Thymoquinone: Biosynthesis, Biological Activities and Therapeutic Potential from Natural and Synthetic Sources

Abstract

Thymoquinone (TQ; 2-isopropyl-5-methyl-1,4-benzoquinone) is a secondary metabolite found in abundance in very few plant species including Nigella sativa L., Monarda fistulosa L. and Satureja montana L. It is found in crystalline triclinic form in a range of organs in these plants. TQ has been synthetically prepared from thymol (2-isopropyl-5-methylphenol); commercially it is synthesized by modification of thymol and carvacrol (5-isopropyl-2-methylphenol). TQ has substantial therapeutic potential because of its anti-cancer, hepato-protective, anti-inflammatory, antioxidant, antimicrobial and cardio-protective activities in cell culture systems and animal models. In this article, we have reviewed recent studies on the natural and synthetic sources of TQ, its biosynthetic pathway and its modes of action in human and experimental models, as well as its commercial preparation. We also compiled the medicinal effects of TQ. The biological activities of TQ support the potential of this plant secondary metabolite as a drug with a wide range of therapeutic applications. To substantiate the benefits and pharmaceutical properties of TQ, further well-designed clinical research is required. © 2021 Friends Science Publishers