Two Undescribed Protostane Triterpenoids from the Rhizome of Alisma plantago-aquatica.

Two undescribed protostane triterpenoids, 11-deoxy-13(17),15-dehydro-alisol B 23-acetate (2) and alisol S (3), together with 21 known ones (1, 4-23), were isolated from the dried rhizome of Alisma plantago-aquatica. Of these compounds, 13(17),15-Dehydro-alisol B 23-acetate (1) and 11-deoxy-13(17),15-dehydro-alisol B 23-acetate (2) are two protostane triterpenoids containing conjugated double bonds in the five-membered ring D that are rarely found from nature resource, while alisol S (3) is a protostane triterpenoid with undescribed tetrahydrofuran moiety linked via C20 -O-C24 at the side chain. Additionally, compound 18 is a new natural product, and cycloartenol triterpenoid 23 is a non protostane triterpenoid firstly isolated from genus Alisma. Their structures were elucidated by extensive spectral analysis of the UV, IR, MS, 1D and 2D NMR, and comparison of the experimental and calculated CD curves.

New Guaiane-Type Sesquiterpene and Norsesquiterpene from Alisma plantago-aquatica and Their Xanthine Oxidase Inhibitory Activity.

A new sesquiterpene (1) and a new norsesquiterpene (2) belonging guaiane-type skeleton together with six known compounds (3-8) were isolated from the rhizomes of Alisma plantago-aquatica. Their structures were determined by HR-ESI-MS, 1D and 2D NMR spectroscopic methods. Absolute configurations of new compounds were established by experimental and TD-DFT computational ECD spectra. Compounds 1-8 exhibited xanthine oxidase inhibitory activity with their IC50 values in range of 9.4-66.7 µM. The sesquiterpenoids 1-5 displayed the inhibitory activity and hence they could be potential xanthine oxidase inhibitors from A. plantago-aquatica.

Translocation of TiO2 nanoparticles enhances phosphorus uptake by wetland plants: Evidence from Pistia stratiotes and Alisma plantago-aquatica.

Titanium dioxide nanoparticles (nTiO2) and phosphorus (P) are widely present in sewages. To verify the hypothesis and the associated mechanisms that root-to-shoot translocation of nTiO2 can enhance plant P uptake thus P removal during sewage treatment, two wetland plants (Pistia stratiotes and Alisma plantago-aquatica) with different lateral root structures were used to examine the effect of nTiO2 (89.7% anatase and 10.3% rutile) on plant growth and P uptake in a hydroponic system. Inductively coupled plasma-optical emission spectroscopy and transmission electron microscopy-energy dispersive spectroscopy showed that P. stratiotes with well-developed lateral roots translocated 1.4-16 fold higher nTiO2 than A. plantago-aquatica with poorly developed roots, indicating P. stratiotes is efficient in nTiO2 uptake. In addition, nTiO2 root-to-shoot translocation in P. stratiotes increased with increasing nTiO2 concentration, while the opposite occurred in A. plantago-aquatica. Corresponding to the stronger nTiO2 translocation in P. stratiotes, its P uptake efficiency (Imax) and P accumulation were greater than that in A. plantago-aquatica, with Imax being increased by 35.8% and -16.4% and shoot P concentrations being increased by 16.2-64.6% and 11.4%, respectively. The strong positive correlation between Ti and P concentrations in plant tissues (r = 0.72-0.89, P < 0.01) indicated that nTiO2 translocation enhanced P uptake. Moreover, nTiO2-enhanced P uptake promoted plant growth and photosynthetic pigment synthesis. Therefore, wetland plants with well-developed lateral roots like P. stratiotes have potential to be used in P removal from nTiO2-enriched sewages.

Comparative analysis of the structure and function of rhizosphere microbiome of the Chinese medicinal herb Alisma in different regions.

Rhizoma Alismatis, a commonly used traditional Chinese medicine, is the dried tuber of Alisma orientale and Alisma A. plantago-aquatica, mainly cultivated in Fujian and Sichuan provinces (China), respectively. Studies have shown that the rhizosphere microbiome is a key factor determining quality of Chinese medicinal plants. Here we applied metagenomics to investigate the rhizosphere microbiome of Alisma in Fujian and Sichuan, focusing on its structure and function and those genes involved in protostane triterpenes biosynthesis. The dominant phyla were Proteobacteria, Actinobacteria, Chloroflexi, Acidobacteria, and Gemmatimonadetes. Compared with Fujian, the rhizosphere of Sichuan has a greater α diversity and stronger microbial interactions but significantly lower relative abundance of archaea. Microbes with disease-suppressing functions were more abundant in Sichuan than Fujian, but vice versa for those with IAA-producing functions. Gemmatimonas, Anaeromyxobacter, and Pseudolabrys were the main contributors to the potential functional difference in two regions. Genes related to protostane triterpenes biosynthesis were enriched in Fujian. Steroidobacter, Pseudolabrys, Nevskia, and Nitrospira may contribute to the accumulation of protostane triterpenes in Alisma. This work fills a knowledge gap of Alisma's rhizosphere microbiome, providing a valuable reference for studying its beneficial microorganisms.

