Department of Pharmacy, Southern University Bangladesh, Mehedibag (Chittagong)-4000, Bangladesh
Northeast Biotechnology Network (RENORBIO), Postgraduate Program in Pharmaceutical Sciences, Federal University of Piaui(UFPI), Teresina (PI)-64.049-550, Brazil
Nigella sativa L. (NS) is evident to have a number of important biological activities, such as antioxidant, anti-inflammatory, antibacterial, antifungal, anti-viral, anti-parasitic and anti-protozoal, cytotoxic, anticancer, neuro-, gastro-, cardio-, hetapto- and nephro-protective activities. In addition, the NS implies beneficiary effects on reproductive, pulmonary and immune systems as well as in diabetes mellitus (DM), fertility (male and female), breast cancer, dermatological complications, dehydration, dyspepsia, and osmotic balance and so on. Among the other isolated constituents, thymoquinone (TQ) is a vastly studied phytochemical in NS. A number of reports suggest that, the NS may be one of the potential herbs in health promotion. This paper will discuss the current scenario of NS activity in a mechanistic way.Keywords: Nigella sativa; biological activities; health promotion.
List of abbreviations: 5-HIAA
5-HIAA: hydroxyindole acetic acid, 5-HT: serotonin, ACC: acetyl CoA carboxylase, AChE: acetylcholinesterase, ADA: adenosine deaminase, Akt: protein kinase B, ALT: alanine aminotransferase, AO: acid output, APAP: N-acetyl-p-aminophenol, AST: aspartate aminotransferase, bax/bcl-4: apoptosis regulator, bcl-1: cyclin b1, bcl-2: cyclin b2, bcl-xl: cyclin b xl, BUN: blood urea nitrogen, CAT: catalase, CDK-p16: cyclin-dependent kinase p16, CGD: conjugated diene, c-JUNK: c-Jun-amino-terminal kinase, CK: creatinine, COX-1: cyclooxygenase-1, COX-2: cyclooxygenase-2, CP: cisplatin, CVS: cardiovascular system, cyclin b1 (bcl-1), cyclin-dependent kinase p16 (CDK-p16), dcl-1: cyclin d1, DM: diabetes mellitus, FABPs: fatty acid binding proteins, FAS: fatty acid synthase, FGF: fibroblast growth factor, GPx: glutathione peroxidase, GSH: reduced glutathione, GSH-ST: glutathione-Stransferase, HbA1c: glycosylated hemoglobin, HDAC: histone deacetylase, HDL-C: high-density lipoprotein-cholesterol, HIV: human immunodeficiency virus, i.g.: intra-gastric, i.p.: intraperitoneal, IFN-γ: interferon-gamma, IL: interleukin, LDH: lactate dehydroginase, LDL-C: low-density lipoprotein-cholesterol, LPO: lipid peroxidase, LPO: lipid peroxidase, LT4: leukotriene-d4, MDA: malonilealdehyde, MPO: myloperoxidase, NF-κB: nuclear factor-kappa-B, NK: natural killer, NLRP3: NACHT, LRR, and pyrin domain-containing protein 3, NO: nitric oxide, OSI: oxidative stress index, OXT: oxytetracycline, p.o.: per oral, PET: pulmonary function test, PGD: prostaglandin, PGE2: prostaglandin, ROS: reactive oxygen species, SCC: squamous cell carcinoma, SOD: superoxide dismutase, SP-1: protein expression in papiloma, TAC: total antioxidant capacity, TBARS: thiobarbituric acid substances, TC: total cholesterol, TG: thyroglobulin, TGF-β: transforming growth factor beta, TNF-α: tumor necrosis factor-alpha, TNO: nitric oxide, TOS: total oxidative status, TQ: thymoquinone, TSH: thyroid stimulating hormone, UI: ulcer index
This study is stimulated by the talks of the noble man, the last Prophet of the religion Islam, Hazrat Muhammad (PBUH); who told that the black seed (Scientific name: Nigella sativa; Urdu: Kalonji; Arabic: Habba-tu sawda/ Habba Al-Barakah; English: Black cumin/ Black seed; Persian: Shonaiz; Bengali: Kalajira; Hindi/Nepali: Mangrail)1 contains all kinds of remedies except death. To date (March 2016) in the databases such as PubMed/ Medline, Science Direct, Web of Science, Scopus, and google, a total of 1290 published evidences were found on the following topics: morphology of the plant, isolated compounds and their derivatives, and pharmacological activities. One general revision of this plant was done by Ahmad et al2 , following to a dermatological revision by Aljabre et al3 , an immunomodulatory and anti-inflammatory revision by Majdalawieh and Fayyad4 , an anti-inflammatory, antioxidant, an immunomodulatory revision by Gholamnezhad et al5 , male fertility revision by Mahdavi et al6 , metabolic parameters in diabetes mellitus revision by Heshmati and Namazi7 , and thymoquinone and its therapeutic potentials by Darakhshan et al8 . This text summarizes the above mentioned seven revision articles. Additionally, data from 2014 to March 2016 were also included in this revision. More emphasize was given to the action mechanisms.
Nigella sativa (NS) in short
The NS is a small shrub (20 to 90 cm in tall) under the family, Ranunculaceae. It is native to Southern Europe, North Africa and Southeast Asia; cultivated in many countries in the world like Middle Eastern, Mediterranean region, South Europe, India, Pakistan, Syria, Turkey, Saudi Arabia2 . It has tapering green leaves and rosaceous white, yellow, pink, pale blue or purplish flowers with 5-10 petals. The ripe fruit (capsule: 3-7 united follicles) contains numerous tiny seeds, dark black in color. The seed and oil of NS was frequently used in ancient remedies (Unani, Ayurveda, Chinese and Arabic) in Asian countries and in the Middle-East. The use of black seeds (seeds of NS) had been mentioned by IbneSina (980-1037) in his famous book Al-Qanoon fitt-Tibb3 .
Traditionally NS is used as a medicament of a variety of disorders, including the respiratory system, digestive tract, cardiovascular system (CVS), kidney, liver, and immune system. The use of NS in fatigue and dispiritedness is antique. The most common traditional uses belong to the ailments, including asthma, bronchitis, rheumatism and related inflammatory diseases, indigestion, loss of appetite, diarrhea, dropsy, amenorrhea, dysmenorrhea, worms and skin eruptions. It is also used as an antiseptic and local anesthetic2 .
