| Polygoni Multiflori Radix (PM) is the tuberous root of Polygonum multiflorum Thunb., which is famous as a tonic TCM. PM is widely used in liver-and-kidney-nourishing and hair-blacking TCM preparations, health-care foods, hairdressing and care products, and the general public diet. Recently, many people are chasing the "humanoid Polygonum multiflorum" which is hyped of miraculous efficacies, such as prolonging life. However, since the British MHRA (Medicines and Healthcare Products Regulatory Agency) reported the liver injury cases of PM and pointed out its safety problems in2006, several follow-up reports on PM or its ingredients causing liver injury appeared all over the world. Canada, Britain, Australia and other countries’drug regulatory departments promulgated the policies to warn and limit the use of PM and its preparations.However, wether the PM-induced liver injury is objective in clinic?Is PM itself toxic? Or the liver adverse effect is caused by irrational use of PM? Is there possibility to reduce the incidence of liver adverse effect of PM by means of early diagnosis and identification of its intoxication? The scientific regulatory and rational use for PM and its preparations are restricted by the absence of systematic study on liver adverse reaction caused by PM and its early diagnosis methods and indices. Considering the broad populations using PM and its serious adverse reaction to liver, there is a great need to assess the hepatotoxicity of PM and establish early diagnosis methods.In this paper, we collected the clinical intoxication cases of PM and used the patients’specimens as the main research materials to clarify the objectivity of PM-induced hepatotoxicity, utilized metabolomics, cell toxicology and network toxicology methods, etc. The potential toxic components in PM and the clinical metabolic biomarker were screened. The injury mechanism of PM was investigated as well. The results provided direct clinical evidences in evaluating PM-induced hepatotoxicity and candidate indices in early diagnosis for PM intoxication in clinic. The study also offered references in reducing hepatotoxicity occurence of PM. The main results and conclusions are as follows:1. There is clinical objectivity of PM-induced hepatotoxicity which is usually caused by misuse or abuse for the main reasons and poor quality of PM for the additional reasons as well.Based on the epidemiological surveys on clinical cases and literature reports of PM-induced liver injury, the objective causes for PM hepatotoxicity were summarized:(1) the PM-induced hepatotoxicity do existed in clinic;(2) The hepatotoxicity of PM might be idiosyncratic;(3) The hepatotoxicity risk factors included the hepatotoxic components of PM and the poor quality of drugs in market circulation as well. Moreover, the efficacy of PM is great exaggerated which misleads to abuse uses of the herb. The misuse or abuse is the most important reason of PM-related adverse events. The nonnormative writing of crude or processed PM in prescription contributed to the misuse of PM.2. The diagnosis methods and biomarkers for PM hepatotoxicity were established based on metabonomics approach and clinical specimens. It was also analyzed for the metabolic pathway related to the PM hepatotoxicity.The metabonomic research is performed by LC-MS/MS Q-TOF using patient serum samples of PM intoxication. The data was processed with multivariate analysis. Totally40biomarkers corresponding to the metabolic disorder caused by PM hepatotoxicity were discovered. Metabolic pathway analysis indicated that this hepatotoxicity might lead to liver injury and cholestasis. Tetrahydronaphthalene, one of the biomarkers, was found to be correlated with the recovery stage of patients or mice. The discovery of these biomarkers provided valuable reference for the early diagnosis and identification of PM-induced hepatotoxicity. The universality and accuracy of these biomarkers need further verification with enlargd sample size.3. The major change pattern of bile acids in PM-induced liver injury rats serum and bile was clarified preliminary and the correlation of bile acid change and PM-induced cholestasis were also discussed. Cholestasis was often occurred in PM-induced hepatotoxicity in patients. In order to explore the mechanism of cholestasis induced by PM, we tested the liver intoxication of PM in rats, determining the total bile acids (TBA), total bilirubin (TBIL),alkaline phosphatase (ALP), and internal relationship between the basic types of liver injury and cholestasis. The results showed that TBA concentration significantly decreased in serum and bile in crude PM-injured rats, while obviously increased in liver, compared to the normal rats. The changes of ALP and TBIL in serum and bile illustrated the