Phytochemical Investigation of Lepionurus sylvestris Blume and Their Anti-Diabetes Effects via Anti-Alpha Glucosidase and Insulin Secretagogue Activities Plus Molecular Docking.

This study presents a phytochemical investigation of Lepionurus sylvestris leaf extracts and their anti-diabetic activities. Traditionally, L. sylvestris leaves were used as vegetables and food in local recipes, but the root extracts of the plant can also be used in body tonic and erectile dysfunction treatments. Following a preliminary anti-diabetic activity screening test, the 80% ethanolic leaf extract exhibited potent anti-alpha glucosidase activity. So, the leaves' active components were selected for further investigation. Firstly, the plant was extracted via maceration using lower to higher polarity solvents such as hexane, ethyl acetate, ethanol, and water, respectively, to obtain the four crude extracts. Then, the phytochemicals contained in this plant were investigated via classical column chromatography and spectroscopy techniques. Anti-diabetic activity was evaluated via anti-alpha glucosidase and insulin secretagogue assays. The results showed that five compounds were isolated from the fractionated ethanolic leaf extract: interruptin A; interruptin C; ergosterol; diglycerol; and 15-16-epoxy-neo-cleoda-3,7(20),13(16),14-tetraene-12,17:18,19-diolide, a new diterpene derivative which is herein referred to as lepionurodiolide. Interruptin A and the new diterpene derivative exhibited the greatest effect on anti-alpha glucosidase activity, showing IC50 values of 293.05 and 203.71 µg/mL, respectively. Then, molecular docking was used to study the sites of action of these compounds. The results showed that interruptin A and the new compound interacted through H-bonds with the GLN279 residue, with a binding energy of -9.8 kcal/mol, whereas interruptin A and C interacted with HIS280 and ARG315 a with binding energy of -10.2 kcal/mol. Moreover, the extracts were investigated for their toxicity toward human cancer cells, and a zebrafish embryonic toxicity model was used to determine herbal drug safety. The results indicated that ethyl acetate and hexane extracts showed cytotoxicity to both Hela cells and human breast adenocarcinomas (MCF-7), which was related to the results derived from using the zebrafish embryonic toxicity model. The hexane and ethyl acetate presented LC50 values of 33.25 and 36.55 µg/mL, respectively, whereas the ethanol and water extracts did not show embryonic toxicity. This study is the first of its kind to report on the chemical constituents and anti-diabetic activity of L. sylvestris, the leaf extract of which has been traditionally used in southern Thailand as a herbal medicine and food ingredient.

Chemical Constituents from Streblus taxoides Wood with Their Antibacterial and Antityrosinase Activities Plus in Silico Study.

Hyperpigmentation frequently occurs after inflammation from bacterial infection. Thus, the inhibition activity of tyrosinase, the key enzyme to catalyze the melanogenesis and/or inhibition of bacterial infection, could decrease melanin production. Hence, the potential inhibitors could be discovered from natural products. ω-Hydroxymoracin C (1), a new compound with two other 2-arylbenzofurans, i.e., moracin M (2) and moracin C (3), and two stilbenes, i.e., 3, 4, 3', 5'-tetrahydroxybibenzyl (4) and piceatannol (5), were isolated from the wood of Streblus taxoides. Compound 4 showed a strong inhibitory activity against tyrosinase enzyme with an IC50 value of 35.65 µg/mL, followed by compound 2 with an IC50 value of 47.34 µg/mL. Conversely, compound 1, 3 and 5 showed moderate activity, with IC50 values of 109.64, 128.67 and 149.73 µg/mL, respectively. Moreover, compound 1 and 3 showed an antibacterial effect against some Staphylococcus spp. Thus, the isolated compounds exhibited potential antityrosine and antibacterial effects. Additionally, an in silico study was performed in order to predict theoretical molecular interactions between the obtained metabolites from S. taxoides and tyrosinase as an extended in vitro enzyme binding assay experiment.