Chemical composition :
The black seeds contain protein (26.7%), fat (28.5%), carbohydrates (24.9%), crude fiber (8.4%), total ash (4.8%), volatile oil (0.5- 1.6%), fatty oil (35.6-41.5%)2 , cellulose (6.8-7.4%) and moisture (8.1-11.6%)9 . The seeds are also rich in various vitamins (e.g. - A, B1, B2, B3 and C) and minerals (e.g. - Ca, K, Se, Cu, P, Zn, Fe). Carotene and vanillic acid are also reported in its seeds and root, and shoot, respectively. As fatty components, linolic acid (50-60%), oleic acid (20%), dihomolinoleic acid (10%) and eicodadienoic acid (3%) are the main unsaturated fatty acids. The palmitic acid and stearic acid belong to two main saturated fatty acids, in which α-sitosterol (44-54%) and stigmasterol (6.57-20.92%) are the pioneers2 . Some other fatty acids such as myristic acid, palmitoleic acid, linoleic acid, linolenic acid, arachidonic acid, cholesterol, campesterol, β-sitosterol, ∆5-avenasterol, ∆7-stigmasterol, and ∆7- avenasterol are also reported by Gharby et al9 in NS.
The seed contained alkaloids are: isoquinoline alkaloids (e.g. - nigellicimine, nigellicimine N-oxide), pyrazole alkaloids or imidazole ring bearing alkaloids (e.g. - nigellidine, nigellicine). It also contains terpenes (e.g. - α-hederin) and saponins. Evidences tell that thymoquinone (2-Isopropyl-5-methylbenzo-1,4-quinone, 30-48%), thymohydroquinone, dithymoquinone, p-cymene (7-15%), carvacrol (6-12%), 4-terpineol (2-7%), t-anethol (1- 4%), sesquiterpene longifolene (1-8%), α-pinene and thymol etc. are the most important active components reported in NS. The other chemical components are: carvone, nigellicine1, nigellone, citrostradienol, cycloeucalenol, gramisterol, lophenol, ostusifoliol, stigmastanol, β-amyrin, butyrospermol, cycloartenol, 24-methylene-cycloartanol, taraxerol, tirucallol, 3-O-[β-D-xylopyranosyl(1→3)-α-L-arabino-pyranosyl]-28-O- [α-L-rhamnopyranosyl(1→4)-β-D-glucopyranosyl(1→6)-β-Dglucopyranosyl] hederagenin, esters of unsaturated fatty acids with ≥ C15 terpenoids, esters of dehydrostearic and linoleic acid, aliphatic alcohol, β-unsaturated hydroxyl ketone, hederagenin glycoside, melanthin, melanthigenin, bitter principle, tannin, resin, reducing sugars, glycosidal saponin, 3-O-[β-D-xylopyranosyl(1→2)-α- L-rhamnopyrasyl(1→2)-β-D-glucopyranosyl]-11-methoxy-16, 23-dihydroxy-28-methylolean-12-enoate,stigma-5,22-dien-3- β-D-glucopyranoside,cycloart-23-methyl-7,20,22-triene-3β,25- diol, nigellidine-4-O-sulfite, N. mines A3, a4, A5, C, N. mines A1, a2, B1, and B22 . Chemical structures of some NS-derived phytochemicals are shown in Figure 1.
Figure 1. Some important chemical moieties isolated from N. sativa
Pharmacological activities of NS :
NS against bacteria :
The NS is found to act against gram positive (Staphylococcus aureus) and gram negative (Pseudomonas aeruginosa and Escherichia coli) species. It showed synergistic effects with streptomycin and gentamycin, while additive with spectinomycin, erythromycin, tobramycin, doxycycline, chloramphenicol, nalidixic acid, ampicillin, lincomycin and co-trimoxazole and similar to topical mupirocin. Moreover, the NS has potent inhibitory activity against antibiotic resistant microorganisms, including many multi-drug-resistant (MDR) gram positive and gram negative bacteria3 . According to Manju et al10 the EO from NS is able to protect Artemia spp. from Vibrio parahaemolyticus Dahv2 infection. According to Hariharan et al11, thymoquinone (TQ) the well known NS compound has shown antimethicillinresistant activity in S. aureus. TQ is also evident to act against a number of gram positive and gram negative pathogenic bacteria8 .
NS against fungi
The NS is found to inhibit the growth of Candida albicans and Madurella mycetomatis, while TQ by Aspergillus niger, Fusarium solani and Scopulariopsis brevicaulis more effectively than the amphotericin-B and griseofulvin. The TQ also acted against Trichophyton spp., Epidermophyton spp., and Microsporum spp. In addition TQ, thymohydroquinone and thymol are also demonstrated to have an antifungal effect against many clinical isolates, including dermatophytes, molds and yeasts3. Furthermore, the NS seed oil (10-200 μg/mL) was found to act against Saccharomyces cerevisiae and C. utilis12.
NS against viruses
In a study, the NS enhanced helper-T-cell (T4) and suppressorT-cell (T8) ratio and increased the natural killer (NK) cell activity in human. Furthermore, it significantly inhibited the human immunodeficiency virus (HIV) protease and murine cytomegalovirus. In the latter case, it was found to increase in number and function of the M-phi and CD4+ve T cells with the production of interferon-gamma (INF-γ)3 .
NS against parasites :
The NS is evident to have anti-leishmaniasis, anti-miracidia, anticercariae and anti-Schistosoma mansoni potentials. In the latter case the oil of the black seed showed a strong activity as compared to the anti-schistosomal and anthelmintic drug for domestic animals, prazequantel; where it produced a potentiating effect with the co-treatment3 . Moreover, Simalango and Utami13 suggested that the ethanol extract of NS (0.5-8%) has significant anti-Ascaris suum activity.
NS in wound infection
The wound healing capacity of NS was evaluated in farm animals, mice and human gingival fibroblast. The accumulated result suggests that there is a reduction in absolute differential leukocytes (WBC) counts, local infection and inflammation, bacterial expansion and tissue impairment, and free radical production. An elevation of basic fibroblast growth factor (FGF) and transforming growth factor beta (TGF-β) were also reported (Aljabre et al. 2015).
