Nigella sativa

Health Care Professional Information

Scientific Name
Nigella sativa
Common Name

Black seeds, Black cumin, black caraway, black onion seed, kalonji

Clinical Summary

Nigella sativa is a flowering plant found throughout India, Arabia, and Europe. The seeds, commonly known as Black Seeds or Black Cumin, are used in cooking and in traditional medicine for inflammation, infection, and cancer. Constituents from Nigella sativa demonstrated immunomodulatory (1) (2) (11), antioxidant (15), antiparasitic (13) and hepatoprotective effects (14) in vitro and in animal studies. Nigella sativa seed, may be useful in the treatment of asthma (21), hypertension (5) (10) (22), rheumatoid arthritis (26), dyspepsia (27) and diabetes (28) in humans. Thymoquinone, a major constituent of Nigella sativa, exhibited anti-epileptic effects in children with refractory seizures (23). Nigella sativa may also relieve symptoms of allergic reactions (12), but allergic contact dermatitis was reported with topical use (19).
Evidence also suggests that Nigella sativa has anticancer properties. The constituents of the seeds, including thymoquinone, reduced the growth and size of tumors in rats (4) (5) (6) (7) (8) (9) ; thymoquinone also enhanced the anticancer effects of doxorubicin in certain cancer cell lines (25). Nigella sativa oil, when injected, demonstrated a protective effect against tissue damage caused by radiation in rats (15). Human studies are lacking.

Adverse effects are rare, but high doses of Nigella sativa oil caused liver and kidney damage in rats (7).

Purported Uses
  • Antioxidant
  • Anticarcinogenic
  • Anti-inflammatory
  • Asthma, bronchitis
  • Rheumatism
  • Hypertension
  • Hepatoprotective
  • Active Ingredients:
  • Thymoquinine (TQ) (mainly in essential oil)
  • Dithymoquinone (DTQ) (nigellone)
  • Thymol (THY)
  • Thymohydroquinone (THQ)



  • Other Components:
  • Alpha-hederin, a triterpene saponin in the seeds
  • Monosaccharides (glucose, rhamnose, xylose, arabinose)
  • Unsaturated fatty acids (linoleic acid, oleic acids (in fixed oil)
    (3) (17)



Mechanism of Action

Thymoquinone, one of the chief constituents of Nigella sativa oil has antioxidant effects and restored the levels of lactate dehydrogenase, glutathione, and SOD in animal models (6) (7) (9). This may explain Nigella sativa's hepatoprotective effects (3) (4). Studies have also shown that Nigella sativa oil has anti-inflammatory property by inhibiting cyclooxygenase and lipoxygenase (18). An in vitro study demonstrated that nigellone, a constituent of the crude extract of Nigella sativa seeds, inhibited histamine release from rat peritoneal mast cells (10) and may reduce allergy symptoms in humans (12). Nigella sativa decreased hypertension in rats possibly due to its diuretic effects (5). It was also shown to decrease uterine smooth muscle contractions (14).

The antioxidant effect is thought to protect tissues from radiation injury (15). However, it is not clear if this would also make radiation therapy less effective. Thymoquinone administered to mice reduced the incidence of stomach tumors (7). Possible mechanisms include inhibition of DNA synthesis (7), and promotion of apoptosis by inhibiting cell growth in G1 phase (8).

Adverse Reactions
  • In animals, the fixed oil of Nigella sativa orally administered to rats for up to 12 weeks did not produce any significant changes in hepatic enzymes and did not cause mortality (16). However, high doses may cause liver damage (29).
  • Topical use of pure oil of Nigella sativa caused allergic contact dermatitis in two people with maculopapular eczema (19).
Herb-Drug Interactions
  • Cytochrome P450 substrates: Nigella sativa inhibits CYP2D6 and CYP3A4 and can affect the intracellular concentration of drugs metabolized by these enzymes (24).
Herb Lab Interactions

In animal studies, Nigella sativa oil decreased serum glucose, triglyceride, cholesterol levels and leukocyte and platelet counts. But there was an increase in hematocrit and hemoglobin levels (16) (20).