In Vitro, In Vivo, and In Silico Analyses of Molecular Anti-Pigmentation Mechanisms of Selected Thai Rejuvenating Remedy and Bioactive Metabolites.

Thai rejuvenating remedies are mixed herbal formulas promoting longevity. Due to the complexity, the biological activities of these remedies are minimal. Therefore, in this study, the authors evaluated the anti-pigmentation effect at the molecular level of the selected Thai rejuvenating remedy to fulfill the knowledge gap. First, the authors found that the selected remedy showed promising activity against the tyrosinase enzyme with an IC50 value of 9.41 µg/mL. In the comparison, kojic acid (positive control) exhibited an IC50 value of 3.92 µg/mL against the same enzyme. Later, the authors identified glabridin as a bioactive molecule against tyrosinase with an IC50 value of 0.08 µg/mL. However, ethyl p-methoxycinnamate was the most abundant metabolite found in the remedy. The authors also found that the selected remedy and glabridin reduced the melanin content in the cell-based assay (B16F1) but not in the zebrafish larvae experiment. Finally, the authors conducted a computational investigation through molecular docking proposing a theoretical molecular interplay between glabridin, ethyl p-methoxycinnamate, and target proteins (tyrosinase and melanocortin-1 receptor, MC1R). Hence, in this study, the authors reported the molecular anti-pigmentation mechanism of the selected Thai rejuvenating remedy for the first time by combining the results from in silico, in vitro, and in vivo experiments.

Flavonoid Constituents and Alpha-Glucosidase Inhibition of Solanum stramonifolium Jacq. Inflorescence with In Vitro and In Silico Studies.

Solanum stramonifolium Jacq. (Solanaceae) is widely found in South East Asia. In Thailand, it is used as vegetable and as a component in traditional recipes. The results of an alpha-glucosidase inhibitory screening test found that the crude extract of S. stramonifolium inflorescence exhibited the potential effect with IC50 81.27 µg/mL. The separation was performed by the increasing solvent polarity method. The ethyl acetate, ethanol, and water extracts of S. stramonifolium inflorescence showed the synergistic effect together with acarbose standard. The phytochemical investigation of these extracts was conducted by chromatographic and spectroscopic techniques. Six flavonoid compounds, myricetin 3, 4', 5', 7-tetramethyl ether (1), combretol (2), kaempferol (3), kaempferol 7-O-glucopyranoside (4), 5-hydroxy 3-7-4'-5'-tetramethoxyflavone-3'-O-glucopyranoside (5), and a mixture (6) of isorhamnetin 3-O-glucopyranoside (6a) and astragalin (6b) were isolated. This discovery is the first report of flavonoid-glycoside 5. Moreover, the selected flavonoids, kaempferol and astragalin, were representatives to explore the mechanism of action. Both of them performed mixed-type inhibition. The molecular docking gave a better understanding of flavonoid compounds' ability to inhibit the alpha-glucosidase enzyme.

Alpha-Glucosidase Inhibition and Molecular Docking of Isolated Compounds from Traditional Thai Medicinal Plant, Neuropeltis racemosa Wall.

Neuropeltis racemosa Wall. (Convolvulaceae) is wildly distributed in Asia. Its stem is used as the component in traditional Thai recipes for treatments of muscle rigidity, skin disorder, dysentery, and hypoglycemia. However, the chemical constituents and biological activities of N. racemosa have not been reported. From a screening assay, N. racemosa stem crude extract showed the potent effect on alpha-glucosidase inhibition at 2 mg/mL as 96.09%. The bioassay-guiding isolation led to 5 compounds that were identified by spectroscopic techniques as scopoletin (1), syringic acid (2), methyl 3-methyl-2-butenoate (3), N-trans-feruloyltyramine (4), and N-trans- coumaroyltyramine (5). Compounds 1, 4, and 5 exhibited an IC50 of 110.97, 29.87, and 0.92 µg/mL, respectively, while the IC50 of positive standard, acarbose was 272.72 µg/mL. Kinetic study showed that compound 1 performed as the mixed-type inhibition mechanism, whereas compounds 4 and 5 displayed the uncompetitive inhibition mechanism. The docking study provided the molecular understanding of isolated aromatic compounds (1, 2, 4 and 5) to alpha-glucosidase. Hence, this study would be the first report of isolated compounds and their anti-alpha-glucosidase activity with the mechanism of action from N. racemosa. Thus, these active compounds will be further studied to be the lead compounds among natural antidiabetic drugs.

