An Overview on Composition and Therapeutic Potentials of the Black Seed (Nigella sativa)

Nigella sativa is an annual herbaceous plant that belongs to the Ranunculaceae family and produces seeds known as black seed or black cumin. Black seed has been used in various civilization around the world for centuries to treat various ailments. It is widely used in a variety of traditional medical systems, including Unani, Ayurveda, and Siddha. Black seed is considered to be nutritionally dense, with high levels of fat, protein, dietary fibre, calcium, and iron. The seed is known to have a wide range of pharmacological properties which are supported by numerous studies. Extensive research has been carried out over decades to confirm the seed’s anti-oxidant, anti-inflammatory, anti-microbial, anti-diabetic, anti-hypertensive, antilipidemic, anti-cancer, gastroprotective, hepatoprotective, neuroprotective properties etc. Black seed has earned a position among the top ranked evidence-based herbal medicines due to its marvellous healing properties. Studies have revealed that the presence of thymoquinone, a major bioactive component of the seed essential oil, is responsible for the majority of its therapeutic properties. Consumption of the seeds for an extended period of time has been shown to have significant effects on lowering blood glucose levels, improving lipid profiles, and other biochemical parameters. The minor or negligible toxicological effects of black seed and its active constituent, thymoquinone, support its long-term use in traditional food and medicine. Because of their low toxicity, black seed is frequently used in food as a flavouring agent, additive in breads, and pickles. The current review summarises the composition, important pharmacological studies, dosage and toxicity of the Blackseed and its application in food industry.

Impact of Replacing Soybean Meal with Sunflower Meal, Sesame Meal, and Black Seed Meal in diets of Barki Lambs

Crude protein content in animal diet is considered the first important factor for nutritionists when they start to formulate a diet for different types of animals. Therefore, this experiment was conducted to investigate the effect of substituting soybean seed meal by different protein sources on lamb’s diet in terms of nutrients digestibility, and growth performance. Therefore, four tested concentrate feed mixtures (CFM, 14% crude protein) were designed. The CFM1 contained soybean meal as the only source of protein, and 50% of soybean meal protein was replaced by either sunflower meal, sesame seed meal, or black seed meal in CFM2, CFM3, and CFM4 groups, respectively. A total of 28 growing Barki male lambs aged 6 months with an average body weight of 38.6 ± 0.4 Kg were used in feeding trials for 120 days. Depending on their body weight, lambs were divided into four groups (7 animals in each). Each group fed on one of the experimental diets, including D1 (CFM1+ clover hay), D2 (CFM2 + clover hay), D3 (CFM3 + clover hay), and D4 (CFM4 + clover hay). Results of digestion coefficients indicted that the digestibility of crude protein and the nitrogen-free extract was significantly higher for D1 and D4, compared to D2 and D3. The same trend was observed in nutritive values expressed as total digestible nutrients (TDN) and digestible crude protein (DCP), whereas the D1 and D4 recorded higher TDN and DCP, compared to D2 and D3. Results of rumen parameters demonstrated that there were insignificant differences among groups regarding the average pH, ammonia (NH3-N), and total volatile fatty acids (TVFAs). Data of growth performance indicated that the final live body weight, total body gain, and average daily gain of lambs feed D4 (56.75 kg, 18.62 kg, and 155 g, respectively) and D1 (56.62 kg, 17.60 kg, and 147 g, respectively) were higher than those for lambs fed D2 (53.40 Kg, 14.64 kg, and 122 g, respectively) and D3 (53.11 kg, 14.61 kg, and 122 g, respectively). The feed conversion ratio (feed/gain) was recorded better value with lambs fed D4 followed by that fed D1. In conclusion, black seed meal could be replaced with the 50% of soybean meal participation of protein in growing Barki lambs’ diets without any adverse effects on digestibility, rumen kinetics, and growth performance.

Antioxidant potential and low-density lipoprotein cholesterol (LDL-c) uptake of the black seed and honey mixture on human hepatocellular carcinoma (HepG2) cells

High lipid levels especially low-density-lipoprotein cholesterol (LDL-c) are associated with increased risk of cardiovascular (CVD) and coronary heart disease (CHD). Both black seed (Nigella sativa L.) and honey are well-known in the hypolipidemic potential and have CVD protective effects. In the present study, LDL-c uptake of the black seed and honey mixture was tested on HepG2 cells. Antioxidant activities of black seed and honey mixtures were determined through the 2, 2’-diphenyl-1-picrylhydrazyl (DPPH) assay. The anticancer potential of black seed and honey mixtures in HepG2 cells was performed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) cytotoxicity assay. Black seed possessed the highest antioxidant activities with EC50 6.54 mg/mL as compared to honey with EC50 value 9.56 mg/mL while the black seed and honey mixture have EC50 between black seed and honey. From the results obtained, no synergistic effect was observed in the mixtures as the EC50 values were within the range of black seed and honey. Furthermore, no significant difference (p>0.05) among ratios (1:1, 2:1 and 1:2). However, the decrease in cell proliferation was the highest in black seed and honey mixture at 1:1 ratio (p<0.05) than individually treated black seed and honey. Thus, the black seed and honey mixture at ratio 1:1 was the most potent anticancer agent with an IC50 value of 7.44 μg/mL. The present study illustrated that black seed and honey mixtures possess a lipid-lowering effect via LDL-c uptake in HepG2 cells (p<0.05). The highest LDL-c uptake was observed at 15 μg/mL with the treatment of black seed and honey mixture at 1:2 ratio which was 294.4%. Further studies should be conducted on primary human liver cells to further justify the correlation between the antioxidant level and LDLc uptake mechanism of black seed and honey mixtures.

