Assessment of the toxicity of two Aconitum herbal medicines by microcalorimetry and chemometrics

In this study, a non-invasive and non-destructive microcalorimetric method was applied to assess the toxic effects of two Aconitum herbal medicines, Radix Aconitum Kusnezoffii and Radix A. carmichaeli, on the multiplying and non-multiplying metabolism of Shigella dysenteriae. Some crucial information, such as the thermogenic curves and thermo-kinetic parameters including growth rate constant k, inhibitory ratio I and half-inhibitory concentration IC50, of S. dysenteriae growth affected by the two Aconitum species was obtained. Coupled with chemometric analysis on this information, it could be found that Radix A. Kusnezoffii and Radix A. carmichaeli could be differentiated according to their toxic effects; Radix A. Kusnezoffii with IC50 of 35.2 mg/mL had stronger toxic effect than Radix A. carmichaeli with IC50 of 49.6 mg/mL. This present study shows the effectiveness of combining microcalorimetry and chemometrics for assessing the toxic effects of herbal medicines and other food matrices.