Cytotoxic effect of ergot alkaloids in Achnatherum inebrians infected by the Neotyphodium gansuense endophyte.

Ergonovine or ergonovinine was isolated from the aerial parts of endophyte (Neotyphodium gansuense) infected (E+) drunken horse grass (Achnatherum inebrians), neither of which existed in endophyte-free (E-) plants. Both of these ergot alkaloids had a cytotoxic effect on animal smooth muscle cells and increased cell growth inhibition with greater concentrations, in a significantly (P < 0.05) positive correlation. The median inhibitory concentrations (IC50) for ergonovine and ergonovinine were 71.95 and 72.75 μg/mL, respectively. These results indicate that endophytic ergot alkaloids may be the cause of drunken horse grass poisoning.