Gardenin A is one of the less abundant hydroxylated polymethoxyflavonoids (OH-PMFs) in nature, and has many potential significant health benefits. In the present study, an efficient strategy was established using high-performance liquid chromatography coupled with linear ion trap-Orbitrap mass spectrometer to profile the in vivo metabolic fate of gardenin A in rat plasma and various tissues. First, an online LC-MS(n) data acquisition method was developed to trace all the probable metabolites. Second, a combination of offline data processing methods including extracted ion chromatography and multiple mass defect filters was employed to screen the common and uncommon metabolites from the background noise and endogenous components. Finally, structures of the metabolites were elucidated based on an accurate mass measurement, the diagnostic product ions of PMFs, and relevant drug biotransformation knowledge. Based on the proposed strategy, a total of 26 metabolites were observed and characterized. The results indicate that some biotransformations, such as methylation, demethoxylation, demethylation, glucuronide conjugation, sulfate conjugation and their composite reactions, have been discovered for OH-PMFs. Moreover, some diagnostic biotransformation pathways are summarized. Overall, this study gives us a first insight into the in vivo metabolism of gardenin A. The study also provides a practical strategy for rapidly screening and identifying metabolites, which can be widely applied for the other biotransformations.

Objective: To evaluate the potential anti-prostate cancer effects of Paris polyphylla ethanol extract (PPEE) and its underlying mechanisms. Materials and Methods: The anti-proliferation activity of PPEE was tested on PC3 and DU145 cells using Cell Counting Kit-8 assay. The pro-apoptotic and cell cycle arrest effects of PPEE were confirmed by flow cytometry. Apoptosis of prostate cancer cells was induced by PPEE through endogenous and exogenous pathways. A mouse xenograft model was used to examine its anti-prostate cancer effects in vivo. Results: We found that the IC50 of PPEE on PC3 cells was 3.98 µg/ml and the IC50 of PPEE on DU145 cells was 8 µg/ml. PPEE induced prostate cancer cell apoptosis in a concentration dependent manner, through endogenous and exogenous pathways. PPEE induced PC3 cell cycle arrest in G0/G1 and G2/M phases, while in DU145cell it induced cell arrest in the G0/G1 phase. PPEE inhibited the growth of prostate cancer cells in vivo. Conclusion: PPEE could inhibit prostate cancer growth in vitro and in vivo, induce apoptosis of prostate cancer cells, and cause cell cycle arrest, which laid the foundation for further research on the anti-tumor mechanism of PPEE.

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Objectives: Paris polyphylla var. yunnanensis (PPVY), a Chinese herb, has long been used for cancer treatment, and its steroidal saponins are suggested to exert an anti-tumor activity, however, the underlying mechanism is incompletely understood and their effect on bladder cancer (BC) remains unknown. The present study is thus designed to address these issues. Material and Methods: Total steroidal saponins were extracted with ethanol from PPVY and used to treat BC cells (HT1197 and J82 carrying mutant p53). Gene expression was determined using qPCR and immunoblotting and cell cycle analyzed using flow cytometry. DNA damage response activation was assessed using immunofluorescence staining. Results: PPVY saponins treatment led to dose-dependent declines in the number of both HT1197 and J82 cells with IC50 approximately 1.2 μg/ml, which was coupled with strong growth arrest at G2/M phase and the activation of DNA damage response pathway. Moreover, the clonogenic potential of these cells was severely impaired even in the presence of low concentrations of PPVY saponins. Mechanistically, PPVY saponins induced the degradation of mutant p53 while stimulated CDKN1A gene transcription. Phosphorylated AKT was diminished in PPVY saponin-treated cells, but its specific inhibitor LY294002 exhibited significantly weaker efficacy in inducing CDKN1A expression than did PPVY saponins. Conclusion: PPVY saponins activate DNA damage response pathway, degrade mutant p53 and stimulate CDKN1A expression, thereby inhibiting BC cell growth. Given their poor absorption via oral administration, PPVY saponins may be applicable for intravesical instillations in BC treatment.