Glycyrrhizic Acid

A total of 18 batches of HQT were included in the present study. Four batches coded as PHY906-6, 7, 8, 10 were manufactured with PhytoCeutica's proprietary SOP. Eight batches of HQT were purchased from Sun Ten Pharmaceutical Co. LTD in Taiwan and designated as HQT-E, F, G, H, I, J, K and L. Six batches of HQT were obtained from various vendors (Chung Song Zong, Ko Da, Min Tong, Sheng Chang, Sheng Foong, Kaiser; Taiwan) who did not provide quality information, and were labeled as HQT-CSZ, KD, MT, SC, SF and KP3. The proprietary standard operating procedures (SOP) by PhytoCeutica for PHY906 used hot water extraction (80°C) of four herbs, namely Scutellaria baicalensis Georgi (S), Paeonia lactiflora Pall. (P), Glycyrrhiza uralensis Fisch. (G) and Ziziphus jujuba Mill. (Z) (ratio 3:2:2:2). The hot water extraction is then spray dried with insoluble dextran into a granulated powder, packaged and stored in foil containers at 4°C.
Chemical standards including baicalin (S), baicalein (S), wogonin (S), scutellarin (S), glycyrrhizin (G), ononin (G), liquiritin (G), liqiritigenin (G), paeoniflorin (P) and albiflorin (P), were obtained from Chromadex (USA). Apigenin and formic acid were obtained from Sigma-Aldrich (USA). Solvents were of LC/MS grade from JT Baker (USA).

Due to the disadvantages of biological experiments as being time-consuming and of high cost, identification of ADME (absorption, distribution, metabolism, and excretion) properties by in silico tools has now become an inevitable paradigm in pharmaceutical research. In this study, three ADME-related models, namely, the evaluation of oral bioavailability (OB), Caco-2 permeability, and drug-likeness (DL), are employed to identify the potential bioactive compounds of DXP [33 (link)].
Oral Bioavailability. OB prescreening is used to determine the fraction of the oral dose of bioactive compound which reaches systemic circulation in the TCM remedy. Here, a reliable in silico model OBioavail 1.1 [34 (link)] which integrates the metabolism (P450 3A4) and transport (P-glycoprotein) information was employed to calculate the OB values of herbal ingredients.
Caco-2 Permeability. The Caco-2 cell monolayers are widely applied as standard permeability-screening assay for prediction of the compound's intestinal absorption and fraction of the oral dose absorbed in humans [35 (link)]. The Caco-2 cell permeation values of all molecules are calculated by in silico model using the VolSurf approach [36 ].
Drug-Likeness Evaluation. Drug-likeness is a qualitative profile used in drug design to evaluate whether a compound is chemically suitable for the drug, and how drug-like a molecule is with respect to parameters affecting its pharmacodynamic and pharmacokinetic profiles which ultimately impact its ADME properties [37 (link)]. In order to identify drug-like compounds, we apply a database-dependent model using the Tanimoto coefficient to calculate the DL (see (1)) of each compound in DXP. $\begin{array}{c}f\left(\mathcal{x},\mathcal{y}\right)=\frac{\mathcal{x}\mathcal{y}}{{\left|\mathcal{x}\right|}^{\mathrm{2}}+{\left|\mathcal{y}\right|}^{\mathrm{2}}-\mathcal{x}\mathcal{y}}.\end{array}$ 𝓍 represents the molecular parameters of herbal ingredients and 𝓎 represents the average molecular properties in DrugBank database (available online: http://www.drugbank.ca).
In this work, the compounds of OB ≥ 30%, Caco-2 > −0.4, and DL ≥ 0.18 are selected for subsequent research, and others are excluded.
According to these indexes, several compounds are included: ergosterol peroxide, ethyl oleate (NF), glabridin, glycyrrhetinic acid, linoleyl acetate, longikaurin A, mairin, mandenol, MOL000273, MOL001910, 508-02-1, 64997-52-0, 8β-ethoxy atractylenolide III, pachymic acid, paeonidanin, palbinone, saikosaponin C, beta-sitosterol, supraene, trametenolic acid, troxerutin, α-amyrin, MOL000285, 4-O-methylpaeoniflorin, glabrene, poricoic acid A, glycyrrhizin, sudan III, ZINC02816192, kaempferol, 7,9(11)-dehydropachymic acid, licochalcone G, paeoniflorgenone, areapillin, quercetin, stigmasterol, isoliquiritigenin, (+)-anomalin, isorhamnetin, vestitol, crocetin, 113269-36-6, α-spinasterol, licochalcone A, 113269-37-7, 3β-acetoxyatractylone, licoricone, 113269-39-9, petunidin, hederagenin, dehydroeburicoic acid, licochalcone B, ergosta-7,22E-dien-3beta-ol, MOL000280, MOL000287, mudanpioside H, NSC684433, octalupine, 18103-41-8, formononetin, 1-methoxyphaseollidin, paeoniflorin, glycyrin, ammidin, poricoic acid B, poricoic acid C, sainfuran, sitosterol, isoimperatorin, isolicoflavonol, cerevisterol, 3-methylkempferol, licoisoflavone B, cubebin, and (+)-catechin, 3′-hydroxy-4′-O-methylglabridin.

To collect the compounds of XYP, we used the TCM Database@Taiwan [24 (link)] (http://tcm.cmu.edu.tw/zh-tw/, updated in March 2014), which is the most comprehensive TCM database in the world, and the Traditional Chinese Medicine Systems Pharmacology Database [25 (link)] (TcmSP™, http://lsp.nwsuaf.edu.cn, updated on May 31, 2014), a unique system pharmacology platform designed for Chinese herbal medicines. Nine hundred and fifty-eight compounds were found, 348 in Radix Bupleuri, 175 in Angelicae Sinensis Radix, 92 in Paeoniae Radix Alba, 52 in Poria Cocos (Schw.) Wolf., 63 in Atractylodes Macrocephala Koidz., and 318 in Licorice. According to research [26 , 27 ], we filtered these compounds and get 11 representative compounds (active compounds); they are saikosaponin, longispinogenin, ferulic acid, ligustilide, total glucosides of peony (TGP), atractylol, atractylenolide I, atractylenolide III, pachyman, pachymic acid, and glycyrrhizin. The details are described in Table S1 (see Supplementary Material available online at http://dx.doi.org/10.1155/2016/2960372).

Nine TCM compounds in GYD were obtained from the TCMSP database (http://tcmspw.com/tcmsp.php). In combination with the analyses of the existing literature, 6 of 9 compounds were selected finally, namely, atractylenolide, atractylon, prim-o-glucosylcimifugin, astragaloside, glycyrrhizic acid, and glycyrrhetinic acid [19–22 ].