(T1430-03-21) Role of Co-Occurring Herbs on Toxicity of Radix Aconiti Lateralis Containing TCM Formulae

Purpose: Radix Aconiti Lateralis (Fuzi) is an extensively used toxic Traditional Chinese Medicine (TCM) to treat cardiovascular diseases, rheumatism arthritis, bronchitis, pains, diarrhea, and hypothyroidism etc.^1,2 Two types of processed Fuzi, namely Heishunpian and Paofupian, are usually used in the TCM formulae. ³ Figure 1 depicts the composition of herbs in Sini Tang and Fuzi Lizhong Tang, in which Heishunpian was added in Sini Tang for acute use and Paofupian was added in Fuzi Lizhong for chronic use. Although the clinical starting dose of Fuzi was commonly within the range recommended by Chinese Pharmacopoeia (3~15 g/day) ⁴, it was also noticed that TCM practitioners might gradually increase the dose of Fuzi to 30 g/day or even higher to enhance its therapeutic effects. Apart from Fuzi, other herbs also existed in these two TCM formulae, among which Radix Glycyrrhizae (licorice) and Rhizoma Zingiberis (ginger) were serving as the major co-occurring herbs (20-25 % w/w) in both Sini Tang and Fuzi Lizhong Tang to restrain the toxicity of Fuzi⁵. Considering the potential overdose of Fuzi in TCM formulae and lack of toxicity assessment of Fuzi-containing formulae, the current study was proposed aiming to 1) provide comprehensive toxicity profiles of the two frequently prescribed Fuzi containing TCM formulae, namely  Sini Tang and Fuzi Lizhong Tang; and 2) investigate detoxification effects of co-occurring herbs via comparing toxicity between Fuzi single herb and its corresponding Fuzi containing TCM formulae at their minimum toxic doses⁶.

Methods: Based on the designated No Observed Adverse Effect Levels (NOAEL) of Heishunpian and Paofupian, their minimum toxic doses determined at one level above NOAEL were 15 g/kg for Heishunpian and 30 g/kg for Paofupian⁶. To prepare the oral administration dosage forms of these two TCM formulae, about 5 g commercially available concentrated granules of Sini Tang (batch number A1700391) or Fuzi Lizhong Tang (batch number A1700299) were suspended in 10 mL boiling water followed by sonication for 30 min under room temperature to form a suspension of 0.5 g/ml. As shown in Figure 2., Sprague Dawley male rats were randomly assigned into Sini Tang and Fuzi Lizhong Tang treatment groups (G1, G4) and their corresponding control groups (G3, G6) with eight per group.Sini Tang at a bolus dose of 12 g/kg (contain same amount of toxic alkaloids as 15 g/kg Heishunpian) and Fuzi Lizhong Tang at daily dose of 12 g/kg (contain same amount of toxic alkaloids as 30 g/kg Paofupian) for two weeks were orally administrated to rats. Electrocardiogram (ECG) was monitored for heart rate and characteristic wave changes followed by blood samplings at day 0 and day 1 for a single dose of Sini Tang, or at day 0, 1,3,6,9, 12, and day 15 for multiple doses of Fuzi Lizhong Tang. After sacrificing the rats on day 1 or day 15, the main organs including liver, kidney, heart and brain were excised, weighed, and stored under -80 ℃ for further analysis. The organ index was calculated with body weight and organ weight. Comprehensive toxicity assessments were performed via monitoring i) the serum concentrations of organ injury related biomarkers of ALT, Urea, Creatinine, CK, AST, and LDH via commercial Abcam^© assay kits; ii) H&E staining in tissues from collected organs. Data from different treatment groups were compared with that from the control group using two-sided t-test with p < 0.05 considered to be statistically significantly different.

Results: It has been summarized in Table 1 that a single dose of Sini Tang led to a significant increase in S segment and ST height in ECG of the rats. These abnormalities were not detected in 15 g/kg of Heishunpian group; Multiple doses of Fuzi Lizhong Tang caused suppression of ST height yet elevation of T amplitude since the first ECG sampling day after oral administration of Fuzi Lizhong Tang (day 3) to the end. The above-mentioned ECG changes in ventricular depolarization (increased S segment) and repolarization (changed ST height and increased T-amplitude) after oral administrations of Sini Tang and Fuzi Lizhong Tang have not been observed for their corresponding Fuzi preparation before, suggesting components from other herbs in these formulae may contribute to the potential cardiotoxicity. From the perspective of serum biomarkers detection, neither Sini Tang nor Fuzi Lizhong Tang induced a significant increase in tested biomarkers of ALT, AST, LDH, Creatinine, and Urea. In terms of histopathology, there was no organ injury related pathological changes could be observed in major organs from Sin Tang and Fuzi Lizhong Tang treated rats.

Conclusion: We for the first time provided scientific evidence on the detoxification role of co-occurring herbs in Fuzi containing TCM. It was also demonstrated that Fuzi containing TCM formulae had a more severe impact on cardiac physiological function, aggravating cardiotoxicity in vivo.

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Acknowledgements:

Funding: This research was funded by the Health and Medical Research Fund (15161541) by the Food and Health Bureau, Hong Kong SAR, P. R. China, and by National Natural Science Foundation of China (81903909), P. R. China.
Conflicts of Interest: The authors declare no conflict of interest.


Figure 1 Composition of Fuzi containing TCM formula Sini Tang (Left) and Fuzi Lizhong Tang (Right).


Figure 2 Animal grouping and treatment schedule for single (Upper) and multiple (Bottom) oral administrations of Sini Tang and Fuzi Lizhong Tang preparations to rats.


Table 1. Comparison of organ injuries in liver, kidney, heart and brain after oral administrations of Sini Tang/Fuzi Lizhong Tang with that from Heishunpian and Paofupian (n=8).