Insights into the Cardiotoxic Effects of Veratrum Lobelianum Alkaloids: Pilot Study.

Jervine, protoveratrine A (proA), and protoveratrine B (proB) are Veratrum alkaloids that are presented in some remedies obtained from Veratrum lobelianum, such as Veratrum aqua. This paper reports on a single-center pilot cardiotoxic mechanism study of jervine, proA, and proB in case series. The molecular aspects were studied via molecular dynamic simulation, molecular docking with cardiac sodium channel NaV1.5, and machine learning-based structure-activity relationship modeling. HPLC-MS/MS method in combination with clinical events were used to analyze Veratrum alkaloid cardiotoxicity in patients. Jervine demonstrates the highest docking score (-10.8 kcal/mol), logP value (4.188), and pKa value (9.64) compared with proA and proB. Also, this compound is characterized by the lowest calculated IC50. In general, all three analyzed alkaloids show the affinity to NaV1.5 that highly likely results in cardiotoxic action. The clinical data of seven cases of intoxication by Veratrum aqua confirms the results of molecular modeling. Patients exhibited nausea, muscle weakness, bradycardia, and arterial hypotension. The association between alkaloid concentrations in blood and urine and severity of patient condition is described. These experiments, while primary, confirmed that jervine, proA, and proB contribute to cardiotoxicity by NaV1.5 inhibition.

Validated HPLC-MS/MS method for quantification of ethylmethylhydroxypyridine succinate in rat brain and its application to a pharmacokinetic study.

2-ethyl-6-methyl-3-hydroxypyridine (EMHP) succinate is the original antioxidant and antihypoxic drug commonly prescribed in Russia. The objective of this study was to develop a rapid, simple and sensitive high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) method for EMHP quantitation in rat brain tissue with the use of a bead beating homogenizer. The comparison between two approaches to brain tissue preparation was performed, when spiking the blank brain tissue with EMHP reference standard and internal standard (IS) before and after homogenization step. Chromatographic separation was achieved using Zorbax Eclipse Plus C18 column (1.8 µm, 2.1 × 50 mm) and elution was performed with the mobile phase, consisting of 10 mM of ammonium formate aqueous solution with 0.1% formic acid as solvent A and 0.1% formic acid in methanol as solvent B [44%(А):56%(В), v/v]. Flow rate was 0.4 mL/min and the total run time for each sample analysis was 2.0 min. EMHP and amantadine, IS of this study, were analyzed in positive ionization mode. Ion transitions of m/z 138.0 → 123.0 for EMHP and m/z 152.0 → 135.0 for amantadine were selected in multiple reaction monitoring mode. The developed method for EMHP determination in rat brain samples was validated for selectivity, linearity, accuracy, precision, matrix effects, and stability. The lower and upper limits of quantification were determined to be 1 and 1500 ng/g, respectively. The developed and validated HPLC-MS/MS method was successfully applied to determine EMHP concentrations in rat brain tissue following the intraperitoneal administration at a dose of 3.4 mg/kg.