In vitro metabolism of 4, 5-dimethoxycanthin-6-one by human liver microsomes and its inhibition on human CYP1A2

4,5-Dimethoxycanthin-6-one Inhibits Glioblastoma Stem Cell and Tumor Growth by Inhibiting TSPAN1 Interaction with TM4SF1

Glioblastoma stem cells (GSCs) have been implicated in the self-renewal and treatment resistance of glioblastoma (GBM). Our previous study found that 4,5-dimethoxycanthin-6-one has the potential to inhibit GBM cell proliferation. This current study aims to elucidate the molecular mechanism underlying the effects of 4,5-dimethoxycanthin-6-one in GBM development. The effect of 4,5-dimethoxycanthin-6-one on GSC formation and differentiation was explored in human GBM cell lines U251 and U87. Subsequently, 4,5-dimethoxycanthin-6-one binding to tetraspanin 1 (TSPAN1) / transmembrane 4 L six family member 1 (TM4SF1) was analyzed by molecular simulation docking. Co-immunoprecipitation (Co-IP) and immunofluorescence (IF) were used to assess the interactions between TSPAN1 and TM4SF1 in GSCs. Cell proliferation was detected by cell counting kit-8 (CCK-8) and colony formation assay. To evaluate cell migration, invasion and apoptosis, we employed wound healing assay, transwell and flow cytometry, respectively. Furthermore, subcutaneous xenograft tumor models in nude mice were constructed to evaluate the impact of 4,5-dimethoxycanthin-6-one on GSCs in vivo by examining tumor growth and histological characteristics. 4,5-Dimethoxycanthin-6-one inhibited GSC formation and promoted stem cell differentiation in a concentration-dependent manner. Molecular docking models of 4,5-dimethoxycanthin-6-one with TM4SF1 and TSPAN1 were constructed. Then, the interaction between TSPAN1 and TM4SF1 in GSC was clarified. Moreover, 4,5-dimethoxycanthin-6-one significantly inhibited the expressions of TM4SF1 and TSPAN1 in vitro and in vivo. Overexpression of TSPAN1 partially reversed the inhibitory effects of 4,5-dimethoxycanthin-6-one on GSC formation, proliferation, migration and invasion. 4,5-Dimethoxycanthin-6-one inhibited GBM progression by inhibiting TSPAN1/TM4SF1 axis. 4,5-Dimethoxycanthin-6-one might be a novel and effective drug for the treatment of GBM.

4,5-Dimethoxycanthin-6-one is a novel LSD1 inhibitor that inhibits proliferation of glioblastoma cells and induces apoptosis and pyroptosis

BACKGROUND

Glioblastoma is one of the most common fatal intracranial malignancies. Lysine-specific demethylase 1 (LSD1) reportedly has therapeutic effects on a variety of tumors. This study explored the therapeutic effect of LSD1 inhibition on glioblastoma cell lines and the possible underlying mechanisms.

METHODS

The MTT assay was utilized to screen for the sensitivity of U87, U251 and T98G cells to 4, 5-dimethoxycarrageenin-6-one. qRT-PCR and western blot were used to measure the proliferation, apoptosis, and pyroptosis signaling pathway expression to observe the effect of LSD1 inhibition on U251 and T98G cells. Flow cytometry, immunofluorescence, immunohistochemistry, wound scratch, clone formation, and TUNEL assay were used to analyze the effects of 4, 5-dimethoxycanthin-6-one on glioblastoma cells. The effect of 4, 5-dimethoxycanthin-6-one was examined in vivo in BALB/c nude mice injected with U251 cells. HE staining was used to detect the histopathology of the tumor.

RESULTS

LSD1 specifically catalyzes the demethylation of monomethylated and demethylated histone H3 lysine at position 4 (h3k4me1, h3k4me2, h3k4me3) and lysine at position 9 (h3k9me1). This regulated the transcriptional activity of proliferation, apoptosis, and pyroptosis signaling pathway genes. In vitro, the proliferation of glioblastoma cells was decreased in the 4, 5-dimethoxycanthin-6-one group. The expression of Caspase1 in glioblastoma cells treated with 4, 5-dimethoxycanthin-6-one increased, and the number of apoptotic cells increased. The tumor volume of mice injected with 4, 5-dimethoxycanthin-6-one decreased significantly.

CONCLUSION

4, 5-Dimethoxycanthin-6-one could act as a novel inhibitor of LSD1 to regulate glioblastoma, which could inhibit the proliferation of U251 and T98G cells and induce their apoptosis and pyroptosis. It is a potential drug for the treatment of glioblastoma.

Pharmacokinetic study of seven bioactive components of Xiaoyan Lidan Formula in cholestatic and control rats using UPLC-MS/MS

A rapid, sensitive, and reliable ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method has been developed to simultaneously determine the major bioactive components of Xiaoyan Lidan Formula (XYLDF) in rat plasma, using sulfamethoxazole as the internal standard (IS). The seven major bioactive components are andrographolide, dehydroandrographolide, enmein, 1-methoxicabony-β-carboline, 4,5-dimethoxy-canthin-6-one, 4-methoxy-5-hydroxy-canthin-6-one, and 1-hydroxymethyl-β-carboline. After pretreating by protein precipitation with methanol, separation was performed on a UPLC C18 column using gradient elution with a mobile phase consisting of acetonitrile and 0.1% formic acid at a flowing rate of 0.7 mL/min. Detection was performed on TSQ Quantum mass spectrometry set at the positive/negative ionization and multiple reaction monitoring (MRM) mode. The intra- and inter-day precision were less than 9.8%, whereas the intra- and inter-day accuracy were within ± 13.4%. The method was validated and applied to compare the pharmacokinetic profiles of the analytes in serum of Alpha-naphthylisothiocyanate (ANIT)-induced cholestasis and control rats after oral administration of XYLDF. The results showed remarkable differences in pharmacokinetic properties of the analytes between cholestatic (model) and control groups, thereby providing essential scientific information for better understanding of mechanism of XYLDF and a reference for its clinical applications.