Drug Target Mendelian Randomization Study of PCSK9 and HMG-CoA Reductase Inhibition and Atrial Fibrillation.

INTRODUCTION: Atrial fibrillation (AF) is a prevalent cardiac arrhythmia with significant clinical implications. The potential influence of lipid-lowering therapies, specifically PCSK9 inhibitors (PCSK9i) and HMG-CoA reductase inhibitors (statins), on AF risk remains a topic of interest. This Mendelian Randomization (MR) study aimed to elucidate the causal relationship between genetically predicted inhibition of PCSK9 and HMG-CoA reductase and the risk of AF. METHODS: Utilizing publicly available, summary-level genome-wide association study (GWAS) data, we employed single-nucleotide polymorphisms (SNPs) associated with lower LDL-C levels as instruments for gene-simulated inhibition of PCSK9 and HMG-CoA reductase. Multiple MR techniques were applied to estimate the causal effects, and sensitivity analyses were conducted to validate the results. RESULTS: Genetically predicted inhibition of PCSK9 demonstrated a reduced risk of AF, with an odds ratio (OR) of 0.92 (95% CI: 0.85 to 0.99, p=0.01) using the inverse variance weighted (IVW) method. In contrast, the inhibition of HMG-CoA reductase did not exhibit a statistically significant association with AF risk (IVW: OR = 1.11, 95% CI: 1.00-1.22, p = 0.05). CONCLUSION: Our MR study suggests that genetically predicted inhibition of PCSK9, but not HMG-CoA reductase, is associated with a lower risk of AF. These findings provide evidence for a causal protective effect of PCSK9i on AF and support the use of PCSK9i for AF prevention in patients with dyslipidemia. Further studies are needed to elucidate the mechanisms underlying the differential effects of PCSK9i and statins on AF and to confirm the clinical implications of our findings.

Quantification and pharmacokinetic property of verubecestat an BACE1 inhibitor in rat plasma.

In the present study, an ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) approach was designed to measure the rat plasma levels of verubecestat with diazepam as the internal standard. Acetonitrile-based protein precipitation was applied for sample preparation, then the analyte verubecestat was subjected to gradient elution chromatography with a mobile phase composed of acetonitrile (A) and 0.1% formic acid in water (B). Verubecestat was monitored by m/z 410.1 → 124.0 transition for quantification by multiple reaction monitoring (MRM) in positive ion electrospray ionization (ESI) source. When the concentration of verubecestat ranged from 1 to 2500 ng/mL, the method exhibited good linearity. For verubecestat, the intra- and inter-day precision were determined with the values of 2.9-9.0% and 0.4-6.5%, respectively; and the accuracy ranged from -2.2% to 10.4%. Matrix effect, extraction recovery, and stability data were in line with the standard FDA guidelines for validating a bioanalytical method. The validity of the developed method was confirmed through the pharmacokinetic study.

Validated UPLC-MS/MS method for quantification of fruquintinib in rat plasma and its application to pharmacokinetic study.

A new, simple, and sensitive ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for quantification of fruquintinib was established to assess the pharmacokinetics of fruquintinib in the rat. The internal standard working solution was added to the plasma sample for extraction before analysis. The Acquity UPLC BEH C18 chromatography column (2.1 mm ×50 mm, 1.7 µm) was used to separated analytes under gradient elution using acetonitrile and 0.1% formic acid as the mobile phase. Positive multiple reaction monitoring modes were chosen to detect fruquintinib and diazepam (IS). The precursor-to-product ion transitions were 394.2 → 363.2 for fruquintinib and m/z 285 → 154 for IS. The current method was linear over the concentration range of 1.0-1000 ng/mL for fruquintinib with a correlation coefficient of 0.9992 or better. The matrix effect of fruquintinib and IS was acceptable under the current method. The intra- and interday precision (RSD%) and accuracy (RE%) were within 11.9% and ±13.7%, respectively. The recovery, stability, and sensitivity were validated according to the United States Food and Drug Administration (FDA) regulations for bioanalytical method validation. The analytical method had been validated and applied to a pharmacokinetic study of fruquintinib in rat.

Simultaneous Determination of Rivaroxaban and Enalapril in Rat Plasma by UPLC-MS/MS and Its Application to A Pharmacokinetic Interaction Study.

BACKGROUND AND OBJECTIVES: There have been no animal experiments and clinical studies on the pharmacokinetic interaction between rivaroxaban and enalapril. To investigate whether a potential pharmacokinetic interaction is present between rivaroxaban and enalapril, a rapid and sensitive Ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated to determine the concentration of rivaroxaban and enalapril in rat plasma and was then applied to a pharmacokinetic interaction study. METHODS: The analytes were separated on an Acquity UPLC BEH C18 chromatography column (2.1 × 50 mm, 1.7 µm) with acetonitrile and 0.1% formic acid as the mobile phase with gradient elution. The mass spectrometer was operated in multiple reaction monitoring mode to monitor the precursor-to-product ion transitions of 436.1 → 145.1 m/z for rivaroxaban, 377.3 → 234.2 m/z for enalapril and 285.2 → 193.1 m/z for diazepam (IS). RESULTS: The method was validated over the concentration range of 1.0-200 ng/mL for rivaroxaban and 0.5-100 ng/mL for enalapril. The intra- and inter-day precision and accuracy of the quality control (QC) samples exhibited relative standard deviations (RSD) < 9.4% and the accuracy values ranged from - 8.3 to 9.6%. After co-administration of rivaroxaban and enalapril, the maximum plasma concentration (Cmax) and area under the systemic drug concentration-time curve from time 0 to infinity (AUC0-∞) of rivaroxaban were significantly increased by 19.6% (p < 0.05) and 21.3% (p < 0.05), respectively. On the contrary, the plasma clearance rate (CL/F) of rivaroxaban and enalapril was significantly decreased by 17.8% (p < 0.05) and 23.8% (p < 0.05), respectively. CONCLUSIONS: The UPLC-MS/MS method was successfully applied to simultaneous determination of rivaroxaban and enalapril in rat plasma and applied to study the pharmacokinetic interaction between rivaroxaban and enalapril. The co-administration of rivaroxaban and enalapril resulted in a significant drug interaction in rats.