The Natural Alkaloid (-)-N-Hydroxyapiosporamide Suppresses Colorectal Tumor Progression as an NF-κB Pathway Inhibitor by Targeting the TAK1-TRAF6 Complex.

Colorectal cancer (CRC) is an exceptionally deadly disease, whereas effective therapeutic drugs for CRC have declined over the past few decades. Natural products have become a reliable source of anticancer drugs. Previously we isolated an alkaloid named (-)-N-hydroxyapiosporamide (NHAP), which exerts potent antitumor effects, but its effect and mechanism in CRC remain unclear. This study aimed to reveal the antitumor target of NHAP and identify NHAP as a promising lead compound for CRC. Various biochemical methods and animal models were used to investigate the antitumor effect and molecular mechanism for NHAP. These results showed that NHAP exhibited potent cytotoxicity, induced both apoptosis and autophagic cell death of CRC cells, and inhibited the NF-κB signaling pathway by blocking the interaction of the TAK1-TRAF6 complex. NHAP also markedly inhibited CRC tumor growth in vivo without obvious toxicities and possessed good pharmacokinetic characteristics. These findings identify, for the first time, that NHAP is an NF-κB inhibitor with potent antitumor activity in vitro and in vivo. This study clarifies the antitumor target of NHAP against CRC, which will contribute to the future development of NHAP as a novel therapeutic lead compound for CRC.

[Simultaneous determination of ergosterol, nucleosides and their bases from natural and cultured Cordyceps by pressurized solvent extraction and high performance liquid chromatography].

AIM: To establish a simple method for simultaneous determination of ergosterol, nucleosides and their bases in Cordyceps by HPLC coupled with pressurized solvent extraction (PSE). METHODS: The extraction was performed by using PSE and the PSE condition was optimized by using orthogonal test, the contents of ergosterol, nucleosides and their bases in Cordyceps were determined by HPLC. RESULTS: The optimized condition of PSE extraction for ergosterol, nucleosides and their bases in Cordyceps was obtained as follow: solvent, methanol; temperature, 160 degrees C; static extraction time, 5 min; pressure, 10 MPa and one extraction cycle and one time. A ZORBAX NH2 column (250 mm x 4.6 mm ID, 5 microm) and a ZORBAX NH2 guard column (12.5 mm x 4.6 mm ID, 5 microm) were used for simultaneous determination of ergosterol, nucleosides and their bases. Solvents that constituted the mobile phase were A (acetonitrile) and B (10 mmol x L(-1) ammonium acetate in water). The elution conditions applied were: 0 -5.0 min, linear gradient 0 --> 15% B; 5.0-25.0 min, linear gradient 15% --> 20% B; 25.0 - 35.0 min, linear gradient 20% --> 40% B; 35.0 - 45.0 min, linear gradient 40% --> 80% B; 45.0 -50.0 min, 80% B isocratic. The flow-rate was 0. 6 mL x min(-1) and the injection volume was 20 microL. The system operated at 25 degrees C. Ergosterol was monitored and quantified at 275 nm, nucleosides and their bases at 254 nm. CONCLUSION: High performance liquid chromatography coupled with pressurized solvent extraction is a rapid and simple method for simultaneous determination of ergosterol, nucleosides and their bases in Cordyceps.