Alisma canaliculatum Extract Affects AGS Gastric Cancer Cells by Inducing Apoptosis.

The anti-cancer effects of Alisma canaliculatum extracts (ACE) were identified in AGS gastric cancer cells. Our results showed that ACE inhibited the growth of AGS cells, increased the proportion of sub-G1 phase cells, and depolarized the membrane potential of mitochondria. ACE-induced gastric cancer cell death was associated with Bcl-2, survivin and Bax level changes, and it activated caspase-3 and -9. In addition, it was involved in the activation of MAPKs and increased the reactive oxygen species (ROS). These results suggest that ACE induces apoptosis in AGS gastric cancer cells, and therefore, ACE may have the potential to treat gastric cancer.

Alisma genus: Phytochemical constituents, biosynthesis, and biological activities.

The genus Alisma contains 11 species distributed worldwide, of which at least two species (A. orientale [Sam.] Juzep. and A. plantago-aquatica Linn.) have been used as common herbal medicines. Secondary metabolites obtained from the genus Alisma are considered to be the material basis for the various biological functions and medicinal applications. In this review, we mainly focused on the recent investigations of secondary metabolites from plants of the genus Alisma and their biological activities, with the highlighting on the diversity of the chemical structures, the biosynthesis of interesting secondary metabolites, the biological activities, and the relationships between structures and bioactivities.

Changes in Triterpenes in Alismatis rhizoma after Processing Based on Targeted Metabolomics Using UHPLC-QTOF-MS/MS.

Alismatis rhizoma (AR) has been used as an herbal medicine in China for over a thousand years. Crude AR, salt-processed AR (SAR), and bran-processed AR (BAR) are recorded in the Pharmacopoeia of the People's Republic of China. However, the differences of chemical composition between crude AR and its processing products remain limited. In this study, triterpenes were identified from crude AR, SAR, and BAR by ultra-high performance liquid chromatography coupled with quadrupole time-of-flight-mass spectrometer (UHPLC-QTOF-MS/MS). Subsequently, the differences of triterpenes between the crude AR and processed ARs were compared via a targeted metabolomics approach. Finally, a total of 114 triterpenes were identified, of which 83, 100, and 103 triterpenes were found in crude AR, SAR, and BAR, respectively. After salt-processing, there were 17 triterpenes newly generated, 7 triterpenes with trends of increasing, and 37 triterpenes decreased. Meanwhile, 56 triterpenes including 21 newly generated and 35 with significant increases were observed in BAR. This study could be benefit to investigate the processing mechanism of AR, as well as support their clinical applications.

Protostane-type triterpenoids as natural soluble epoxide hydrolase inhibitors: Inhibition potentials and molecular dynamics.

The inhibition of soluble epoxide hydrolase (sEH) is a promising therapeutic approach to treat inflammation and other disorders. In our present investigation on searching for sEH inhibitors from traditional Chinese medicines, we found that Alisma orientale displayed inhibition of sEH. We constructed a small library of protostane-type triterpenoids (1-25) isolated from A. orientale, and screened their inhibitory activities. Alismanin B (1), 11-deoxy-25-anhydro alisol E (4), 11-deoxy alisol B (5), and 25-O-ethyl alisol A (15) displayed concentration-dependently inhibitory activities against sEH with IC50 values from 3.40 ± 0.57 µM to 9.57 ± 0.88 µM. 11-Deoxy-25-anhydro alisol E (4) and 11-deoxy alisol B (5) were defined as mixed-type competitive inhibitors with Ki values of 12.6 and 3.48 µM, respectively, based on the result of inhibition kinetics. The potential interaction mechanism of 11-deoxy alisol B (5) with sEH was analyzed by molecular docking and molecular dynamics, revealing that amino acid residues Trp336 and Tyr466 were vital for its inhibitory activity.