Alpha-Glucosidase Inhibitory Assay-Screened Isolation and Molecular Docking Model from Bauhinia pulla Active Compounds.

The aim of this research was to establish the constituents of Bauhinia pulla as anti-diabetic agents. A phytochemistry analysis was conducted by chromatographic and spectroscopic techniques. The alpha-glucosidase inhibitory assay screening resulted in the isolation of eight known compounds of quercetin, quercitrin, luteolin, 5-deoxyluteolin, 4-methyl ether isoliquiritigenin, 3,2',4'-trihydroxy-4-methoxychalcone, stigmasterol and ß-sitosterol. Ethanol leaf extracts showed potential effects, which led to a strong inhibitory activity of isolated quercetin at 138.95 µg/mL and 5.41 µg/mL of IC50, respectively. The docking confirmed that flavonoids and chalcones had the same potential binding sites and responsibilities for their activity. This study was the first report of Bauhinia pulla chemical constituents and its alpha-glucosidase inhibition.

Anti-insulin resistance effect of constituents from Senna siamea on zebrafish model, its molecular docking, and structure-activity relationships.

Senna siamea has been used as an antidiabetic drug since antiquity. With regard to traditional Thai medicine, the use of S. siamea was described for diabetes therapy. To understand the molecular mechanism regarding insulin resistance. Pure compounds were isolated from wood extract. We studied their biological activities on insulin-resistance using an in vivo zebrafish model. We also performed an in silico study; molecular docking, and in vitro study by taking advantage of the enzyme inhibitory activities of α-glucosidase, PTP1B, and DPP-IV. Based on the preliminary investigation that ethyl acetate and ethanol extracts have potent effects against insulin resistance on zebrafish larvae, five compounds were isolated from two fractions following: resveratrol, piceatannol, dihydropiceatannol, chrysophanol, and emodin. All of the isolated compounds had anti-insulin resistance effects on zebrafish larvae. Resveratrol, piceatannol, and dihydropiceatannol also demonstrated inhibitory effects against α-glucosidase. Chrysophanol and emodin inhibited PTP1B activity, while resveratrol showed a DPP-IV inhibition effect via the molecular docking. The results of enzyme assay were similar. In conclusions, S. siamea components demonstrated effects against insulin resistance. The chemical structure displayed identical biological activity to that of the compounds. Therefore, S. siamea wood extract and their components are potential therapeutic options in the treatment of diabetes.

Three New Isoprenylated Flavones from Artocarpus chama Stem and Their Bioactivities.

Phytochemical investigation of Artocarpus chama stem was performed by chromatographic techniques, resulting from the isolation and structure elucidation of three new compounds, namely 3'-farnesyl-apigenin (1), 3-(hydroxyprenyl) isoetin (2), and 3-prenyl-5,7,2',5'-tetrahydroxy-4'-methoxyflavone (3), and five known compounds, namely homoeriodictyol (4), isocycloartobilo-xanthone (5), artocarpanone (6), naringenin (7), and artocarpin (8). From the screening result, A. chama extract showed a potent tyrosinase inhibitory effect. Ihe isolated compounds 1, 4 and 6 also exhibited tyrosinase inhibition with IC50 of 135.70, 52.18, and 38.78 µg/mL, respectively. Moreover, compounds 3, 4, 5, 6, and 8 showed strong activity against Staphylococcus epidermidis, S. aureus, methicillin-resistant S. aureus, and Cutibacterium acnes. This study is the first report on phytochemical investigation with new compounds and biological activities of A. chama. Skin infection can cause dark spots or hyperpigmentation. The isolated compounds that showed both anityrosinase and antimicrobial activities will be further studied in in vivo and clinical trials in order to develop treatment for hyperpigmentation, which is caused by infectious diseases by microorganisms.

