Streamlining apartment provider evaluation: A spherical fuzzy multi-criteria decision-making model.

In the context of the thriving real estate market in developing countries like Vietnam, understanding consumer preferences and effectively addressing them through a comprehensive multi-criteria decision-making (MCDM) framework is paramount for real estate providers. This study presents a two-stage MCDM model that integrates the Delphi technique and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) based on Spherical Fuzzy Sets (SFSs). Initially, the SF-Delphi technique validates critical criteria influencing customers' apartment selection in Vietnam. Secondly, the SF-TOPSIS method evaluates the top ten apartment providers. To ensure robustness and validity, a comparative analysis compares the results with those from the Intuitionistic Fuzzy TOPSIS (IF-TOPSIS) and Fuzzy TOPSIS (F-TOPSIS) methods. Subsequently, five rank correlation coefficients (Spearman, Kendall, Goodman-Kruskal, Weighted rank measure of correlation, Weighted Similarity) are used to assess the relationships between various TOPSIS techniques applied to apartment suppliers in Vietnam. The correlation coefficients demonstrate strong agreement among the TOPSIS methods, with the smallest coefficient being 0.7778, surpassing the threshold of 0.7. This high level of consistency confirms the efficacy of the proposed TOPSIS approach with different Fuzzy Sets in reliably evaluating customers' preferences for apartment suppliers. Notably, the legal aspect's prominence underscores its critical role in shaping customer choices, emphasizing the significance of considering legal factors in the context of apartment supply and demand in Vietnam. Furthermore, using SFSs makes this approach particularly suited to capture consumer perceptions within the dynamic and uncertain business environment characterized by volatility, uncertainty, complexity, and ambiguity (VUCA).

Dataset on the compounds from the leaves of Vietnamese Machilus thunbergii and their anti-inflammatory activity.

Machilus thunbergii has a history of traditional applications including treating dyspepsia, apoplexy, headaches, abdominal pain, abdominal distension, and leg edema [1]. It is also employed for alleviating allergies, inflammation, pain relief, promoting blood circulation, addressing costal chondritis, and sinusitis [2]. Research into the chemical composition of M. thunbergii has revealed the presence of lignans, flavonoids, lactones, and essential oils [1,[3], [4], [5]. While some investigations have explored the inhibitory effects of extracts and lignan compounds from this species on NO production [6], [7], [8], there has been no research into the flavonoids isolated from this plant and their potential for inhibiting NO production, given our reachable referencing. The ethyl acetate (EtOAc) soluble fraction of M. thunbergii leaves was subjected to column chromatography (CC) using silica gel and Sephadex LH-20 for compound isolation. Nuclear magnetic resonance (NMR) data primarily facilitated the determination of isolated compound structures. Anti-inflammatory activity was evaluated against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in macrophage RAW264.7 cells. Anti-inflammatory activity-guided fractionation led to the isolation of twelve secondary metabolites (1-12). The compounds were identified as quercetin (1), kaempferol (2), rhamnetin (3), quercitrin (4), hyperoside (5), reynoutrin (6), guaijaverin (7), afzelin (8), astragalin (9), rutin (10), kaempferol-3-O-rutinoside (11), and rhamnetin-3-O-rutinoside (12). Compounds 3, 5, 6, 9, 11, and 12 were isolated from M. thunbergii for the first time. Evaluation against LPS-induced NO production in macrophage RAW264.7 cells showed that 1-3 exhibited potent inhibitory activity with IC50 values of 15.45, 25.44, and 19.82 µM, respectively. Compounds 4-9 demonstrated IC50 values ranging from 42.15 to 67.42 µM, while 10-12 exhibited inactivity (IC50 > 100 µM).

Component and Content of Lipid Classes and Phospholipid Molecular Species of Eggs and Body of the Vietnamese Sea Urchin Tripneustes gratilla.

