Alisol C

Studies on the lipid-regulating mechanism of alisol-based compounds on lipoprotein lipase.[Pubmed:29986183]

Bioorg Chem. 2018 Oct;80:347-360.

Studies on the lipid-regulating effects of Alisol Compounds are reported that include alisol B, alisol A 24-acetate (24A), alisol A and an alisol B - 24A - alisol A mixture (content ratio=1:1:1). The effects on the activity of lipoprotein lipase (LPL), a key lipid-modulating enzyme, were studied to investigate the molecular mechanism of lipid-regulating activity of alisols. The effects of alisols on regulating blood lipids and the activities of LPL were determined using a reagent kit method. The structure of LPL was obtained by homology modeling and the interactive mechanism of alisol monomers and the mixture with LPL was investigated by molecular simulation. The alisol monomer and mixture were shown to regulate blood lipids, suggesting that alisols may decrease the level of triglyceride (TG) by improving the activity of LPL. The order of intensity was: mixture>alisol A>alisol B>24A, indicating that alisols of alismatis rhizoma feature a synergistic effect on LPL. The N- and C-terminus of LPL both represented the catalytic active domains of this lipid-regulating effect. Cys306, Gln129 and Ser166 were the key amino acid residues resulting in the lipid-regulating effect of the alisol monomer while Ser166 and Arg18 were found to be responsible for the lipid-regulating effect of the mixture. The C-terminus of LPL was indirectly involved in the enzymatic process. A folded side chain of alisols or the parent ring was found to bind somewhat weaker to LPL than an open side chain or parent ring. The hydroxyl groups on the C14-, C22-, C28-, C30- and C31-terminus in the side chain, the ring ether structure in C23-position, and the acetyl group in C29-position represented the key sites for the lipid-regulating action of alisols. Meanwhile, the C30-site hydroxyl group played an important role in the synergistic effect of the alisol mixture.

Pharmacokinetics and tissue distribution of five major triterpenoids after oral administration of Rhizoma Alismatis extract to rats using ultra high-performance liquid chromatography-tandem mass spectrometry.[Pubmed:28910706]

J Pharm Biomed Anal. 2017 Nov 30;146:314-323.

Rhizoma Alismatis (RA) was wildly used for treatment of dysuria, pyelonephritis, hyperlipidemia, enteritis diarrhea, diabetes, inflammation, and cancer. Triterpenoids are the major active components of RA, and its extract is mainly composed of alisol A (ALA), alisol B (ALB), Alisol C 23-acetate (ALC-23A), alisol A 24-acetate (ALA-24A), and alisol B 23-acetate (ALB-23A). In this study, a simple, reliable, and sensitive ultra high-performance liquid chromatography with triple quadrupole mass spectrometry (UHPLC-MS/MS) method was created and validated for the quantification of the five major triterpenoids in rat plasma and various tissues biosamples (including intestine, stomach, liver, kidney, fat, muscle, brain, heart, lung, spleen, and testes). The plasma and tissues biosamples were pretreated by direct precipitation deproteinization method with acetonitrile. 17alpha-Hydroxyprogesterone was used as internal standard (IS). The chromatography was performed on a Phenomenex C8 column (30x2.00mm, 1.8mum) at room temperature with gradient elution. Compounds were quantified by selected multi-reactions monitoring (SRM) scanning with positive electric spray ionization mode. The linearity of detection for each triterpene was respectively from 1 to 1000ng/mL for ALC-23A and ALA, from 4 to 4000ng/mL for ALA-24A, from 10 to 10,000ng/mL for ALB, and from 2 to 2000ng/mL for ALB-23B (r>0.99) with low quantification limits of 1-10ng/mL for all analytes. All of the other validation parameters were also in an acceptable range. The validated UHPLC-MS/MS method subsequently applied for the pharmacokinetic and tissue distribution studies of RA extract. After orally given 100mg/kg of RA extract, ALA was the most exposed component, followed by ALB and ALA-24A. Whereas significant gender difference was observed for ALB, ALA, and ALA-24A between female and male rats. The AUC(0-infinity) of ALA, ALB, and ALA-24A in female rats were approximately 2-5 fold larger than that in male rats. These triterpenoids also displayed approximately 1.5-2 times longer half-life (t1/2) in female rats. Appearant Km, Vmax and Clint of ALA, ALB, and ALA-24A were calculated by substrate depletion approach, rat P450 CYP3A2 plays an important role in the metabolism of ALA, ALB, and ALA-24A, which is an important factor leading to the different exprosures of ALA, ALB, and ALA-24A between the male rats and the female rats. Furthermore, results from tissue distribution in male rats showed that the main tissue depots of five triterpenoids were the stomach/intestine, followed by the liver, brain, and fat. However, ALA was still measured in the kidney after a long elimination time. ALB and ALB-23B exhibited lower elimination rate in the testis. These results provide a fundamental support for further pharmacological development and clinical safety application of RA.

Diuretic Activity of Compatible Triterpene Components of Alismatis rhizoma.[Pubmed:28878160]

Molecules. 2017 Sep 6;22(9). pii: molecules22091459.

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.

Simultaneous determination of four active components in Alisma orientale (Sam.) Juz. by HPLC-DAD using a single reference standard.[Pubmed:29403919]

J Pharm Anal. 2015 Apr;5(2):85-92.

A rapid, simple and practical high-performance liquid chromatography method coupled with diode array detector (HPLC-DAD) was developed to evaluate the quality of Alisma orientale (Sam.) Juz. through a simultaneous determination of four major active triterpenes using a single standard to determine the multi-components (SSDMCs). Alisol B 23-acetate was selected as the reference compound for calculating the relative response factors. All calibration curves showed good linearity (R(2)>0.9998) within test ranges. RSDs for intra- and inter-day of four analytes were less than 3.6% and 2.3%; the overall recovery was 92.1-110.2% (SSDMC). The proposed method was successfully applied to quantify the four components in 20 samples from different localities in China. Moreover, significant variations were demonstrated in the content of these compounds. In addition, hierarchical clustering analysis (HCA) and principal components analysis (PCA) were performed to differentiate and classify the samples based on the contents of Alisol C 23-acetate, Alisol A, Alisol A 24-acetate and Alisol B 23-acetate. This simple, rapid, low-cost and reliable HPLC-DAD method using SSDMC is suitable for routine quantitative analysis and quality control of A. orientale (Sam.) Juz.