Establishment of biological assess for quality control of Fuzi based on determination of premature ventricular contractions in rats

Aconiti Lateralis Radix (Fuzi) is a toxic traditional Chinese medicine with definite efficacy. In order to improve the quality control of its different prepared products and ensure the security in clinic, it is significant to establish a method of quality evaluation related to clinic adverse effects. Aiming at the important biological marker of early cardiac toxicity reaction, there was no method to detect it. In this manuscript, a novel approach for measuring the minimal toxic dose (MTD) of premature ventricular contractions (PVC) poisoning of rats was established. Then, the determination methodology and conditions were optimized to meet the needs of the quality and biological assessment, including animal sex, weight, stability of standards and test solutions. Using this method, the MTD value of different Fuzi products were determined, such as Heishunpian, Baifupian, Zhengfupian, Baofupian, and Paotianxiong. The results showed that the MTD of Fuzi was significantly decreased after detoxification processed (P<0.05) and the MTD of Heishunpian, Zhengfupian, Baofupian and Baifupian was as much as 15.76, 22.36, 19.65 and 20.97 times to that of unprocessed Shengfuzi. In addition, Paotianxiong could not induce PVC in rats, which indicated that Paotianxiong was nontoxic and safe.This method could appropriately reflects the cardiotoxity of Fuzi and its prepared samples. Together with the chemical composition analysis, the contents of diester alkaloids were explored including aconitine, mesaconitine and hypaconitine as well as monoester alkaloids in Fuzi and its prepared products were significantly associated with PVC. Furthermore, there may be some components undetermined facilitating arrhythmia to be worth exploring. This research provides an overall and comprehensive approach to diagnose early clinical cardiotoxity and control the quality of Fuzi, which could not only be a complementary solution for the chemical evaluation, but a new method to ensure its efficacy and security of clinical application.