biochemical characters of cholestasis. TBA concentration in the serum and bile decreased in liver injury rats induced by raw PM, then further detection of several major bile acids in serum and bile with mass spectrometric was done, and the results were that:the bile acid content in serum and bile decreased mostly, especially in bile except for TCA, the other eight kinds of bile acid showed a declining trend. The decrement of bile acid will affect bile in food digestion, particularly for lipid substances. Clinical hepatotoxicity patients induced by PM always showed such symptoms as recurrent inappetence, tired of oil, etc.4. The toxic action of PM and its main components was investigated in cultured human normal liver cell line L02, regarding the effect to liver apopotosis.The total extract of PM as well emodin, rhein, gallic acid and their mixture were tested in cultured human normal liver cell line L02. The expression quantity of Caspase-3and Bax increased in all the drug-treatment groups twenty four hours after administration. Emodin had a more significant promotion effect on Caspase-3and Bax compared to control group, whilegallic acid had the weakest effect. The expression quantity of Caspase-9increased in rhein group, while decreased in the other groups. Emodin had the strongest effect on decreasing the expression quantity of Caspase-9. The expression quantity of bal-2decreased in PM group, while increased in the other groups. Rhein had the strongest effect, while emodin was the weakest. The toxicity of PM and its main components were related in the caspase pathway of apoptosis. They could regulate the expression of apoptosis-related proteins such as Bcl-2and Bax. The results of this experiment provided the molecular level proof for explaining the types of hepatotoxicity caused by PM. Except for emodin, rhein and gallic acid, further research on the toxicity of the other components in PM should be carried out.5. It was predicted of5possible hepatotoxic components in PM and11possible enzyme targets, using network pharmacology methods and "disease-gene-target-drug" interactive networks.To comprehensively understand the hepatotoxicity of PM, we used the network pharmacology approach, constructed "disease-genes-targets-drugs" interactive networks on the basis of preliminary studies, and then analyzed existing database information such as gene network bank, protein network bank, disease network bank and drug network bank, and combined with spectral data obtained from the previous experiments, then predicted entirely the components and mechanisms of PM hepatotoxicity by professional network analysis software and algorithms. The results predicted5components closely related to PM hepatotoxicity, and11major enzymes, from which we could know hepatotoxicity mechanism may generate from the impact of enzymes changes. The PM hepatotoxicity components and mechanisms predicted needs further experimental verification, and such work will be carried out in our research group.6. The rational use guideline for PM was proposed according to the results of PM hepatotoxicity.According to the abovementiioned results, it could be concluded that the PM-induced hepatotoxicity exists objectively in clinic. The hepatobiliary system damage is the most important and leading adverse reactions. A small number of patients may show severe liver injury, but the patient’s overall prognosis is very well. Based on this research, we present guidance for the rational use of PM as follows:(1) Raw PM should not be used in health food, the processed one should be used with caution in health food;(2) The dose and indications should be strictly controlled in use of PM;(3) The illegal sale of PM should be prohibited to avoid poor quality herbs flowing into market;(4) quality control standard of PM should be perfected with increment of biological noxious value assessment and control indexes;(5) The warning information of hepatotoxicity caused by PM should be announced as soon as possible, to improve the people’s awareness of the risk.In summary, aiming at serious adverse reaction problems caused by PM, we confirmed the objectivity of PM-induced hepatotoxicity by clinical evidence and experimental data. The main reason of PM-induced hepatotoxicity refers to misuse or abuse without physicians’ guidance. Also, some candidate clinical biomarkers for early diagnosis of PM-induced hepatotoxicity were screened and identified in this study. We also proposed the guidance for the rational use of PM to reduce the occurence of liver injury, and avoid unnecessary hurts and economic losses of patients. At the same time, the translational research model of this study would provide references for objective evaluation and research on the toxicity of other TCMs. |
PDF Full Text Request