodic prepeak height of DBBQ was decreased with an increase in the Na2CO3 concentration. The decrease of the cathodic prepeak height of DBBQ was found to be linearly related to the Na2CO3 concentration ranging from 0.025 to 2.5 mM (r2 = 0.998). The total equivalent concentrations of inorganic bases in samples of mineral water and tap water were determined, and then the results were converted to the total alkalinities of the water samples (mg/L CaCO3). The total alkalinities of the water samples determined by the present electrochemical analysis were essentially the same compared with those by the neutralization titration method. From these results, we were able to demonstrate that the present electrochemical analysis with accuracy and precision could be applied to determine the total alkalinity, which is one of the indicators to examine water quality. The present electrochemical analysis would contribute to achieving the sustainable development goals (SDGs) of #6 and #14.

Mixture toxicity of 6PPD-quinone and polystyrene nanoplastics in zebrafish.

Plastic pollution, including micro- and nanoplastics, is a growing concern. Tyre-wear particles (TWPs) are the second largest source of microplastics in the ocean following abrasion of synthetic fibres. In addition to the particles themselves, TWPs contain many harmful chemicals, including 6PPD. This chemical reacts with atmospheric ozone and forms the toxic compound 6PPD-quinone (6PPDq), which poses a danger to aquatic life. There is a knowledge gap in understanding risks associated with the combined toxicity of nanoplastics (NPs) and 6PPDq. The present study aimed to investigate the toxicity of NPs and 6PPDq on adult zebrafish using phenotypic (behaviour, histology) and transcriptomic endpoints. Zebrafish were exposed to four treatments: control (contaminant-free), 50 µg/L 6PPDq, 3 mg/L polystyrene (PS)-NPs, and a combination of 50 µg/L 6PPDq and 3 mg/L PS-NPs. We did not observe locomotory dysregulation in zebrafish exposed to NPs. However, we found significant hyperlocomotion in zebrafish exposed to 6PPDq and this effect was even more substantial after co-exposure with PS-NPs. This study explores the molecular mechanisms behind these effects, identifying genes associated with neurotransmitters and fatty acid metabolism that were dysregulated by the co-exposure. Transcriptomic analysis further showed that both 6PPDq and PS-NPs impacted cellular processes associated with sterol biosynthesis, cholesterol metabolism, and muscle tissue development. The effects on these mechanisms were stronger in co-exposed zebrafish, indicating a heightened risk to cellular integrity and mitochondrial dysfunction. These results highlight the significance of mixture toxicity when studying the effects of NPs and associated chemicals like 6PPDq.

Fragmentation Pattern-Based Screening Strategy Combining Diagnostic Ion and Neutral Loss Uncovered Novel para-Phenylenediamine Quinone Contaminants in the Environment.

Identifying transformed emerging contaminants in complex environmental compartments is a challenging but meaningful task. Substituted para-phenylenediamine quinones (PPD-quinones) are emerging contaminants originating from rubber antioxidants and have been proven to be toxic to the aquatic species, especially salmonids. The emergence of multiple PPD-quinones in various environmental matrices and evidence of their specific hazards underscore the need to understand their environmental occurrences. Here, we introduce a fragmentation pattern-based nontargeted screening strategy combining full MS/All ion fragmentation/neutral loss-ddMS2 scans to identify potential unknown PPD-quinones in different environmental matrices. Using diagnostic fragments of m/z 170.0600, 139.0502, and characteristic neutral losses of 199.0633, 138.0429 Da, six known and three novel PPD-quinones were recognized in air particulates, surface soil, and tire tissue. Their specific structures were confirmed, and their environmental concentration and composition profiles were clarified with self-synthesized standards. N-(1-methylheptyl)-N'-phenyl-1,4-benzenediamine quinone (8PPD-Q) and N,N'-di(1,3-dimethylbutyl)-p-phenylenediamine quinone (66PD-Q) were identified and quantified for the first time, with their median concentrations found to be 0.02-0.21 µg·g-1 in tire tissue, 0.40-2.76 pg·m-3 in air particles, and 0.23-1.02 ng·g-1 in surface soil. This work provides new evidence for the presence of unknown PPD-quinones in the environment, showcasing a potential strategy for screening emerging transformed contaminants in the environment.

