A 90-day subchronic oral toxicity study of triterpene-enriched extract from Alismatis Rhizoma in rats

Alismatis Rhizoma Triterpenes Alleviate High-Fat Diet-Induced Insulin Resistance in Skeletal Muscle of Mice

Alismatis rhizoma (AR), which is the dried rhizome of Alisma orientale (Sam.) Juz. (Alismataceae), is an important component of many famous Chinese formulas for hypoglycemic. This study aimed to evaluate the insulin resistance (IR) alleviating effects of AR triterpenes (ART) and ART component compatibility (ARTC, the mixture of 16-oxo-alisol A, 16-oxo-alisol A 23-acetate, 16-oxo-alisol A 24-acetate, alisol C, alisol C 23-acetate, alisol L, alisol A, alisol A 23-acetate, alisol A 24-acetate, alisol L 23-acetate, alisol B, alisol B 23-acetate, 11-deoxy-alisol B and 11-deoxy-alisol B 23-acetate) in high-fat diet-induced IR mice and plamitate-treated IR C2C12 cells, respectively. A dose of 200 mg/kg of ART was orally administered to IR mice, and different doses (25, 50, and 100 μg/ml) of ARTC groups were treated to IR C2C12 cells. IPGTT, IPITT, body weight, Hb1AC, FFA, TNF-α, MCP-1, and IR-associated gene expression (p-AMPK, p-IRS-1, PI3K, p-AKT, p-JNK, and GLUT4) were measured in IR mice. Glucose uptake, TNF-α, MCP-1, and IR-associated gene expression were also measured in IR C2C12 cells. Results showed that ART alleviated high-fat diet-induced IR in the skeletal muscle of mice, and this finding was further validated by ARTC. This study demonstrated that ART presented a notable IR alleviating effect by regulating IR-associated gene expression, and triterpenes were the material basis for the IR alleviating activity of AR.

Identifying selective agonists targeting LXRβ from terpene compounds of alismatis rhizoma

Hyperlipidemia is thought of as an important contributor to coronary disease, diabetes, and fatty liver. Liver X receptor β (LXRβ) was considered as a validated target for hyperlipidemia therapy due to its role in regulating cholesterol homeostasis and immunity. However, many current drugs applied in clinics are not selectively targeting LXRβ, and they can also activate LXRα which activates SREBP-1c that worked as an activator of lipogenic genes. Therefore, exploiting agonists selectively targeting LXRβ is urgent. Here, computational tools were used to screen potential agonists selectively targeting LXRβ from 112 terpenes of alismatis rhizoma. Firstly, a structural analysis between selective and nonselective agonists was used to explore key residues of selective binding with LXRβ. Our data indicated that Phe²⁷¹, Ser²⁷⁸, Met³¹², His⁴³⁵, and Trp⁴⁵⁷ were important to compounds binding with LXRβ, suggesting that engaging ligand interaction with these residues may provide directions for the development of ligands with improved selective profiles. Then, ADMET analysis, molecular docking, MD simulations, and calculation of binding free energy and its decomposition were executed to screen the agonists whose bioactivity was favorable from 112 terpenes of alismatis rhizoma. We found that two triterpenes 16-hydroxy-alisol B 23-acetate and alisol M 23-acetate showed favorable ADMET properties and high binding affinity against LXRβ. These compounds could be considered as promising selective agonists targeting LXRβ. Our work provides an alternative strategy for screening agonists selectively targeting LXRβ from alismatis rhizoma for hyperlipidemia disease treatment.

