Ackermann G, Peil M, Quarz C, Schmidt A, Halaczkiewicz M, Thomas A D, Stegmüller S, Richling E, Manolikakes G, Christmann M, Küpper J H, Schrenk D, Fahrer J
Division of Food Chemistry and Toxicology, Department of Chemistry, RPTU Kaiserslautern-Landau, Erwin-Schrödinger-Str. 52, 67663, Kaiserslautern, Germany.
Institute of Toxicology, University Medical Center, Obere Zahlbacher Str. 67, 55131, Mainz, Germany.
Arch Toxicol. 2025 May 21. doi: 10.1007/s00204-025-04084-2.
The phenylpropene estragole (ES) is found in essential oils of herbs and spices, such as bitter fennel and basil. Humans are exposed to ES through the diet and phytomedicines. After its absorption, ES undergoes metabolic activation by CYP1A2 and SULT1A1 in the liver, which can give rise to DNA adducts and hepatocarcinogenesis. Until now, quantitative genotoxicity data for ES in human liver cells are scarce, correlating DNA adduct levels with critical effects such as clastogenicity. Here, we used human HepG2 and HepG2-CYP1A2 cells as well as primary human hepatocytes (PHH) to study the genotoxic, clastogenic and cytotoxic potential of ES and its crucial metabolite 1'-hydroxyestragole (1'OH-ES). In addition, primary rat hepatocytes (PRH) were used for selected endpoints. Treatment of HepG2-CYP1A2 cells with ES (0-2 mM) led to the concentration-dependent formation of E3'-N-dG adducts. Apart from a moderate γH2AX induction, neither p53 accumulation nor cytotoxicity was observed. However, clastogenicity was demonstrated at ES concentrations ≥ 1 mM. Incubation of HepG2 cells with 1'OH-ES (0-35 µM) led to 10-50-fold higher E3'-N-dG adduct levels compared to equimolar ES concentrations. Furthermore, 1'OH-ES caused γH2AX formation, p53 accumulation and cytotoxicity, which was confirmed in PHH. In agreement, 1'OH-ES induced clastogenicity at concentrations ≥ 25 µM. Molecular dosimetry revealed that a certain E3'-N-dG adduct level is required to trigger clastogenicity and cytotoxicity. This was confirmed by Benchmark Concentration (BMC) modelling, showing that the BMC for clastogenicity is 12-17-fold higher than the respective BMC for DNA adduct formation. Our data indicate that a threshold level of DNA adducts is required, both in rat and human liver cells, to trigger markers of clastogenicity. These levels are unlikely to be reached in humans following chronic ES exposure through phytomedicines or the diet.
苯丙烯类化合物草蒿脑（ES）存在于草药和香料的精油中，如苦茴香和罗勒。人类通过饮食和植物药接触到ES。吸收后，ES在肝脏中经CYP1A2和SULT1A1代谢活化，这可能导致DNA加合物形成及肝癌发生。到目前为止，关于ES在人肝细胞中的定量遗传毒性数据稀缺，且缺乏将DNA加合物水平与诸如致染色体断裂等关键效应相关联的数据。在此，我们使用人HepG2和HepG2 - CYP1A2细胞以及原代人肝细胞（PHH）来研究ES及其关键代谢物1'-羟基草蒿脑（1'OH - ES）的遗传毒性、致染色体断裂性和细胞毒性潜力。此外，还使用原代大鼠肝细胞（PRH）进行了选定的终点研究。用ES（0 - 2 mM）处理HepG2 - CYP1A2细胞导致E3'-N - dG加合物浓度依赖性形成。除了中等程度的γH2AX诱导外，未观察到p53积累或细胞毒性。然而，在ES浓度≥1 mM时显示有致染色体断裂性。与等摩尔ES浓度相比，用1'OH - ES（0 - 35 μM）孵育HepG2细胞导致E3'-N - dG加合物水平高10 - 50倍。此外，1'OH - ES导致γH2AX形成、p53积累和细胞毒性，这在PHH中得到证实。同样，1'OH - ES在浓度≥25 μM时诱导致染色体断裂性。分子剂量学表明，需要一定的E3'-N - dG加合物水平来触发致染色体断裂性和细胞毒性。这通过基准浓度（BMC）建模得到证实，表明致染色体断裂性的BMC比DNA加合物形成的相应BMC高12 - 17倍。我们的数据表明，在大鼠和人肝细胞中都需要一定阈值水平的DNA加合物来触发致染色体断裂性标志物。通过植物药或饮食长期接触ES后，人类不太可能达到这些水平。
