The protective role of dietary black cumin (Nigella sativa L.) oil against waterborne boric acid in Nile tilapia (Oreochromis niloticus): hematological, biochemical, oxidative stress, and histopathological responses

This study was conducted to investigate the effects of dietary black cumin (Nigella sativa L.) oil on growth performance, hemato‐biochemical, and histopathology of cypermethrin‐intoxicated Nile tilapia. After determining the LC50 (96 h) value of cypermethrin, cypermethrin was added to the water at a ratio of 1:20 of this concentration, and the fish were fed for 42 days. To reduce the effects of cypermethrin, 1% black cumin oil was added to the fish feed as a potential protectant. Growth parameters, hematology, blood biochemistry, and histopathological changes of Nile tilapia were examined after the feeding period. In this study, the best growth was observed in the group fed with feed containing 1% black cumin oil, while the worst growth performance was observed in the group fed with water containing cypermethrin and without black cumin oil in the feed. As a result of the study, it was observed that black cumin oil added to the fish diet reduced the negative effects of water‐borne cypermethrin on growth, hematology, blood biochemistry, and histopathological parameters of Nile tilapia.

ABSTRACTIntroduction: Black cumin (Nigella sativa) oil is a natural antibacterial product containing thymoquinone. Thymoquinone is a powerful antibacterial substance towards gram-positive bacteria. The research objective was to compare the inhibitory effects of black cumin oil, Cresophene® and Ca(OH)2 towards the growth of Staphylococcus aureus. Methods: Experimental laboratory by taking Staphylococcus aureus from deciduous teeth pulp necrosis that has been isolated in Brain-Heart Infusion (BHI) medium. Inhibitory of black cumin oil, Cresophene® and Ca(OH)2 were measured by making three different 6 mm diameter wells contained each substances. Data then analyzed by two-way ANOVA using statistical analysis program. Results: Cresophene® had the largest inhibitory zone with the average zone was 32 ± 0.05mm and stable from the 1st day until the 4th day then decreased on the 5th day and remain stable until the 7th day. Ca(OH)2 had average inhibitory zone of 15.9 ± 0:10 mm and remain stable from the 1st day until the 7th day. Black cumin oil had average inhibitory zone of ± 7.9 ± 0.2 mm and remain stable from the 1st day until the 7th day. Conclusion: The inhibitory zone towards Staphylococcus aureus isolated from deciduous teeth pulp necrosis consecutively was Cresophene®, Ca(OH)2 and black cumin oil.Keywords: Staphylococus aureus, Black cumin oil, Cresophene®, Ca(OH)2, Inhibitory zone

The pathogenesis and treatment of ulcerative colitis remain poorly understood. The aim of the present study is to investigate the effects of black cumin (Nigella sativa) oil on rats with colitis. Experimental colitis was induced with 1 mL trinitrobenzene sulfonic acid (TNBS) in 40% ethanol by intracolonic administration with 8-cm-long cannula under ether anesthesia to rats in colitis group and colitis + black cumin oil group. Rats in the control group were given saline at the same volume by intracolonic administration. Black cumin oil (BCO, Origo "100% natural Black Cumin Seed Oil," Turkey) was given to colitis + black cumin oil group by oral administration during 3 days, 5 min after colitis induction. Saline was given to control and colitis groups at the same volume by oral administration. At the end of the experiment, macroscopic lesions were scored and the degree of oxidant damage was evaluated by colonic total protein, sialic acid, malondialdehyde, and glutathione levels, collagen content, and tissue factor, superoxide dismutase, and myeloperoxidase activities. Tissues were also examined by histological and cytological analysis. Proinflammatory cytokines [tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, and IL-6], lactate dehydrogenase activity, and triglyceride and cholesterol levels were analyzed in blood samples. We found that black cumin oil decreased the proinflammatory cytokines, lactate dehydrogenase, triglyceride, and cholesterol, which were increased in colitis. BCO, by preventing inflammatory status in the blood, partly protected colonic tissue against experimental ulcerative colitis.

In this study, effects of red (Palisada perforata and Gracilaria corticata), brown (Sargassum angustifolium and Polyclada indica) and green (Ulva compressa and Caulerpa taxifolia) Persian Gulf seaweed extracts on thermal kinetic parameters of black cumin (Nigella sativa) oil was investigated in comparison with those of BHT and α-tocopherol. Oxidative stability of black cumin oil samples were investigated using Rancimat at 363, 383, and 403 K. Apart from P. indica extract, all other seaweed extracts were effective on improving oxidative stability indices of black cumin oil samples. Red seaweed extracts were the most effective in reducing the severity of temperature-related effects on black cumin oil oxidation rate. In addition, these antioxidants were able to reduce black cumin oil oxidation by forming an activated complex with more structured configuration. The extent of decrease in frequency factor and entropy were 80.77% and 14.83% for G. corticata extract, respectively and also 82.66% and 15.45% for P. perforata extract, respectively. The highest increase in Gibbs free-energy of activation was observed for G. corticata extract followed by BHT, P. perforata extract, and α-tocopherol. In conclusion, red seaweed extracts can be proposed as suitable sources of natural antioxidants for improving oxidation kinetic of black cumin oil.

