Power-packed cousin to Cannabis Sativa
Nigella sativa is an annual flowering plant. It grows to 20–30 cm (7.9–11.8 inch) tall and has linear lanceolate leaves. The delicate flowers have 5-10 petals and the colors are usually yellow, white, pink, pale blue or pale purple. The fruit of plant is large and inflated capsule composed of 3-7 united follicles, that each of them has numerous seeds. The black colored seeds are flattened, oblong and angular, funnel shaped, with the length of 0.2 cm and 0.1 cm wide (1).
This plant is known by numerous names, for example black cumin (English), black caraway seeds (USA), shonaiz (Persian) and kalajira (Bangali) (2).
Extensive studies were done to identify the composition of the black cumin seed, the ingredients of N. sativa seed includes: fixed oil, proteins, alkaloid, saponin and essential oil.
The fixed oil (32-40 %) contains: unsaturated fatty acids which includes: arachidonic, eicosadienoic, linoleic, linolenic, oleic, almitoleic, palmitic, stearic and myristic acid as well as beta-sitosterol, cycloeucalenol, cycloartenol, sterol esters and sterol glucosides (3–5).
The volatile oil (0.4-0.45 %) contains saturated fatty acids which includes: nigellone that is the only component of the carbonyl fraction of the oil, Thymoquinone (TQ), thymohydroquinone (THQ), dithymoquinone, thymol, carvacrol, α and β-pinene, d-limonene, d-citronellol, p-cymene volatile oil of the seed also contains: p-cymene, carvacrol, t-anethole, 4-terpineol and longifoline (3, 4, 6).
Black cumin seed have two different forms of alkaloids: isoquinoline alkaloid that includes: nigellicimine, nigellicimine n-oxide and pyrazol alkaloid that includes: nigellidine and nigellicine (3, 4).
By sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) the fractionation of whole N. sativa seeds was done which shows the bands ranged from 94 to 100 kDa molecular mass (7).
Black cumin seeds also have saponin and alpha hederine and in trace amount has carvone, limonene and citronellol, as well as provide relatively good amounts of different vitamins and minerals such as Fe, Ca, K, Zn, P, Cu (3, 4).
Most of the pharmacological effects are due to quinine constituent, of which TQ is the mainly abundant. TQ possess anticonvulsant activity (8–10), antioxidant (11), anti-inflammatory (12), anti-cancer (13), antibacterial (14) and antifungal activity (15).