A component of the <i>Nigella sativa</i> plant as a radioprotector and antitumor drug

To date, natural species are widely used as pharmaceutical agents for many human diseases. One of these is the seeds of Nigella sativa and its constituent thymoquinone (TQ). Being a biologically active compound, TQ has a variety of therapeutic properties, including antioxidant, anti-inflammatory, antitumor and a number of others. TQ is an absorber of free and superoxide radicals, therefore it is a promising natural radioprotector against the immunosuppressive and oxidative effects of ionizing radiation. The review presents data on the radioprotective properties of TQ and some mechanisms of its activity. In addition, TQ exhibits antitumor activity by inhibiting cell proliferation, migration and invasion. Despite the fact that TQ induces apoptosis by regulating the expression of pro-apoptotic and anti-apoptotic genes in many types of cancer, the mechanism of action of TQ in oncological diseases has not yet been fully studied. Thus, this review highlights the mechanisms of action of TQ as a promising radioprotector and as a future candidate for antitumor therapy.