Rheumatoid Arthritis (RA) is a complex autoimmune disorder involving chronic and persistent inflammation, principally influencing the synovial joints which further prompting the obliteration of articular cartilage. Although black cumin (Nigella sativa) oil has already studied for its anti-arthritic properties, the current study was focused on the comparative evaluation of the antioxidant and anti-inflammatory properties of a thymoquinone (TQ)-rich (5% w/v) black cumin oil (BQ) with the commonly available standard black cumin oil (BM) containing 0.4% (w/v) TQ, and subsequent investigation on the potential application of BQ in the management of RA. Adjuvant-induced arthritis (AA) was instigated by a single intradermal infusion of 0.1 mL of Complete Freund's adjuvant (CFA) on the paw of adult Wistar rats. Based on the primary dose-response study using the carrageenan-induced paw edema model, 50 mg/kg b.wt. of BQ was employed for the treatment. The endogenous antioxidants (SOD, Catalase, GPx, and GSH), pro-inflammatory cytokines (COX-2, Nitrate, iNOS, TNF-α, IL-6), lipid peroxidation, and histopathology were evaluated to monitor the influence of BQ in AA rats. Adjuvant-induced animals showed a critical downregulation in antioxidant status with elevated levels of pro-inflammatory cytokines and lipid peroxidation. But, the treatment with BQ significantly reversed the antioxidant and inflammatory markers with downregulation of the pro-inflammatory gene expressions. Histopathology showed a significant reduction in the massive cell infiltration and epidermal edema of the paw tissue in AA rats when administered with BQ and indicated its potential effect to alleviate RA conditions in experimental rats.

Garlic (Allium sativum) and Black Cumin (Nigella sativa) oils have been used for centuries in traditional medicine and as food ingredients, due to their numerous health benefits and nutritional worth. This study aimed to carry out a comparative analysis of the phytochemical, physicochemical, and proximate composition of garlic and black cumin oils. Soxhlet extraction method using hexane was used for extracting the oil. Phytochemical screening was conducted using standard methods. Physicochemical, antinutritional and proximate analysis were done by standard methods. The qualitative phytochemical analysis revealed the presence of flavonoids, terpenoids, phenols, saponins, steroids and glycosides. Proximate analysis, revealed the nutrients as: moisture (6.57-7.12%), crude ash (1.33.-7.39%), crude protein (7.87-20.3%), crude fat (0.52.-31.4%), crude fibre (0.73-2.03%) and carbohydrate (18.06-19.7%). Antinutritional factors were recorded with values: oxalate (3.4-5.5%), alkaloids (5.4-6.3%) and phytic acid (6.7- 8.3%). Physicochemical analysis showed these values: free fatty acid (2.10-7.34%), acid value (4.18-12.93 mg/g), saponification value (192-190.35 mgKOH), pH value (6.64-6.03), iodine value (12.69-120.65mg/g) and colour (whitish to blackish). Phytochemicals in the oils may be responsible for its use in treatment of diseases. The study highlights the potential health benefits of Garlic and Black Cumin oils, particularly in the prevention and treatment of diseases such as diabetes, hypertension, and cancer.

A series of five different oils from Turkish black cumin ( Nigella sativa ) used in foods mainly for their flavour, preservation and natural therapies were screened for their antibacterial effects at 0.5 %, 1.0 % and 2.0 % concentrations using the agar diffusion method against twenty four pathogenic, spoilage and lactic acid bacteria (LAB). All tested oils showed antibacterial activity against all the bacteria used in the assay. The oils at 2.0 % concentration were more effective than of the other concentrations. The most sensitive bacterium against all of the oil concentrations was Aeromonas hydrophila, while the most resistant was Yersinia enterocolitica. Generally, lactic acid bacteria had more resistance than pathogenic and spoilage bacteria against black cumin oils. Consequently, black cumin oil may be used as an antimicrobial agent in food products to prevent spoilage.

