Impact of thymoquinone on cyclosporine A pharmacokinetics and toxicity in rodents

Objectives Cyclosporine A (CsA) is an immunosupprsant drug used to prevent graft rejection and in the treatment of several autoimmune diseases. Thyomquinone (TQ), a bioactive component of Nigella sativa, has strong antioxidant properties and has been used in prevention of many toxicities, hence its protective effect and pharmacokinetic interactions with CsA was investigated in this study. Methods For bioavailability study, the rats were divided into four groups: TQ (PO, 10 mg/kg) was given alone for 7 days, then TQ plus CsA for another 5 days, CsA was given by two routes (po) and (IP) in a dose of 10 mg/kg 1 h after administration of TQ. Blood samples were taken at the 12th day at specified times, CsA level was determined by immune assays. The protective effect of TQ was studied. Blood samples for lab investigations and histopathology were taken at the 28th day. Key findings Thyomquinone reduced the bioavailability of oral CsA by around 32% (P > 0.05). However, bioavailability of IP administered CsA was not affected. Chronic administration of CsA increased concentrations of fasting glucose and Cystatin C and produced marked s kidney alteration of parenchyma which was reversed by concomitant administration of TQ. Conclusions A potential drug interaction between TQ and CsA, which may reduced its oral bioavailability. Independently TQ caused significant attenuation of CsA induced renal toxicity and diabetogenic effect.