Toxicity of substituted p-phenylenediamine antioxidants and their derived novel quinones on aquatic bacterium: Acute effects and mechanistic insights.

Substituted para-phenylenediamines (PPDs) are synthetic chemicals used globally for rubber antioxidation, with their quinone derivatives (PPD-Qs) raising particular environmental concerns due to their severe toxicity to aquatic organisms. Emerging research has identified a variety of novel PPD-Qs ubiquitously detected in the environment, yet experimental proof for the toxicity of PPD-Qs has not been forthcoming due to the unavailability of bulk standards, leaving substantial gaps in the prioritization and mechanistic investigation of such novel pollutants. Here, we use synthesized chemical standards to study the acute toxicity and underlying mechanism of 18 PPD-Qs and PPDs to the aquatic bacterium V. fischeri. Bioluminescence inhibition EC50 of PPD-Qs ranged from 1.76-15.6 mg/L, with several emerging PPD-Qs demonstrating significantly higher toxicity than the well-studied 6PPD-Q. This finding suggests a broad toxicological threat PPD-Qs pose to the aquatic bacterium, other than 6PPD-Q. Biological response assays revealed that PPD-Qs can reduce the esterase activity, cause cell membrane damage and intracellular oxidative stress. Molecular docking unveiled multiple interactions of PPD-Qs with the luciferase in V. fischeri, suggesting their potential functional impacts on proteins through competitive binding. Our results provided crucial toxicity benchmarks for PPD-Qs, prioritized these novel pollutants and shed light on the potential toxicological mechanisms.

Thymoquinone potentiates anti-cancer effects of cisplatin in oral squamous cell carcinoma via targeting oxidative stress.

Recent evidence has proved that thymoquinone as a natural polyphenol has great anticancer and anti-proliferative effects in cancer cells. In this study, we aimed to examine the effects of thymoquinone on increasing cisplatin-induced apoptosis human oral squamous cell carcinoma cells and its underlying molecular mechanisms. SCC-25 cancer cells treated by thymoquinone and cisplatin with different concentrations. Cell viability will determine by using MTT assay. The concentrations of reactive oxygen species (ROS) and antioxidant activities were determined using specific related kits. DNA damage, lipid, and protein oxidation were assessed. Real-time PCR and Western blot analysis will be used to determine the expression of apoptosis-related proteins including Bax, Bcl-2, and caspase-3. Combination of thymoquinone and cisplatin suppressed synergistically SCC-25 cancer cell viability and induced apoptosis in dose-depended manner. Cell treatment with combination of thymoquinone and cisplatin led to accumulation of ROS within cells and increase in the intracellular levels of DNA damage, protein and lipid peroxidation. In addition, the combination of thymoquinone and cisplatin modulated the mRNA and protein expression levels of apoptosis-related proteins including Bax, Bcl-2, and caspase-3. Thymoquinone potentiated cisplatin anti-cancer effect on OSCC by inducing oxidative stress in cells.

Investigating anti-cancer activity of dual-loaded liposomes with thymoquinone and vitamin C.

Background: Thymoquinone (TQ) and vitamin C (Vit C) have demonstrated individual anticancer effects in various studies. TQ exhibits inhibitory properties against tumor growth, induces apoptosis, while Vit C protects against DNA damage and oxidative stress. Aim: Formulation of TQ and Vit C combination into liposomes using two methods and investigate the synergistic anticancer. Method: Liposomal preparations were characterized, and the purity of drug components was confirmed using encapsulation efficiency (EE %). Results: In vitro cell viability studies demonstrated the inhibitory effect of TQ and Vit C against colorectal (HT29, 5.5 ± 0.9 µM) and lung cancer (A549, 6.25 ± 0.9 µM) cell lines with combination index <1. Conclusion: The formulation of TQ and Vit C displayed synergistic anticancer activity.

Exploring MTH1 inhibitory potential of Thymoquinone and Baicalin for therapeutic targeting of breast cancer.