  1. Haq A, Lobo PI, Al-Tufail M, et al. Immunomodulatory effect of Nigella sativa proteins fractionated by ion exchange chromatography. Int J Immunopharmacol 1999;21(4):283-95.
  2. Haq A, Abdulatif M, Lobo PI, et al. Nigella sativa: effect on human lymphocytes and polymorphonuclear leukocyte phagocytic activity. Immunopharmacology 1995;30(2):147-55.
  3. Ali BH and Blunden G. Pharmacological and toxicological properties of Nigella sativa. Phytother Res 2003;17(4):299-305.
  4. Dada MH and Abdel-Rahman MS. Hepatoprotective activity of thymoquinone in isolated rat hepatocytes.Toxicol Lett 1998. 95(1): p. 23-9.
  5. El Tahir KE, Ashour MM, al-Harbi MM. The cardiovascular actions of the volatile oil of the black seed (Nigella sativa) in rats: elucidation of the mechanism of action.Gen Pharmacol 1993;24(5):1123-31.
  6. El-Abhar HS, Abdallah DM, Saleh S. Gastroprotective activity of Nigella sativa oil and its constituent, thymoquinone, against gastric mucosal injury induced by ischaemia/reperfusion in rats. J Ethnopharmacol 2003;84(2-3):251-8.
  7. Badary OA, et al. Inhibition of benzo(a)pyrene-induced forestomach carcinogenesis in mice by thymoquinone. Eur J Cancer Prev 1999;8(5):435-40.
  8. Gali-Muhtasib H, Diab-Assaf M, Boltze C, et al. Thymoquinone extracted from black seed triggers apoptotic cell death in human colorectal cancer cells via a p53-dependent mechanism. Int J Oncol 2004;25(4): 857-66.
  9. Ait Mbarek L, et al. Anti-tumor properties of blackseed (Nigella sativa L.) extracts. Braz J Med Biol Res 2007;40(6):839-47.
  10. Chakravarty N. Inhibition of histamine release from mast cells by nigellone. Ann Allergy 1993;70(3):237-42.
  11. Islam SN, Begum P, Ahsan T, et al. Immunosuppressive and cytotoxic properties of Nigella sativa. Phytother Res 2004;18(5):395-8.
  12. Kalus U, Pruss A, Bystron J, et al. Effect of Nigella sativa (black seed) on subjective feeling in patients with allergic diseases. Phytother Res 2003;17(10):1209-14.
  13. Mohamed AM, Metwally NM, Mahmoud SS. Sativa seeds against Schistosoma mansoni different stages.Mem Inst Oswaldo Cruz 2005;100(2):205-11.
  14. Iddamaldeniya SS, Thabrew MI, Wickramasinghe SM, et al. A long-term investigation of the anti-hepatocarcinogenic potential of an indigenous medicine comprised of Nigella sativa, Hemidesmus indicus and Smilax glabra. J Carcinog 2006;11.
  15. Cemek M, Enginar H, Karaca T, Unak P. In vivo radioprotective effects of Nigella sativa L oil and reduced glutathione against irradiation-induced oxidative injury and number of peripheral blood lymphocytes in rats.Photochem Photobiol 2006;82(6):1691-6.
  16. Zaoui A, Cherrah Y, Alaoui K, et al. Effects of Nigella sativa fixed oil on blood homeostasis in rat. J Ethnopharmacol 2002;79(1):23-6.
  17. Ghosheh OA, Houdi AA, Crooks PA. High performance liquid chromatographic analysis of the pharmacologically active quinones and related compounds in the oil of the black seed (Nigella sativa L.). J Pharm Biomed Anal 1999;19(5):757-62.
  18. Houghton PJ, Zarka R, de las Heras B, Hoult JR. Fixed oil of Nigella sativa and derived thymoquinone inhibit eicosanoid generation in leukocytes and membrane lipid peroxidation. Planta Med 1995;61(1):33-6.
  19. Steinmann A, Schatzle M, Agathos M, Breit R. Allergic contact dermatitis from black cumin (Nigella sativa) oil after topical use. Contact Dermatitis 1997;36(5):268-9.
  20. Zaoui A, Cherrah Y, Mahassini N, et al. Acute and chronic toxicity of Nigella sativa fixed oil. Phytomedicine 2002;9(1):69-74.
  21. Boskabady MH, Javan H, Sajady M, Rakhshandeh H. The possible prophylactic effect of Nigella sativa seed extract in asthmatic patients. Fundam Clin Pharmacol. 2007 Oct;21(5):559-66.
  22. Dehkordi FR, Kamkhah AF. Antihypertensive effect of Nigella sativa seed extract in patients with mild hypertension. Fundam Clin Pharmacol. 2008 Aug;22(4):447-52.
  23. Akhondian J, Kianifar H, Raoofziaee M, et al. The effect of thymoquinone on intractable pediatric seizures (pilot study). Epilepsy Res. 2011 Jan;93(1):39-43.
  24. Al-Jenoobi FI, Al-Thukair AA, Abbas FA, et al. Effect of black seed on dextromethorphan O- and N-demethylation in human liver microsomes and healthy human subjects. Drug Metab Lett. 2010 Jan;4(1):51-5.
  25. Effenberger-Neidnicht K, Schobert R. Combinatorial effects of thymoquinone on the anti-cancer activity of doxorubicin. Cancer Chemother Pharmacol. 2011 Apr;67(4):867-74.
  26. Gheita TA, Kenawy SA. Effectiveness of Nigella sativa oil in the management of rheumatoid arthritis patients: a placebo controlled study. Phytother Res. 2012 Aug;26(8):1246-8.
  27. Salem EM, Yar T, Bamosa AO, et al. Comparative study of Nigella Sativa and triple therapy in eradication of Helicobacter Pylori in patients with non-ulcer dyspepsia. Saudi J Gastroenterol. 2010 Jul-Sep;16(3):207-14.
  28. Bamosa AO, Kaatabi H, Lebdaa FM, et al. Effect of Nigella sativa seeds on the glycemic control of patients with type 2 diabetes mellitus. Indian J Physiol Pharmacol. 2010 Oct-Dec;54(4):344-54.
  29. Khader M1, Bresgen N, Eckl PM. In vitro toxicological properties of thymoquinone. Food Chem Toxicol. 2009 Jan;47(1):129-33. doi: 10.1016/j.fct.2008.10.019.