Sea urchins (Tripneustes gratilla) are among the most highly prized seafood products in Vietnam because of their nutritional value and medicinal properties. In this research, lipid classes and the phospholipid (PL) molecular species compositions from the body and eggs of T. gratilla collected in Hon Tam, Nha Trang, Khanh Hoa, Vietnam, were investigated. Hydrocarbon and wax (HW), triacylglycerol (TG), mono- and diacylglycerol (MDAG), free fatty acid (FFA), sterol (ST), polar lipid (PoL), and monoalkyl-diacylglycerol are the major lipid classes. In PL, five main glycerophospholipid classes have been identified, in which 137 PL molecular species were detected in the body and eggs of T. gratilla, including 20 inositol glycerophospholipids (PI), 11 serine glycerophospholipids (PS), 22 ethanolamine glycerophospholipids (PE), 11 phosphatidic acids (PA), and 73 choline glycerophospholipids (PC). PI 18:0/20:4, PS 20:1/20:1, PE 18:1e/20:4, PA 20:1/20:1, and PC 18:0e/20:4 are the most abundant species with the highest content values of 38.65-48.19%, 42.48-44.41%, 41.21-40.03%, 52.42-52.60%, and 7.77-7.18% in each class of the body-eggs, respectively. Interestingly, PL molecules predominant in the body sample were also found in the egg sample. The molecular species with the highest content account for more than 40% of the total species in each molecular class. However, in the PC class containing 73 molecular species, the highest content species amounted to only 7.77%. For both the body and egg TL samples of the sea urchin T. gratilla, a substantial portion of C20:4n polyunsaturated fatty acid was found in PI, PE, and PC, but C16, C18, C20, and C22 saturated fatty acids were reported at low levels. The most dominant polyunsaturated fatty acid in PI, PE, and PC was tetracosapolyenoic C20, while unsaturated fatty acid C20:1 was the most dominant in PS and PA. To our knowledge, this is the first time that the chemical properties of TL and phospholipid molecular species of the PoL of Vietnamese sea urchin (T. gratilla) have been studied.

A two-phased decision-making based grey theory framework for the best choice of payment methods in international trade.

This study aims to propose a two-staged Analytic Hierarchy Process and COmplex PRoportional ASsessment model-based Grey Theory (AHP-G and COPRAS-G) to explore critical elements affecting international payment method selection in the case of import-export Small and Medium-Sized Enterprises (SMEs) from emerging countries. First, the AHP-G model is applied to determine the relative weights of essential factors. Second, the COPRAS- G approach prioritizes international payment method alternatives. From the literature review and experts' opinions, five main criteria were established, including: "relationship between the two parties" (RE), "type of goods" (GO), "political-economic framework factor" (MA), "characteristics of payment method" (PA); "opinions and requirements of external parties" (EX) and four international payment methods are considered as frequent payment alternatives. A real-world case study from Vietnamese SMEs in the import-export industry is presented to exemplify the applicability and robustness of the proposed approach. The weighting results indicated that (PA) had the most significant impact on international payment method selection, followed by (MA) and (RE). Letter of credit (L/C) is considered the most reliable payment method for SMEs. Furthermore, a comparative analysis was performed to examine the validity of the proposed model. The proposed approach would assist stakeholders in import-export SMEs and other industries in effectively selecting suitable payment methods in international trade.

Essential Oils from the Leaves, Stem, and Roots of Blumea lanceolaria (Roxb.) Druce in Vietnam: Determination of Chemical Composition, and In Vitro, In Vivo, and In Silico Studies on Anti-Inflammatory Activity.

Blumea lanceolaria (Roxb.) Druce, a flowering plant, is used for treating cancer and inflammatory diseases. In this study, we determined the chemical composition of the EOs extracted from the leaves (LBEO), stem (SBEO), and roots (RBEO) of B. lanceolaria and analyzed their anti-inflammation potential. Overall, 30 compounds representing 99.12%, 98.44%, and 96.89% of total EO constituents of the leaves, stem, and roots, respectively, were identified using GC-MS. ELISA, Western blotting, and qRT-PCR studies showed that LBEO, SBEO, and RBEO inhibited multiple steps in the inflammatory responses in the RAW 264.7 cell model, including NO production; TNF-α, IL-6, iNOS, and COX-2 transcription and translation; and phosphorylation of IκBα and p65 of the NF-κB pathway. In the carrageenan-induced paw edema model, all three EOs inhibited paw edema at both early and delayed phases. Molecular docking studies indicated that the main components of B. lanceolaria EOs (BEOs) targeted and inhibited major components of inflammation-related pathways, including the arachidonic acid metabolic pathway, NF-κB pathway, and MAPK pathway. We present the first study to characterize the chemical composition of BEOs and confirm their potent anti-inflammatory effects in in vitro, in vivo, and in silico analysis. These results can facilitate the development of effective anti-inflammatory drugs with limited side effects in the future.

