Thymoquinone: an emerging natural drug with a wide range of medical applications

Nigella sativa has attracted healers in ancient civilizations and researchers in recent times. Traditionally, it has been used in different forms to treat many diseases including asthma, hypertension, diabetes, inflammation, cough, bronchitis, headache, eczema, fever, dizziness and influenza. Experimentally, it has been demonstrated that N. sativa extracts and the main constituent of their volatile oil, thymoquinone, possess antioxidant, anti-inflammatory and hepatoprotective properties. In this review we aimed at summarizing the most recent investigations related to a few and most important effects of thymoquinone. It is concluded that thymoquinone has evidently proved its activity as hepatoprotective, anti-inflammatory, antioxidant, cytotoxic and anti-cancer chemical, with specific mechanisms of action, which provide support to consider this compound as an emerging drug.  Further research is required to make thymoquinone a pharmaceutical preparation ready for clinical trials.