Blends (5%, 10% and 20%, w/w) of cold-pressed black cumin (Nigella sativa) oil (BCO) with sunflower oil (SO) were formulated. Oxidative stability (OxS) of SO and blends during storage at thermal accelerated oxidation conditions including Rancimat method (110C) and Schaal oven test (60C) was studied. Progression of oxidation was followed by measuring peroxide value (PV), conjugated dienes (CD) and conjugated trienes (CT). Changes in the volatile oxidation compounds, thymoquinone and tocopherols levels of oils and blends during thermal oxidation were also recorded. Blending did not affect significantly the fatty acids profile of blends wherein linoleic and oleic acids were the main constituents. Inverse relationships were noted between PV and OxS at termination of storage. Levels of CD and CT in SO and blends increased with increase in time. Nine volatile oxidation compounds including hexanal, (E)-2-hexenal, 2-heptanone, (E)-2-heptenal, 1-octen-3-one, 1-octen-3-ol, (E)-2-octenal, (E,E)-2,4-octadienal and (E,E)-2,4-decadienal were identified using the headspace/solid phase microextraction-gas chromatography/mass spectrometry (HS/SPME-GC/MS). Hexanal and (E)-2-heptenal were predominant identified compounds wherein these compounds increased during oxidation at 60C. Stability of blends was better than SO, most likely due to changes in the levels of thymoquinone and tocopherols’ found in BCO. Practical Application Blending of edible oils have emerged as an economical way of improving organoleptic and physicochemical characteristics of vegetable oils besides enhancement the oxidative stability. Among new sources of edible oils with high levels of bioactive compounds, cold pressed black cumin oil (BCO) is of interest and may play a role in human health. At different levels of blending SO with BCO, the stability of sunflower oil (SO) was enhanced. The optimal level of BCO enrichment will depend on the actual food application. It is expected that commercial exploitation of BCO:SO blends with affordable cost for consumers will be soon realized.

The present study was aimed to assess the effect of black cumin (Nigella sativa) oil on serum lipid profile and β-hydroxy, β-methylglutaryl coenzyme-A reductase (HMG CoA reductase) gene expression in adult layer birds. Thirty six weeks old White Leg Horn (WLH) layer birds were randomly divided into five groups consisting of 6 birds each. Their diets were supplemented with 0 (control), 1.0, 2.0, 3.0 and 4.0 g black cumin oil kg−1 feed, respectively. Blood samples were collected on day 0, 14, 28, 42 and 56 and study further continued for one more month without supplementing the diet with herbal preparations in order to observe the withdrawal effect. Gene expression studies of HMG CoA reductase were carried out in the liver tissue of the birds by real time quantitative PCR analysis on day 56. Serum total lipids, cholesterol, tri-glycerides, HDL, LDL and VLDL-cholesterol varied highly significantly (p 3> 2> 1> 0 g cumin oil kg−1 feed. The study revealed that the supplementation of black cumin oil @ 4 g kg−1 feed is most effective in reducing serum lipid profile and HMG CoA reductase gene expression after 56 days. These effects gradually reduced with time after the withdrawal of oil.

Edam cheese samples were prepared with the addition of different concentrations of black cumin (Nigella sativa L) oil (0.2, 0.4 and 0.6 % v/w). Significant differences (P≤0.05) in chemical composition and ripening indices among treated cheese sample (0.6 % oil) and control was observed in all examined parameters. The added black cumin oil increased cheese acidity from 0.79 % in control to 1.13 % in cheese with 0.6 % oil at fresh time, with continuously increase in all cheese samples during ripening. Soluble nitrogen/Total Nitrogen reached 15.91 % in cheese with higher level of black cumin oil at the end of ripening. Free amino acids recorded 1.21 g leucine/g cheese in Edam cheese with 0.6 % oil at end of ripening times. Free fatty acids increased with increasing level of oil in Edam cheese samples. Incorporation of black cumin oil in Edam cheese reduced the total viable count (5.97 log cfu/g), yeast & molds (1.00 log cfu/g) at the end of ripening and inhibited the growth of coliform groups. Proteolytic bacteria recorded higher counts (3.19 log cfu/g), while lipolytic bacteria recorded lower counts (2.59 log cfu/g) in Edam cheese with 0.6 % oil comparing to other cheese samples at 60 days of ripening. Panelists accepted the taste of Edam cheese with higher concentration of black cumin oil (0.6 %) with no complains on appearance and smell, while they favored the texture of Edam cheese with higher percentage of oil, then overall acceptability went to 0.6 % oil treated cheese.

In the present study, 0.00% (control), 0.10%, 0.40%, 0.70%, 1.00% and 1.30% black cumin oil was added to rainbow trout feed and the fish were fed for 120 days. Following the feeding period, the harvested fish were stored in the refrigerator at ±2 ºC, in Styrofoam boxes filled with ice, for 23 days. During the storage period, the effects of black cumin oil on ammonia and biogenic amine production in rainbow trout were examined. An increase was observed in the ammonia content during the storage period, with the most substantial increase observed in the control group and the least substantial increase observed in the 1.30% black cumin oil group. The biogenic amine level increased during the storage period. A significant increases was observed in the tyramine level during the storage period ( less than 3.08 mg/100 g), and significant differences were observed between the groups in terms of spermidine, spermine, histamine, and tyramine content (p less than 0.05). The results of the present study suggest that the addition of black cumin oil reduced ammonia and biogenic amine production in rainbow trout.

