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1.
Surg Endosc ; 37(9): 7218-7225, 2023 09.
Article in English | MEDLINE | ID: mdl-37369948

ABSTRACT

BACKGROUND: Socioeconomic status (SES) is multifactorial, and its effect on post-bariatric weight recurrence is unclear. Distressed Community Index (DCI) is a composite SES score measuring community economic well-being. This study aims to evaluate the effect of DCI on long-term post-bariatric weight outcomes. METHODS: Retrospective analysis of patients undergoing primary laparoscopic Roux-en-Y gastric bypass or sleeve gastrectomy between 2015 and 2020 was performed. All weights in the electronic medical record (EMR), including non-bariatric visits, were captured. Patients were stratified into low tier (LT) and high tier (HT) DCI groups. RESULTS: Of 583 patients, 431 (73.9%) were HT and 152 (26.1%) were LT. Average bariatric follow up was 1.78 ± 1.6 years and average postoperative weight in the EMR was 3.96 ± 2.26 years. Rates of bariatric follow up within the last year were similar (13.8% LT vs 16.2% HT, p = 0.47). LT had higher percent total body weight loss (%TWL; 26% LT vs 23% HT, p < 0.01) and percent excess weight loss (%EWL; 62% vs 57%, p = 0.04) at 1 year on univariate analysis. On multivariate linear regression adjusting for baseline characteristics and surgery type, there were no differences in %EWL between groups at 1 year (p = 0.22), ≥ 3 years (p = 0.53) or ≥ 5 years (p = 0.34) postop. While on univariate analysis LT only trended towards greater percentage of patients with > 15% increase from their 1-year weight (33.3% LT vs 21.0% HT, p = 0.06), on multivariate analysis this difference was significant (OR 2.0, LT 95%CI 1.41-2.84). There were no differences in the percentage of patients with > 15% decrease in %EWL from 1 to 3 + years postop between groups (OR 0.98, LT 95% CI 0.72-1.35). CONCLUSIONS: While low tier patients had similar weight loss at 1 year, they were twice as likely to have weight recurrence at ≥ 3 years. Further studies are needed to identify factors contributing to greater weight recurrence among this population.


Subject(s)
Bariatric Surgery , Gastric Bypass , Laparoscopy , Obesity, Morbid , Humans , Obesity, Morbid/surgery , Retrospective Studies , Weight Loss , Gastrectomy , Treatment Outcome
2.
Chemistry ; 27(34): 8832-8845, 2021 Jun 16.
Article in English | MEDLINE | ID: mdl-33890349

ABSTRACT

Stilbenoids are natural compounds endowed with several biological activities, including cardioprotection and cancer prevention. Among them, (±)-trans-δ-viniferin, deriving from trans-resveratrol dimerization, was investigated in its ability to target DNA duplex and G-quadruplex structures by exploiting NMR spectroscopy, circular dichroism, fluorescence spectroscopy and molecular docking. (±)-trans-δ-Viniferin proved to bind both the minor and major grooves of duplexes, whereas it bound the 3'- and 5'-ends of a G-quadruplex by stacking on the outer quartets, accompanied by rearrangement of flanking residues. Specifically, (±)-trans-δ-viniferin demonstrated higher affinity for the investigated DNA targets than its monomeric counterpart. Additionally, the methoxylated derivatives of (±)-trans-δ-viniferin and trans-resveratrol, i. e. (±)-pterostilbene-trans-dihydrodimer and trans-pterostilbene, respectively, were evaluated, revealing similar binding modes, affinities and stoichiometries with the DNA targets as their parent analogues. All tested compounds were cytotoxic at µM concentration on several cancer cell lines, showing DNA damaging activity consistent with their ability to tightly interact with duplex and G-quadruplex structures.