A biochemometrics strategy for tracing diuretic components of crude and processed Alisma orientale based on quantitative determination and pharmacological evaluation.

We proposed a biochemometrics strategy for tracing diuretic components of herbs based on quantitative determination and pharmacological evaluation. First, a sensitive and robust liquid chromatography coupled with tandem mass spectrometry approach was established for simultaneous quantification of six major triterpenoids in crude and salt-processed Alisma orientale. The separation of triterpenoids was achieved on a BEH C18 column with a mobile phase consisting of acetonitrile and water spiked with 0.1% formic acid. Six major triterpenoids were detected by multiple reaction monitoring in the negative ion mode. Glycyrrhetinic acid was used as the internal standard. The approach showed good linearity. Intra- and inter-day precisions were all within 2.9%. The recovery rates of each triterpenoid ranged from 97.9% to 103.2%. The approach was then successfully employed for quantitative analysis of six triterpenoids in ten batches of crude and salt-processed A. orientale. Second, the diuretic effects of crude and salt-processed A. orientale were evaluated in mice. Third, principal component analysis and canonical correlation analysis were used to uncover the relationship between the contents of six major triterpenoids and the diuretic effect of different crude and salt-processed samples. Alisol B, alisol F, and alisol A have a close positive correlation with the diuretic effect.

Chemical constituents from Alismatis Rhizoma and their anti-inflammatory activities in vitro and in vivo.

Six new compounds, including a new compound with an unusual 2, 4, 6-cycloheptatrien ketone skeleton (1), two new diphenylpropanoid ethers (2, 3), a new protostane-type triterpenoid (4), two new norsesquiterpene (5a, 5b), and two new natural products (6, 7), together with eleven known compounds (8-18) were isolated from the aqueous extract of Alismatis Rhizoma (AR). Their structures were elucidated by a combination of 1D and 2D NMR (1H and 13C NMR, COSY, HSQC, HMBC, and NOESY), HRESIMS spectroscopic data, experimental and calculated electronic circular dichroism (ECD) spectra. Some of the compounds were evaluated for their inhibitory effects on nitric oxide (NO) production in LPS-induced RAW 264.7 cells. Two protostane-type triterpenoids, compounds 4 and 17, exhibited potent inhibitory activities with the IC50 values of 39.3 and 63.9 µM compared with indomethacin. In the meanwhile, their anti-inflammatory effects were also confirmed by acute inflammation model induced by CuSO4 in zebrafish.

The Alisma and Rhizoma decoction abates nonalcoholic steatohepatitis-associated liver injuries in mice by modulating oxidative stress and autophagy.

BACKGROUND: To investigate the effects of the Alisma and Rhizoma decoction on nonalcoholic steatohepatitis (NASH) and to further shed light on the underlying mechanisms of the actions of the Alisma and Rhizoma decoction. METHODS: Plasma alanine aminotransferase (ALT) content was determined and liver inflammation and fibrosis were evaluated. Intrahepatocellular malondialdehyde and superoxide dismutase contents were determined using commercially available kits Furthermore, α-SMA expression in liver tissues was examined by immunohistochemistry and LC3-II was detected by immunoblotting assays. RESULTS: Mice receiving the Alisma and Rhizoma decoction by gastric lavage had significantly lower plasma ALT content and markedly higher hepatic superoxide dismutase activity than mice receiving the methionine-choline deficient (MCD) diet. Furthermore, the decoction aborted MCD-induced increase in liver malondialdehyde content. Immunohistochemistry showed that the decoction suppressed hepatic α-SMA expression. Our transmission electronic microscopy revealed that the decoction markedly reduced the number of autophagosomes and immunoblotting assays showed that the decoction caused a dose-dependent decrease in LC3-II in hepatic tissues. CONCLUSION: The Alisma and Rhizoma decoction lessens NASH-associated liver injuries by modulating oxidative stress and autophagy in hepatocytes of mice fed with MCD.

[Exploration of objective quality evaluation parameter of Alismatis Rhizoma decoction pieces].