Does loan growth impact on bank risk?

In the context of competition between domestic banks but also foreign banks become more and more fierce. The increasing penetration of foreign banks brings certain risks to domestic banks. This study was conducted to assess the effect of loan growth on banking risk in Vietnam. The study collects data on 29 banks listed on the Vietnam stock exchange from 2010 to 2020. The results of panel data analysis with Generalized least squares (GLS) have shown a relationship between loan growth and bank risk. In which loan growth has a negative impact on Non-performing loans (NPL), liquidity risk equity on asset (ETA); loan growth has a positive impact on return (ROA). In addition, the study also conducts a comparative assessment by bank size and loan growth rate. The results indicate a difference in loan growth's impact on banks' bank risk with lower and higher assets and lower and higher loan growth rates. From the results of this study, the authors also provide some implications to help banks reduce bank risk based on loan growth strategy.

Social media and COVID-19 vaccination hesitancy: mediating role of the COVID-19 vaccine perception.

Individuals' COVID-19 vaccination behaviors were examined when the government introduced a new vaccine into the immunization program. The purpose of this study is to thoroughly examine the effects of COVID-19 risk perception (CR), COVID-19 vaccination perception (VC), and Social Media (SO) on COVID-19 vaccine hesitancy (HE) in Vietnam. Three hundred fifty samples were collected regarding a reluctance to vaccinate against COVID-19 from 6/2021 to 7/2021. This is when immunizations are administered and injected in Vietnam; hence, hesitation regarding injection is rather prevalent. Multivariate regression analysis is conducted on a dataset of 350 Vietnamese respondents using the Partial Least Squares-Structural Equation Modeling (PLS-SEM) approach. The main results indicated that the Perception Vaccine functions as a link between VC and HE. CR has a positive effect on both HE and VC; whereas VC has a negative impact on HE. Simultaneously, the study illustrates the detrimental effect of SO on immunity by comparing it to the influence of social media. The study's findings also demonstrated the critical role of protection motivational theory (PMT) and information theory in promoting vaccination efforts in Vietnam.

Survey data on perceived COVID-19 risk, COVID-19 vaccine perception, and COVID-19 vaccination intention among Vietnamese.

In the context of the COVID-19 response, this study presents an illustrated dataset to examine trust, COVID-19 risk perception, COVID-19 vaccination perception, subject norms, social media and intention to vaccinate among Vietnamese. Our questionnaire was conducted in Vietnamese and then translated into English and distributed to respondents through email and Facebook from June to July 2021, gathering 329 responses. Participation was voluntary, and participants were allowed to withdraw from the survey at any time. Data analysis was carried out using the SPSS 24.0 and Smart PLS 3.0 software packages following data cleansing and coding. The data summarizes respondents' socio-economic and demographic characteristics, and Statistical techniques were deployed to assess the validity and reliability of scales relating to COVID-19 vaccination intention in Vietnam. Additionally, these data will contribute to the existing literature about COVID-19 vaccination perceptions and intention to vaccinate among Vietnamese.

On the Inhibitability of Natural Products Isolated from Tetradium ruticarpum towards Tyrosine Phosphatase 1B (PTP1B) and α-Glucosidase (3W37): An In Vitro and In Silico Study.

Folk experiences suggest natural products in Tetradium ruticarpum can be effective inhibitors towards diabetes-related enzymes. The compounds were experimentally isolated, structurally elucidated, and tested in vitro for their inhibition effects on tyrosine phosphatase 1B (PTP1B) and α-glucosidase (3W37). Density functional theory and molecular docking techniques were utilized as computational methods to predict the stability of the ligands and simulate interaction between the studied inhibitory agents and the targeted proteins. Structural elucidation identifies two natural products: 2-heptyl-1-methylquinolin-4-one (1) and 3-[4-(4-methylhydroxy-2-butenyloxy)-phenyl]-2-propenol (2). In vitro study shows that the compounds (1 and 2) possess high potentiality for the inhibition of PTP1B (IC50 values of 24.3 ± 0.8, and 47.7 ± 1.1 µM) and α-glucosidase (IC50 values of 92.1 ± 0.8, and 167.4 ± 0.4 µM). DS values and the number of interactions obtained from docking simulation highly correlate with the experimental results yielded. Furthermore, in-depth analyses of the structure-activity relationship suggest significant contributions of amino acids Arg254 and Arg676 to the conformational distortion of PTP1B and 3W37 structures overall, thus leading to the deterioration of their enzymatic activity observed in assay-based experiments. This study encourages further investigations either to develop appropriate alternatives for diabetes treatment or to verify the role of amino acids Arg254 and Arg676.