Subject(s)
G-Quadruplexes , Stilbenes , Circular Dichroism , DNA , Molecular Docking Simulation , Resveratrol
3.
Int J Mol Sci ; 22(12)2021 Jun 17.
Article in English | MEDLINE | ID: mdl-34204214

ABSTRACT

Curaxins and especially the second-generation derivative curaxin CBL0137 have important antitumor activities in multiple cancers such as glioblastoma, melanoma and others. Although most of the authors suggest that their mechanism of action comes from the activation of p53 and inactivation of NF-kB by targeting FACT, there is evidence supporting the involvement of DNA binding in their antitumor activity. In this work, the DNA binding properties of curaxin CBL0137 with model quadruplex DNA oligomers were studied by 1H NMR, CD, fluorescence and molecular modeling. We provided molecular details of the interaction of curaxin with two G-quadruplex structures, the single repeat of human telomere d(TTAGGGT)4 and the c-myc promoter Pu22 sequence. We also performed 1H and 31P NMR experiments were also performed in order to investigate the interaction with duplex DNA models. Our data support the hypothesis that the interaction of curaxin with G-quadruplex may provide a novel insight into the DNA-binding properties of CBL0137, and it will be helpful for the design of novel selective DNA-targeting curaxin analogues.


Subject(s)
Carbazoles/chemistry , DNA/chemistry , G-Quadruplexes , Macromolecular Substances/chemistry , Carbazoles/pharmacology , DNA/metabolism , G-Quadruplexes/drug effects , Humans , Macromolecular Substances/metabolism , Magnetic Resonance Spectroscopy , Molecular Conformation , Molecular Structure , Structure-Activity Relationship , Telomere/genetics , Telomere/metabolism
4.
Int J Mol Sci ; 22(16)2021 Aug 14.
Article in English | MEDLINE | ID: mdl-34445442

ABSTRACT

DNA repair inhibitors are one of the latest additions to cancer chemotherapy. In general, chemotherapy produces DNA damage but tumoral cells may become resistant if enzymes involved in DNA repair are overexpressed and are able to reverse DNA damage. One of the most successful drugs based on modulating DNA repair are the poly(ADP-ribose) polymerase 1 (PARP1) inhibitors. Several PARP1 inhibitors have been recently developed and approved for clinical treatments. We envisaged that PARP inhibition could be potentiated by simultaneously modulating the expression of PARP 1 and the enzyme activity, by a two-pronged strategy. A noncanonical G-quadruplex-forming sequence within the PARP1 promoter has been recently identified. In this study, we explored the potential binding of clinically approved PARP1 inhibitors to the G-quadruplex structure found at the gene promoter region. The results obtained by NMR, CD, and fluorescence titration confirmed by molecular modeling demonstrated that two out the four PARP1 inhibitors studied are capable of forming defined complexes with the PARP1 G-quadruplex. These results open the possibility of exploring the development of better G-quadruplex binders that, in turn, may also inhibit the enzyme.


Subject(s)
G-Quadruplexes , Models, Molecular , Poly (ADP-Ribose) Polymerase-1/genetics , Poly(ADP-ribose) Polymerase Inhibitors/chemistry , Promoter Regions, Genetic , Benzimidazoles/chemistry , Benzimidazoles/pharmacology , DNA/chemistry , DNA/drug effects , Humans , Indazoles/chemistry , Indazoles/pharmacology , Magnetic Resonance Spectroscopy , Phthalazines/chemistry , Phthalazines/pharmacology , Piperazines/chemistry , Piperazines/pharmacology , Piperidines/chemistry , Piperidines/pharmacology , Poly(ADP-ribose) Polymerase Inhibitors/pharmacology
5.
Int J Mol Sci ; 21(6)2020 Mar 21.
Article in English | MEDLINE | ID: mdl-32245220

ABSTRACT

In a recent study, we investigated the antimicrobial activity of a collection of resveratrol-derived monomers and dimers against a series of foodborne pathogens. Out of the tested molecules, dehydro-δ-viniferin and dehydro-ε-viniferin emerged as the most promising derivatives. To define the structural elements essential to the antimicrobial activity against the foodborne pathogen L. monocytogenes Scott A as a model Gram-positive microorganism, the synthesis of a series of simplified benzofuran-containing derivatives was carried out. The systematic removal of the aromatic moieties of the parent molecules allowed a deeper insight into the most relevant structural features affecting the activity. While the overall structure of compound 1 could not be altered without a substantial loss of antimicrobial activity, the structural simplification of compound 2 (minimal inhibitory concentration (MIC) 16 µg/mL, minimal bactericidal concentration (MBC) >512 µg/mL) led to the analogue 7 with increased activity (MIC 8 µg/mL, MBC 64 µg/mL).


