Systematic toxicokinetic analysis and early hepatic effects evaluation of BbF following acute oral exposure in mice.

Benzo [b]fluoranthene (BbF), a representative high molecular weight polycyclic aromatic hydrocarbon (HMW PAH), poses significant health risks through dietary intake. However, limited research exists regarding its toxicity and absorption, distribution, and metabolism in vivo. In this study, male Balb/c mice were administered a single oral dose of 100 mg/kg·bw BbF. The toxicokinetics, tissue distribution, and metabolic enzyme activities of BbF were systematically analyzed, and early hepatic effects induced by BbF were evaluated. The results demonstrated that BbF had a plasma clearance half-life of 5.18 h, with a peak concentration of 1.87 μg/mL reached at 1 h, indicating rapid absorption and elimination. Tissue-specific accumulation shows a high concentration of BbF in the liver, a major target and metabolic site. BbF tended to accumulate in adipose tissues compared to other organs, displaying a peak-lag effect. Liver function tests and oxidative stress markers revealed early biochemical alterations following BbF exposure, including modest elevations in plasma transaminases and significant changes in hepatic antioxidant status, indicative of cellular stress. However, histopathological examination of liver tissue and ultrastructural analysis of mitochondria revealed no overt structural damage at the 24-h time point. These findings provide a comprehensive toxicokinetic profile of BbF and identify early oxidative stress responses as potential indicators of exposure, offering foundational data for future studies on the hepatotoxic potential of dietary HMW-PAHs.