Evaluation of Marine Diindolinonepyrane in Vitro and in Vivo: Permeability Characterization in Caco-2 Cells Monolayer and Pharmacokinetic Properties in Beagle Dogs

A marine fibrinolytic compound was studied for use in thrombolytic therapy. Firstly, the absorption and transportation characteristics of 2,5-BHPA (2,5-BHPA:2,5-Bis-[8-(4,8-dimethyl-nona-3,7-dienyl)-5,7-dihydroxy-8-methyl-3-keto-1,2,7,8-tertahydro-6H-pyran[a]isoindol-2-yl]-pentanoic acid, a novel pyran-isoindolone derivative with bioactivity isolated from a rare marine microorganism in our laboratory) in the human Caco-2 cells monolayer model were investigated. We collected 2,5-BHPA in the cells to calculate the total recovery, and its concentration was analyzed by LC/MS/MS (Liquid Chromatography/Mass Spectrum/Mass Spectrum). The results showed that 2,5-BHPA has low permeability and low total recoveries in the Caco-2 cells membrane. Pharmacokinetics and tissue distribution of 2,5-BHPA were investigated in beagle dogs using HPLC (High Performance Liquid Chromatography) after intravenous administration of three different doses (7.5, 5.0, 2.5 mgkg(-1)). Pharmacokinetic data indicated that 2,5-BHPA fitted well to a two-compartment model. Elimination half-lives (T-1/2) were 49 +/- 2, 48 +/- 2, and 49 +/- 2 min, respectively; the peak concentrations (C-max) were 56.48 +/- 6.23, 48.63 +/- 5.53, and 13.64 +/- 2.76 mu gmL(-1), respectively; clearance rates (CL) were 0.0062 +/- 0.0004, 0.0071 +/- 0.0008, and 0.0092 +/- 0.0006 Lmin(-1)kg(-1), respectively; mean retention times (MRT) were 28.17 +/- 1.16, 26.23 +/- 0.35, and 28.66 +/- 0.84 min, respectively. The low penetrability of 2,5-BHPA indicated that the intravenous route of administration is more appropriate than the oral route. Meanwhile, 2,5-BHPA showed a good pharmacokinetic profile in beagle dogs. The tissue distribution showed that 2,5-BHPA could quickly distribute into the heart, intestines, liver, stomach, spleen, lungs, testicles, urine, intestine, kidneys, brain, and feces. The concentration of 2,5-BHPA was higher in the liver and bile. Interestingly, 2,5-BHPA was detected in the brain. Taken together, the above results suggested that our work might be beneficial in the development of agents for thrombolytic treatment.