Pharmacokinetic and brain distribution study of an anti-glioblastoma agent in mice by HPLC-MS/MS

A newly developed UPLC-MS/MS method for simultaneous quantitative analysis of ajuforrestin A, ajuforrestin B, ajugamacrin and 8-O-acetylharpagide derived from Ajuga plants in mice blood and the in vivo pharmacokinetics

OBJECTIVE

To develop a sensitive and fast detection method via ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to assess the concentration of ajuforrestin A, ajuforrestin B, ajugamacrin and 8-O-Acetylharpagide primarily derived from Ajuga plants in mice blood and their pharmacokinetics.

METHODS

Single protein precipitation with high-proportioned acetonitrile is chosen for sample clean-up. The UPLC HSS T3 (2.1 mm × 100 mm, 1.8 µm) column with a mobile phase in gradient elution mode at the flow rate of 0.4 mL/min was used for sample separation. Acetonitrile was selected as the organic phase solution and water containing 0.1% formic acid was chosen as the aqueous solution. A tandem mass spectrometer containing an electrospray ionization (ESI) source in the positive ionization mode was used to detect four compounds via multiple reaction monitoring (MRM).

RESULTS

The calibration curves (5-1000 ng/mL) of four compounds were linear with correlation coefficients > 0.997. The matrix effects, accuracy, precision, and recovery were all within permissible scope.

CONCLUSIONS

In this approach, the corresponding pharmacokinetic parameters were successfully clarified in mouse for the first time, which provided a theoretical basis for the improvement of the standard of Ajuga plants and the safety of clinical medication. Furthermore, this method may provide the UPLC-MS/MS evidence for the differentiation of the main close relative varieties of genus Ajuga according to these plants contain different mixtures of the four marker compounds.

Lead Optimization of Androgen Receptor-HSP27 Disrupting Agents in Glioblastoma

Glioblastoma (GBM) is the most common malignant brain tumor with poor prognosis under the current standard treatment. It is critical to develop new approaches to selectively battle the disease. GBM sex differences suggest that an androgen receptor (AR) is a potential therapeutic target to treat AR-overexpressed GBM. Heat shock 27 kDa protein (HSP27) is a well-documented chaperone protein that stabilizes AR. Inhibition of HSP27 leads to AR degradation, indicating that HSP27 inhibitors could suppress AR activity in GBM. We have identified a lead HSP27 inhibitor that could induce AR degradation. Lead optimization resulted with two new derivatives (compounds 4 and 26) showing potent anti-GBM activity and improved drug distribution in comparison to the lead compound. Compounds 4 and 6 exhibit IC50s of 35 and 23 nM, respectively, to inhibit cell proliferation and also show significant activity to decrease the tumor growth in vivo.