Subject(s)
Anti-Bacterial Agents/chemistry , Benzofurans/chemistry , Listeria monocytogenes/drug effects , Resorcinols/chemistry , Stilbenes/chemistry , Anti-Bacterial Agents/pharmacology , Benzofurans/chemical synthesis , Benzofurans/pharmacology , Cell Line , Fibroblasts/drug effects , Food Microbiology , Humans , Microbial Sensitivity Tests , Resorcinols/pharmacology , Resveratrol/chemistry , Resveratrol/pharmacology , Skin/drug effects , Stilbenes/pharmacology
6.
Molecules ; 24(18)2019 Sep 05.
Article in English | MEDLINE | ID: mdl-31491840

ABSTRACT

To improve the current understanding of the role of stilbenoids in the management of diabetes, the inhibition of the pancreatic α-amylase by resveratrol derivatives was investigated. To approach in a systematic way, the mechanistic and structural aspects of the interaction, potential bioactive agents were prepared as single molecules, that were used for the biological evaluation of the determinants of inhibitory binding. Some dimeric stilbenoids-in particular, viniferin isomers- were found to be better than the reference drug acarbose in inhibiting the pancreatic α-amylase. Racemic mixtures of viniferins were more effective inhibitors than the respective isolated pure enantiomers at an equivalent total concentration, and displayed cooperative effects not observed with the individual enantiomers. The molecular docking analysis provided a thermodynamics-based rationale for the measured inhibitory ability and for the observed synergistic effects. Indeed, the binding of additional ligands on the surface of the alpha-amylase was found to decrease the dissociation constant of inhibitors bound to the active site of the enzyme, thus providing a mechanistic rationale for the observed inhibitory synergies.


Subject(s)
Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Pancreatic alpha-Amylases/antagonists & inhibitors , Resveratrol/chemistry , Resveratrol/pharmacology , Binding Sites , Molecular Conformation , Molecular Docking Simulation , Molecular Dynamics Simulation , Molecular Structure , Protein Binding , Quantitative Structure-Activity Relationship , Resveratrol/analogs & derivatives
7.
bioRxiv ; 2024 May 08.
Article in English | MEDLINE | ID: mdl-38766000

ABSTRACT

Light has myriad impacts on behavior, health, and physiology. These signals originate in the retina and are relayed to the brain by more than 40 types of retinal ganglion cells (RGCs). Despite a growing appreciation for the diversity of RGCs, how these diverse channels of light information are ultimately integrated by the ~50 retinorecipient brain targets to drive these light-evoked effects is a major open question. This gap in understanding primarily stems from a lack of genetic tools that specifically label, manipulate, or ablate specific RGC types. Here, we report the generation and characterization of a new mouse line (Opn4FlpO), in which FlpO is expressed from the Opn4 locus, to manipulate the melanopsin-expressing, intrinsically photosensitive retinal ganglion cells. We find that the Opn4FlpO line, when crossed to multiple reporters, drives expression that is confined to ipRGCs and primarily labels the M1-M3 subtypes. Labeled cells in this mouse line show the expected intrinsic, melanopsin-based light response and morphological features consistent with the M1-M3 subtypes. In alignment with the morphological and physiological findings, we see strong innervation of non-image forming brain targets by ipRGC axons, and weaker innervation of image forming targets in Opn4FlpO mice labeled using AAV-based and FlpO-reporter lines. Consistent with the FlpO insertion disrupting the endogenous Opn4 transcript, we find that Opn4FlpO/FlpO mice show deficits in the pupillary light reflex, demonstrating their utility for behavioral research in future experiments. Overall, the Opn4FlpO mouse line drives Flp-recombinase expression that is confined to ipRGCs and most effectively drives recombination in M1-M3 ipRGCs. This mouse line will be of broad use to those interested in manipulating ipRGCs through a Flp-based recombinase for intersectional studies or in combination with other, non-Opn4 Cre driver lines.

