Introduction
Kalonji (Nigella sativa of Family Ranunculaceae) is a popular herbal plant, with white, yellow, pink, pale blue, and purplish delicate flowers. Its ripe fruit contains a large number of tiny black seeds and is used in traditional medicine systems such as Greece, Ayurveda, Siddha, and Bible. Kalonji benefits are it acts as an antimicrobial, immune stimulant, hypotensive, anti-inflammatory, anti-cancer, and antioxidant.
Common names
Kalonji in English is known as Black cumin, black seed, the seed of blessing. Arabic countries call is Al-Habba Al-Sauda and Al-Habba Al-Barakah, Habatul-barakah or Habbah Sawda and kalonji (Urdu), Siyah Daneh (Persian), çörek Out (Turkish) (1).
Geographical distribution
The plant commonly grows in Eastern Europe, the Middle East, and Western Asia. Kalonji is also found in Middle Eastern and Western Asian countries including Syria, Lebanon, Pakistan, India, and Afghanistan.
Nutritional value of kalonji or black cumin
Kalonji contains a high amount of protein (216 g kg-1), fat (406 g), crude fiber (84 g), and nitrogen-free extract (249 g) moreover kalonji is also rich in minerals and vitamins such as iron, (105 mg kg-1) copper (18 mg), zinc (60 mg) phosphorus (527 mg), calcium (1860 mg), thiamin (15.4 mg), niacin (57 mg), pyridoxine (5.0 mg) and folic acid (160 micrograms) (2).
Kalonji also contains 30% fixed oils (mainly fatty acids), 0.40–0.45% volatile oils, and other bioactive compounds like thymoquinone (up to 50%) besides p-cymene (40%), pinene (up to 15%), thymohydroquinone and dithymoquinone, etc.
Black cumin or Kalonji benefits
Kalonji and its oil are used to treat conditions and diseases like asthma, bronchitis, cough, diarrhea, dysentery, dyspepsia, fever, flatulence, jaundice, paralysis, and piles. It also helps in treating disorders like cardiovascular, digestive, immune, liver, respiratory, and kidney systems and acts as an antimicrobial, immune stimulant, hypotensive, anti-inflammatory, anti-cancer, antioxidant, hypoglycemic, spasmolytic, and bronchodilator. Let’s take a close look at some of these properties (3).
1. Treat the liver injury
Thymoquinone found in kalonji protects the liver from injury via inhibition of lipid peroxidation, increases radical scavenging, increases the activity of good enzymes, and decreases the activity of the bad enzyme (4).
2. Manage diabetes
Kalonji shows a wonderful effect on the treatment of diabetes by the reduction in the elevated level of blood glucose (5). It also helps to increase the insulin level, and antioxidant activity and improves glucose tolerance while decreasing intestinal glucose absorption and oxidative damage of DNA thus playing a therapeutic role in the treatment of diabetes (6).
3. Prevents stomach issue
The presence of thymoquinone in kalonji prevents diarrhea, reduces body weight loss, and prevents colitis-induced damage thus helpful for the treatment of patients with inflammatory bowel disease (7). Furthermore, kalonji also protects gastric mucosa caused by alcohol and promotes ulcer healing (8).
4. Antimicrobial properties
Thymoquinone obtained from kalonji and its oil fight against different Gram-negative, and Gram-positive bacteria, viruses, parasites, schistosoma and fungi such as Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogene Helicobacter pylori, Pseudomonas aeruginosa, Proteus vulgaris, Escherichia coli, Candida albicans, Candida tropicalis, Aspergillus flavus, Aspergillus parasiticus, Chrysosporium evolceanui, Chrysosporium tropicum, Trichophyton simii, Trichophyton rubrum Microsporum gypseum, Schistosoma mansoni, hepatitis C virus, and Plasmodium yoelii, therefore, kalonji may useful for the treatment of various microbial diseases (9).
5. Analgesic, Anti-inflammatory, and Immunomodulatory properties
Kalonji oil and extract contain a high amount of thymoquinone which possesses antinociceptive and anti-inflammatory effects and is useful in treating encephalomyelitis, colitis, peritonitis, odema, and arthritis pain (10). Moreover, kalonji helps to activate immune responses for fighting various diseases (11).
6. Keep the heart-healthy
Metabolic syndrome is an important risk reason for cardiovascular disease however kalonji shows a beneficial effect on the treatment of metabolic syndrome and cardiovascular disease risk factors including high blood pressure, obesity, dyslipidemia, and high blood glucose (12).
7. Treat muscle injury
The presence of thymoquinone in kalonji shows protective effects against muscle tissue injury and also possesses muscle relaxation properties (13).
8. Anticancer properties
Kalonji seed and its oil is a rich source of thymoquinone which enhances antioxidant defenses in the body, induces apoptosis, and inhibits cancer cell growth thus fighting against cancer in the blood system (leukemia), colon, pancreatic, lung, kidney, liver, prostate, breast, cervix and skin (14).
9. Lower cholesterol level
Kalonji seed helps to decrease serum low-density lipoprotein, and cholesterol levels and increases serum high-density lipoprotein cholesterol levels as well as glutathione content thus preventing the risk of atherosclerosis (15, 16). Furthermore, the intake of kalonji (2 g/ day) combined with anaerobic exercise also improves cholesterol levels in sedentary overweight females (17).
10. Treat Asthma
Kalonji extracts act as a bronchodilator agent which opens (dilate) the airways (bronchial tubes) and increases the airflow to the lungs by relaxing bronchial muscles and allowing people who have difficulty breathing to breathe better, therefore, kalonji alleviates airway inflammation and controls asthma symptoms (18).
11. Treat hypertension
Daily intake of kalonji seed extract for 2 months significantly lowers both systolic and diastolic blood pressure by decreasing the creatinine and increasing the glutathione to the normal level which is due to the presence of thymoquinone in kalonji thus treating hypertension (19, 20).
12. Treat kidney injury
Renal ischemia leads to acute renal (kidney) failure however kalonji oil helps to reduce blood urea nitrogen in serum, protect tissues from oxidative damage, prevent organ damage, and preserve the normal morphology of the kidney (21).
13. Good for skin and hair
Kalonji benefits due to the rich amount of bioactive compounds such as thymoquinone, thymohydroquinone, dithymoquinone, thymol, nigellicine, carvacrol, nigellimine, nigellicine, nigellidine, and alpha-hederin which show a wonderful effect on wound healing, psoriasis, acne vulgaris, skin cancer, pigmentation, and many cosmeceutical applications like body soap cleaner, complete hair care, improved shine, texture, and volume, and reduced hair problem, skin cream, etc (22).
14. Keep the brain healthy
Black cumin or kalonji benefits are due to its bioactive constituents enhancing ‘head and brain’ function, improving memory impairment, anxiety, depression, epilepsy, neurotoxicity, pain, and delaying age-associated cognitive declines such as dementia, Alzheimer’s disease, and aggression (23).
15. Treat allergic diseases
Kalonji oil is effective in treating various allergic diseases such as allergic rhinitis, bronchial asthma, and atopic eczema (24).
Side effect of kalonji
Kalonji contains a very low degree of toxicity. There are only 2 cases of contact dermatitis that have been reported so far. Therefore, precaution should be needed before application. Moreover, the administration of seed extract or its oil did not induce significant adverse effects on liver or kidney functions (25).