Structural Diversity, Spectral Data, and Pharmacological Effects of Genus Nigella.

Nigella is one of the most studied plants because of its pharmacological properties like anti-parasitic, anti-inflammatory, neuro-protective, hepatoprotective, and anti-cancerous. In this study, about 20 species of the genus Nigella were reviewed and among them, N. damascene, N. glandulifera, and N. sativa are widely studied for their phytochemical and pharmacological effects. This review describes the phytochemical composition of the genus Nigella, which constitutes many of the compounds including alkaloids, flavonoids, saponins, and terpenoids. The extracts produced by using different solvents and the isolated compounds displayed a wide range of biological activity. These compounds were identified by different spectral techniques. The spectral detail of some advanced techniques including EIS-MS, UV/VIS, IR, 13 C-NMR, and 1 H-NMR of some important phytoconstituents of Nigella spp. has been compiled for the first time in this review which will be helpful to explore and further investigate the chemical composition of this genus.

Biological Properties, Phenolic Profile, and Botanical Aspect of Nigella sativa L. and Nigella damascena L. Seeds: A Comparative Study.

The use of Nigella seeds in the food, pharmaceutical, and cosmetic fields is common, since the iniquity and the virtues of these plants are directly related to their characteristic phytochemical composition. This investigation focused on the comparative study of the botanical aspect, phenolic profile, and in vitro and in vivo biological activities of Nigella sativa L. (NS) and Nigella damascena L. (ND) seeds. The macro- and micro-morphological properties of these seeds were studied, and the key dissimilarities between them were clearly illustrated. The phytochemical contents and phenolic profiles were determined, and the in vitro antioxidant activity was assessed using four methods. The in vivo antioxidant and biochemical parameters of the blood of supplemented mice were determined. The results of the macro- and micro-structure analysis revealed differences between the two plants. Here, ND is characterized by higher phytochemical contents and the best antioxidant activities. The HPLC analysis indicated the presence of nine compounds, namely seven phenolic acids, particularly hydroxybenzoic and caffeic acids, and two flavonoids. The administration of ND extract to mice for 21 days at a concentration of 500 mg/kg allowed a substantial amelioration of plasma antioxidant properties. In addition, the extracts ameliorate blood parameters (cholesterol, triglycerides, glycemia, and urea). Furthermore, the antimicrobial activity of extracts demonstrated their effects on Staphylococcus and Aspergillus. Nigella seeds, in particular ND, expressed considerable in vitro antioxidant properties and demonstrated significant amelioration of mice blood properties. Consequently, these species can serve as a valuable source of compounds with various applications.

Biological Potentials and Phytochemical Constituents of Raw and Roasted Nigella arvensis and Nigella sativa.

Nigella species are widely used to cure various ailments. Their health benefits, particularly from the seed oils, could be attributed to the presence of a variety of bioactive components. Roasting is a critical process that has historically been used to facilitate oil extraction and enhance flavor; it may also alter the chemical composition and biological properties of the Nigella seed. The aim of this study was to investigate the effect of the roasting process on the composition of the bioactive components and the biological activities of Nigella arvensis and Nigella sativa seed extracts. Our preliminary study showed that seeds roasted at 50 °C exhibited potent antimicrobial activities; therefore, this temperature was selected for roasting Nigella seeds. For extraction, raw and roasted seed samples were macerated in methanol. The antimicrobial activities against Streptococcus agalactiae, Streptococcus epidermidis, Streptococcus pyogenes, Candida albicans, Escherichia coli, Enterobacter aerogenes, Klebsiella pneumoniae, and Klebsiella oxytoca were determined by measuring the diameter of the zone of inhibition. The cell viability of extracts was tested in a colon carcinoma cell line, HCT-116, by using a microculture tetrazolium technique (MTT) assay. Amino acids were extracted and quantified using an automatic amino acid analyzer. Then, gas chromatography-mass spectrometry (GC-MS) analysis was performed to identify the chemical constituents and fatty acids. As a result, the extracts of raw and roasted seeds in both Nigella species showed strong inhibition against Klebsiella oxytoca, and the raw seed extract of N.arvensis demonstrated moderate inhibition against S. pyogenes. The findings of the MTT assay indicated that all the extracts significantly decreased cancer cell viability. Moreover, N. sativa species possessed higher contents of the measured amino acids, except tyrosine, cystine, and methionine. The GC-MS analysis of extracts showed the presence of 22 and 13 compounds in raw and roasted N. arvensis, respectively, and 9 and 11 compounds in raw and roasted N. sativa, respectively. However, heat treatment decreased the detectable components to 13 compounds in roasted N. arvensis and increased them in roasted N. sativa. These findings indicate that N. arvensis and N. sativa could be potential sources of anticancer and antimicrobials, where the bioactive compounds play a pivotal role as functional components.