GC-MS, FTIR and Antiulcer Screening of Aqueous Seed Extract and Oil of Nigella sativa in Wistar Rats

Peptic ulcer disease (PUD) is a sore in the lining of the stomach or duodenal mucosa. This study was aimed at evaluating the antiulcer activity of the aqueous extract of Nigella sativa (black seed) and its constitutents. The pharmacognostic properties of the dry seeds were determined. The seeds were extracted using two methods digestion and hydro-distillation. The acute toxicity, phytochemical constituents and the antiulcer evaluation were performed on ethanol-induced ulcer in wistar rats using a standard method. FTIR and GC-MS analysis of the aqueous seed extract was also determined using standard methods. Nigella sativa seed shows the presence of starch grains, lignified tissues, tannins, cellulose, protein and oil globules. The aqueous extract has a high safety margin. The phytochemical studies revealed the presence of saponins, flavonoids, alkaloids, tannins, glycosides, fats and oil. The black seed aqueous and oil extract at 500 mg/kg significantly reduced the acidity, total acidity, and ulcer index, and pH of gastric content when compared with the positive control (Famotidine). The FTIR analysis identified the presence of the following functional groups chloro, ether, amine, carboxylic acid, nitriles, methylene, alcohol, while the GC-MS identified five compounds such as glycerin, n-Hexadecanoic acid, 9, 12-octadecadienoic acid-methyl ester, 9, 12-octadecadienoic acid and 9, 12-octadecadienoyl chloride. The pharmacognostic properties can act as a reliable tool for the standardization of the plant part. This study suggests that aqueous and oil extract possess antiulcer properties. Thus the aqueous and oil extract of black seed can be considered as antiulcer medication traditionally. Keywords: Nigella sativa, Black seed, Pharmacognostic, Phytochemical, Acute toxicity (LD50), Antiulcer.

Clopidogrel-Herb Interactions: A Pharmacokinetic and Pharmacodynamic Assessment in a Rat Model

Background: Herbs usually contain a mixture of biologically active constituents, which can interact with numerous prescribed drugs and alter their safety profiles. Objective: The current investigation was aimed to evaluate the effect of commonly used herbal products, including black seed (Nigella sativa), garden cress (Lepidium sativum), and fenugreek (Trigonella foenum-graecum), on the pharmacokinetics and pharmacodynamics of clopidogrel using a Wistar rat model. Methods: A GC-MS analysis revealed the presence of several phytoconstitutents (polyphenols) in the extracts of the black seed, garden cress, and fenugreek. These polyphenols have the potential to interfere with the clopidogrel effect. Plasma concentrations of clopidogrel were measured at different time points in the absence and presence of the concurrent use of tested herbal products and the pharmacokinetic parameters were calculated. Bleeding time was measured in various groups as a measure of the antiplatelet effect of clopidogrel. Results: Area under the plasma concentration-time curves (AUC0-∞) of clopidogrel were 35.53 ±0.89 µg/ml*h (p<0.05), 26.01 ±0.90 µg/ml*h (p>0.05) and 32.80 ±2.51 µg/ml*h (p<0.05) in the black seed, garden cress and fenugreek group, respectively, compared with that of the control group (27.02 ±0.42 µg/ml*h). Treatment with black seed also caused an increase in clopidogrel Cmax by 31.52% (p<0.05) and with fenugreek by 21.42% (p<0.05); Cmax, did not changed with garden cress treatment (6.48 ±0.15 µg/ml versus 6.12 ±0.21 µg/ml, p>0.05). The pharmacodynamic evaluation of the antiplatelet effect of clopidogrel in the presence of herbal products treatment showed a significant prolongation in the bleeding time from a control baseline by ~22-26%, and by added ~8-12% about clopidogrel therapeutic effect (p<0.05). The concurrent use of black seed, fenugreek, or garden cress can alter the pharmacokinetics and pharmacodynamics of clopidogrel to varying degrees due to the presence of various bioactive polyphenols. Conclusion: This is probably due to changes in drug disposition and its antiplatelet action. Further confirmation can determine the clinical relevance of these observations and identify the exact constituents responsible for such activities.