Antimicrobial Action of Thymoquinone

Abstract

In recent years, pathogens have adopted various mechanisms to combat the onslaught of currently available antibiotics. This led to the emergence of the phenomenon of antibiotic resistance in microorganisms. Antibiotic resistance has rendered many previously effective antibiotics into useless chemicals that are resulting in the dearth of available therapeutic options to treat some very serious infections. Moreover, the widespread antibiotic resistance is also contributing to a very high economic burden on the population by increasing the cost of treatment. It compelled the scientists and clinicians to find new antimicrobials that are safe and effective with chances of antibiotic resistance. Medicinal plants and their extracts have been in use for hundreds of years to treat many infectious diseases. In the current chapter, we are describing the therapeutic potentials of thymoquinone (TQ), an active component of N. sativa, in treatment of common infectious diseases. TQ showed activities against a wide range of microorganisms including bacteria, fungi, and viruses. TQ not only inhibited the growth of certain pathogenic bacteria but also prevented the formation of biofilms, an important virulence factor in bacterial diseases. Furthermore, TQ also lowered the MICs of standard antibacterials when used in combination. TQ also demonstrated an antifungal activity against some very important fungal pathogens including Candida albicans, Aspergillus fumigatus, and certain dermatophytes. A limited numbers of studies also suggested the efficacy of N. sativa and TQ against viruses including cytomegalovirus (CMV), hepatitis C virus (HCV), and influenza virus. The consideration of TQ as an antimicrobial therapeutic is still under initial phases. Further studies are needed to explore the implications of TQ in treatment of infectious diseases.