Potential herb-drug interaction risk of thymoquinone and phenytoin.

Thymoquinone is a main bioactive compound of Nigella sativa L. (N.sativa), which has been used for clinical studies in the treatment of seizures due to its beneficial neuroprotective activity and antiepileptic effects. It has been evidenced that thymoquinone may inhibit the activity of cytochrome P450 2C9 (CYP2C9). However, little is known about the effect of thymoquinone or N.sativa on the pharmacokinetic behavior of phenytoin, a second-line drug widely used in the management of status epilepticus. In this study, we systematically investigated the risk of the potential pharmacokinetic drug interaction between thymoquinone and phenytoin. The inhibitory effect of thymoquinone on phenytoin hydroxylation activity by CYP2C9 was determined using UPLC-MS/MS by measuring the formation rates for p-hydroxyphenytoin (p-HPPH). The potential for drug-interaction between thymoquinone and phenytoin was quantitatively predicted by using in vitro-in vivo extrapolation (IVIVE). Our data demonstrated that thymoquinone displayed effective inhibition against phenytoin hydroxylation activity. Enzyme kinetic studies showed that thymoquinone exerted a competitive inhibition against phenytoin hydroxylation with a Ki value of 4.45 ± 0.51 µM. The quantitative prediction from IVIVE suggested that the co-administration of thymoquinone (>18 mg/day) or thymoquinone-containing herbs (N.sativa > 1 g/day or N.sativa oil >1 g/day) might result in a clinically significant herb-drug interactions. Additional caution should be taken when thymoquinone or thymoquinone-containing herbs are co-administered with phenytoin, which may induce unexpected potential herb-drug interactions via the inhibition of CYP2C9.

Saponins from Nigella glandulifera seeds attenuate collagen-induced rheumatoid arthritis in rats via the OPG/RANKL/NF-κB and Ang/Tie-2 pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Nigella glandulifera Freyn et Sint. (N. glandulifera) seeds are widely used in traditional Uyghur medicine for a variety of immuno-inflammatory diseases. The total saponins from N. glandulifera seeds (TSNGS) have been shown to have analgesic, antioxidant, and anti-inflammatory effects that can alleviate joint pain and swelling. AIM OF THE STUDY: Rheumatoid arthritis (RA) is a chronic and progressive, debilitating autoimmune disease for which current treatments are not sufficiently effective and result in unsatisfactory side effects. This study aimed to mechanistically investigate the therapeutic effects of TSNGS on RA. MATERIALS AND METHODS: Qualitative analysis of TSNGS was performed using ultra-high-performance liquid chromatography-Q-Orbitrap-high-resolution mass spectrometry. Rats with collagen-induced arthritis (CIA), IL-1ß-induced HFLS-RAs, and VEGF-induced HUVECs were analyzed to determine the efficacy and mechanism of TSNGS on RA. RESULTS: Twenty-one compounds were identified in TSNGS. TSNGS (10, 50, or 250 mg/kg) reduced the severity of arthritis, indicated by a lower arthritis score, reduced paw swelling, and body weight in rats with CIA. TSNGS ameliorated histopathological changes involving inflammatory infiltration, bone degeneration, and angiogenesis in knee and ankle joints. TSNGS improved the immuno-inflammatory response by restoring the levels of the cytokines IFN-γ, TNF-α, IL-1ß, IL-6, IL-17A, IL-4, and IL-10, and increasing the number of CD4+CD25+ Tregs in the peripheral circulation and Foxp3 levels in knee joints in rats with CIA. Furthermore, TSNGS increased the OPG/RANKL ratio and downregulated p-p65 in serum and joint synovia. Inhibition of angiogenesis by TSNGS was associated with recovery of the angiogenesis-related Ang/Tie-2 signaling pathway. CONCLUSIONS: It was established that TSNGS provides a therapeutic effect on RA by alleviating synovitis, bone degeneration, and angiogenesis via the OPG/RANKL/NF-κB and Ang/Tie-2 pathways and may be used for the treatment of RA.