Modification of brain waves and sleep parameters by Citrus reticulata Blanco. cv. Sai-Nam-Phueng essential oil.

BACKGROUND: Citrus essential oil (EO) has been used for mood elevation and sedative hypnotic purposes. However, scientific proofs of its central nervous system (CNS) action remained largely unexplored. This study investigated chemotypes, electrical brain waves and sleep-wake effects of the essential oil from Citrus reticulata in rat model. METHODS: Chemical contents of citrus EO were analyzed using gas chromatography-mass spectrometry (GC-MS). Male Wistar rats implanted with electrodes on the frontal and parietal skulls were used for electroencephalographic (EEG) recording while inhaling the citrus EO (200 µl on cotton wool). Diazepam (10 mg/kg, p.o.) was used as a standard anxiolytic drug. EEG frequency analyses were performed by using Fast Fourier transform. All data were statistical analyzed using One-way ANOVA followed by Tukey's test. RESULTS: GC-MS analysis revealed d-limonene (95.7%) as a major constituent of citrus EO. The EEG results showed that overall EEG patterns of citrus EO effects were relatively similar to that of diazepam. However, significant differences between treatments were seen from sleep-wake analyses. Diazepam significantly increased episode numbers of awake and non-rapid eye movement (REM) sleep and reduced averaged episode duration. On the other hand, the citrus EO significantly decreased REM sleep latency and increased total time and episode numbers of REM sleep. CONCLUSION: These findings demonstrated unique CNS effects of C. reticulata EO with EEG fingerprints and sleep-wake profiles. The data might be useful for citrus essential oil sub-classification and clinical application.

Anti-inflammatory effect of isopimarane diterpenoids from Kaempferia galanga.

Two new isopimarane diterpenes, 1α-hydroxy-14α-methoxyisopimara-8(9),15-diene (7) and 1α,14α-dihydroxyisopimara-8(9),15-diene (9) and eight known isopimarane diterpenes including (-)-sandaracopimaradiene (1), 6ß-acetoxysandaracopimaradiene-9α-ol (2), sandaracopimaradiene-7ß,9α-diol (3), sandaracopimaradiene-1α,9α-diol (4), 6ß-acetoxysandaracopimaradiene-9α-ol-1-one (5), 6ß-acetoxysandaracopimaradiene-1α,9α-diol (6), 6ß,14α-dihydroxyisopimara-8(9),15-diene (8), and 6ß,14ß-dihydroxyisopimara-8(9),15-diene (10) were isolated from hexane fraction of Kaempferia galanga ethanol extract. Compounds 5, 6, 8, and 9 exerted the good anti-inflammatory effect on lipopolysaccharide-stimulated nitric oxide production from RAW264.7 cells with IC50 of 11.2, 7.7, 14.3, and 12.1 µM, respectively. These four compounds inhibited nitric oxide synthase (iNOS) mRNA expression. Compounds 5 and 6 also suppressed cyclooxygenase 2 (COX-2) mRNA expression; in addition, compound 6 had mild inhibitory effect on TNF-α mRNA. Among these compounds, 5 dramatically inhibited iNOS and COX-2 mRNA expression. The influential structures were proposed to be oxygen substitute at C-1, C-6, and α-OH at C-14.

Synthesis of 2-(2-oxo-2H-chromen-4-yl)acetamides as potent acetylcholinesterase inhibitors and molecular insights into binding interactions.

