Black cumin ( Nigella sativa ) and its constituent (thymoquinone): a review on antimicrobial effects Fatemeh Forouzanfar , 1 Bibi Sedigheh Fazly Bazzaz , 2 and Hossein Hosseinzadeh 3, * Go to: Abstract Nigella sativa seeds have wide therapeutic effects and have been reported to have significant effects against many ailments such as skin diseases, jaundice, gastrointestinal problems, anorexia, conjunctivitis, dyspepsia, rheumatism, diabetes, hypertension, intrinsic hemorrhage, paralysis, amenorrhea, anorexia, asthma, cough, bronchitis, headache, fever, influenza and eczema. Thymoquinone (TQ) is one of the most active constituent and has different beneficial properties. Focus on antimicrobial effects, different extracts of N. sativa as well as TQ, have a broad antimicrobial spectrum including Gram-negative, Gram-positive bacteria, viruses, parasites, schistosoma and fungi. The effectiveness of N. sativa seeds and TQ is variable and depends on species of targ