A review of Nigella sativa and its active principles as anticancer agents

Nigella sativa or black seed or Nigella sativa L. member of buttercup family Ranunculacea, is extensively practiced to prevent and treat various disease, which includes cancer, diabetes, obesity, and neurological disorders. In the present chapter, we have summarized different anticancer activities associated with N. sativa. The beneficial pharmacological activities (particularly anticancer activity) associated with N. sativa has been mainly because of its major bioactive component, thymoquinone (TQ). Both in vitro and in vivo studies have reveal that TQ exhibits potent antiproliferative and anticancer activities against various types of cancers, including blood, hepatic, kidney, respiratory tract, colon, and prostate cancers. In combinational therapy to cancer patients, administration of N. sativa extract or TQ with other cancer preventing drugs has been proven to ameliorate tumor growth and development with simultaneous reduction in toxicity associated with conventional drugs. We have also discussed several pharmaceutical approaches that proved to improve the bioavailability of TQ, thereby reducing the therapeutic dosage. We have further discussed several mechanisms by which TQ regulates different molecular pathways, which play an important role in the development of cancer. In the present times, there is an utmost need for traditional medicines which are believed to be promising therapeutics for cancer. Molecular mechanisms of the most prominent components such as TQ and other components should be further evaluated as the current understanding is somewhat unclear.