8.
Nat Genet ; 17(1): 79-83, 1997 Sep.
Article in English | MEDLINE | ID: mdl-9288102

ABSTRACT

Approximately 130,000 cases of colorectal cancer (CRC) are diagnosed in the United States each year, and about 15% of these have a hereditary component. Two well-defined syndromes, familial adenomatous polyposis (FAP) and hereditary non-polyposis colorectal cancer (HNPCC), account for up to 5% of the total new cases of CRC. Truncating APC mutations are responsible for FAP, and defective mismatch repair genes cause HNPCC. However, the genes responsible for most of the familial cases are unknown. Here we report a mutation (T to A at APC nucleotide 3920) found in 6% of Ashkenazi Jews and about 28% of Ashkenazim with a family history of CRC. Rather than altering the function of the encoded protein, this mutation creates a small hypermutable region of the gene, indirectly causing cancer predisposition.


Subject(s)
Adenomatous Polyposis Coli/genetics , Colorectal Neoplasms, Hereditary Nonpolyposis/genetics , Genes, APC , Jews/genetics , Point Mutation , Adult , Base Sequence , Codon , DNA Primers , Europe/ethnology , Female , Humans , Male , Pedigree , Polymerase Chain Reaction
9.
Curr Biol ; 33(21): 4741-4750.e5, 2023 11 06.
Article in English | MEDLINE | ID: mdl-37827153

ABSTRACT

The rate of primary productivity is a keystone variable in driving biogeochemical cycles today and has been throughout Earth's past.1 For example, it plays a critical role in determining nutrient stoichiometry in the oceans,2 the amount of global biomass,3 and the composition of Earth's atmosphere.4 Modern estimates suggest that terrestrial and marine realms contribute near-equal amounts to global gross primary productivity (GPP).5 However, this productivity balance has shifted significantly in both recent times6 and through deep time.7,8 Combining the marine and terrestrial components, modern GPP fixes ≈250 billion tonnes of carbon per year (Gt C year-1).5,9,10,11 A grand challenge in the study of the history of life on Earth has been to constrain the trajectory that connects present-day productivity to the origin of life. Here, we address this gap by piecing together estimates of primary productivity from the origin of life to the present day. We estimate that ∼1011-1012 Gt C has cumulatively been fixed through GPP (≈100 times greater than Earth's entire carbon stock). We further estimate that 1039-1040 cells have occupied the Earth to date, that more autotrophs than heterotrophs have ever existed, and that cyanobacteria likely account for a larger proportion than any other group in terms of the number of cells. We discuss implications for evolutionary trajectories and highlight the early Proterozoic, which encompasses the Great Oxidation Event (GOE), as the time where most uncertainty exists regarding the quantitative census presented here.


Subject(s)
Atmosphere , Oxygen , Oceans and Seas , Atmosphere/chemistry , Biomass , Carbon
10.
Antioxidants (Basel) ; 11(7)2022 Jul 19.
Article in English | MEDLINE | ID: mdl-35883889

ABSTRACT

The slow pace of discovery of bioactive natural products can be attributed to the difficulty in rapidly identifying them in complex mixtures such as plant extracts. To overcome these hurdles, we explored the utility of two machine learning techniques, i.e., Elastic Net and Random Forests, for identifying the individual anti-inflammatory principle(s) of an extract of the inflorescences of the hops (Humulus lupulus) containing hundreds of natural products. We fractionated a hop extract by column chromatography to obtain 40 impure fractions, determined their anti-inflammatory activity using a macrophage-based bioassay that measures inhibition of iNOS-mediated formation of nitric oxide, and characterized the chemical composition of the fractions by flow-injection HRAM mass spectrometry and LC-MS/MS. Among the top 10 predictors of bioactivity were prenylated flavonoids and humulones. The top Random Forests predictor of bioactivity, xanthohumol, was tested in pure form in the same bioassay to validate the predicted result (IC50 7 µM). Other predictors of bioactivity were identified by spectral similarity with known hop natural products using the Global Natural Products Social Networking (GNPS) algorithm. Our machine learning approach demonstrated that individual bioactive natural products can be identified without the need for extensive and repetitive bioassay-guided fractionation of a plant extract.