Comprehensive metabolic profiling of Alismatis Rhizoma triterpenes in rats based on characteristic ions and a triterpene database

Alismatis Rhizoma (AR) is widely used in Chinese medicine, and its major bioactive components, triterpenes, reportedly possess various pharmacological activities. Therefore, it is very important to study the metabolism of triterpenes in vivo. However, the metabolism of AR triterpene extract has not been comprehensively elucidated due to its complex chemical components and metabolic pathways. In this study, an ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry method, which was based on the characteristic ions from an established database of known triterpenes, was used to analyze the major metabolites in rats following the oral administration of Alismatis Rhizoma extracts (ARE). As a result, a total of 233 constituents, with 85 prototype compounds and 148 metabolites, were identified for the first time. Hydrogenation, oxidation, sulfate and glucuronidation conjugation were the major metabolic pathways for triterpenes in AR. In addition, the mutual in vivo transformation of known ARE triterpenes was discovered and confirmed for the first time. Those results provide comprehensive insights into the metabolism of AR in vivo, which will be useful for future studies on its pharmacodynamics and pharmacokinetics. Moreover, this established strategy may be useful in metabolic studies of similar compounds.

Methyl jasmonate promote protostane triterpenes accumulation by up-regulating the expression of squalene epoxidases in Alisma orientale

Protostane triterpenes, which are found in Alisma orientale, are tetracyclic triterpenes with distinctive pharmacological activities. The natural distribution of protostane triterpenes is limited mainly to members of the botanical family Alismataceae. Squalene epoxidase (SE) is the key rate-limiting enzyme in triterpene biosynthesis. In this study, we report the characterization of two SEs from A. orientale. AoSE1 and AoSE2 were expressed as fusion proteins in E. coli, and the purified proteins were used in functional research. In vitro enzyme assays showed that AoSE1 and AoSE2 catalyze the formation of oxidosqualene from squalene. Immunoassays revealed that the tubers contain the highest levels of AoSE1 and AoSE2. After MeJA induction, which is the main elicitor of triterpene biosynthesis, the contents of 2,3-oxidosqualene and alisol B 23-acetate increased by 1.96- and 2.53-fold, respectively. In addition, the expression of both AoSE proteins was significantly increased at four days after MeJA treatment. The contents of 2,3-oxidosqualene and alisol B 23-acetate were also positively correlated with AoSEs expression at different times after MeJA treatment. These results suggest that AoSE1 and AoSE2 are the key regulatory points in protostane triterpenes biosynthesis, and that MeJA regulates the biosynthesis of these compounds by increasing the expression of AoSE1 and AoSE2.

A 90-Day Repeated Oral Dose Toxicity Study of Alismatis Rhizoma Aqueous Extract in Rats

Alismatis rhizoma (AR), the dried rhizome of Alisma orientale (Sam.) Juzep, is a well-known, traditional medicine that is used for the various biological activities including as a diuretic, to lower cholesterol and as an anti-inflammatory agent. The present study was carried out to investigate the potential toxicity of the Alismatis rhizoma aqueous extract (ARAE) following 90-day repeated oral administration to Sprague-Dawley rats. ARAE was administered orally to male and female rats for 90 days at 0 (control), 500, 1,000 and 2,000 mg/kg/day (n = 10 for male and female rats for each dose). Additional recovery groups from the control group and high dose group were observed for a 28-day recovery period. Chromatograms of ARAE detected main compounds with four peaks. Treatment-related effects including an increase in the red blood cells, hemoglobin, hematocrit, albumin, total protein, and urine volume were observed in males of the 2,000 mg/kg/day group (p < 0.05). However, the diuretic effect of ARAE was considered, a major cause of hematological and serum biochemical changes. The oral no-observed-adverse-effect level (NOAEL) of the ARAE was > 2,000 mg/kg/day in both genders, and no target organs were identified.

Orientalol L–P, novel sesquiterpenes from the rhizome of Alisma orientale (Sam.) Juzep and their nephrotoxicity on HK2 cells

Two new sesquiterpenes and three new nor-sesquiterpenes from the rhizome of Alisma orientale (Sam.) Juzep, and their nephrotoxicities.

