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, high blood pressure, asthma, bronchitis and as a protective agent during radiation therapy. Human studies are lacking.
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 forestomach 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, black cumin seed decreased hypertension in anesthetized rats. This has not been studied in humans
To decrease symptoms of asthma and bronchitis
Laboratory studies showed that black cumin seed inhibits the release of histamine from rat cells, suggesting a possible effect in asthma and bronchitis.
Warnings
Black cumin seed oil may cause allergic reaction.
Black cumin seeds may make certain chemotherapy drugs and radiation therapy less effective. Patients should talk to doctors or pharmacists before using black cumin during cancer treatment.
Do Not Take If
You are pregnant (Black cumin seeds can affect smooth muscle contractions in the uterus.)
Scientific Name
Nigella sativa
Common Name
Black seeds, Black cumin, fennel flower, black caraway, nutmeg flower, Roman coriander, 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. In vivo and in vitro studies show that constituents from Nigella sativa may have immunomodulatory
(1) (2) (11), antioxidant
(15), antiparasitic
(13) and hepatoprotective effects
(14). Some studies also suggest
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). In another study, Nigella sativa oil, when injected, demonstrated a protective effect against tissue damage caused by radiation
(15). Human studies for these indications are lacking. Other data indicate that nigellone, a component of
Nigella sativa seed, might be useful in the treatment of diarrhea, asthma, and hypertension
(5) (10).
Nigella sativa may also relieve symptoms of allergic reactions
(12), but allergic contact dermatitis associated with topical use was reported
(19).
Adverse effects are rare. However, 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
Constituents
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, gluthathione, and SOD in animal models
(6) (7) (9). This may explain
Nigella sativa's hepatoprotective effects
(3) (4). 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). 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).
Adverse Reactions
There is low level of toxicity (3).
In animals, 10mL/kg of 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 of 2g/kg or more caused damage to the liver and kidneys in rats (7).
Topical use of pure oil of Nigella sativa caused allergic contact dermatitis in two people with maculopapular eczema (19).
Herb-Drug Interactions
Nigella sativa has antioxidant effects. In theory, it may interfere with the actions of certain chemotherapy drugs and radiation therapy.
Nigella sativa may have additive hypotensive effect when used with other antihypertensive or diuretic drugs.
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).
References
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.