11.
ACS Pharmacol Transl Sci ; 4(6): 1782-1793, 2021 Dec 10.
Article in English | MEDLINE | ID: mdl-34927010

ABSTRACT

The energy intake exceeding energy expenditure (EE) results in a positive energy balance, leading to storage of excess energy and weight gain. Here, we investigate the potential of a newly synthesized compound as an inducer of EE for the management of diet-induced obesity and insulin resistance. Xanthohumol (XN), a prenylated flavonoid from hops, was used as a precursor for the synthesis of a pyrazole derivative tested for its properties on high-fat diet (HFD)-induced metabolic impairments. In a comparative study with XN, we report that 4-(5-(4-hydroxyphenyl)-1-methyl-1H-pyrazol-3-yl)-5-methoxy-2-(3-methylbut-2-en-1-yl)benzene-1,3-diol (XP) uncouples oxidative phosphorylation in C2C12 cells. In HFD-fed mice, XP improved glucose tolerance and decreased weight gain by increasing EE and locomotor activity. Using an untargeted metabolomics approach, we assessed the effects of treatment on metabolites and their corresponding biochemical pathways. We found that XP and XN reduced purine metabolites and other energy metabolites in the plasma of HFD-fed mice. The induction of locomotor activity was associated with an increase in inosine monophosphate in the cortex of XP-treated mice. Together, these results suggest that XP, better than XN, affects mitochondrial respiration and cellular energy metabolism to prevent obesity in HFD-fed mice.

12.
Eur J Med Chem ; 202: 112541, 2020 Sep 15.
Article in English | MEDLINE | ID: mdl-32652408

ABSTRACT

Viruses continue to be a major threat to human health. In the last century, pandemics occurred and resulted in significant mortality and morbidity. Natural products have been largely screened as source of inspiration for new antiviral agents. Within the huge class of plant secondary metabolites, resveratrol-derived stilbenoids present a wide structural diversity and mediate a great number of biological responses relevant for human health. However, whilst the antiviral activity of resveratrol has been extensively studied, little is known about the efficacy of its monomeric and oligomeric derivatives. The purpose of this review is to provide an overview of the achievements in this field, with particular emphasis on the source, chemical structures and the mechanism of action of resveratrol-derived stilbenoids against the most challenging viruses. The collected results highlight the therapeutic versatility of stilbene-containing compounds and provide a prospective insight into their potential development as antiviral agents.


Subject(s)
Antiviral Agents/pharmacology , Biological Products/pharmacology , Stilbenes/pharmacology , Viruses/drug effects , Antiviral Agents/chemistry , Biological Products/chemistry , Microbial Sensitivity Tests , Molecular Structure , Stilbenes/chemistry
13.
Sci Rep ; 9(1): 19525, 2019 12 20.
Article in English | MEDLINE | ID: mdl-31862939

ABSTRACT

Plant polyphenolic compounds are considered a promising source for new antibacterial agents. In this study, we evaluated the antimicrobial activity of a collection of resveratrol-derived monomers and dimers screened as single molecules against a panel of nine foodborne pathogens. The results demonstrated that two monomers (i.e., pterostilbene 2 and (E)-3-hydroxy-4',5-dimethoxystilbene 9) and three dimers (i.e., δ-viniferin 10, viniferifuran 14 and dehydro-δ-viniferin 15) were endowed with significant antibacterial activity against gram-positive bacteria. The exposure of gram-positive foodborne pathogens to 100 µg/mL of 2, 9 and 15 induced severe cell membrane damage, resulting in the disruption of the phospholipid bilayer. The most promising dimeric compound, dehydro-δ-viniferin 15, was tested against Listeria monocytogenes, resulting in a loss of cultivability, viability and cell membrane potential. TEM analysis revealed grave morphological modifications on the cell membrane and leakage of intracellular content, confirming that the cell membrane was the principal biological target of the tested derivative.


Subject(s)
Anti-Bacterial Agents/pharmacology , Resveratrol/chemistry , Food Microbiology , Gram-Positive Bacteria/drug effects , Listeria monocytogenes/drug effects , Membrane Potentials/drug effects , Microbial Sensitivity Tests
14.
J Microsc ; 229(Pt 3): 402-6, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18331486

ABSTRACT

Porous glass-ceramics is an extremely important material to be used in combination with metallic nanolayers as a Surface-Enhanced Raman Scattering (SERS) substrate for biological and chemical analysis, demonstrating excellent biocompatibility and chemical inertness. These materials show their own Raman background signal lateral distribution, mostly from crystalline skeleton, which has to be considered. A nano-Raman setup using the optical fibre of a Scanning Near-Field Optical Microscope (SNOM), working in collection mode, is described and applied for mapping of such glass-ceramic. The collected Raman signal of Ti and P containing phase distribution in this near-field geometry reaches spatial resolution around 50 nm.