Sixteen novel coumarin-based compounds are reported as potent acetylcholinesterase (AChE) inhibitors. The most active compound in this series, 5a (IC50 0.04 ± 0.01 µM), noncompetitively inhibited AChE with a higher potency than tacrine and galantamine. Compounds 5d, 5j, and 5 m showed a moderate antilipid peroxidation activity. The compounds showed cytotoxicity in the same range as the standard drugs in HEK-293 cells. Molecular docking demonstrated that 5a acted as a dual binding site inhibitor. The coumarin moiety occupied the peripheral anionic site and showed π-π interaction with Trp278. The tertiary amino group displayed significant cation-π interaction with Phe329. The aromatic group showed π-π interaction with Trp83 at the catalytic anionic site. The long chain of methylene lay along the gorge interacting with Phe330 via hydrophobic interaction. Molecular docking was applied to postulate the selectivity toward AChE of 5a in comparison with donepezil and tacrine. Structural insights into the selectivity of the coumarin derivatives toward huAChE were explored by molecular docking and 3D QSAR and molecular dynamics simulation for 20 ns. ADMET analysis suggested that the 2-(2-oxo-2H-chromen-4-yl)acetamides showed a good pharmacokinetic profile and no hepatotoxicity. These coumarin derivatives showed high potential for further development as anti-Alzheimer agents.

Antiinflammation constituents from Curcuma zedoaroides.

Curcuma zedoaroides, a Zingiberaceae species, has been used for snake bite antidote and wound care in Thailand. Seven compounds were isolated from the bioactive chloroform extract consisted of one new guaiane sesquiterpene lactone, 5-epiphaeocaulisin A (4) and one new diarylheptanoid, 1,2,3,5-tetrahydroxy-1-(4-hydroxy-3-methoxyphenyl)-7-(4-hydroxyphenyl) heptane (7), together with five known guaiane-type sesquiterpene lactones including gweicurculactone (1), zedoalactone B (2), phaeocaulisin C (3), zedoalactone H (5), and zedoalactone E (6). The antiinflammation was investigated on NO and TNF-α production using RAW264.7 cells. In addition, the expressions of genes involved in inflammation including iNOS, COX-2, and TNF-α were assessed. The results found that Compounds 1-7 presented their antiinflammation against NO production. The most potential effects were demonstrated on Compounds 1 and 7 with IC50 of 27.3 and 32.6 µM, respectively. Although, Compounds 1 and 7 did not inhibit TNF-α production, their suppression on iNOS and COX-2 mRNA expression were revealed. These results support the ability of chloroform fraction, Compounds 1 and 7 on antiinflammation, whereas others exhibited moderate and mild effect.

Wound healing property of isolated compounds from Boesenbergia kingii rhizomes.

ETHNOPHARMACOLOGICAL RELEVANCE: Boesenbergia kingii have been traditionally used in the treatment of inflammatory bowel disease, ulcerative colitis, aphthous ulcer, stomach discomfort, dysentery and abscess. Previously, we reported the B. kingii extract exert potential wound healing properties. Therefore the search of responsible constituents for wound healing property from these rhizomes is still relevant. AIM OF STUDY: This study was aimed to investigate for wound healing property of compounds from this plant in order to support its traditional uses. MATERIAL AND METHODS: Wound healing activities were tested using in vitro assays including cell proliferation and migration assays, collagen production and H2O2-induced oxidative stress in mouse fibroblast L929 cells. The DPPH assay was also used to determine antioxidant activity. RESULTS: Fourteen compounds from the chloroform fraction possessed potent anti-oxidant and wound healing activities. Compound 11 exhibited the most potent anti-DPPH effect (IC50=21.0µM) and also active against 0.5mMH2O2-induced oxidative stress by increasing cell survival ability up to 60.3% at 10µM. In addition, compounds 3, 8 and 14 at 10µM significantly enhanced L929 viability with 119.2%, 122.7% and 113.7%, respectively. Compounds 2, 7, 8 and 14 markedly enhanced L929 migration on day 2 up to 60-76% at 10µM, whereas 7 and 14 strongly stimulated collagen production at 75.0 and 96.7µg/ml compared to the control group (57.5µg/ml), respectively. CONCLUSION: B. kingii is responsible for wound healing property via antioxidative effect, stimulation of fibroblast proliferation and migration as well as enhancement of collagen production.

Anti-HIV-1 integrase compounds from Dioscorea bulbifera and molecular docking study.