Antioxidant capacity of NS
A number of in vitro, ex vivo and in vivo antioxidant studies have been conducted with NS extracts, seed oil and TQ. The finding suggests that, NS and its derived components have potent radical scavenging as well as oxidative stress inhibitory capacities. TQ significantly changed the parameters including adenosine deaminase (ADA), catalase (CAT), myloperoxidase (MPO), lipid peroxidase (LPO), reduced glutathione (GSH), glutathione-Stransferase (GSH-ST), glutathione peroxidase (GPx), superoxide dismutase (SOD) and nitric oxide (NO) in the favor of reducing oxidative stress. It also reduced the malonilealdehyde (MDA), conjugated diene (CGD) levels and pro-inflammatory mediators interleukin (IL)-1-beta, IL-6, tumor necrosis factor-alpha (TNF-α), IFN-γ, and prostaglandin (PGE2 ) rather than IL-102,14. Figure 2 tells the basic antioxidant pathways of NS.
NS in inflammation:
Findings from different animal models suggest that, the NS extracts, seed oil and TQ have strong anti-inflammatory activities. In some studies, they were found to reduce the synthesis of NO, IL-1, cyclooxygenase (COX)-1, COX-2, histone deacetylase (HDAC) along with other pro-inflammatory mediators such as - IL-1β, IL-6, TNF-α, IFN-γ, and PGE2 2 . The topical application of TQ was found to induce an expression of hemeoxygenase (HO)- 1, NAD(P)H-quinoneoxidoreductase-1, GSH-ST and glutamate cysteine ligase in mice; while the seed oil inhibited COXs, 5-LPO in the pathways of arachidonate metabolism in rats3 . TQ is also evident to down-regulate the nuclear translocation and the DNA binding of nuclear factor-kappa-B (NF-κB) via the blockade of phosphorylation and subsequent degradation of IκBα in mice. Moreover, the TQ was also attenuated the phosphorylation of Akt (protein kinase B), c-Jun-amino-terminal kinase (c-JUNK) and p38 mitogen-activated protein kinase (MAPK-p38). In another study, a decrease in expression of the NLRP3 (NACHT, LRR, and pyrin domain-containing protein 3) in B16F10 mouse resulted in inactivation of caspase-1 followed by the inhibition of IL-1β and IL-18. In addition, the inhibitory effect of TQ to NF-κB and reactive oxygen species (ROS) resulted in the partial inactivation of NLRP3 inflammasome3,4,14. Figure 3 tells the basic antiinflammatory activity pathways of NS.
NS in cancer
The black seed oil can stimulate the NK cells, which is a potential applicability in immune therapy. Otherwise, the oil components may induce pro-oxidative effects thus the carcinogeneticity. The TQ tested in a number cancer cells derived from mice, suggesting its ability to arrest G0 /G1 phases of cell-cycle, which correlated with sharp increases in the expression of the cyclindependent kinase p16 (CDK-p16) and a decrease in cyclin d1 (dcl-1) protein expression in papiloma (SP-1) cell line and G2 /M arrest associated with an increase in the expression of the tumor suppressor protein p53 with a decreased level of cyclin b1 (bcl-1) protein. The chemopreventive potential of TQ may be due to its ability to increase the ratio of apoptosis regulator (bcl-4)/cyclin-2 (bax/bcl-2) expression and decreasing cyclin-xl (bcl-xl) protein. The antitumor activity of TQ was also reported in squamous cell carcinoma (SCC VII), FsaR and murine tumor models of fibrosarcoma and SCC. TQ showed potent anticancer activity in A431 and Hep2 cells via apoptosis by increasing the sub-G1 population, live/dead cytotoxicity, chromatin condensation, DNA laddering and Tunel-positive cells. Along with an increase in bax/ bcl-2 ratio activation of cell proliferation of caspases and cleavage of poly ADP ribose polymerase was also observed3 .
A research done by Khalife et al15 suggesting that TQ induced apoptosis through p53-independent pathway with an expression of p21 and cell-cycle S phase arresting in human colon cancer cells. TQ also exerted an anticancer effect in a number of cancer cell lines, including MCF-7/Topo breast carcinoma cells. It was found to down-regulate the NF-κB and MMP-9 in Panc-1 cells and bcl-2 in gastric cancer cells, while up-regulator of caspase-3 and caspase-9 in the later one. A number of derivatives of TQ namely 6-menthoxybutyryl, 6-hencosahexanyl conjugate, 4-acylhydrazones and 6-alkyl derivatives are also evident to produce anticancer activity in cancer cell lines2 .
Recent evidence suggests that the nanoemulsion of NS oil at a concentration of 20-80 µL/mL caused cell membrane blebbing, cytoplasmic vacuolation, marginalization of chromatin, and fragmentation of the nucleus in MCF-7 cells16. A recent evidence suggests that topical use of black seed oil (600 mg) reduced cyclic mastalgia in woman (n = 52), where the activity was found significant when compared to the painkiller, diclofenac17. A basic NS-anticancer traits has been sketched in Figure 4.
NS in diabetes :
The NS was found to reduce blood glucose level with an augmenting insulin level and C-peptide in rats. Whereas, TQ reduces the tissue MDA levels, DNA damage, mitochondrial vacuolization and fragmentation, and preserves pancreatic β-cell integrity via antioxidant capacity. In a study TQ increased the levels of insulin, Hb with a significant decrease in glucose and glycosylated hemoglobin (HbA1c) levels. The NS showed a synergistic activity with parathyroid hormone in improving bone mass, connectivity, biomechanical behavior and strength in T2D rats. The NS is also evident to show some advantages in insulin resistance syndrome and dislipidemic patients. Furthermore, an insulin-sensitization action via enhancing ACC phosphorylation (mainly MAPK signaling pathway) and muscle GLUT4 content as well as progressive normalization of glycaemia are also seen in NA-treated diabetic Meriones shawi2,7. In a study, the lipid (4%) and volatile oil fractions (3%) of NS in streptozotocin-induced diabetes mellitus (DM) rats reduced toxicological and adverse consequences significantly18. In addition, an improved glycemic status and lipid profile with NS oil treatment at 3 g/3-times/day in DM patients (n = 72) were also reported by Heshmati et al19.