Nigella and Milk Thistle Seed Oils: Potential Cytoprotective Effects against 7ß-Hydroxycholesterol-Induced Toxicity on SH-SY5Y Cells.

Oxysterols are assumed to be the driving force behind numerous neurodegenerative diseases. In this work, we aimed to study the ability of 7ß-hydroxycholesterol (7ß-OHC) to trigger oxidative stress and cell death in human neuroblastoma cells (SH-SY5Y) then the capacity of Nigella sativa and Milk thistle seed oils (NSO and MTSO, respectively) to oppose 7ß-OHC-induced side effects. The impact of 7ß-OHC, associated or not with NSO or MTSO, was studied on different criteria: cell viability; redox status, and apoptosis. Oxidative stress was assessed through the intracellular reactive oxygen species (ROS) production, levels of enzymatic and non-enzymatic antioxidants, lipid, and protein oxidation products. Our results indicate that 7ß-OHC (40 µg/mL) exhibit pr-oxidative and pro-apoptotic activities shown by a decrease of the antioxidant enzymatic activities and an increase of ROS production, lipid, and protein oxidation end products as well as nitrotyrosine formation and caspase 3 activation. However, under the pre-treatment with NSO, and especially with MTSO (100 µg/mL), a marked attenuation of oxidative damages was observed. Our study suggests harmful effects of 7ß-OHC consisting of pro-oxidative, anti-proliferative, and pro-apoptotic activities that may contribute to neurodegeneration. NSO and especially MTSO showed potential cytoprotection against the cytotoxicity of 7ß-OHC.

Chitosan coated synergistically engineered nanoemulsion of Ropinirole and nigella oil in the management of Parkinson's disease: Formulation perspective and In vitro and In vivo assessment.

The research presented aims at developing Ropinirole hydrochloride (RHCl) nanoemulsion (NE) with nigella oil for Parkinson's disease (PD). In silico study was done to explore interactions of ropinirole and thymoquinone at receptor site (TNF-α and NFK-ß). Ropinirole and Thymoquinone forms a hydrogen bond with residue Arginine 201 and residue Arginine 253 with a bond length of 1.89 Å and 2.30 Å at the NF-κß receptor. NE was optimized using Central Composite Rotatable Design (CCRD). The globule size of chitosan coated NE, Polydispersity index (PDI) and zeta potential were 183.7 ± 5.2 nm, 0.263 ± 0.005, and 24.9 mV respectively. NE exhibited 85.28% transmittance showing the formulation was clear and transparent. TEM showed that NE had spherical globules with no aggregation. The formulation had a stable pH value of 5.8 ± 0.18. In vitro release and permeation studies exhibited 2 folds and 3.4 folds enhancement when compared with the drug suspension. Neurobehavioral activity and biochemical parameters corroborated well with the pharmacokinetic results. Histopathological study and immunohistochemical analysis were performed to get better picture of 6-OHDA induced toxicity and reversal of PD symptoms. Thus, the NE tailored is a promising synergistic approach yielding enticing outcomes for better management of PD related symptoms.

Vapors of Volatile Plant-Derived Products Significantly Affect the Results of Antimicrobial, Antioxidative and Cytotoxicity Microplate-Based Assays.

