Fiori Giovana Maria Lanchoti, D'Agate Salvatore, Rocha Adriana, Pereira Ana Maria Soares, Della Pasqua O, Lopes Norberto Peporine
Department of Physics and Chemistry, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, CEP 14049-900, Brazil.
Clinical Pharmacology & Therapeutics, University College London, London, UK.
J Pharm Biomed Anal. 2017 Sep 10;144:99-105. doi: 10.1016/j.jpba.2017.02.021. Epub 2017 Feb 20.
Cucurbitacin E is a potential drug candidate due to its anticancer activity, recognition of its molecular targets, and synergism with other drugs used for cancer treatment. However, the use of cucurbitacin E in clinical practice is not possible because of important knowledge gaps in its preclinical and clinical pharmacokinetic characteristics. Cucurbitacin E is hydrolyzed to cucurbitacin I in plasma and in human liver microsomes. The aim of this study was to evaluate the population pharmacokinetics of cucurbitacin E and of its metabolite cucurbitacin I in rats. The method for the sequential analysis of cucurbitacins E and I in rat plasma was developed using LC-MS/MS. Plasma aliquots of 50μL were deproteinized with acetonitrile and clobazam was added as internal standard. The extracts were injected into an RP-18 column and eluted with a mobile phase consisting of a mixture of acetonitrile:water:methanol (32:35:33, v/v/v). The method was precise and accurate, showing linearity in the range of 1-100ng cucurbitacin E/mL plasma and of 0.4-200ng cucurbitacin I/mL plasma. The method was applied to the pharmacokinetic evaluation of cucurbitacin E administered intravenously to male Wistar rats (1mg/kg). Serial blood samples were collected up to 24h after administration. The plasma concentrations of cucurbitacin E were quantified up to 16h, while the plasma concentrations of cucurbitacin I remained below the limit of quantification. A population pharmacokinetic model was developed for cucurbitacin E using the NONMEM program, with adequate goodness of fit and predictive performance. The following pharmacokinetic parameters were obtained: release time of 0.45h, volume of distribution of 27.22L, clearance of 4.13L/h, and elimination half-life of 4.57h.
葫芦素E因其抗癌活性、分子靶点的识别以及与其他用于癌症治疗的药物的协同作用，是一种潜在的候选药物。然而，由于其临床前和临床药代动力学特征方面存在重要的知识空白，葫芦素E无法在临床实践中使用。葫芦素E在血浆和人肝微粒体中会水解为葫芦素I。本研究的目的是评估葫芦素E及其代谢产物葫芦素I在大鼠体内的群体药代动力学。采用液相色谱-串联质谱法（LC-MS/MS）建立了大鼠血浆中葫芦素E和I的顺序分析方法。取50μL血浆等分试样，用乙腈进行蛋白沉淀，并加入氯巴占作为内标。将提取物注入RP-18柱，用由乙腈：水：甲醇（32:35:33，v/v/v）混合而成的流动相洗脱。该方法精确且准确，在1 - 100ng葫芦素E/mL血浆和0.4 - 200ng葫芦素I/mL血浆范围内呈线性。该方法应用于对雄性Wistar大鼠静脉注射葫芦素E（1mg/kg）后的药代动力学评估。给药后长达24小时收集系列血样。葫芦素E的血浆浓度在16小时内可定量，而葫芦素I的血浆浓度低于定量限。使用NONMEM程序为葫芦素E建立了群体药代动力学模型，拟合优度和预测性能良好。获得了以下药代动力学参数：释放时间为0.45小时，分布容积为27.22L，清除率为4.13L/h，消除半衰期为4.57小时。