The strategy for establishment of the multiple reaction monitoring based characteristic chemical profile of triterpenes in Alismatis rhizoma using two combined tandem mass spectrometers

It was reported that triterpenes compounds in Alismatis rhizoma (AR) contributed to the lipid lowering effect on high fat diet (HFD)-induced hyperlipidemia. To date only 24 triterpenes (including the isomers) were characterized by LC-QTOF-MS/MS due to the lack of strategies for systematic discovery, classification and identification of triterpenes in AR. In this study, an integrated strategy combining various QTOF-MS/MS and QTRAP-MS/MS scan functions was developed for systematic identification and specific characterization of triterpenes in AR and processed AR. First, MS/MS fragmentation behaviors of different types of triterpenes were investigated and their diagnostic product ions were systematically summarized for discovery and classification of triterpenes. Second, diagnostic product ions were used to filter the data acquired by UHPLC-QTOF MS/MS for efficient identification of targeted triterpenes. Third, MRM-based characteristic chemical profile (CCP) of triterpenes was established using 30 MRM transitions by UHPLC-QTRAP-MS/MS. Fourth, MRM-based CCP was applied for comparative analyses of triterpenes in AR from different regions and from two other processed AR (salt processed AR and bran processed AR). Consequently, a total of 80 triterpenes including 14 novel compounds were identified in the AR, and 7 more triterpenes compounds were discovered using MRM-based CCP in the processed AR. This work is the most comprehensive characterization of triterpenes compounds in AR to date. The established MRM-based CCP of triterpenes compounds can be instructive for qualitative analyses and relative quantitative analyses of triterpenes in AR and its related medicinal products for potential applications including quality control and classification of different AR materials.

Diuretic Activity of Compatible Triterpene Components of Alismatis rhizoma

Alismatis rhizoma (AR), the dried rhizoma of Alisma orientale Juzepzuk (Alismataceae), is a traditional Chinese medicine. AR is an important part of many prescriptions and is commonly used as a diuretic agent in Asia. This study aimed to evaluate the diuretic effects of total triterpene extract (TTE) and triterpene component compatibility (TCC, the mixture of alisol B 23-acetate, alisol B, alisol A 24-acetate, alisol A, and alisol C 23-acetate) of AR in saline-loaded rats. The optimal diuretic TCC of AR was optimized using a uniform design. Different doses (5, 20, and 40 mg/kg) of TTE and TCC groups (N1–N8) were orally administered to rats. Urinary excretion rate, pH, and electrolyte excretion were measured in the urine of saline-loaded rats. Results showed that TTE doses increased urine volume and electrolyte excretion compared with the control group. All uniformly designed groups of TCC also increased urine excretion. In addition, optimal diuretic TCC was calculated (alisol B 23-acetate: alisol B: alisol A 24-acetate: alisol A: alisol C 23-acetate 7.2:0.6:2.8:3.0:6.4) and further validated by saline-loaded rats. This study demonstrated that TTE presented a notable diuretic effect by increasing Na⁺, K⁺, and Cl⁻ displacements. The most suitable TTC compatible proportion of alisol B 23-acetate: alisol B: alisol A 24-acetate: alisol A: alisol C 23-acetate for diuretic activity was validated, and triterpenes were the material basis for the diuretic activity of AR.

Alisma orientale: Ethnopharmacology, Phytochemistry and Pharmacology of an Important Traditional Chinese Medicine

Alisma orientale (Sam.) Juzep. (Alismataceae) is a traditional and famous Chinese medicinal herb. Its rhizomes, which possess versatile bioactivities, are commonly used to treat oliguria, edema, gonorrhea with turbid urine, leukorrhea, diarrhea and dizziness. Approximately 120 compounds have been isolated from A. orientale. Terpenoids have been identified as A. orientale's characteristic constituents, which include protostane triterpenoids and guaiane sesquiterpenoids. The traditional medical uses of A. orientale in TCM have been evaluated in modern pharmacological studies, which have shown that A. orientale and its active constituents exhibit a wide range of bioactivities, such as diuretic, anti-urolithiatic, antinephritic, anti-atherosclerotic, immunomodulatory, and hepatoprotective activities. The medicinal potential of A. orientale makes it an ideal candidate for new drug development. Further studies are still required to identify its bioactive constituents, and elucidate the structure-activity relationship and detailed mechanisms of action. Additionally, the use of the other medicinal parts of A. orientale may reduce resource waste and afford novel secondary metabolites.

