Hypotensive effect and toxicology of total alkaloids and veratramine from roots and rhizomes of Veratrum nigrum L. in spontaneously hypertensive rats.

Total alkaloids (VTA) and veratramine of Veratrum nigrum L. were tested for hypotensive effect using spontaneously hypertensive rats (SHR). Acute toxicities were also evaluated. There was a dose-dependent reduction in blood pressure and heart rate after a single ingestion (1.0 to 4.0 mg/kg, intragastric administration) of VTA. A single oral ingestion (0.56 to 2.24 mg/kg) of veratramine, the major component of VTA, dose-dependently decreased blood pressure and heart rate, suggesting that veratramine was involved in the hypotensive effect of VTA in SHR. The hypotensive effects of VTA and veratramine are directly positively correlated with the dosage. Side effects were not obvious.