TQ when tested in clonal β-cells and rodent islets it caused a protective effect with normalization of chronic accumulation of malonyl CoA, and elevation of acetyl CoA carboxylase (ACC), fatty acid synthase (FAS) and fatty acid binding proteins (FABPs) following a chronic glucose overload, suggesting the modulation in β-cell redox circuitry and enhancing sensitivity of β-cell metabolic pathways to glucose and glucose-stimulated insulin secretion (GSIS) under both normal conditions and hyperglycemia20. Generally, the MAPK regulates a number of transcriptional factors, altering of which interferes in cell-cycle. Thus, NS and TQ may be a good remedy for both type 1 and 2 DM patients, as in this consequence maintenance of beta-cell integrity and secretion of insulin sufficient for glycogenesis and phosphorylation of raised glucose in the blood are crucial. Otherwise, along with ingested food, oxidative stress, infection and trauma are the factors that increase in blood sugar levels. Thus, the antidiabetic activity of NS and TQ may connect with their antioxidant, antimicrobial, cytotoxic and anti-inflammatory activities. Otherwise, the decreasing level of HbA1c is one of the remedy for cardiovascular disease, nephropathy, neuropathy, and retinopathy. Figure 5 tells the possible anti-diabetic action pathways of NS.
NS effects on immune system
Along with NK antitumor activity, the NS is a demodulator of the secretion of a number of pro-inflammatory mediators with upmodulation of secretion of Th2/Th1, cytokines in splenocytes. The NS is also evident to restore the resistance against granulocytedependent C. albicans. A study performed by the NS oil suggests decreasing antibody production in typhoid vaccination, which may be due to its immunosuppressive cytotoxic effect. It is also evident to correct the imbalance situation caused by oxytetracycline
(OXT) in leukocyte, lymphocyte counts, heterophil:lymphocyte ratio, lysosomal enzyme activity and reticuloendothelial system function. Moreover, the NS produced an immunoprotective effect in chronic antibiotic loaded pigeons. The NS oil was also exerted radioprotectivity, immune-stimulatory, reducing the effects of ionizing radiation-induced situations. In addition, an increased level of IFN-γ with a significant decreased in pathological changes of the guinea pigs’ lung was reported by NS oil treatment. It is also effective in allergic diarrhea3,4,14. A recent evidence suggests that, the seed oil is protective against γ-radiation-induced damage in jejunal mucosa21. Moreover, EO from NS at 5-20 g/kg (oral feed for 6 weeks) in chickens improved FCR and plasma lipid profile and antibody-mediated immunity22. In a study, the NS oil also reduced thyroid stimulating hormone (TSH) and anti-thyroid peroxidase antibodies in patients with Hashimoto’s thyroiditis23.
NS on nervous system :
Methanolic extract of NS is reported as a potent analgesic and antidepressant. In addition, an anxiolytic activity via increasing serotonin (5-HT) and decreasing hydroxyindole acetic acid (5- HIAA) levels were also reported in rat brain. In another study, an increased 5-HT secretion along with improving learning and memory capacity in rats were detected with NS treatment. As NS may augment in tryptophan levels, it may be helpful in anxiety treatment. Otherwise, TQ produced GABA-mediated anxiolyticlike effect in mice with a decline of NO and MDA production2 . The possible neuroprotective activity may be due to its antioxidant, free radical scavenging and anti-inflammatory capacities. Along with these, anti-acetylcholinesterase (anti-AChE) and anticonvulsant activities were also evident with NA and TQ treatments, respectively. There is a suggestion for GABAA-ergic anticonvulsant effect of TQ2 .
NS EO at 1 g/kg (i.g.)/day and TQ 30 at mg/kg/day (i.p.) in Wistar albino rats produced anti-nitrosative effects after a 10 days treatment24. The NS EO is also evident to prevent cerebral edema in the hippocampus tissue of the rat brain25. Fahmy et al26 suggested that NS oil at a dose of 2.8 g/kg when treated orally (p.o.) in autoimmune encephalomyelitis rats for 4 weeks, significantly reduced the oxidative stress parameters in the cortex and hippocampus with the enhancing in remyelination in the hippocampus. Otherwise, oil at a dose of 4 mL/kg/day (p.o.) in tramadol treated male albino rats protected the cortical neurons and myelinated axons27. Furthermore, the NS EO at 500 mg (4 weeks treatment) in adolescent human males (n = 48) significantly stabilized mood, decreased anxiety and modulated cognition28. A possible neurological activity of NS is shown in Figure 6.
Effects on gastrointestinal tract (GIT) :
TQ is gastroprotective as it decreases gastric acid secretion, acid output (AO), pepsin, the mucosal content/activity of lipid peroxidase (LPO), proton (H+) pump, MPO and ulcer index (UI) while an increased in the content/activity of gastric mucin, GSH, total nitric oxide (TNO) and SOD. Decreased ulcer severity in rats was guessed via prostaglandin (PGD)-mediated and/or through antioxidant and anti-secretion pathways. A decreased in LPO and lactate dehydroginase (LDH), MPO, MDA and increased in GSH, SOD, GPx, GSH-ST without altering of gastric CAT was also reported in rats. TQ was found to exert significant effects in diarrhea, colitis, inflammatory bowel diseases, anti-Helicobacter pylori as well as in loss of body weight2 . Possible GIT protective pathways of TQ are shown in Figure 7.
Effects on cardiovascular system (CVS)
TQ is evident to decrease motor fuel (diesel particle)-induced systolic blood pressure, leukocytes, IL-6 and plasma SOD activity. It is also prevented to decrease platelet counts and the prothrombin events rather than platelet aggregation2 . The black seed oil reduced the total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), and thyroglobulin (TG) with an increased high-density lipoprotein-cholesterol (HDL-C) level29.