Effects of alisol B 23-acetate on ovarian cancer cells: G1 phase cell cycle arrest, apoptosis, migration and invasion inhibition

BACKGROUND

Ovarian cancer is the first leading cause of death among gynecologic malignancies worldwide. Discovery of new chemotherapeutic drugs is still imperative for the improvement of the survival rate.

PURPOSE

This study aims to investigate the anti-cancer potential of alisol B 23-acetate (AB23), a protostane-type triterpene isolated from the Alismatis Rhizoma, in the parental and paclitaxel-resistant ovarian cancer cells.

METHODS

MTT assay was performed to evaluate cell viability after treatment with AB23, along with flow cytometry for apoptosis and cell cycle analysis. Western blotting was conducted to determine the relative protein level. Wound healing and transwell assays were performed to investigate the effect of AB23 on cell migration and invasion.

RESULTS

AB23 obviously inhibited proliferation of the three ovarian cancer cell lines, down-regulated the protein levels of CDK4, CDK6, and cyclin D1, and blocked the cell cycle progressions in G1 phase. Meanwhile, AB23 induced accumulation of the sub-G1 phase in the three cell lines in a concentration dependent manner. The protein levels of cleaved poly ADP-ribose polymerase (PARP) and the ratio of Bax/Bcl-2 were up-regulated after treatment with AB23. Further study showed that AB23 induced endoplasmic reticulum stress through IRE1 signaling pathway and silencing of IRE1α partially enhanced AB23-induced apoptosis. Wound healing and transwell assays showed that AB23 could also suppress the migration and invasion of HEY cells. Moreover, it down-regulated the protein levels of matrix metalloproteinases MMP-2 and MMP-9.

CONCLUSION

AB23 possessed anti-proliferation, anti-migration and anti-invasion activities as a single agent on ovarian cancer cells.

The metabolic change of serum lysophosphatidylcholines involved in the lipid lowering effect of triterpenes from Alismatis rhizoma on high-fat diet induced hyperlipidemia mice

ETHNOPHARMACOLOGICAL RELEVANCE

Alismatis rhizoma (AR), a Traditional Chinese Medicine with lipid-regulating properties, is usually used to treat hyperlipidemia. Lysophosphatidylcholines (Lyso PCs) play a crucial role in lipid metabolism disorders. In this study, the triterpene fraction purified from boiling water extract of AR was evaluated for its lipid lowering activity using mice with high-fat diet (HFD) induced hyperlipidemia. The metabolic changes of individual Lyso PCs treated with the triterpene fraction were detected by ultra-high performance liquid chromatography-triple quadrupole-linear ion trap mass spectrometer (UHPLC-QTRAP-MS/MS).

MATERIALS AND METHODS

HFD induced hyperlipidemia mice were administrated with triterpene and non-triterpene fractions at doses of 180, 360 and 720 mg/kg body weight/day for 4 weeks, respectively. Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and atherogenic Index (AI) in mice serum were measured. The chemical components in the lipid-lowering fraction were characterized by ultra-high performance liquid chromatography-quadrupole time of flight tandem mass spectrometry (UHPLC-QTOF-MS/MS). The changes of Lyso PC in the serum of mice treated with the lipid-lowering fraction were quantified by UHPLC-QTRAP-MS/MS.

RESULTS

A total of 18 alisol derivatives were identified in the triterpene fraction. The hyperlipidemia mice treated with the triterpene fraction showed a significant decrease in serum TC, LDL-C and AI after continuous consumption of HFD for 4 weeks. The results also showed that 27 serum Lyso PCs in mice fed with HFD were down-regulated, and 19 were up-regulated. The abnormal serum level of Lyso PCs associated with hyperlipidemia was intervened by the alisol derivatives, with increase of unsaturated Lyso PCs and decrease of saturated ones.

CONCLUSIONS

The study demonstrated for the first time that triterpenes from the AR extract can lower serum lipid level in HFD induced hyperlipidemia mice. These metabolism changes of Lyso PCs could further improve our understanding of the potential mechanism of lipid lowering effect of AR.