Consumer Information

How It Works



BOTTOM LINE: Black cumin seed has not been shown to treat cancer in humans.
Black cumin seed is used for cooking and in medicine in India, Arabia, and Europe. Laboratory studies have shown that some components have antioxidant and anti-inflammatory effects. Therefore, there is some speculation that black cumin seed may be useful in the treatment of cancer and protect against the side effects of radiation therapy, but these have been proven in humans. Early phase studies suggest that black cumin seed may help to control high blood pressure, asthma, diabetes, and rheumatoid arthritis.  



Purported Uses
  • To treat cancer
    Animal studies have shown that black cumin seed can stop the growth of tumor cells and reduce the incidence of tumors. However, the effects in humans are unclear.
  • To protect the body from the adverse effect of radiation therapy
    Animal studies have shown that black cumin seed oil, when injected, may protect against tissue damage caused by radiation. However, the effects in humans are unknown.
  • To decrease hypertension
    In one study in humans, daily use of black cumin seed extract for 2 months may have help to lower blood pressure in patients with mild hypertension.
  • To decrease symptoms of asthma
    An early phase study suggests black cumin seed may help to prevent the asthmatic symptoms. More research is warranted.  
  • To treatment rheumatoid arthritis
    One study shows black cumin seed oil when taken orally, can help reduce symptoms of rheumatoid arthritis
Do Not Take If
  • If you are taking drugs that are substrates of Cytochrome P450 3A4 and 2D6 (Nigella sativa may increase the risk of side effects of these drugs).
Side Effects
  • High doses of Nigella sativa caused liver and kidney damage in rats.
  • Topical use of Nigella sativa caused allergic reactions.
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