PTP1B and α-glucosidase inhibitors from Selaginella rolandi-principis and their glucose uptake stimulation.

As part of an ongoing search for new protein tyrosine phosphatase 1B inhibitors and glucose uptake stimulators from nature, a new coumarin, selaginolide A (1) and four known isoflavones (2‒5) were isolated from the ethanol extract of a Vietnamese medicinal plant Selaginella rolandi-principis. The chemical structures of the isolates were elucidated by extensive analysis of spectroscopic and physicochemical data. Compounds 3‒5 have been identified from Selaginella genus for the first time. The antidiabetic properties of the isolates (1‒5) were investigated using in vitro assay on 2-NBDG uptake in 3T3-L1 adipocytes and against PTP1B and α-glucosidase enzyme activities as well. Compounds 1 exhibited the most potency with inhibitory IC50 values of 7.40 ± 0.28 and 7.52 ± 0.37 µM against PTP1B and α-glucosidase, respectively. Compounds 3 and 5 possessed potential inhibitions on PTP1B enzyme with IC50 values of 23.02 ± 1.29 and 11.08 ± 0.92 µM and moderate inhibitions on α-glucosidase with IC50 values of 36.47 ± 1.87 and 55.73 ± 2.58 µM, respectively. Compounds 2 and 4 showed weak PTP1B inhibitory activity (IC50 > 30 µM) but displayed remarkable α-glucosidase inhibition with IC50 values of 3.39 ± 0.87 and 9.72 ± 0.62 µM, respectively. Furthermore, ursolic acid as a positive control (IC50 3.42 ± 0.26 µM) and compounds 1 and 5 acted as mixed-competitive inhibitors against PTP1B enzyme with Ki values of 6.46, 10.28, and 15.01 µM, respectively. In addition, compounds 1 and 5 also showed potent stimulatory effects on 2-NBDG uptake at a concentration of 10 µM. The obtained result might suggest the potential of new coumarin (1) as a new type of natural PTP1B and α-glucosidase inhibitor for further research and development of antidiabetic and obese agents.Graphic abstract.

Anti-inflammatory xanthone derivatives from Garcinia delpyana.

Two new xanthones delpyxanthone A (1) and delpyxanthone B (3), together with four known ones, gerontoxanthone I (2), α-mangostin (4), cowanin (5) and cowanol (6) were isolated from the stem bark of Garcinia delpyana. The chemical structures of 1-6 were established mainly using nuclear magnetic resonance (NMR) and mass spectrometry (MS). The anti-inflammatory activity of the isolated compounds was evaluated against lipopolysaccharide (LPS)-induced nitric oxide (NO) production in RAW264.7 cells in vitro. Compounds 1-4 showed significant inhibitory activity against the LPS-induced NO production in RAW264.7 cells with IC50 values ranging from 14.5 to 28.2 µM, but the others were inactive. The results suggested that G. delpyana and its constituents might be potential anti-inflammatory agents on RAW 264.7 cells.[Formula: see text].

Cytotoxic components from the leaves of Erythrophleum fordii induce human acute leukemia cell apoptosis through caspase 3 activation and PARP cleavage.

Cassaine diterpenoids as erythrofordins A-C (1-3), pseudo-erythrosuamin (4), and erythrofordin U (5) isolated from the leaves of Vietnamese Erythrophleum fordii Oliver were tested cytotoxic activity against human leukemia cancer cells. The results showed that these metabolites exhibited dose-dependent cytotoxicity against human leukemia HL-60 and KG cells with IC50 values ranging from 15.2 ± 1.5 to 42.2 ± 3.6 µM. Treatment with erythrofordin B led to the apoptosis of HL-60 and KG cells due to the activation of caspase 3, caspase 9, and poly (ADP-ribose) polymerase (PARP). Erythrofordin B significantly increased Bak protein expression, but downregulated the anti-apoptotic protein Bcl-2, in HL-60 cells. In silico results demonstrated that erythrofordin B can bind to both the procaspase-3 allosteric site and the PARP-1 active site, with binding energies of -7.36 and -10.76 kcal/mol, respectively. These results indicated that the leaves of Vietnamese E. fordii, which contain cassaine diterpenoids, can induce the apoptosis of human leukemia cancer cells.

