ABSTRACT
Objective: Astragalus Radix (AR, Huangqi in Chinese) has been widely used as a qi (energy) restoring herb that is thought to act through reinvigorating the spleen and lung. Aconite is used to rebalance the body temperature during illness and played an irreplaceable role in disease control since ancient times, but it is limited by its strong neuro and cardiotoxicity. Since the Song Dynasty (1227), the two herbs have been commonly used as herbal pairs including in the famous Qifu Decotion, from the "Wei's Family Prescription". However, many ancient texts also record that they are not compatible using together, suggesting they can have negative outcomes when mixed. This study investigated whether Astragali Radix had either positive or negative effects on absorption of six different active alkaloids derived from aconite. Methods: Single intestinal perfusion model was used to study the effects of Astragali Radix on aconite alkaloids absorption. Response of ABC transporters and distribution of three tight junction proteins on the surface of intestinal enothelium were assessed by Reverse Transcription-Polymerase Chain Reaction (RT-PCR), Western blot and immunofluorescence microscopy, respectively. Results: The results showed that aconite alkaloids absorption could be inhibited, and different concentrations of Astragali Radix considerably increased the expression levels of the ABC transporters and tight junction proteins with Astragali Radix treatment. Conclusion: These results suggest that Astragali Radix can block absorption of aconite alkaloids through the upregulation expression of ATP-binding cassette transporters (ABC transporters) and tight junction proteins. It demonstrates that co-administration of Astragali Radix with other drugs might change the absorption profile of the second drug which is important to know in clinic therapy.
ABSTRACT
Pharmacological inhibition of DNA repair pathways has been emerging as an effective tool for cancer treatment. Poly(ADP-ribose) polymerase (PARP) is involved in DNA repair and transcriptional regulation and is now recognized as a key regulator of cell survival and cell death. In vitro and in vivo data suggest that PARP inhibitors could be used not only as chemo/radiotherapy sensitizers but also as single agents to selectively kill cancer cells in certain types of tumors. In the present study, we investigate the effects of 3-aminobenzamide (3-AB), a potent inhibitor of PARP, on human osteosarcoma cells and whether or not it can sensitize the tumor cells to chemotherapeutic agents. The results indicated that 3-AB suppressed U2OS cell growth in a time- and dose-dependent manner, and the suppressive effects of 3-AB were associated with increased cell apoptosis. In addition, 3-AB suppressed cell invasion in vitro and enhanced the suppressive effects of cisplatin in U2OS cells. Our work suggests that this PARP-1 inhibitor may be developed into an effective agent for the treatment of human osteosarcoma.