Effects on hepatic system
The NS effect on alanine aminotransferase (ALT), aspartate aminotransferase (AST), LDH, total antioxidant capacity (TAC), CAT, MPO, total oxidative status (TOS) and oxidative stress index (OSI) tells that it has hepatoprotective activity. In addition GSH, TQ increased protein carbonyl content, thus the attenuation of protein oxidation and upgrading of the depleted antioxidant cellular fraction2 . Moreover, the NS oil at a dose of 25-100 μg/ mL protected hepatocytes from N-acetyl-p-aminophenol (APAP)- induced hepatotoxicity and metabolic disturbances in TIB-73 cells of mice30. A similar activity was also observed by Hamza and Al-Harbi31 with aqueous extract of NS, where the activity was thought to be linked with an improved antioxidant potential and suppressed in lipid peroxidation and ROS generation30. In addition, the black seed oil at a dose of 2 mg/kg (p.o.) with cisplatin (CP)- treated rats are also evident for its hepatoprotective activity via improving energy metabolism and strengthening antioxidant defense pathways32.
Effects on urinary system
The NS along with ascorbic acid (Vitamin C) produced a nephroprotective effect by lowering serum creatinine (CK), blood urea nitrogen (BUN) and antioxidant activity in rabbits. On the other hand, the TQ showed an effect on renal expression of organic ion transporters and multidrug resistance-associated proteins in rats. TQ-mediated increased in protein levels of the efflux transporters MRP2 and MRP4, and decreased expression of OAT1, OAT3, OCT1 and OCT2 was also observed in rats. Along with decreasing tubular necrosis score, NS significantly reduced the CK, urea, MDA, NO, ROS, OSI and TOS levels and augmenter of TAC, SOD, GPx in kidney tissue and blood. Furthermore, the TQ is also evident to antagonize the gentamicin (GM)-induced alteration of serum CK, BUN, thiobarbituric acid substances (TBARS), total nitrite/nitrate content, GSH, GPx, CAT and ATP values in rats2 . Moreover, the ethanol extract of NS at 250-100 mg/kg (p.o.) in female Wistar Albino rats showed a significant nephroprotective activity against paracetamol-induced nephrotoxicity33. In another study, the NS exhibited a significant nephroprotective effect in Cdinduced nephrotoxicity in rats34.
Effects on respiratory system
Both nigellone and TQ are evident to inhibit leukotriene-d4 (LT4) in the trachea, where the activity of the first one was suggested via mucociliary clearance. However, NS is evident to reduce the peribronchial inflammatory cell infiltration, alveolar septal infiltration, alveolar edema, alveolar exudates, alveolar macrophages, intestinal fibrosis, granuloma, necrosis formation, NOS and surfactant protein D in the pulmonary system. The NS is also evident to have beneficial effects against lung injury and hypoxia-induced lung damage. In a study, the NS puffs were proven to relieve asthma symptoms, frequency of asthma symptoms/weakness, chest wheezing and pulmonary function test (PFT) values with a bronchodilatory effect2 .
Effects on reproductive system
TQ decreased TAC and MPO levels in C57BL/6 male mice. In addition, TQ alerted the events produced by methotrexate such as intestinal space dilatation, edema, disruption in the somniferous epithelium and reduced diameter of the semniferous tubules. Moreover, infertile men (n = 34) when treated with 2.5 mL NS oil for 2 months, significantly improved abnormal semen quality without producing any adverse effect was observed35. According to Mahdavi et al36 the NS oil is a good candidate for treating male infertility. Hexane and methanol extracts of NS produced significant anti-fertility in Sprague-Dawley male and female rats, respectively. Otherwise, NS is evident to inhibit the uterine smooth muscle contraction in rats and guinea pigs2,36. TQ when treated with olive oil caused a reduction in polycystic overy in rats possibly, via NF-κB signaling pathway37
NS in dyspepsia
Patients (n = 70) with functional dyspepsia when treated with NS oil of 5 mL (p.o.) for 8 weeks, a significant lowering of dyspepsia was observed38.
NS in osmotic balance
The geriatric patients (n = 42) when treated with NS oil (22.6 µg/25 µL) for 2 weeks, it was demonstrated that NS may be an alternative therapy of the isotonic sodium chloride (0.9% NaCl) solution39.
A TQ-induced skin darkening via chlonergic mechanisms of muscarinic receptor in the melanin dispersion is evident, whereas, NS oil for decreasing vitiligo area scoring index without seeing adverse effects. Moreover, TQ and nigellone inhibited histamine release, protected histamine-induced bronchospasm in guinea pigs, decreased lung ensiphilia, elevated Th2 cytokines and raised IgE and IgG1 antibodies in mice. To be mentioned that, the NS has a good recommendation in hand eczema. Linoleic acid from this plant is known for its percutaneous adsorption enhancing capability of drugs, while the oil emulsion for reducing skin irritation and improving moisturizing and epidermal barrier function. It has also anti-aging, mitigating, and protective effects3 . Both NS and TQ can be used in oral health and hygiene40
Toxicological data of NS/TQ
In mice, the dose causing death of fifty percent experimental animals (LD50) values of fixed oil of NS was found 26.2-31.6 mg/ kg and 1.86-2.26 mg/kg with single oral (p.o.) and intraperitoneal (i.p.) doses, respectively. In another study, calculated LD50 for TQ was 89.7-119.7 mg/kg and 647.1-1094.8 mg/kg after i.p. and p.o. administrations, respectively. In rat it was found to be 45.6-69.4 mg/kg and 469.8-1118.8 mg/kg after i.p. and p.o. administration, respectively. Data suggest TQ is more tolerated than the extract from NS2 . Some important biological activities of NS have been given in Table 1.
Drug interactionsTable 2 suggests NS interaction profiles with drugs/chemicals/biochemicals.
At low levels and temporary spikes of ROS are beneficial for health55 rather than high production and chronic effects as they may up-regulate pro-inflammatory cytokines, chemokines and pro-inflammatory transcription factors56 and induces cell death by damaging macromolecules such as lipids, DNA, RNA, and other proteins. In extrinsic pathway, excessive ROS are generated by Fas ligand which in association with death domain and caspase-8 cause apoptosis56. Otherwise, in the caspase cascade pathway (intrinsic) ROS facilitate to release cytochrome C by activating bcl-2 and bcl-xl and bcl-2-associated X protein as well as bcl- 2 homologous antagonist/killer57. ROS implicates a variety of detrimental responses, including CVS diseases (e.g. – stroke and heart attack), hearing impairment via cochlear damage, decline memory capability (degenerative diseases, e.g. – AD), ischaemic injury, and so on. Unlike apoptosis and necrosis, autophagy cell death occurs by self-digest of the damaging portion to take an attempt to minimize the damage and can no longer survive. However, it is possible to make available ROS to the other normal cells by this process as cellular programming is enough for a programmed cell death. Radiations form radiotherapy induces ROS-mediated cell death and mitotic failure56. However, an ideal ROS neutralizer (antioxidant/cytoprotective agent) is not enough in the cancer therapy, even if it has antioxidant-mediated prooxidant effect, as it may act like dual nature of ROS! Therefore, cell targeting, self-redox balancing; genotoxic, but non-mutagenic, exact concentrations of ROS at the targeted site along with action period are the major concerns in the chemo-/radio-therapeutic cancer treatments.