Antioxidant and Cell Proliferation Properties of the Vietnamese Traditional Medicinal Plant Peltophorum pterocarpum.

Peltophorum pterocarpum is regarded as one of the most important medicinal plants in the traditional medicine system of Vietnam. However, scientific evidence for the antioxidant effects against lipid peroxidation and the potential effects in cancer of this plant are lacking. In our experiments, 70% ethanolic extracts of P. pterocarpum leaves (LPP) and stem bark (SPP) were evaluated for their low-density lipoprotein (LDL) oxidation and cytotoxic activity against cancer cell lines. Both LPP and SPP inhibited Cu2+-mediated LDL by increasing the lag time of conjugated diene formation and inhibiting the generation of thiobarbituric acid reactive substances (TBARS) in a dose-dependent manner. In cancer cells, LPP and SPP triggered the most potent cytotoxic effects against human leukemia cells, CRF-SBA and HL-60, with half-maximal inhibitory concentration (IC50) values ranging from 118.5 to 157.2 µg/mL. SPP exhibited significant cytotoxicity against MIA PACA2, A549, and KG cell lines with IC50 values of 167.5, 244.1 and 255.0 µg/mL, respectively. Meanwhile, LPP showed cytotoxic activity against KG with an IC50 value of 228.1 µg/mL. SPP mediated cytotoxicity in HL-60 and CCRF-SBA cells through the activation of the apoptosis pathway, including the activation of caspases 3, and 9 and poly (ADP-ribose) polymerase (PARP). These results suggested that SPP may prevent the development and progression of atherosclerosis and leukemia in humans.

Cassaine Diterpenoid Amide from Stem Bark of Erythrophleum fordii Suppresses Cytotoxic and Induces Apoptosis of Human Leukemia Cells.

Cassaine diterpenoids amides from the stem bark of Vietnamese Erythrophleum fordii Oliver were screened for their cytotoxic activity against human cancer cells. The cell proliferation assay results showed that, among the active compounds, 3ß-acetyl-nor-erythrophlamide (3AEP) exhibited the most potential cytotoxicity against human leukemia HL-60 and KG cells with IC50 values of 12.0 ± 1.2 and 18.1 ± 2.7 µM, respectively. Treatment of 3AEP resulted in the apoptosis of HL-60 cells via the activation of caspase 3, and poly (ADP-ribose) polymerase (PARP). Molecular docking in silico results showed that the 3AEP can bind to both the procaspase-3 allosteric site and the PARP-1 active site, with binding energies of -7.51 and -9.63 kcal/mol respectively. These results indicated that the stem bark of Vietnamese E. fordii and its cassaine diterpenoid amides may be useful in the apoptosis induction of human leukemia cancer cells.

Strong and Selective Inhibitory Effects of the Biflavonoid Selamariscina A against CYP2C8 and CYP2C9 Enzyme Activities in Human Liver Microsomes.

Like flavonoids, biflavonoids, dimeric flavonoids, and polyphenolic plant secondary metabolites have antioxidant, antibacterial, antiviral, anti-inflammatory, and anti-cancer properties. However, there is limited data on their effects on cytochrome P450 (P450) and uridine 5'-diphosphoglucuronosyl transferase (UGT) enzyme activities. In this study we evaluate the inhibitory potential of five biflavonoids against nine P450 activities (P450s1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, and 3A) in human liver microsomes (HLMs) using cocktail incubation and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The most strongly inhibited P450 activity was CYP2C8-mediated amodiaquine N-dealkylation with IC50 ranges of 0.019~0.123 µM. In addition, the biflavonoids-selamariscina A, amentoflavone, robustaflavone, cupressuflavone, and taiwaniaflavone-noncompetitively inhibited CYP2C8 activity with respective Ki values of 0.018, 0.083, 0.084, 0.103, and 0.142 µM. As selamariscina A showed the strongest effects, we then evaluated it against six UGT isoforms, where it showed weaker inhibition (UGTs1A1, 1A3, 1A4, 1A6, 1A9, and 2B7, IC50 1.7 µM). Returning to the P450 activities, selamariscina A inhibited CYP2C9-mediated diclofenac hydroxylation and tolbutamide hydroxylation with respective Ki values of 0.032 and 0.065 µM in a competitive and noncompetitive manner. However, it only weakly inhibited CYP1A2, CYP2B6, and CYP3A with respective Ki values of 3.1, 7.9, and 4.5 µM. We conclude that selamariscina A has selective and strong inhibitory effects on the CYP2C8 and CYP2C9 isoforms. This information might be useful in predicting herb-drug interaction potential between biflavonoids and co-administered drugs mainly metabolized by CYP2C8 and CYP2C9. In addition, selamariscina A might be used as a strong CYP2C8 and CYP2C9 inhibitor in P450 reaction-phenotyping studies to identify drug-metabolizing enzymes responsible for the metabolism of new chemicals.