To establish a quality constant evaluation system of Alismatis Rhizoma decoction pieces,in order to provide reference for regulating the market circulation of this decoction pieces. A total of 18 batches of Alismatis Rhizoma decoction pieces were collected from different pharmaceutical factories,and the morphological parameters of each sample were tested. The content of alisol B 23-acetate in Alismatis Rhizoma decoction pieces was determined by HPLC in the 2015 edition of Chinese Pharmacopoeia,and the parameters such as quality constant and relative quality constant were calculated. The quality constant range of 18 batches of Alismatis Rhizoma decoction pieces was 0. 390-2. 076. If 18 batches of Alismatis Rhizoma decoction pieces were divided into 3 grades,taking 80% of the maximum quality constant as first grade,50% to 80% as second grade,and the rest as third grade,then the quality constant of firstgrade samples was ≥1. 66,the quality constant of second-grade samples was ≥1. 04 and <1. 66,and the quality constant of third-grade samples was <1. 04. The established quality constant evaluation method is objective and feasible,which can be used to classify the grade of Alismatis Rhizoma decoction pieces and provide a reference method to control the quality of this decoction pieces.

[Correlation study between accumulation of triterpenoids and expression of relative genes in Alisma orientale].

To research the correlation between accumulation of triterpenoids and expression of key enzymes genes in triterpenoid biosynthesis of Alisma orientale,the study utilized UPLC-MS/MS method to detect eight triterpenoids content in the tuber of A. orientale from different growth stages,including alisol A,alisol A 24 acetate,alisol B,alisol B 23 acetate,alisol C 23 acetate,alisol F,alisol F 24 acetate and alisol G,and then the Real time quantitative PCR was used to analyze the expression of key enzymes genes HMGR and FPPS in triterpenoid biosynthesis. Correlation analysis showed that there was a significant positive relation between the total growth of these eight triterpenoids and the average relative expression of HMGR and FPPS(HMGR: r = 0. 998,P<0. 01; FPPS: r = 0. 957,P<0. 05),respectively. Therefore,the study preliminarily determined that HMGR and FPPS genes could regulate the biosynthesis of triterpenoids in A. orientale,which laid a foundation for further research on the biosynthesis and regulation mechanism of triterpenoids in A. orientale.

Alisol B-23-acetate, a tetracyclic triterpenoid isolated from Alisma orientale, induces apoptosis in human lung cancer cells via the mitochondrial pathway.

Alisol B-23-acetate (AB23A), a tetracyclic triterpenoid isolated from the rhizome of Alisma orientale, has been reported to exert anti-proliferative activities in human colon, ovarian and gastric cancer cells. However, the anti-cancer effect of this compound on human lung cancer cells has not yet been thoroughly elucidated. In the present study, we investigated the effects of AB23A on the cell viability and apoptosis in human lung cancer A549 and NCI-H292 cells. The results indicated that AB23A inhibited the growth of A549 and NCI-H292 cells in dose- and time-dependent manner, however, there was only weak cytotoxicity on normal bronchial epithelial cells. The induction of apoptosis by AB23A was demonstrated by DAPI and annexin-V-FITC/PI staining. Further investigation revealed that AB23A decreased mitochondrial membrane potential (MMP) and up regulated reactive oxygen species (ROS) level. Meanwhile, the increased Bax/Bcl-2 ratio, activated caspase-3, caspase-9 and PARP were observed. In addition, AB23A increased the release of cytochrome c from mitochondria and the translocation of apoptotic inducing factor (AIF) into nuclei. Taken together, these results indicated that AB23A induced apoptosis by activating the intrinsic pathway, and suggested that AB23A can be used as a potential modulating agent in lung cancer.

Geographic impact evaluation of the quality of Alismatis Rhizoma by untargeted metabolomics and quantitative assay.

The geographic impact on the quality of Alismatis Rhizoma (derived from the tuber of Alisma orientale), a reputable diuretic traditional Chinese medicine, has seldom been evaluated. Here a metabolomics-driven approach targeting the bioactive protostane triterpenes was developed, by incorporating UHPLC with quadrupole time-of-flight mass spectrometry-based untargeted metabolite profiling and multiple reaction monitoring quantitative assay, to probe the triterpene differences between Alismatis Rhizoma samples collected from Sichuan, Fujian, and Jiangxi Provinces. Following the metabolomics workflows, the samples from Sichuan and Jiangxi displayed distinct differences in their triterpene profiles, whereas those from Fujian showed remarkable intra-class variation. Twenty-three triterpenes were identified to contribute most to the differentiated clustering. A sensitive, precise, repeatable, and accurate quantitative assay method was established on a hybrid triple quadrupole-linear ion trap mass spectrometer to quantify the contents of eight triterpene compounds. Taking into account the metabolomics and quantitation results, alisol B 23-acetate and alisol A are significantly different in Alismatis Rhizoma from Sichuan and Jiangxi Provinces, and they may have the potential for geographic discrimination. These results illustrate how geographic difference impacts the triterpene chemistry of Alismatis Rhizoma. Metabolomics-driven chemical comparison is suitable for the quality evaluation of traditional Chinese medicine.