Volatile plant-derived products were observed to exhibit broad spectrum of biological effects. However, due to their volatility, results of conventional microplate-based bioassays can be significantly affected by the vapors. With aim to demonstrate this phenomenon, antimicrobial, antioxidant, and cytotoxic activities of three essential oils (Alpinia elegans, Cinnamomum iners, and Xanthostemon verdugonianus), one supercritical CO2 extract (Nigella sativa), and four plant-derived compounds (capsaicin, caryophyllene oxide, 8-hydroxyquinoline, and thymoquinone) were evaluated in series of experiments including both ethylene vinyl acetate (EVA) Capmat sealed and nonsealed microplates. The results clearly illustrate that vapor transition to adjoining wells causes false-positive results of bioassays performed in nonsealed microtiter plates. The microplate layout and a duration of the assay were demonstrated as the key aspects defining level of the results affection by the vapors of volatile agents. Additionally, we reported biological activities and chemical composition of essential oils from A. elegans seeds and X. verdugonianus leaves, which were, according to our best knowledge, analyzed for the first time. Considering our findings, certain modifications of conventional microplate-based assays are necessary (e.g., using EVA Capmat as vapor barrier) to obtain reliable results when biological properties of volatile agents are evaluated.

Profile of Fatty Acids, Tocopherols, Phytosterols and Polyphenols in Mediterranean Oils (Argan Oils, Olive Oils, Milk Thistle Seed Oils and Nigella Seed Oil) and Evaluation of their Antioxidant and Cytoprotective Activities.

BACKGROUND: The effects of vegetable oils on human health depend on their components. Therefore, their profiles of lipid nutrients and polyphenols were determined. OBJECTIVE: To establish and compare the fatty acid, tocopherol, phytosterol and polyphenol profiles of Mediterranean oils: cosmetic and dietary argan oils (AO; Morocco: Agadir, Berkane); olive oils (OO; Morocco, Spain, Tunisia); milk thistle seed oils (MTSO; Tunisia: Bizerte, Sousse, Zaghouane); nigella seed oil (NSO). METHODS: The biochemical profiles were determined by gas chromatography-flame ionization, high performance liquid chromatography and gas chromatography, coupled with mass spectrometry as required. The antioxidant and cytoprotective activities were evaluated with the KRL (Kit Radicaux Libres) and the fluorescein diacetate tests on nerve cells treated with 7-ketocholesterol (7KC). RESULTS: The fatty acid profile revealed high linoleic acid (C18:2 n-6) content in AO, OO, MTSO and NSO. The highest levels of oleic acid (C18:1 n-9) were found in AO and OO. The tocopherol profile showed that Agadir AO contained the highest amount of α-tocopherol, also present at high level in MTSO and Tunisian OO; Berkane AO was rich in γ-tocopherol. The phytosterol profile indicated that ß-sitosterol was predominant in the oils, except AO; spinasterol was only present in AO. Polyphenol profiles underlined that OO was the richest in polyphenols; hydroxytyrosol was only found in OO; few polyphenols were detected in AO. The oils studied have antioxidant activities, and all of them, except NSO, prevented 7KC-induced cell death. The antioxidant characteristics of AO were positively correlated with procatechic acid and compestanol levels. CONCLUSION: Based on their biochemical profiles, antioxidant and cytoprotective characteristics, AO, OO, and MTSO are potentially beneficial to human health.

Formulation evaluation of ketoconazole microemulsion-loaded hydrogel with nigella oil as a penetration enhancer.

