Table 2.

Bioactive constituents of N. sativa Linn affecting the gastrointestinal system.

Active constituents	Proposed mechanism	References
Thymoquinone	Cytoprotection, hydroxyl radical scavenging activity, digestive, immune boosting, Carminative	(Ahmad and Beg, 2013)
Fatty acids: palmitic acid, myristic acid, stearic acid, oleic acid, arachidonic acid, linoleic acid, linolenic acid, eicosadienoic acid	Immune boosting, anti-inflammatory and maintain skin moisture	(Ahmad and Beg, 2013; Ramadan and Morsel, 2002)
Alkaloids: nigelline-N-oxide, nigellone, nigellimine, triterpene-alpha-hederin, Saponin	Anti-histamine, anticancer and anti-leishmanial property	(Ahmad et al., 2013a; Ahmad and Beg, 2013)
α, β and γ-tocopherols	Antioxidant, immune boosting	(MatthauS and Ozcan, 2011)
Minerals: iron, calcium, zinc, copper, phosphorous	Chelating action: Inhibition of generations of free radical by stabilization of transition metals, thereby reducing free radicals damage	(Atta, 2003)
Vitamins: carotene, thiamine, riboflavin, niacin, folic acid	Immune boosting, free radical scavenger and antioxidant	(Ahmad and Beg, 2013)