The current research explored the effect of hepatic and renal dysfunctions on the pharmacokinetics of thymoquinone (TQ) in a rat model.An acute kidney injury was induced using gentamicin and a liver damage was elicited using a single dose of d-galactosamine. For the pharmacokinetic studies, TQ was administered as IV injection or and PO route to rats.The concentrations of TQ and pharmacokinetic parameters were calculated using a non-compartmental analysis. The systemic clearance (Cl) of TQ after IV dosing was slightly reduced in the liver dysfunction group compared to healthy controls (p = 0.0013). Similarly, the estimated volume of distribution at steady state (Vss) was marginally decreased (p = 0.001). However, in rats with acute kidney injury exhibited a larger Vss as opposed to normal renal function (511.28 ± 21.03 ml/kg vs. 442.25 ± 31.43 ml/kg; p = 0.0001). Whereas oral Cl and terminal volume of distribution (Vz) of TQ were reduced by ∼50% in the liver dysfunction group (p = 0.0001). These changes were associated with more systemic exposure as measured by AUC0-∞ in rats with compromised liver functions. The estimated plasma protein binding TQ was 99.84 ± 0.03% in healthy controls, 97.05 ± 0.57% with kidney injury rats, and 95.75 ± 0.64% in liver dysfunctionThe findings of the present study suggest that liver dysfunction could potentially modify the disposition of TQ administered orally, and therefore, a smaller maintenance dose is probably required to avoid accumulation.
Keywords: Thymoquinone; animal model; kidney injury; liver dysfunction; pharmacokinetics; plasma protein binding.