BACKGROUND: Onychomycosis is an opportunistic fungal infection often infecting people with compromised immune system. Currently available treatment interventions such as physical, surgical, and chemical-based approaches are successful in treating the condition, however, are painful and nonpatient complaint. Moreover, dermal creams with antifungal agents do not penetrate nail plate as required; hence, there is a necessity of developing a novel formulation with enhanced penetration. AIMS: The aim of the present research work was to develop ketoconazole microemulsion-loaded hydrogel formulation containing nigella oil as permeation enhancer for the treatment of onychomycosis. METHODS: Screening of oils, surfactants, and cosurfactants were done based on solubility studies followed by the construction of pseudo-ternary phase diagrams with 2% ketoconazole. The microemulsion was characterized for globule size, zeta potential, viscosity, and thermodynamic stability. Ex-vivo studies were carried out using Franz diffusion cells using porcine skin membrane. The antifungal activity of microemulsion-loaded hydrogel was evaluated using cup plate method using Candida albicans and Aspergillus niger. RESULTS: The optimized microemulsion had a composition of 54.97% Capryol:Nigella (2:1), 36.07% Transcutol:Propylene glycol (2:1), and 7.13% water and was later incorporated into polymeric gel base. The microemulsion-loaded hydrogel exhibited a 10 hours sustained release profile as compared to the marketed cream and an enhanced activity against marketed ketoconazole cream and compared with marketed ketoconazole formulation. CONCLUSION: The thermodynamic stability, sustained drug release with greater permeation, and enhanced activity due to the presence of nigella oil in microemulsion-loaded hydrogel warrant its application as an excellent vehicle for treating fungal infections.

In Vitro Human Dihydroorotate Dehydrogenase Inhibitory, Anti-inflammatory and Cytotoxic Activities of Alkaloids from the Seeds of Nigella glandulifera.

Four new dolabellane-type diterpene alkaloids, glandulamines A - D (1:  - 4: ), together with twelve known compounds (5:  - 16: ), were isolated from the seeds of Nigella glandulifera using repeated column chromatography and semipreparative HPLC. The structures of 1:  - 16: were elucidated based on NMR data analysis, HRMS experiments and other spectroscopic interpretations. The absolute configuration of 5: was determined by single-crystal X-ray diffraction data for the first time. Compounds 10: and 12: showed human dihydroorotate dehydrogenase inhibitory activity with IC50 values of 61.1 ± 5.3 and 45.9 ± 3.0 µM, respectively. Molecular docking of the active compound 12: and positive control teriflunomide on the inhibitor-binding site of human dihydroorotate dehydrogenase was subsequently performed to visualize the interaction pattern. In addition, compounds 8: and 10: exhibited inhibitory effects against lipopolysaccharide-induced nitric oxide production with inhibition rates of 61 and 41%, respectively, at the concentration of 10 µM. Compounds 9: and 12: showed cytotoxic activities with cell viability varying from 29 ~ 57% at 100 µM against T98G, U87, U251, and GL261 glioma cancer cell lines. These data provide new insights on the pharmacologically active compounds of this plant widely used in folk medicine.

Green approach for synthesis of gold nanoparticles from Nigella arvensis leaf extract and evaluation of their antibacterial, antioxidant, cytotoxicity and catalytic activities.

In the present work, we studied the reduction of gold ions into gold nanoparticles using Nigella arvensis leaf extract in the one-step green synthesis method. The formation of N. arvensis gold nanoparticles (NA-GNPs) was confirmed by UV-Vis spectroscopy, XRD, FT-IR and TEM analyses. The XRD pattern confirmed the crystal structure of NA-GNPs, and TEM image showed the small size (3-37 nm) and almost spherical shape of NA-GNPs. NA-GNPs have not shown enhanced antioxidant properties compared to the plant extract while they were active against the clinical isolated bacterial strains. These nanoparticles showed the cytotoxicity effects against H1299 and MCF-7 cancer cell lines with an IC50 value of 10 and 25 µg/ml, respectively. The extract of N. arvensis contained 212 µg/ml flavonoids and 145 µg/ml phenolic compounds. The contents of total phenolics and flavonoids of biosynthesized NA-GNPs were 68 and 189 µg/ml, respectively. Plant extract and NA-GNPs exhibited a maximum DPPH scavenging activity of 32% and 12%, respectively. The catalytic activity of NA-GNPs against methylene blue was 44%. In conclusion, these results suggest that NA-GNPs can act as a promising candidate for different medical applications produced by cost-effective, eco-friendly and straightforward green method.

Protective effects of traditional Uighur medicine-seeds of Nigella glandulifera Freyn extracts against ccl4-induced acute hepatic injury in mice.

