Black Seed (Nigella sativa L) is an herbaceous plant and belongs to the Ranunculaceae family. The plant is also known by other names e.g., Black Cumin, Fitch (Biblical), Love in the Mist, Black Caraway Seed, Habbatul Baraka (the Blessed Seed), Kalonji (Urdu and Hindi) Shonaiz (Persian) and by its botanical name "Nigella Sativa". The plants of Nigella Sativa are found throughout Pakistan and India in the form of bushes. The height of the plant is approximately half a meter. It possesses blue flowers. It originated in Turkey and Italy. Later on, it was brought to Asia by physicians and cultivated in Pakistan and India. Seeds are triangular in shape, black in color and possess a strong pungent smell, and contain a considerable amount of oil. The Seed of this plant have proclaimed medicinal usage dating back to the ancient times.

 

Alanine, arginine, isoleucine, leucine, lysine, tryptophan, tyrosine, threonine, asparagine, cystine, glycine, ascorbic acid (vitamine C), dehydroascorbic acid, glutamic acid, campesterol, carvone, cymene, d-limonene, eicosadienoic acid, linoleic acid, linolenic-acid, lipase, methionine, myristic acid, oleic acid, palmitic acid, phenylalanine, phytosterols, beta-sitosterol, alpha-spinasterol, stearic acid, stigmasterol, tannin, thymohydroquinone, thymoquinone, nigellin, nigellone, glucose, calcium, iron, copper, zinc, phosphorus potassium.

 

Black Seeds obtained from several different countries have been analyzed and shown to have a high nutritional potential e. g., protein, fat, carbohydrates, thiamin, riboflavin, pyridoxine, niacin, folacin, calcium, iron, copper, zinc, phosphorus.

Anti-inflammatory

It has been thought that nigellone, a carbonyl polymer of thymoquinone, thymoquinone and thymohydroquinone are the active principles responsible for the anti-inflammatory properties of Black Seeds. The results have suggested nigellone (a quinine polymer, present in Black Seed) as a promising substance for the prevention and control of bronchial asthma and other allergic conditions³. In another study, the expressed fixed oil of Black Seed has shown to have strong inhibitory cyclooxygenase and 5-lipoxygenase pathway of arachidonic acid metabolism activity in rat ⁴. There were other several studies suggested the efficacy of Black Seed extract against inflammatory conditions.

Antioxidant Activity

The combined effect of an alcoholic extract of Black Seed (Nigella sativa) and UV irradiation on animal muscle has been investigated. The highest percentage of hydrogen peroxide inhibition in hepatic microsomes of mice treated with lindane was shown by Black Seed extract. On the basis of this and other studies results it has been suggested that a nutritional supplement of the Black Seed extract may offer better protection to the human body against oxidative damage than supplementation with synthetic antioxidants^5-7. 

Antimicrobial properties

The antimicrobial properties of Black Seeds have been investigated. In a study extract of Black Seeds extract was tested against pathogenic bacteria Staphylococcus aureus, Pseudomonas aeruginosa and pathogenic yeast such as a Candida albicans, that are known to cause disease in human. The extract showed concentration dependent inhibition of all the microorganisms tested⁸. In another study, an antidiarrhoeals (miscellaneous agents found useful in the symptomatic treatment of diarrhoea. They have no effect on the agent(s) that cause diarrhoea, but merely alleviate the condition) activity was identified with the Black Seed extract⁹. 

Immunological activity

It has been found that the plant extract modulates the immune system by increasing the number and activity of immune competent cells in humans¹⁰. It has also been found that Black Seed (Nigella sativa) extract had some inhibitory effect on the human immunodeficiency virus (HIV) protease but, however, the active principle(s) responsible for this activity were not identified¹¹. A study was carried out to see effect of Black Seed on human T-cells. For this purpose Black Seed was tested in volunteer with a low helper T-cell to suppressor T-cell ratio. The results indicted an increase in the helper T-cell population in the experimental group. Further, the helper T-cell to suppressor T-cell ratio increased while the ratio within the control groups remain the same¹². In another study scientists have shown that pure Black Seed Seeds stimulate Th1 lymphocytes and selectively switch-off the eosinophilic airway inflammation. Th1 stimulating agents are used in treatment of asthma and allergy. The BCG-like Th1 stimulation is also used in treating diseases in which the body defensive mechanism is a cell-mediated immunity, including viral infections, including influenza and common cold, chronic and recurrent urinary tract infection, pelvic inflammatory diseases as neuroimmune appendicitis, cancer, Crohn's disease and facial palsy¹³   

Anticestodal activities

The essential oil of the Black Seed has been reported to exhibit fairly good antiparasitic (anthelimintic) activity against earthworms (Pheritima posthuma), tapeworms (Taenia solium), hookworms (Bunostomum trigonocephalum) and nodular warms (Oesophagostomum colombionum). The anthelimintic activity against earthworms and tapeworms was found to be comparable with that of the chemical agent piperizine phosphate^14,16

Anticancer activity

Certain fatty acids of Black Seed Seeds were studied for antitumour activities against Ehrlich ascites carcinoma (EAC), Dalton's lymphonia ascites (DLA) and Sarcoma-180 (S-180) cells. The results of in vitro and in vivo antitumor experiments were found that the active principle present in Black Seeds (certain fatty acids) was cytotoxic for EAC cells and KB cells¹⁷. In another study reported that the effect of the active principle isolated from Black Seed is inhibiting chemically induced skin carcinogenesis. Intraperitoneal administration of Black Seed (Nigella sativa) extract was shown to prevent the incidents of soft tissues sarcomas and reduced tumor diameters in the treated group¹⁸. Black Seed extract also showed anti-angiogenic activity. A study confirmed that the plant extract inhibits cancer and endothelial cell progression, decrease the production of the angiogenic protein-fibroblastic growth factor (FGF) made by tumor cells and inhibits growth factor for endothelial cells. The activity of Black Seed extract blocked the tumor growth and dissemination in metastasis and have remarkable promises for clinical use¹⁹. The potential antitumor effect of thymoquinone (TQ), the main constituent of the volatile oil of Black Seed, on fibrosarcoma induced by 20-methylcholanthrene (MC) in male Swiss albino mice was investigated in vivo and in vitro¹⁹. The data indicate the potential of TQ as a powerful chemopreventive agent against MC-induced fibrosarcoma tumors. The possible modes of action of TQ may be through its antioxidant activity and interference with the DNA synthesis coupled with enhancement of detoxification processes. Thymoquinone and dithymoquinone are also used in treatment of parental and multi-drug resistant human cancers²⁰.