In the above discussion, TQ, the well-known NS-derived quinone and other NS constitutions are evident to have targeted effects in a range of cellular proteins. It is doubtless, that TQ is ready to go for a clinical trial, due to its numerous promising biological effects and therapeutic potentials8 . Having strong antioxidant capacity through antiradical including ROS, direct reduction of oxidizable substrates and induction of cellular antioxidant molecules, they may be good sources as cytoprotective agents, especially, the TQ, although’ its mutagenic effect is yet to be found out. The carcinogenic and immunosuppressive cytotoxic effects of NS oil can be overcome by the co-treatment with antibiotics or radiotherapy. Being a spacious habitual world-wide and having good number already isolated chemical moieties, NS is a weapon to the drug scientists. A number of researches have been done on this plant and its isolated compounds, especially on TQ and its derivatives and nigellone telling that chemical modification may bring a fruitful outcome to the drug library. In addition, some clinical uses suggest that NS is a safe and health promoter, especially observed in antifertility test. Although, the exact mechanism of actions of the investigated pharmacological potentials is yet to be found out, but the toxicological and its interaction profiles suggesting beneficial rather than detrimental effects. Generally, substances having antioxidant, antimicrobial or cytotoxic other than genotoxic and mutagenic potentials are good for healthy consumption. NS falls in this category. Finally, for its wide variety of activities, NS may be called the ‘marvelous shrub’.
Drugs from the shrubs are one of the potential plant derived sources. Interestingly, now a day herbal medicaments are in a great attention to the consumers world-wide. Doubtless, the traditional medicines are still occupying potential sources of phyto-based remedies. A potential and diverse activity of a scrupulous source is the stimulation to the drug researchers. The NS and few of its isolated compounds such as TQ (including its derivatives), nigellone, α-hederin and linoleic acid have been demonstrated for a number of important pharmacological activities. In addition, the clinical usages of NS, making the herb and its constituents potential phytotherapeutic tools. The NS is a health promoting herb.
I am owed to the NTF, Federal University of Piaui (UFPI), Brazil for providing internet facility to carry out this revision.
CONFLICT OF INTERESTNone declared.
- Adam GO, Rahman MM, Lee S-J, Kim G-B, Kang H-S, Kim J-S, Kim S-J (2016) Hepatoprotective effects of Nigella sativa seed extract against acetaminophen-induced oxidative stress. Asian Pac J Trop Med 9:221-227.
- Ahlatci A, Kuzhan A, Taysi S, Demirtas OC, Alkis HE, Tarakcioglu M, Demirci A, Caglayan D, Saricicek E, Cinar K (2014) Radiation-modifying abilities of Nigella sativa and Thymoquinone on radiation-induced nitrosative stress in the brain tissue. Phytomed 21:740-744.
- Ahmad A, Husain A, Mujeeb M, Khan SA, Najmi AK, Siddique NA, Damanhouri ZA, Anwar F (2013) A review on therapeutic potential on Nigella sativa: a miracle herb. Asian Pac J Trop Biomed 3:337-352.
- Ahmad S, Beg ZH (2015) Evaluation of therapeutic effect of omega-6 linoleic acid and thymoquinone enriched extracts from Nigella sativa oil in the mitigation of lipidemic oxidative stress in rats. Nutri [In Press].
- Al-Attass SA, Zahran FM, Turkistany SA (2016) Nigella sativa and its active constituent thymoquinone in oral health. Saudi Med J 37:235-244.
- Mahdavi R, Namazi N, Alizadeh M, Farajnia S. Nigella sativa oil with a calorie-restricted diet can improve biomarkers of systemic inflammation in obese women: A randomized doubleblind, placebo-controlled clinical trial. J Clin Lipidol 2015. 10: 1203-1211.
- Alu’datt MH, Rababah T, Alhamad MN, Gammoh S, Ereifej K, Alodat M, Hussein NM, Kubow S, Torley PJ (2016) Antioxidant and antihypertensive properties of phenolic–protein complexes in extracted protein fractions from Nigella damascena and Nigella arvensis. Food Hydrocolloids 56:84-92.
- Darakhshan S, Pour AB, Colagar AH, Sisakhtnezhad S. Thymoquinone and its therapeutic potentials. Pharmacol Res 2015. 95-96: 138-158.
- Beheshti F, Hosseini M, Vafaee F, Shafei MN, Soukhtanloo M (2015) Feeding of Nigella sativa during neonatal and juvenile growth improves learning and memory of rats. J Traditional Complement Med [In Press]
- Boudiaf K, Hurtado-Nedelec M, Belambri SA, Marie JC, Derradji Y, Benboubetra M, El-Benna J, Dang PM (2016) Thymoquinone strongly inhibits fMLF-induced neutrophil functions and exhibits anti-inflammatory properties in vivo. Biochem Pharmacol 104:62-73.
- Canayakin D, Bayir Y, Kilic Baygutalp N, Sezen Karaoglan E, Atmaca HT, Kocak Ozgeris FB, Keles MS, Halici Z (2016) Paracetamol-induced nephrotoxicity and oxidative stress in rats: the protective role of Nigella sativa. Pharm Biol p. 1-10. [Epub ahead of print]
- Develi S, Evran B, Kalaz EB, Koçak-Toker N, Erata GO (2014) Protective effect of Nigella sativa oil against binge ethanolinduced oxidative stress and liver injury in rats. Chinese J Nat Med 12:495-499.
- Elkhateeb A, El Khishin I, Megahed O, Mazen F (2015) Effect of Nigella sativa Linn oil on tramadol-induced hepato- and nephrotoxicity in adult male albino rats. Toxicol Rep 2:512-519.