15.
J Microsc ; 229(Pt 3): 551-4, 2008 Mar.
Article in English | MEDLINE | ID: mdl-18331509

ABSTRACT

Human HaCaT cells, exposed for 24 h to a 1 mT (rms) 50 Hz sinusoidal magnetic field in a temperature-regulated solenoid, suffer detectable changes in their biochemical properties and shapes. By using infrared wavelength-selective scanning near-field optical microscopy, we observed changes in the distribution of the inner chemical functional groups and in the cell morphology with a resolution of 80-100 nm.


Subject(s)
Electromagnetic Fields , Keratinocytes , Skin/cytology , Cell Line , Humans , Infrared Rays , Keratinocytes/metabolism , Keratinocytes/radiation effects , Keratinocytes/ultrastructure , Microscopy, Scanning Probe
17.
Front Plant Sci ; 9: 1745, 2018.
Article in English | MEDLINE | ID: mdl-30564253

ABSTRACT

Gomphrena marginata Seub. (Amaranthaceae) is an endemic species from Brazilian campos rupestres with a fructan accumulating underground reserve system. Analyses of high performance anion exchange chromatography (HPAEC-PAD) revealed the presence of the soluble carbohydrates glucose, fructose, sucrose, 1-kestose, 6-kestose, nystose and fructans with degree of polymerization (DP) up to approximately 40 fructose units. Data of 1H and 13C Nuclear Magnetic Resonance (NMR) spectroscopy, including Heteronuclear Single-Quantum Correlation (HSQC) and Heteronuclear Multiple-Bonds Correlation (HMBC) showed the presence of ß (2,6) linkages, characteristic of the linear molecule of levan-type fructan(2,6). These results confirmed previous studies suggesting that the reserve carbohydrate in the underground system of this species was levan-type fructans, similar to that of G. macrocephala. Structural analyses of the thickened underground system using light microscopy revealed a mixed origin system consisting mainly of a gemmiferous tuberous root with the upper region formed by short branched stems, both presenting vascular cylinders with unusual growth patterns. Fructan spherocrystals were visualized under polarized light and scanning electron microscopy (SEM) mostly in the cortex and vascular cylinder in both thickened stem and root. In addition to data reported in the literature concerning the occurrence of fructans in the Amaranthaceae, the results presented here suggest that fructans are a trait in this family while the levan-type fructan prevail in Gomphrena species.

18.
J Clin Invest ; 98(1): 199-206, 1996 Jul 01.
Article in English | MEDLINE | ID: mdl-8690794

ABSTRACT

The phenomenon of alkylation tolerance has been observed in cells that are deficient in some component of the DNA mismatch repair (MMR) system. An alkylation-induced cell cycle arrest had been reported previously in one MMR-proficient cell line, whereas a MMR-defective clone derived from this line escapes from this arrest. We examined human cancer cell lines to determine if the cell cycle arrest were dependent upon the MMR system. Growth characteristics and cell cycle analysis after MNNG treatment were ascertained in seven MMR-deficient and proficient cell lines, with and without confirmed mutations in hMLH1 or hMSH2 by an in vitro transcription/translation assay. MMR-proficient cells underwent growth arrest in the G2 phase of the cell cycle after the first S phase, whereas MMR-deficient cells escaped an initial G2 delay and resumed a normal growth pattern. In the HCT116 line corrected for defective MMR by chromosome 3 transfer, the G2 phase arrest lasted more than five days. In another MMR-proficient colon cancer cell line, SW480, cell death occurred five days after MNNG treatment. A competent MMR system appears to be necessary for G2 arrest or cell death after alkylation damage, and this cell cycle checkpoint may allow the cell to repair damaged DNA, or prevent the replication of mutated DNA by prohibiting clonal expansion.


