Potential role of thymoquinone to treat gastrointestinal cancers: insights into its molecular mechanisms

Gastrointestinal (GI) malignancies, including esophageal cancer, gastric cancer, and colon cancer, are associated with high mortality rates worldwide. Thymoquinone is one of the main bioactive components of Nigella sativa, and it has been documented to have anticancer effects including GI cancer. Thymoquinone inhibits GI cancer progression by inducing cell cycle arrest, apoptosis, and oxidative stress and inhibiting inflammation, migration, invasion, metastasis, histone deacetylases, STAT3, PI3K/AKT/mTOR, and Wnt/beta-catenin signaling pathways. Although the beneficial effects of thymoquinone have been documented, some limitations, including poor bioavailability and hydrophobicity, have hindered its clinical application. Nanotechnology approaches bypass these limitations. In this review article, we outline the different cellular and molecular pathways influenced by thymoquinone and its nanoformulations in GI cancer.