CONTEXT: Dioscorea bulbifera L. (Dioscoreaceae) has been used in a traditional Thai longevity medicine preparation. Isolation of inhibitors from natural products is a potential source for continuous development of new HIV-1 integrase (IN) inhibitors. OBJECTIVE: The objective of this study is to isolate the compounds and evaluate their anti-HIV-1 IN activity, as well as to predict the potential interactions of the compounds with an IN. MATERIALS AND METHODS: The ethyl acetate and water fractions (1-100 µg/mL) of Dioscorea bulbifera bulbils were isolated and tested for their anti-HIV-1 IN activity using the multiplate integration assay (MIA). The interactions of the active compounds with IN were investigated using a molecular docking method. RESULTS AND DISCUSSIONS: The ethyl acetate and water fractions of Dioscorea bulbifera bulbils afforded seven compounds. Among these, allantoin (1), 2,4,3',5'-tetrahydroxybibenzyl (2), and 5,7,4'-trihydroxy-2-styrylchromone (5) were isolated for the first time from this plant. Myricetin (4) exhibited the most potent activity with an IC50 value of 3.15 µM, followed by 2,4,6,7-tetrahydroxy-9,10-dihydrophenanthrene (3, IC50 value= 14.20 µM), quercetin-3-O-ß-D-glucopyranoside (6, IC50 value = 19.39 µM) and quercetin-3-O-ß-D-galactopyranoside (7, IC50 value = 21.80 µM). Potential interactions of the active compounds (3, 4, 6, and 7) with the IN active site were additionally investigated. Compound 4 showed the best binding affinity to IN and formed strong interactions with various amino acid residues. These compounds interacted with Asp64, Thr66, His67, Glu92, Asp116, Gln148, Glu152, Asn155, and Lys159, which are involved in both the 3'-processing and strand transfer reactions of IN. In particular, galloyl, catechol, and sugar moieties were successful inhibitors for HIV-1 IN.

Anti-HIV-1 integrase activity and molecular docking of compounds from Albizia procera bark.

CONTEXT: Albizia procera (Roxb.) Benth. (Mimosaceae) has been traditionally used in Thai longevity preparations. Thus, searching for HIV-1 integrase (HIV-1 IN) agents from natural sources is of interest. OBJECTIVE: The objective of this study is to examine the inhibitory activity against HIV-1 IN of compounds isolated from the stem bark of Albizia procera. MATERIALS AND METHODS: The EtOH extract and isolated compounds of Albizia procera bark were examined for anti-HIV-1 IN activity at various concentrations (10-100 µg/mL and 10-100 µM) using the multiplate integration assay and molecular docking. RESULTS AND DISCUSSIONS: The results showed that the ethanol extract had good anti-HIV-1 IN activity with an IC50 value of 19.5 µg/mL, whereas ethyl acetate fraction exhibited the most potent with an IC50 value of 19.1 µg/mL, followed by water fraction (IC50 value = 21.3 µg/mL), hexane and chloroform fractions (IC50 value > 100 µg/mL), respectively. From bioassay-guided isolation, the ethyl acetate fraction was further separated to give two compounds which are (+)-catechin (1) and protocatechuic acid (2), respectively. Of the tested samples, (+)-catechin (1) exhibited appreciable activity against HIV-1 IN with an IC50 value of 46.3 µM, whereas protocatechuic acid (2) showed mild activity with 46.0% inhibition at concentration of 100 µM. (+)-Catechin (1) could interact with Thr66, Gly148, and Glu152 in the core domain of IN enzyme, whereas protocatechuic acid (2) could bind with Thr66, His67, Glu152, Asn155, and Lys159. This is the first report on anti-HIV-1 IN activity of Albizia procera bark. These results may suggest that Albizia procera bark has potential as anti-HIV-1 IN agent.

Histological studies of neuroprotective effects of Curcuma longa Linn. on neuronal loss induced by dexamethasone treatment in the rat hippocampus.

