Anti- Cancer Activity of Thymoquinone in Gasterointestinal Tract: A Comprehensive Review

Gastrointestinal (GI) cancers are known as malignant condition of the GI system associated with the organs which have role in digestion. More cancers and more deaths from cancer are related to the cancers occurred in this system. Nigella sativa(N. sativa) seeds which are traditionally used as a food additive, preservative or a spice in many cultures, has been considered for treatment of various diseases. Thymoquinone (TQ) is the main bioactive component of the volatile oil of N. sativa seeds. Therapeutic effects of TQ for treatment of various diseases such as cancers, in both in vivo and in vitro conditions, have recently been interested.  In this comprehensive review, we summarized the new studies related to anti- cancer activity of TQ associated with its possible mechanisms  in GI  cancers including oral cancer, esoghageal cancer, gastric cancer, colorectal cancer and also liver and pancreatic cancers.  It is concluded that TQ could be considered as an anticancer agent alone or in combination with chemotherapeutic drugs in treatment of GI tract cancers, however well designed clinical trials in humans are required to confirm these effects.