The herbaceous plant black cumin (Nigella sativa L.) has a variety of medical benefits. For therapeutic uses, effective utilization of black cumin oil (BCO) depends upon its functional groups. The objective of the current study was to investigate the physicochemical characteristics, extraction methods' effects, shelf-life, and functional groups of BCO. Mechanical, cold, and Soxhlet extraction methods were used to extract oil from seeds. Proximate analysis of black cumin seeds showed 20.37 % protein, 34.24 % fat, 6.86 % moisture, 7.02 % ash, and 31.51 % carbohydrate. The density of mechanically extracted oil (MEO), Soxhlet extracted oil (SEO), Cold extracted oil (CEO), Locally labeled oil (LLO) and Locally unlabeled oil (LUO) were 0.957 g/cm3, 1.151 g/cm3, 1.170 g/cm3, 1.068 g/cm3 and 1.066 g/cm3, respectively, whereas the refractive indices were approximately similar in all oil samples. In terms of color, CEO and MEO were respectively the lightest and reddest ones among the oils. Initially, free fatty acid (FFA) contents in MEO, SEO, CEO, LCO and LUO were 6.663 %, 6.041 %, 8.214 %, 8.458 %, and 7.573 % respectively, where the highest peroxide value (PV), iodine value (IV) and saponification value (SV) were found as 26.232 mEq O2/kg, 122.275 g I2/100 g and 201.282 mg KOH/g in LCO, CEO and LUO. respectively. By 14 weeks of storage FFA, PV and SV in MEO increased from 6.663 to 14.289 %, 23.508 to 32.229 mEq O2/kg and 196.207–202.629 mg KOH/g respectively while IV decreased from 122.275 to 117.319 g I2/100 g. FTIR analysis reveals the MEO mostly consists of unsaturated fatty acids (cis). The overall findings conclude that MEO remains consumable until 10 weeks indicating a better stability against oxidation and rancidity.

For the increase of oxidative stability and phytonutrient contents of rapeseed oil 5, 10 and 20% blends with rice bran oil and black cumin oil were prepared. Profiles of different bioactive lipid components of blends including tocopherols, tocotrienols, phytosterols and phytostanols as well as fatty acid composition were carried out using HPLC and GLC. Rancimat was used for detecting oxidative stability of the fatty material. The blends with black cumin seed oil characterized higher level of α- and γ-tocopherols as well as all isomers of tocotrienols. Presence of rice bran oil in blends leads to increased tocotrienols amounts, β-sitosterol and squalene. Blending resulted in lowering ratio of PUFA/SFA and improves stability of these oils. The ratio of omega-6/omega-3 raises from 2.1 in rapeseed oil to 3.7 and 3.0 in blends with black cumin and rice bran oils, respectively. Addition of 10 and 20% of black cumin and rice bran oils to rapeseed oil were influenced on the oxidative stability of prepared blends. The results appear that blending of rapeseed oil with black cumin seed oil or rice bran oil enhanced nutritional and functional properties via higher oxidative stability as well as improved phytonutrient contents.

Thymoquinone-rich black cumin oil attenuates ibotenic acid-induced excitotoxicity through glutamate receptors in Wistar rats

The study was conducted to evaluate the effect of black cumin extract (BCD), green tea extract (GTD), black cumin oil (BCO), and green tea oil (GTO) (10%) on the proximate, microbial, physicochemical, textural, and sensorial quality of vacuum packaged rainbow trout during 16 days of storage at 2 ± 1°C. Results indicated that both BCD and BCO had significant effects on reduction of bacterial growth. Thiobarbituric acid (TBA) values (0.21–0.48 mg MA/kg) of all groups at the end of storage did not exceed the limit values. The BCD and BCO showed lower total volatile basic nitrogen (TVB-N) values than control, GTD, and GTO during storage, and TVB-N limit value was exceeded on the 11th day in the CO, GTD, and GTO, and on the 16th day in the BCD and BCO. During the research, pH and water activity of trout fillets ranged between 6.03–6.34 and 0.9863–0.9942, respectively. The results also showed that the BCD and BCO significantly improved the sensorial quality of the samples compared to CO, GTD, and GTO. Based on the results, the application of black cumin extract and oil was effective with at least a 5-day extension of shelf life in preserving the quality of rainbow trout fillets.