Long term exposure to dexamethasone (Dx) is associated with brain damage especially in the hippocampus via the oxidative stress pathway. Previously, an ethanolic extract from Curcuma longa Linn. (CL) containing the curcumin constituent has been reported to produce antioxidant effects. However, its neuroprotective property on brain histology has remained unexplored. This study has examined the effects of a CL extract on the densities of cresyl violet positive neurons and glial fibrillary acidic protein immunoreactive (GFAP-ir) astrocytes in the hippocampus of Dx treated male rats. It showed that 21 days of Dx treatment (0.5mg/kg, i.p. once daily) significantly reduced the densities of cresyl violet positive neurons in the sub-areas CA1, CA3 and the dentate gyrus, but not in the CA2 area. However, CL pretreatment (100mg/kg, p.o.) was found to significantly restore neuronal densities in the CA1 and dentate gyrus. In addition, Dx treatment also significantly decreased the densities of the GFAP-ir astrocytes in the sub-areas CA1, CA3 and the dentate gyrus. However, CL pretreatment (100mg/kg, p.o.) failed to protect the loss of astrocytes in these sub-areas. These findings confirm the neuroprotective effects of the CL extract and indicate that the cause of astrocyte loss might be partially reduced by a non-oxidative mechanism. Moreover, the detection of neuronal and glial densities was suitable method to study brain damage and the effects of treatment.

Ivy gourd (Coccinia grandis L. Voigt) root suppresses adipocyte differentiation in 3T3-L1 cells.

BACKGROUND: Ivy gourd (Coccinia grandis L. Voigt) is a tropical plant widely distributed throughout Asia, Africa, and the Pacific Islands. The anti-obesity property of this plant has been claimed but still remains to be scientifically proven. We therefore investigated the effects of ivy gourd leaf, stem, and root on adipocyte differentiation by employing cell culture model. METHODS: Dried roots, stems, and leaves of ivy gourd were separately extracted with ethanol. Each extract was then applied to 3T3-L1 pre-adipocytes upon induction with a mixture of insulin, 3-isobutyl-1-methylxanthine, and dexamethasone, for anti-adipogenesis assay. The active extract was further fractionated by a sequential solvent partitioning method, and the resulting fractions were examined for their abilities to inhibit adipogenesis in 3T3-L1 cells. Differences in the expression of adipogenesis-related genes between the treated and untreated cells were determined from their mRNA and protein levels. RESULTS: Of the three ivy gourd extracts, the root extract exhibited an anti-adipogenic effect. It significantly reduced intracellular fat accumulation during the early stages of adipocyte differentiation. Together with the suppression of differentiation, expression of the genes encoding PPARγ, C/EBPα, adiponectin, and GLUT4 were down-regulated. Hexane-soluble fraction of the root extract also inhibited adipocyte differentiation and decreased the mRNA levels of various adipogenic genes in the differentiating cells. CONCLUSIONS: This is the first study to demonstrate that ivy gourd root may prevent obesity based mainly on the ability of its active constituent(s) to suppress adipocyte differentiation in vitro. Such an inhibitory effect is mediated by at least down-regulating the expression of PPARγ-the key transcription factor of adipogenesis in pre-adipocytes during their early differentiation processes.

Anti-inflammatory activity of compounds from Boesenbergia longiflora rhizomes.

