Subacute 28 days repeated toxicity assessment of thymoquinone (volatile oil of black seed) in wistar rats

Thymoquinone is a major active principle of Nigella sativa (volatile oil of black seed or kalonji Seed) and constitutes about more than 30% its volatile oil. The kalonji seed are believed to be commonly used as natural remedy for all disease except death. The study was subjected to subacute toxicological testing to dose dependant toxicity to use as traditional medicine and establishing dose criteria to human being. Thymoquinone orally administered to male and female wistar rat at dose level of 2.5, 5.0, 10.0 mg/kg body weight for 28 days repeatedly, did not produce any sign of toxicity, mortality, pathological and blood parameters changes. It is suggested that thymoquinone at higher dose level is well tolerated by male and female rats. The Higher dose of thymoquinone 10.0 mg/kg body weight determined to be no observed adverse effect level (NOAEL).