NMR-based metabolomics approach to evaluate the toxicological risks of Tibetan medicine 'Ershiwuwei Shanhu' pill in rats.

Abstract Ethnopharmacological relevance ‘Ershiwuwei Shanhu’ Pill (ESP) is a classic Tibetan medicine to treat neurological disorders in nervous system, especially for neurological pains and epilepsy. It contains many Tibet-specific mineral medicines, among which Halloysite (Halloysitum rubrum, HR) was regarded as the main active one. As mineral medicines contain heavy metals with poor solubility, the doubts about its safety restricted its clinical application and further development. Aim of the study A 7-day acute toxicity of ESP and its main active mineral medicine HR was systematically studied for investigating the safety of ESP and exploring the role of HR in ESP's potential toxicity. Materials and methods In this study, the acute oral toxicity assessment of formula-ESP and HR were performed on rats for 7 days at doses equivalent to 10 (1 g/kg) and 40 times (4 g/kg) the typical clinical dose (0.1 g/kg). 1H NMR based metabolomics profiling, aided with biochemical analysis and histopathology, was conducted to explore the global metabolic changes in the livers and kidneys of the administrated rats. Results High-dose HR caused oxidative stress, energy metabolism disorders, purine metabolism impairments and amino acid metabolism imbalance in rats, resulting in hepatotoxicity and nephrotoxicity, which in accordance with the increased biochemical index in blood (ALT, AST, BUN and CRE). ESP (low-dose) induced metabolites changes were far more less than HR in livers, showcasing the distinct advantage of formula in reducing toxicity. Furthermore, low-dose ESP disturbed renal metabolism in a way similar to high-dose HR, which implies that HR might be the major source of the potential nephrotoxicity of ESP. Conclusion HR exhibited potential hepatoxicity and nephrotoxicity, but the formula- ‘Ershiwuwei Shanhu’ Pill which contains HR is considered relatively safe.