- Erboga M, Kanter M, Aktas C, Sener U, Fidanol Erboga Z, Bozdemir Donmez Y, Gurel A (2016) Thymoquinone Ameliorates Cadmium-Induced Nephrotoxicity, Apoptosis, and Oxidative Stress in Rats is Based on its Anti-Apoptotic and Anti-Oxidant Properties. Biol Trace Elem Res 170:165-172.
- Fahmy HM, Noor NA, Mohammed FF, Elsayed AA, Radwan NM (2014) Nigella sativa as an anti-inflammatory and promising remyelinating agent in the cortex and hippocampus of experimental autoimmune encephalomyelitis-induced rats. J Basic Appl Zool 67:182-195.
- Farooqui Z, Afsar M, Rizwan S, Khan AA, Khan F (2016) Oral administration of Nigella sativa oil ameliorates the effect of cisplatin on membrane enzymes, carbohydrate metabolism and oxidative damage in rat liver. Toxicol Rep 3:328-335.
- Gharby S, Harhar H, Guillaume D, Roudani A, Boulbaroud S, Ibrahimi M, Ahmad M, Sultana S, Hadda TB, ChafchaouniMoussaoui I, Charrouf Z (2015) Chemical investigation of Nigella sativa L. seed oil produced in Morocco. J Saudi Soc Agric Sci 14:172-177.
- Ghasemi HA, Kasani N, Taherpour K (2014) Effects of black cumin seed (Nigella sativa L.), a probiotic, a prebiotic and a synbiotic on growth performance, immune response and blood characteristics of male broilers. Livestock Sci 164:128-134.
- Gholamnezhad Z, Keyhanmanesh R, Boskabady MH (2015) Anti-inflammatory, antioxidant, and immunomodulatory aspects of Nigella sativa for its preventive and bronchodilatory effects on obstructive respiratory diseases: A review of basic and clinical evidence. J Functional Foods 17:910-927.
- Gray JP, Zayasbazan Burgos D, Yuan T, Seeram N, Rebar R, Follmer R, Heart EA. Thymoquinone, a bioactive component of Nigella sativa, normalizes insulin secretion from pancreatic β-cells under glucose overload via regulation of malonyl-CoA. Am J Physiol Endocrinol Metab 2016. 310: E394-404.
- Orhon ZN, Uzal C, Kanter M, Erboga M, Demiroglu M. Protective effects of Nigella sativa on gamma radiation-induced jejunal mucosal damage in rats. Pathol Res Pract 2016. 212: 437- 443.
- Gray JP, Zayasbazan Burgos D, Yuan T, Seeram N, Rebar R, Follmer R, Heart EA (2016) Thymoquinone, a bioactive component of Nigella sativa, normalizes insulin secretion from pancreatic β-cells under glucose overload via regulation of malonyl-CoA. Am J Physiol Endocrinol Metab doi: 10.1152/ajpendo.00250.2015.
- Tajmiri S, Farhangi MA, Dehghan P. Nigella Sativa treatment and serum concentrations of thyroid hormones, transforming growth factor β (TGF-β) and interleukin 23 (IL-23) in patients with Hashimoto’s Thyroiditis. Eur J Integrative Med 2016. 8: 576-580.
- Hamza RZ, Al-Harbi MS (2015) Amelioration of paracetamol hepatotoxicity and oxidative stress on mice liver with silymarin and Nigella sativa extract supplements. Asian Pac J Trop Biomed 5:521-531.
- Hariharan P, Paul-Satyaseela M, Gnanamani A (2016) In vitro profiling of antimethicillin-resistant Staphylococcus aureus activity of thymoquinone against selected type and clinical strains. Lett Appl Microbiol 62:283-289.
- Heshmati J, Namazi N, Memarzadeh M-R, Taghizadeh M, Kolahdooz F (2015) Nigella sativa oil affects glucose metabolism and lipid concentrations in patients with type 2 diabetes: A randomized, double-blind, placebo-controlled trial. Food Res Int 70:87-93.
- Omar NM. Nigella sativa oil alleviates ultrastructural alterations induced by tramadol in rat motor cerebral cortex. J Microscopy Ultrastructure 2016. 4: 76-84.
- Hobbenaghi R, Javanbakht J, Sadeghzadeh Sh, Kheradmand D, Abdi FS, Jaberi, Mohammadiyan MHMR, Mollaei FKY (2014) Neuroprotective effects of Nigella sativa extract on cell death in hippocampal neurons following experimental global cerebral ischemia-reperfusion injury in rats. J Neurol Sci 337:74-79.
- Huseini HF, Kianbakht S, Mirshamsi MH, Zarch AB (2016) Effectiveness of Topical Nigella sativa Seed Oil in the Treatment of Cyclic Mastalgia: A Randomized, Triple-Blind, Active, and Placebo-Controlled Clinical Trial. Planta Med 82:285-288.
- Irwin ML, Smith AW, McTiernan A, Ballard-Barbash R, Cronin K, Gilliland FD, Baumgartner RN, Baumgartner KB, Bernstein L (2008) Influence of pre- and postdiagnosis physical activity on mortality in breast cancer survivors: the health, eating, activity, and lifestyle study. J Clin Oncol 26:3958-3964.
- Karna SKL (2013) Phytochemical Screening and Gas Chromatography –Mass Spectrometry and Analysis of Seed Extract of Nigella sativa, Linn. Int J Chem Studies 1:183-187.
- Khalife R, Hodroj MH, Fakhoury R, Rizk S (2016) Thymoquinone from Nigella sativa Seeds Promotes the Antitumor Activity of Noncytotoxic Doses of Topotecan in Human Colorectal Cancer Cells in Vitro. Planta Med 82:312-321.
- Kolahdooz M, Nasri S, Modarres SZ, Kianbakht S, Huseini HF (2014) Effects of Nigella sativa L. seed oil on abnormal semen quality in infertile men: A randomized, double-blind, placebocontrolled clinical trial. Phytomed 21:901-905.
- Mahdavi R, Heshmati J, Namazi N (2015) Effects of black seeds (Nigella sativa) on male infertility: A systematic review. J Herbal Med 5:133-139.
