Gastrointestinal effects of Nigella sativa and its main constituent, thymoquinone: a review

Gastrointestinal (GI) diseases affect a large number of people all over the world. Uncontrolled acid secretion and occurrence of gastric ulcers are common disorders of GI tract which pose serious problems to human health. Many synthetic drugs have been used to treat GI disorders but a definite cure has not been discovered so far and the available medications cause several side effects. Nigella sativa (N. sativa) (Ranunculacea) has several therapeutic effects which are attributed to its constituents like nigellicine, nigellidine, thymoquinone, dithymoquinone, thymol and carvacrol. Several beneficial pharmacological properties of this plant such as anti-oxidant, anti-bacterial, anti-histaminic, anti-hypertensive, hypoglycemic, anti-fungal, anti-inflammatory, anti-cancer and immunomodulatory effects were reported and different therapeutic properties such as reliving bronchial asthma, jaundice, hydrophobia, paralysis, conjunctivitis, piles, skin diseases, anorexia, headache, dysentery, infections, obesity, back pain, hypertension and gastrointestinal problems, have been described for the seeds of N. sativa and its oil. The present review provides a detailed summery of scientific researches regarding gastrointestinal effect of N. sativa and its main constituent, thymoquinone.