Glucose Uptake Stimulatory and PTP1B Inhibitory Activities of Pimarane Diterpenes from Orthosiphon stamineus Benth.

Seven pimarane diterpenes (1-7) were isolated from Orthosiphon stamineus Benth. by assay-guided isolation. All of the isolates possessed a 2-deoxy-2-((7-nitro-2,1,3-benzoxadiazol-4-yl)amino)-d-glucose uptake effect in 3T3-L1 adipocytes at concentrations of 5 and 10 µM. Most of them showed potent inhibition against protein tyrosine phosphatase 1B with IC50 values ranging from 0.33 to 9.84 µM. In the kinetic study, all inhibition types were exposed for the examined potencies, including mixed-competitive (1), non-competitives (3 and 5), competitive (6), and uncompetitive (7). The results suggested that O. stamineus and its pimarane diterpenes might exert the hypoglycemic effect via the insulin signaling pathway targeting inhibition of protein tyrosine phosphatase 1B (PTP1B) activity.

Inhibitory Effect of Selaginellins from Selaginella tamariscina (Beauv.) Spring against Cytochrome P450 and Uridine 5'-Diphosphoglucuronosyltransferase Isoforms on Human Liver Microsomes.

Selaginella tamariscina (Beauv.) has been used for traditional herbal medicine for treatment of cancer, hepatitis, and diabetes in the Orient. Numerous bioactive compounds including alkaloids, flavonoids, lignans, and selaginellins have been identified in this medicinal plant. Among them, selaginellins having a quinone methide unit and an alkylphenol moiety have been known to possess anticancer, antidiabetic, and neuroprotective activity. Although there have been studies on the biological activities of selaginellins, their modulatory potential of cytochrome P450 (P450) and uridine 5'-diphosphoglucuronosyltransferase (UGT) activities have not been previously evaluated. In this study, we investigated the drug interaction potential of two selaginellins on ten P450 isoforms (CYP1A2, 2A6, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 2J2 and 3A) and six UGT isoforms (UGT1A1, 1A3, 1A4, 1A6, 1A9 and 2B7) using human liver microsomes and liquid chromatography-tandem mass spectrometry. Selaginellin and selaginellin M had high inhibitory potential for CYP2C8-mediated amodiaquine O-demethylation with IC50 values of 0.5 and 0.9 µM, respectively. Selaginellin and selaginellin M also showed medium inhibitory potential against CYP2C9, CYP2J2, UGT1A1, and UGT1A3 (1 µM < IC50 < 5 µM). These two selaginellins had low inhibitory potential against CYP1A2, CYP2A6, CYP2E1, and UGT1A6 (IC50 > 25 µM). This information might be helpful to predict possible drug interaction potential of between selaginellins and co-administered drugs.

Chemical constituents from a Gynostemma laxum and their antioxidant and neuroprotective activities.