To explore the protective effects of Traditional Uighur medicine Seeds of Nigella glandulifera Freyn (SNF) extracts against CCl4-induced acute hepatic injury in mice. Hepatic injury mice models induced by intraperitoneal injection of 0.1% CCl4 olive oil were established. Liver and spleen coefficient, Serum ALT and AST activities, SOD, GSH-Px activities and MDA content in hepatic homogenate were measured and the hepatic histological changes were observed by optical microscope. Serum activities of ALT (P<0.01) and AST (P<0.05) in Alcohol extraction group was decreased; Activity of hepatic homogenate SOD increased in Alcohol extraction group and Water extraction group significantly (P<0.05). Content of MDA was decreased in Alcohol extraction group (P<0.01). Water extracts of SNF have obvious protective effects on hepatic injury induced by CCl4 in mice.

Nigegladines A-C, Three Thymoquinone Dimers from Nigella glandulifera.

Nigegladines A-C (1-3), three thymoquinone dimers, were isolated from the seeds of Nigella glandulifera. Racemic 1 possesses a unique tricyclo[5.4.0.12,6]dodecane carbon skeleton, and compounds 2 and 3 are two unusual diterpenoid alkaloids with indole cores. Their structures were determined by extensive spectroscopic analyses, and that of 1 was confirmed by single-crystal X-ray diffraction. Both (+)-1 and (-)-1 exhibited significant protective effects against hypoxia/reoxygenation-induced H9c2 myocardial cell injury.

Molecular characterization and bio-functional property determination using SDS-PAGE and RP-HPLC of protein fractions from two Nigella species.

This study aimed to investigate the molecular and bio-functional properties of protein fractions from Nigella damascena and Nigella arvensis, including the albumin, globulin, glutein-1, glutein-2 and prolamin fractions. Protein subunits were not observed in globulin and prolamin fractions. No peaks appeared in RP-HPLC chromatograms of globulin for either species. Two predominant peaks were observed in the RP-HPLC profiles of all protein fractions. Proteins separated by RP-HPLC have potential inhibitory and antioxidant activities in all fractions. Optimum ACE-inhibitory and antioxidant activities of proteins separated by RP-HPLC were observed in glutein-2 and albumin, respectively, for both species. For pepsin and combined pepsin-trypsin hydrolyses, the highest degree of hydrolysis (DH) was obtained in glutein-2 fraction of Nigella arvensis. Highest ACE-inhibitory activity of hydrolyzed protein fractions was found at 4h via pepsin hydrolysis in globulin fraction of Nigella damascena. Highest antioxidant activities of hydrolyzed protein fractions were found in glutelin-2 for both species.

Three new alkaloids from the seeds of Nigella glandulifera.

Three new alkaloids namely 8-(4-hydroxyphenyl)-6-methoxy-3,4-dihydroisoquinolin-1(2H)-one (1), 4-aminonigellidine (2), and N-[(4-hydroxy-2-isopropyl-5-methyl)]phenylurea (3), along with six known ones (4-9), were isolated from the seeds of Nigella glandulifera. The structures of 1-3 were determined through spectroscopic analyses (HRESIMS, 1D/2D NMR). Compound 1 was a rare isoquinolinone alkaloid with phenyl substituted at C-8.

Effects of Thymoquinone on the Pharmacokinetics and Pharmacodynamics of Glibenclamide in a Rat Model.

Glibenclamide and thymoquinone plasma concentrations were analysed using a sensitive RP-HPLC method, and non-compartmental model pharmacokinetic parameters were calculated. The maximum reduction in blood glucose level was observed 3 hours following glibenclamide administration, which reached 47.4% of baseline, whereas it was reduced by 53.0% to 56.2% when co-administrated with thymoquinone. Plasma concentration of glibenclamide was increased by 13.4% and 21.8% by the co-administration of thymoquinone as single and multiple doses, respectively (P<0.05). The AUC and TI/2 of glibenclamide were also increased respectively by 32.0% and 17.4% with a thymoquinone single dose, and by 52.5% and 92.8% after chronic treatment. Furthermore, diabetic rats treated with thymoquinone demonstrated a marked decrease in hepatic protein expressions of CYP3A2 and CYP2C 11 enzymes that are responsible for the metabolism of glibenclamide. The current data suggest that thymoquinone exhibits a synergistic effect with glibenclamide on glucose level, which could be explained by reducing CYP450 activity at the protein level.