Subject(s)
DNA Damage , DNA Repair , DNA-Binding Proteins , G2 Phase/drug effects , Methylnitronitrosoguanidine/pharmacology , Neoplasms/genetics , Alkylating Agents/pharmacology , Carcinoma , Colonic Neoplasms , Female , Humans , Models, Genetic , MutS Homolog 2 Protein , Ovarian Neoplasms , Proto-Oncogene Proteins/genetics , RNA, Messenger/analysis , Sequence Deletion , Stem Cells , Tumor Cells, Cultured
19.
J Ethnopharmacol ; 111(1): 1-7, 2007 Apr 20.
Article in English | MEDLINE | ID: mdl-17166678

ABSTRACT

This work assessed the mechanism underlying the antisecretory gastric acid effect of Plectranthus barbatus Andrews (Lamiaceae) and active constituents. Popularly known as "false-boldo", this plant is used in Brazilian folk medicine to treat gastrointestinal and hepatic ailments. The plant aqueous extract (AE) and isolated compounds were assayed in vivo in pylorus-ligated mice, and in vitro on acid secretion measured as [(14)C]-aminopyrine ([(14)C]-AP) accumulation in rabbit gastric glands and gastric H(+),K(+)-ATPase preparations. Injected into the duodenal lumen, the AE of the plant leaves (0.5 and 1.0 g/kg) decreased the volume (62 and 76%) and total acidity (23 and 50%) of gastric acid secretion in pylorus-ligated mice. Bioguided purification of the AE yielded an active fraction (IC(50)=24 microg/ml) that inhibited acid secretion in rabbit gastric glands with a potency 10 to 18 times greater than that of the originating extract, on both the basal and stimulated acid secretion by histamine (His) (1 microM) or bethanechol (100 microM). At the same concentrations the gastric H(+),K(+)-ATPase activity was also inhibited. The active constituent was chemically identified as the abietanoid dienedione plectrinone A which reduced the H(+),K(+)-ATPase activity with IC(50)=171 microM. The results indicate that inhibition of the gastric proton pump by this diterpenoid may account for the antisecretory acid effect and reputed anti ulcer activity of Plectranthus barbatus.


Subject(s)
Abietanes/pharmacology , Anti-Ulcer Agents/pharmacology , Enzyme Inhibitors/pharmacology , Gastric Acid/metabolism , Lamiaceae , Proton Pump Inhibitors , Stomach/drug effects , Abietanes/isolation & purification , Aminopyrine/metabolism , Animals , Anti-Ulcer Agents/isolation & purification , Bethanechol/pharmacology , Brazil , Chemical Fractionation/methods , Dose-Response Relationship, Drug , Enzyme Inhibitors/isolation & purification , Gastric Acidity Determination , Gastric Mucosa/drug effects , Gastric Mucosa/enzymology , H(+)-K(+)-Exchanging ATPase/metabolism , Histamine/pharmacology , In Vitro Techniques , Male , Mice , Muscarinic Agonists/pharmacology , Plant Leaves , Rabbits , Stomach/enzymology
20.
Front Microbiol ; 8: 595, 2017.
Article in English | MEDLINE | ID: mdl-28443078

ABSTRACT

Terminalia catappa Linn bark is used to treat dysentery by various populations in Southeast Asian countries, and its leaves have also been used in traditional medicine to treat hepatitis in India and the Philippines. Here, the antifungal actions of crude hydro-alcoholic extract (TcHE) and fractions from T. catappa leaves were assessed via the agar diffusion and microdilution tests on Candida reference strains and clinical isolates from patients with acquired immunodeficiency syndrome (AIDS). Additionally, the potential cytotoxic effects of TcHE were assessed on cultured human peripheral blood mononuclear cells (PBMC). T. catappa fractions and sub-fractions were analyzed by gas chromatography coupled to mass spectrometry with electron impact (GC/MS/EI), high-performance liquid chromatography coupled to mass spectrometry "electrospray" ionization in positive mode (HPLC/MS/MS/ESI+) and hydrogen nuclear magnetic resonance (1HNMR). TcHE and its fractions were able to inhibit the growth of all tested Candida strains with the n-butanol (FBuOH) fraction presenting the best antifungal activity. Testing of different FBuOH sub-fractions (SF) showed that SF10 was the most active against Candida spp. Fractioning of SF10 demonstrated that 5 out of its 15 sub-fractions were active against Candida spp., with SF10.5 presenting the highest activity. Chemical analysis of SF10 detected hydrolysable tannins (punicalin, punicalagin), gallic acid and flavonoid C-glycosides. Overall, the results showed that T. catappa L. leaf extract, fractions and sub-fractions were antifungal against Candida spp. and may be useful to treat diseases caused by this fungus.

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