KalOnji seeds and their oil have a long history of folklore usage in Arabian and Indian civilisation and are used in food as well as medicine. The seeds are used as flavouring, to improve digestion and produce warmth, especially in cold climates. They are sometimes scattered in the folds of woollen fabrics to preserve them from insect damage.
The plant is indigenous to the Mediterranean region but now found widely in Jammu, Kashmir, Himachal Pradesh, Bihar, Assam and Punjab. The herb is also cultivated in Bengal and north-east India.
A small prostrate annual herb about 45 cm high (Plate 39), 2-3 slender leaves pinnatisect, 2-4 cm long cut into linear segment, segments oblong-Ian ceo late. Flowers pale, blue on solitary long peduncles, seeds trigonous and black in colour.
Kalonji seeds are used as a carminative, aromatic, stimulant, diuretic, anthelmintic, galactagogue and diaphoretic. They are used as a condiment in curries. A tincture prepared from the seeds is useful in indigestion, loss of appetite, diarrhoea, dropsy, amenorrhoea and dysmenorrhoea and in the treatment of worms and skin eruptions. Externally the oil is used as an antiseptic. To arrest vomiting, seeds are roasted and given internally.
In ruminants seeds are used as a galactagogue in cases of reduced milk flow and as an antioxytocic agent during pregnancy and birthing to retain placenta.
The major alkaloids are nigellidine, nigellicine and nigellimine.
A number of quercetin and kaempferol glycosides have been isolated!
The seeds have been reported to contain a he de ragen in saponin, melanthin and melanthigenin.
Cholesterol, campesterol, stigmasterol, ?-Sitosterol and a-spinastero.
Thymoquinone, thymol, carvone dithymoquinone, monoterpenes including d-limonene, p-cymene and (+) citronellol have been isolated.
Linoleic acid, palmitic acid, stearic acid and oleic acid are present.
Antimicrobial activity: Nigella sativa exhibited strong antimicrobial activity against Salmonella typhi, Pseudomonas aeruginosa and others. The essential oil has been shown to have activity against Gram-positive and Gram-negative bacteria. However, sensitivity against Gram-positive bacteria such as Staphylococcus aureus and Vibrio cholerae was found to be stronger. Bacteria like Staph. aureus, Strep. pyogenes and Strep. viridans are more susceptible to Nigella sativa. In an in vitro study, volatile oil showed activity comparable to ampicillin. The activity of the volatile oil also extended to drug-resistant strains of Shigella spp, Vibrio cholerae and Escherichia coli and was found to have a . synergistic action with streptomycin and gentamicin.
Hepatoprotective activity: Thymoquinone, one of the active constituents of Nigella sativa, is reported to have hepatoprotective activity." An in vitro study showed the protective effect against tert-butyl hydroperoxide (TBHP)-induced oxidative damage to hepatocytes. The activity was demonstrated by a decreased leakage of alanine transaminase (ALT), aspartic transaminase (AST) and decreased trypan blue uptake, in comparison to the control TBHP-treated hepatocytes.
Antidiabetic activity: Significant hypoglycaemic activity has been reported and is thought to be due to the essential oil present. Clinical studies have confirmed these results and suggest that the antidiabetic action of the plant extract may be mediated partly through decreased hepatic gluconeogenesis.
Antiinflammatory activity: Asthma and arthritis are chronic inflammatory disorders involving a variety of inflammatory mediators and different pathways. The fixed oil and thymoquinone from the seeds were found to inhibit eicosanoid generation in leucocytes and membrane lipid peroxidation and a significant reduction in rat paw oedema and a reduction in granuloma pouch weight were also observed. Nigellone in low concentration is effective in inhibiting the histamine release from the mast cells, which supports an antiasthmatic role for the plant. Antifertility adivity: The antifertility activity of Nigella sativa in male rats has been established, shown by an inhibition of spermatogenesis and a significant reduction in sialic acid content of the testis, epididymis, seminal vesicles and prostate. A weak oestrogenic activity of the seeds was indicated with antiimplantational effects in experimental models.
Antioxytocic adivity: Preliminary reports suggest antioxytocic properties, in that a reversible inhibition of spontaneous smooth muscle contraction and inhibition of uterine smooth muscle contraction induced by oxytocin stimulation have been observed in rat and guinea pig.
Cytotoxic adivity: Cytotoxic and immunopotentiating effects of Nigella sativa have been established. The long chain fatty acids are thought to contribute to the antitumour activity. The extract shows a modulatory effect in cisplatin-induced toxicity in mice and a protective effect against cisplatin-induced falls in haemoglobin levels and leucocyte counts. A cytotoxic effect of Nigella sativa was observed by the retardation of ascites growth in a Dalton's lymphoma ascites model.
Anthelmintic adivity: Nigella sativa was found to have an anthelmintic activity against tapeworm comparable to that of piperazine. The pure essential oil showed activity against Monezia in sheep comparable to niclosamide.
Analgesic adivity: The essential oil produced significant analgesic activity using chemical and thermal noxious stimuli methods such as acetic acid-induced writhing, hot plate and tail flick tests. The activity was antagonised by naloxone, suggesting that the effects were mediated through opioid receptors.
Other adivites: Other reports include hypocholesterolaemic, antihypertensive and galactagogue effects.
Seeds of Nigella sativa have a long history of use for food and medicinal purposes. No adverse or side effects have been reported when used within the recommended dosage, although dermatitis has been reported.