- Mahdavi R, Namazi N, Alizadeh M, Farajnia S (2015) Nigella sativa oil with a calorie-restricted diet can improve biomarkers of systemic inflammation in obese women: A randomized doubleblind, placebo-controlled clinical trial. J Clin Lipidol [In Press].
- Mahmoudvand H, Sepahvand A, Jahanbakhsh S, Ezatpour B, Ayatollahi Mousavi SA (2014) Evaluation of antifungal activities of the essential oil and various extracts of Nigella sativa and its main component, thymoquinone against pathogenic dermatophyte strains. J Mycol Médicale / J Medical Mycol 24:155-161.
- Majdalawieh AF, Fayyad MW (2015) Immunomodulatory and anti-inflammatory action of Nigella sativa and thymoquinone: A comprehensive review. Int Immunopharmacol 28:295-304.
- Manju S, Malaikozhundan B, Vijayakumar S, Shanthi S, Jaishabanu A, Ekambaram P, Vaseeharan B (2016) Antibacterial, antibiofilm and cytotoxic effects of Nigella sativa essential oil coated gold nanoparticles. Microb Pathogenesis 91:129-135.
- Manju S, Malaikozhundan B, Withyachumnarnkul B, Vaseeharan B (2016) Essential oils of Nigella sativa protects Artemia from the pathogenic effect of Vibrio parahaemolyticus Dahv2. J Invertebrate Pathol 136:43-49.
- Martindale JL, Holbrook NJ (2002) Cellular response to oxidative stress: signaling for suicide and survival. J Cellul Physiol 192:1-15.
- Mohtashami R, Huseini HF, Heydari M, Amini M, Sadeqhi Z, Ghaznavi H, Mehrzadi S (2015) Efficacy and safety of honey based formulation of Nigella sativa seed oil in functional dyspepsia: A double blind randomized controlled clinical trial. J Ethnopharmacol 175:147-152.
- Nadaf NH, Gawade SS, Muniv AS, Waghmare SR, Jadhav DB, Sonawane KD (2015) Exploring anti-yeast activity of Nigella sativa seed extracts. Industrial Crops Prod 77:624-630.
- Omar NM (2015) Nigella sativa oil alleviates ultrastructural alterations induced by tramadol in rat motor cerebral cortex. J Microscopy Ultrastructure [In Press].
- Orhon ZN, Uzal C, Kanter M, Erboga M, Demiroglu M (2016) Protective effects of Nigella sativa on gamma radiation-induced jejunal mucosal damage in rats. Pathol Res Pract doi: 10.1016/j. prp.2016.02.017.
- Beheshti F, Hosseini M, Vafaee F, Shafei MN, Soukhtanloo M. Feeding of Nigella sativa during neonatal and juvenile growth improves learning and memory of rats. J Traditional Complement Med 2015. 6: 146-152.
- Seghatoleslam M, Alipour F, Shafieian R, Hassanzadeh Z, Mohammad Amin Edalatmanesh MA, Sadeghnia HR, Hosseini M. The effects of Nigella sativa on neural damage after pentylenetetrazole induced seizures in rats. J Traditional Complement Med 2015. 6: 262-268.
- Ahmad S, Beg ZH. Evaluation of therapeutic effect of omega-6 linoleic acid and thymoquinone enriched extracts from Nigella sativa oil in the mitigation of lipidemic oxidative stress in rats. Nutri 2015. 32: 449-455.
- Gökce EC, Kahveci R, Gökce A, Cemil B, Aksoy N, Sargon MF, Kısa Ü, Erdoğan B, Güvenç Y, Alagöz F, Kahveci O. Neuroprotective effects of thymoquinone against spinal cord ischemia-reperfusion injury by attenuation of inflammation, oxidative stress, and apoptosis. J Neurosurg Spine 2016. 24: 949- 959.
- Salem NA, Mahmoud OM, Al Badawi MH, Gab-Alla AA. Role of Nigella sativa seed oil on corneal injury induced by formaldehyde in adult male albino rats. Folia Morphol (Warsz) 2016. doi: 10.5603/FM.a2016.0010.
- Salem NA, Mahmoud OM, Al Badawi MH, Gab-Alla AA (2016) Role of Nigella sativa seed oil on corneal injury induced by formaldehyde in adult male albino rats. Folia Morphol (Warsz) doi: 10.5603/FM.a2016.0010.
- Sayeed MSB, Shams T, Hossain SF, Rahman MR, Mostofa AGM, Kadir MF, Mahmood S, Asaduzzaman M (2014) Nigella sativa L. seeds modulate mood, anxiety and cognition in healthy adolescent males. J Ethnopharmacol 152:156-162.
- Seghatoleslam M, Alipour F, Shafieian R, Hassanzadeh Z, Mohammad Amin Edalatmanesh MA, Sadeghnia HR, Hosseini M (2015) The effects of Nigella sativa on neural damage after pentylenetetrazole induced seizures in rats. J Traditional Complement Med [In Press]
- Shahraki S, Khajavirad A, Shafei MN, Mahmoudi M, Tabasi NS (2016) Effect of total hydroalcholic extract of Nigella sativa and its n-hexane and ethyl acetate fractions on ACHN and GP-293 cell lines. J Traditional Complement Med 6:89-96.
- Simalango DM, Utami NV (2014) In-Vitro Antihelminthic Effect of Ethanol Extract of Black Seeds (Nigella sativa) Against Ascaris suum. Procedia Chemi 13:181-185.
- Suguna P, Geetha A, Aruna R, Siva GV (2014) Nigella sativa Linn. seed extract modulates the activity of ASC complex of NLRP3 inflammasome in rats subjected to experimental pancreatitis. Biomed Preventive Nutri 4:113-120.
- Sultan MT, Butt MS, Karim R, Ahmad AN, Suleria HAR, Saddique MS (2014) Toxicological and safety evaluation of Nigella sativa lipid and volatile fractions in streptozotocin induced diabetes mellitus. Asian Pac J Trop Dis 4:693-697.
- Tajmiri S, Farhangi MA, Dehghan P (2016) Nigella Sativa treatment and serum concentrations of thyroid hormones, transforming growth factor β (TGF-β) and interleukin 23 (IL-23) in patients with Hashimoto’s Thyroiditis. Eur J Integrative Med [In Press]