Inhibitory Effect of Alisma canaliculatum Ethanolic Extract on NF-κB-Dependent CXCR3 and CXCL10 Expression in TNFα-Exposed MDA-MB-231 Breast Cancer Cells.

CXC motif chemokine ligand 10 (CXCL10) and its receptor CXC motif chemokine receptor 3 (CXCR3), play important roles in the motility of breast cancer cells. Alisma canaliculatum is a herb that has been used as a traditional medicine for thousands of years in Korea and China. Whether A. canaliculatum inhibits the motility of metastatic breast cancer cells is not clear yet. In this study, we show that A. canaliculatum ethanolic extract (ACE) prevented tumor necrosis factor-alpha (TNFα)-induced migration of MDA-MB-231 cells. ACE significantly attenuated TNFα-induced upregulation of CXCL10 and CXCR3 expression at the gene promoter level. Mechanistically, ACE inhibits TNFα-induced phosphorylation of inhibitor of κB (IκB) kinase (IKK), IκB and p65/RelA, leading to the suppression of nuclear translocation of p65/RelA nuclear factor kappa-B (NF-κB). Also, ACE inhibited NF-κB-dependent CXCR3 and CXCL10 promoter activities. These results suggest that ACE abrogates TNFα-induced migration of MDA-MB-231 breast cancer cells through down-regulation of IKK-NF-κB-dependent CXCR3 and CXCL10 expression. Our results suggest that ACE has potential as a herbal supplement for the inhibition of breast cancer metastasis.

Alisol B, a triterpene from Alismatis rhizoma (dried rhizome of Alisma orientale), inhibits melanin production in murine B16 melanoma cells.

To develop new whitening agents from natural products, we screened 80 compounds derived from crude drugs in Kampo medicine in a melanin synthesis inhibition assay using murine B16 melanoma cells. The screen revealed that treatment with alisol B, a triterpene from Alismatis rhizoma, significantly decreased both melanin content and cellular tyrosinase activity in B16 cells. However, alisol B did not directly inhibit mushroom tyrosinase activity in vitro. Therefore, we investigated the mechanism underlying the inhibitory effect of alisol B on melanogenesis. Alisol B suppressed mRNA induction of tyrosinase and its transcription factor, microphthalmia-associated transcription factor (MITF). Furthermore, alisol B reduced the phosphorylation of CREB and maintained the activation of ERK1/2. These results suggest that the reduction in melanin production by alisol B is due to the downregulation of MITF through the suppression of CREB and activation of ERK and that alisol B may be useful as a new whitening agent.

Urinary biomarker and treatment mechanism of Rhizoma Alismatis on hyperlipidemia.

Rhizoma Alismatis (RA), a diuretic in Asia and Europe, was found to possess anti-hyperlipidemic activity. Since the biomarkers and mechanisms of RA in the treatment of hyperlipidemia are inadequate, ultra-performance liquid chromatography coupled with quadrupole time-of-flight synapt high-definition mass spectrometry and multivariate data analysis were employed to investigate the urinary metabolomics of RA on hyperlipidemic rats induced by high-fat diet. The metabolic profile of RA-treated hyperlipidemic group located between control and diet-induced hyperlipidemic groups. Nineteen metabolites with significant fluctuations were identified as potential biomarkers related to the hyperlipidemia and anti-hyperlipidemia of RA using partial least-squares-discriminate analysis, heatmap analysis and correlation coefficient analysis. The fluctuations of these biomarkers represented disturbances in amino acid metabolism, purine metabolism, pyrimidine metabolism and energy metabolism. After RA treatment, these perturbed metabolites were restored to normal or nearly normal levels. RA can alleviate high-fat diet-induced dysfunctions in these metabolic pathways.

Protostane-Type Triterpenoids from Alisma orientale.

Twenty-eight protostane triterpenoids, including a new degraded one (1), nine new ones (2 - 10), and two new natural ones (11 and 12), have been isolated from the dried rhizomes of Alisma orientale. Alisol R (1) was the first 20,21,22,23,24,25,26,27-octanorprotostane triterpenoid. The absolute configurations of 25-methoxyalisol F (2) and 16ß-hydroperoxyalisol B 23-acetate (3) were determined by X-ray diffraction analysis. In addition, alismaketone-B 23-acetate (28) showed potent vasorelaxant activity on endothelium-intact thoracic aorta rings precontracted with KCl.

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.