New phenolic compounds from the seeds of Nigella glandulifera and their inhibitory activities against human cancer cells.

Four phenolic compounds, including two new ones, Nigephenol A and B (1-2), and a new natural product, Nigephenol C (3), were isolated from the seeds of Nigella glandulifera. Their structures were elucidated on the basis of spectroscopic analyses using HR-ESI-MS, 1D and 2D NMR spectra. All compounds were evaluated by MTT method for in vitro cytotoxicity against four human cancer cell lines (Bel7402, HepG2, HCT-8 and A549). The results revealed that Compounds 1-4 showed more selective activities against HepG2 cells, and that Compound 2 showed significant inhibitory effects against four human tumor cell lines with IC50 values comparable to those of 5-fluorouracil.

Physicochemical and phytochemical standardization with HPTLC fingerprinting of Nigella sativa L. seeds.

This study was designed to perform the physicochemical and phytochemical standardization with HPTLC fingerprinting of Nigella sativa seeds in order to establish the standard pharmacognostical parameters of this miracle herb. Different parameters like extractive values; total ash value, acid insoluble ash value and water soluble ash value, moisture content, loss on drying, pH values of Nigella sativa seeds were performed. Preliminary phytochemical screening was done to detect different phytoconstituents by using the Harborne's phytochemical methods. Quantification of phenolic and flavonoid contents, determination of pesticides residues, aflatoxin and heavy metals were also carried out. HPTLC fingerprinting of methanolic extract was performed using CAMAG-HPTLC system connected with win CAT software. Preliminary phytochemical screening of the extracts in different solvent revealed the presence of carbohydrates, phenolic compounds, flavonoids, alkaloids, proteins, saponins, lipids, sterols and tannins. Total flavonoid and phenolic contents in methanolic extract was found to be 1.4 mg/gm and 9.8 mg/gm extract respectively. Concentrations of heavy metals were found within acceptable limits. Pesticides residues and aflatoxins were not detected. The physicochemical and phytochemical standards along with HPTLC fingerprint profile established as an outcome of this research may be utilized as substantial data for identification, purification and standardization of Nigella sativa seeds.

Development and validation of liquid chromatography-tandem mass spectrometry method for quantification of a potential anticancer triterpene saponin from seeds of Nigella glandulifera in rat plasma: application to a pharmacokinetic study.

Nigella glandulifera Freyn et Sit is a folk medicinal plant, whose seeds show significant anticancer activities attributed to triterpene saponins and volatile oil. In this study, an in vitro cytotoxicity assay demonstrated that Nigella A, the major component of triterpene saponins extracted from N. glandulifera, exhibited growth inhibition in the human lung carcinoma A-549 cell line. Due to this potential activity, a reliable liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify Nigella A in rat plasma for a pharmacokinetic study was developed. Nigella A and pravastatin, as internal standard (IS), were extracted from rat plasma using acetonitrile to precipitate protein. Separation was performed on an Agilent Zorbax SB-Aq (3.0 × 150 mm, 3.5 µm) column using a gradient elution method with acetonitrile-0.1% formic acid in water at a flow rate of 0.35 mL/min. Detection was performed using an electrospray ionization in a negative ion multiple reaction monitoring mode. The deprotonated precursor to product ion transitions monitored for Nigella A and IS was at m/z 1352.7→882.6 and m/z 423.1→321.0, respectively. The linear range was 0.240-120 µg/mL with a square regression coefficient (r=0.9996). The intra-day and inter-day precision was less than 6.93%. The simple extraction procedure provided recovery ranged from 92.32 to 95.44% for both analyte and IS. The method was proved to be reliable, precise, and accurate, and was successfully applied to a pharmacokinetic study of Nigella A in rats after i.v. administration via the tail vein at doses of 10, 20, and 30 mg/kg.