Cancers frequently have increased ROS levels due to disrupted redox balance, leading to oxidative DNA and protein damage, mutations, and apoptosis. The MTH1 protein plays a crucial role by sanitizing the oxidized dNTP pools. Hence, cancer cells rely on MTH1 to prevent the integration of oxidized dNTPs into DNA, preventing DNA damage and allowing cancer cell proliferation. We have discovered Thymoquinone (TQ) and Baicalin (BC) as inhibitors of MTH1 using combined docking and MD simulation approaches complemented by experimental validations via assessing binding affinity and enzyme inhibition. Docking and MD simulations studies revealed an efficient binding of TQ and BC to the active site pocket of the MTH1, and the resultant complexes are appreciably stable. Fluorescence measurements estimated a strong binding affinity of TQ and BC with Ka 3.4 ×106 and 1.0 ×105, respectively. Treating breast cancer cells with TQ and BC significantly inhibited the growth and proliferation (IC50 values 28.3 µM and 34.8 µM) and induced apoptosis. TQ and BC increased the ROS production in MCF7 cells, imposing substantial oxidative stress on cancer cells and leading to cell death. Finally, TQ and BC are proven strong MTH1 inhibitors, offering promising prospects for anti-cancer therapy.

Development and Characterization of Transdermal Patches Using Novel Thymoquinone-L-Arginine-Based Polyamide Nanocapsules for Potential Use in the Management of Psoriasis.

Thymoquinone (TQ) is a phytochemical compound present in Nigella sativa and has potential benefits for treating dermatological conditions such as psoriasis. However, its clinical use is limited due to its restricted bioavailability, caused mainly by its low solubility and permeability. To overcome this, a new transdermal drug delivery system is required. Nanoparticles are known to enhance material solubility and permeability, and hence, this study aimed to synthesize TQ-loaded L-arginine-based polyamide (TQ/Arg PA) nanocapsules incorporated into transdermal patches for prolonged delivery of TQ. To achieve this, Eudragit E polymer, plasticizers, and aloe vera as penetration enhancer were used to develop the transdermal patch. Furthermore, novel TQ/Arg-PA was synthesized via interfacial polymerization, and the resultant nanocapsules (NCs) were incorporated into the matrix transdermal patch. The Arg-PA NCs' structure was confirmed via NMR and FTIR, and optimal TQ/Arg-PA NCs containing formulation showed high entrapment efficiency of TQ (99.60%). Molecular and thermal profiling of TQ/Arg-PA and the transdermal patch revealed the effective development of spherical NCs with an average particle size of 129.23 ± 18.22 nm. Using Franz diffusion cells and synthetic membrane (STRAT M®), the in vitro permeation profile of the prepared patches demonstrated an extended release of TQ over 24 h, with enhanced permeation by 42.64% when aloe vera was employed. In conclusion, the produced formulation has a potential substitute for corticosteroids and other drugs commonly used to treat psoriasis due to its effectiveness, safety, and lack of the side effects typically associated with other drugs.

Variation in the Composition and Quality of Nigella sativa L. Seed Oils-The Underestimated Impact on Possible Health-Promoting Properties.

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, ß-tocotrienol and γ-tocopherol prevailed. Oils' volatile compounds were dominated by seven terpenes (p-cymene, α-thujene, α-pinene, ß-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.

Structure-based investigation of pyruvate dehydrogenase kinase-3 inhibitory potential of thymoquinone, targeting lung cancer therapy.

Protein kinases are an attractive therapeutic target for cardiovascular, cancer and neurodegenerative diseases. Cancer cells demand energy generation through aerobic glycolysis, surpassing "oxidative phosphorylation" (OXPHOS) in mitochondria. The pyruvate dehydrogenase kinases (PDKs) have many regulatory roles in energy generation balance by controlling the pyruvate dehydrogenase complex. Overexpression of PDKs is associated with the overall survival of cancer. PDK3, an isoform of PDK is highly expressed in various cancer types, is targeted for inhibition in this study. PDK3 has been shown to binds strongly with a natural compound, thymoquinone (TQ), which is known to exhibit anti-cancer potential. Detailed interaction between the PDK3 and TQ was carried out using spectroscopic and docking methods. The overall changes in the protein's structures after TQ binding were estimated by UV-Vis spectroscopy, circular dichroism and fluorescence binding studies. The kinase activity assay was also carried out to see the kinase inhibitory potential of TQ. The enzyme inhibition assay suggested an excellent inhibitory potential of TQ towards PDK3 (IC50 = 5.49 µM). We observed that TQ forms a stable complex with PDK3 without altering its structure and can be a potent PDK3 inhibitor which may be implicated in cancer therapy after desired clinical validation.