ETHNOPHARMACOLOGICAL RELEVANCE: The rhizomes of Boesenbergia longiflora (Wall.) Kuntze have been traditionally used in treatment of inflammatory bowel disease, ulcerative colitis, aphthous ulcer and abscess. Our previous study indicated that CHCl3 fractions of Boesenbergia longiflora had potential on anti-inflammatory properties. In the present study, we investigated the active constituents of this plant for anti-inflammatory activity in order to support its traditional use. MATERIAL AND METHODS: The CHCl3 fraction was isolated using chromatographic techniques. Isolated compounds were tested using relevant in vitro anti-inflammatory assays against LPS-induced NO and TNF-α releases as well as their mechanisms in transcription levels in murine macrophage RAW264.7 cells. RESULTS: The isolation of the CHCl3 fraction from Boesenbergia longiflora rhizomes led to the isolation of three new daucane sesquiterpenes, which were identified as 8-hydroxy-dauca-9, 11-diene-7-one (longiferone A; 1), dauca-8, 11-diene-7-one (longiferone B; 2) and dauca-8, 11-diene-7, 10-dione (longiferone C; 3); together with four known flavonoids, six known diarylheptanoids as well as one sterol. The longiferone B (2) and longiferone C (3) showed anti-inflammatory activity against NO release with IC50 values of 21.0 and 31.3µM, respectively. Longiferone B (2) also suppressed the iNOS and COX-2 mRNA expression. Moreover, the flavonoids and diarylheptanoids inhibited NO and TNF-α production in a dose dependent manner. CONCLUSION: This study demonstrated that sesquiterpenes, diarylheptanoids and some methoxyflavonoids found in Boesenbergia longiflora are responsible for anti-inflammatory activity.

Nitric oxide and tumor necrosis factor-alpha inhibitory substances from the rhizomes of Kaempferia marginata.

The ethanol extract of the rhizomes of Kaempferia marginata showed a potent inhibitory effect against lipopolysaccharide (LPS)-induced nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) release in RAW264.7 cells. Moreover, the partition with various organic solvents also inhibited NO production. One new pimarane-type diterpene, 1alpha-acetoxysandaracopimaradien-2alpha-ol (5), along with four known diterpenes (1-4), were isolated from the n-hexane and chloroform layers, respectively. Among these metabolites, compounds 1 and 4 were isolated for the first time from K. marginata. Compounds 1-5 showed significant inhibitory effects on NO production, with IC50 values ranging from 38.6 to 51.9 microM. Furthermore, compound 2 also exhibited significant activity against TNF-alpha release (IC50 = 48.3 microM). These findings may support the use of K. marginata by traditional doctors for treatment of inflammatory-related diseases.

Anti-cancer activity of compounds from Bauhinia strychnifolia stem.

ETHNOPHARMACOLOGICAL RELEVANCE: The stem and root of Bauhinia strychnifolia Craib (Fabaceae family) have been traditionally used in Thailand to treat fever, alcoholic toxication, allergy and cancer. An EtOH extract of Bauhinia strychnifolia showed good inhibitory activity against several cancer cell lines including HT-29, HeLa, MCF-7 and KB. As there has been no previous reports on chemical constituents of Bauhinia strychnifolia, this study is aimed to isolate the pure compounds with anti-cancer activity. MATERIALS AND METHODS: Five pure compounds were isolated from EtOH extract of Bauhinia strychnifolia stem using silica gel, dianion HP-20 and sephadex LH-20 column chromatography and were tested for their cytotoxic effects against HT-29, HeLa, MCF-7 and KB cell lines using the Sulforhodamine B (SRB) assay. RESULTS: Among five compounds, 3,5,7,3',5'-pentahydroxyflavanonol-3-O-α-l-rhamnopyranoside (2) possessed very potent activity against KB (IC50=0.00054µg/mL), HT-29 (IC50=0.00217 µg/mL), MCF-7 (IC50=0.0585 µg/mL) and HeLa cells (IC50=0.0692 µg/mL). 3,5,7-Trihydroxychromone-3-O-α-l-rhamnopyranoside (3) also showed good activity against HT-29 (IC50=0.02366 µg/mL), KB (IC50=0.0412 µg/mL) and MCF-7 (IC50=0.297 µg/mL), respectively. The activity of 2 (IC50=0.00054 µg/mL) against KB cell was ten times higher than that of the positive control, Camptothecin (anti-cancer drug, IC50=0.0057 µg/mL). All compounds did not show any cytotoxicity with normal cells at the concentration of 1 µg/mL. CONCLUSION: This is the first report of compounds 2 and 3 on anti-cancer activity and based on the anti-cancer activity of extracts and pure compounds isolated from Bauhinia strychnifolia stem, it might be suggested that this plant could be useful for treatment of cancer.