BACKGROUND: A few bioactivities of constituents from Gynostemma laxum, which has been collected in Vietnam, have been reported until now. There is no report about the effects of constituents from G. laxum although the nuclear factor (erythroid-derived 2)-like 2 (Nrf2)-mediated heme oxygenase-1 (HO-1) antioxidant defense system is involved in neuroprotection in the brain. Therefore, we investigated whether quercetin (2), benzoic acid (10) and their analogues (1, 3-9 and 11) from G. laxum have the antioxidant and neuroprotective activities and also their underlying mechanism. METHODS: To examine their neuroprotective and antioxidant activities, oxytosis, total oxidant scavenging capacity (TOSC), 2,7-dichlorofluorescein (DCFDA), dihydroethidium (DHE), antioxidant response element (ARE)-luciferase reporter gene assays, Western blot analysis, real time-PCR, immunocytochemistry and in silico 3D molecular docking simulation were performed. RESULTS: The study of constituents using chromatographic techniques and spectroscopic analysis showed that G. laxum contained an abundance of quercetin (2), benzoic acid (10) and their analogues (1, 3-9 and 11). Our data demonstrated that quercetin (2) and its analogue (4) among the constituents from G. laxum showed the strongest neuroprotective effect against oxytosis triggered by the excessive amount of glutamate. Compounds 2, 4, 6 and 11 exhibited reactive oxygen species (ROS) inhibitory and ARE transcriptional activities in immortalized hippocampal HT22 cell line. Among them, compound 4, a second active compound, induced Nrf2/HO-1 activation. They were also fit stable onto the Tramtrack and Bric-à-Brac (BTB) domain of Kelch-like ECH-associated protein 1 (Keap1), a known Nrf2 inhibitor protein, based on the results of docking and interaction energies. Overall, these data suggest that -OH and -OCH3 groups of quercetin and its analogues are responsible for their neuroprotective effect. CONCLUSIONS: In summary, the major constituents of G. laxum had strong antioxidant and neuroprotective activities so that they could consider as a natural antioxidant supplement. Furthermore, G. laxum might be used beneficially in reducing oxidative complications with the further deep investigation in vivo.

Anthraquinones from Morinda longissima and their insulin mimetic activities via AMP-activated protein kinase (AMPK) activation.

AMP-activated protein kinase (AMPK) activators are known to increase energy metabolism and to reduce body weight, as well as to improve glucose uptake. During for searching AMPK activators, a new anthraquinone, modasima A (10), along with eighteen known analogues (1-9 and 11-19) were isolated from an ethanol extract of the roots of Morinda longissima Y. Z. Ruan (Rubiaceae). Using the fluorescent tagged glucose analogues, 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxy-D-glucose (2-NBDG), insulin mimetics were screened with compounds 1-19 in 3T3-L1 adipocytes. Among them, compounds 2, 8 and 10 enhanced significantly glucose uptake into adipocytes and up-regulated the phosphorylated AMPK (Thr172) whereas the glucose uptake enhancing activities of compounds 2, 8 and 10 were abrogated by treatment of compound C, an AMPK inhibitor. Taken together, these anthraquinones showed the potential action as insulin mimetic to improve glucose uptake via activation of AMPK.

PTP1B, α-glucosidase, and DPP-IV inhibitory effects for chromene derivatives from the leaves of Smilax china L.

Two new flavonoids, bismilachinone (11) and smilachinin (14), were isolated from the leaves of Smilax china L. together with 14 known compounds. Their structures were elucidated using spectroscopic methods. The PTP1B, α-glucosidase, and DPP-IV inhibitory activities of compounds 1-16 were evaluated at the molecular level. Among them, compounds 4, 7, and 10 showed moderate DPP-IV inhibitory activities with IC50 values of 20.81, 33.12, and 32.93 µM, respectively. Compounds 3, 4, 6, 11, 12, and 16 showed strong PTP1B inhibitory activities, with respective IC50 values of 7.62, 10.80, 0.92, 2.68, 9.77, and 24.17 µM compared with the IC50 value for the positive control (ursolic acid: IC50 = 1.21 µM). Compounds 2-7, 11, 12, 15, and 16 showed potent α-glucosidase inhibitory activities, with respective IC50 values of 8.70, 81.66, 35.11, 35.92, 7.99, 26.28, 11.28, 62.68, 44.32, and 70.12 µM. The positive control, acarbose, displayed an IC50 value of 175.84 µM. In the kinetic study for the PTP1B enzyme, compounds 6, 11, and 12 displayed competitive inhibition with Ki values of 3.20, 8.56, and 5.86 µM, respectively. Compounds 3, 4, and 16 showed noncompetitive inhibition with Ki values of 18.75, 5.95, and 22.86 µM, respectively. Molecular docking study for the competitive inhibitors (6, 11, and 12) radically corroborates the binding affinities and inhibition of PTP1B enzymes. These results indicated that the leaves of Smilax china L. may contain compounds with anti-diabetic activity.