Non-clinical toxicity studies on bioactive compounds within the framework of nutritional and health claims

The growing presence of products on the market with added value in terms of health makes essential their regulation and harmonization in critical aspects such as safety. The toxicology applied to the bioactive compounds should demonstrate the absence of toxic effects at doses advised for consumption, as well as evaluate the potential toxic effects in the assumption that the products are used in quantities superior to those recommended. The specific strategy should be defined case by case; therefore, prior to any toxicological development, it is essential to study all the information regarding the bioactive compounds (BACs) characterization, nutridynamics and nutrikinetics, that is available. In this guideline, a general strategy to be applied in the development of BACs is proposed. It includes a first in vitro phase to discard genotoxicity and endocrine effects and a second in vivo phase with different possibilities regarding the duration and the extension of the studies.

Traditional uses, phytochemistry, pharmacology, toxicology and quality control of Alisma orientale (Sam.) Juzep: a review

ETHNOPHARMACOLOGICAL RELEVANCE

Rhizoma alismatis (simplified as RA, "Zexie" in Chinese, ) is a well-known natural medicine with long history in Chinese medicine. As a traditional medicine in China, RA is an important part of many prescriptions and has been commonly used for treating a wide range of ailments related to dysuria, edema, nephropathy, hyperlipidaemia, diabetes, inflammation as well as tumor in clinical applications. Based on scientific literatures, the present paper aims to provide comprehensive and up-to date information about the traditional uses, phytochemistry, pharmacology, toxicology and quality control of RA as well as critical analysis of the research. The review will provide a new foundation and direction for the further studies of RA.

MATERIALS AND METHODS

All available information about RA was supplied by library database and electronic search (ScienceDirect, Web of Science, Pubmed, Google Scholar, etc.). The different types of useful information were collected and arranged in corresponding part of the paper.

RESULTS

Phytochemical studies showed that the main chemical composition of RA was the terpenoid including sesquiterpene, diterpene and triterpene. The crude extracts and isolated compounds from RA showed diverse pharmacological activities including diuretic, nephroprotective, anti-hyperlipidemic, anti-atherosclerotic, anti-cancer, anti-inflammatory and anti-oxidative activities. However, high-dose or long-term use of RA can lead to water-electrolyte imbalance, bloody urine, acidosis and even hepatotoxicity or nephrotoxicity, which have been proven by several studies.

CONCLUSIONS

Pharmacological researches show RA possessing various bioactivities including diuresis, nephroprotective effect, anti-hyperlipidemia, etc. However, more bioactive components especially diuretic and nephroprotective compounds need to be isolated and identified, and more rigorous researches on action mechanisms are required. More experiments in vitro or in vivo and clinical studies are encouraged to clarify correlation between traditional uses and modern applications, and the toxicity need to be further and precisely explored. In addition, a standardized fingerprint for RA is indispensable and emergent. These achievements will further expand to therapeutic potential and usage of RA and provide a powerful support for clinical use.

A review on the traditional Chinese medicinal herbs and formulae with hypolipidemic effect

Hyperlipidemia, characterized by the abnormal blood lipid profiles, is one of the dominant factors of many chronic diseases such as diabetes, obesity, and cardiovascular diseases (CVD). For the low cost, effectiveness, and fewer side effects, the popularity of using traditional Chinese medicine (TCM) to handle hyperlipidemia is increasing and its role in health care has been recognized by the public at large. Despite the importance of TCM herbs and formulations, there is no comprehensive review summarizing their scientific findings on handling hyperlipidemia. This review summarizes the recent experimental and clinical results of nine representative single Chinese herbs and seven classic TCM formulae that could improve lipid profiles so as to help understand and compare their underlying mechanisms. Most of single herbs and formulae demonstrated the improvement of hyperlipidemic conditions with multiple and diverse mechanisms of actions similar to conventional Western drugs in spite of their mild side effects. Due to increasing popularity of TCM, more extensive, well-designed preclinical and clinical trials on the potential synergistic and adverse side effects of herb-drug interactions as well as their mechanisms are warranted. Hyperlipidemic patients should be warned about the potential risks of herb-drug interactions, particularly those taking anticoagulants and antiplatelet drugs.