Xanthones Isolated from Cratoxylum cochinchinensis Reduced Oxidative Stress in Periodontal Ligament Stem Cells.

Xanthone compounds from Cratoxylum cochinchinensis (C. cochinchinensis) have demonstrated antioxidant effects and potency in treating many inflammatory diseases. However, the efficiency of the three xanthone extracts isolated from the young fruit of this plant, i.e., two geranyloxy xanthones (F6, F8) and one 1,3,7-hydroxy xanthone (F137), as antioxidants and therapeutics for periodontal disease has not been evaluated. The aim of this study was to investigate the antioxidant effects of three xanthones isolated from C. cochinchinensis on periodontal ligament stem cells (PDLSCs) and their osteogenic differentiation. The antioxidant activity of the aqueous extracts was determined using a DPPH assay, and their cytotoxicity was evaluated using an MTT assay. H2O2 was used to induce intracellular stress, and the scavenging effect of the isolated compounds against reactive oxygen species (ROS) was analyzed with a fluorescence assay. The expression of nuclear factor-erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) was evaluated, and the effects of the three compounds on PDLSCs osteogenic differentiation were investigated. The isolated compounds reduced both extracellular and intracellular ROS in a dose-dependent manner and induced the expression of Nrf2 and HO-1 in PDLSCs. Under redox conditions, these compounds potentiated PDLSCs osteogenic differentiation. Our study demonstrated that the hydroxy xanthones from C. cochinchinensis had antioxidant effects on the Nrf2/HO-1 pathway and might be effective therapeutic substrates for damage prevention and the regeneration of damaged periodontal tissues in periodontitis patients.

Ameliorative effects of hexane extract of Garcinia kola seeds Heckel (Clusiaceae) in cisplatin-induced hepatorenal toxicity in mice.

Garcinia kola seed is used to manage liver diseases in ethnomedicine. However, there is limited information on its role in Cisplatin (CIS)-induced toxicity. Here, we investigated the potential of hexane extract of Garcinia kola (HEGK) in lessening CIS-induced hepatorenal- and gene- toxicity. Male mice (22 ± 3 g) randomly assigned into groups (n = 5) were treated for five days: Corn oil only, HEGK (200 mg/kg), CIS (20 mg/kg; i.p; 48-hours), CIS + HEGK (100 mg/kg), CIS + HEGK (200 mg/kg), CIS + Quercetin (25 mg/kg), and Quercetin(25 mg/kg). Corn oil, HEGK, and Quercetin were administered daily by gavage. GC-MS revealed the presence of 9,19-Cyclolanost-24-en-3-ol as the most abundant component in HEGK, with an LC50 of 1023 µg/mL. HEGK significantly (p < 0.05) scavenged DPPH, inhibited lipid peroxidation and exhibited reducing activity dose-dependently. CIS treatment increased (p < 0.05) urinary albumin and creatinine by 18 and 56%, respectively, serum levels of total bilirubin, creatinine, and hepatic transaminases, while albumin decreased (p < 0.05) by 57%. CIS treatment increased renal and hepatic malondialdehyde (MDA) levels by 67 and 70% individually, while the activities of glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT) and reduced glutathione (GSH) levels were decreased (p < 0.05). Furthermore CIS-induced the formation of mononucleated polychromatic erythrocytes (mnPCEs) 150% in the bone marrow of mice. Histology revealed necrosis of hepatocytes, congestion of renal interstitial vessel, and hyperplasia of the Kupffer cells. Pretreatment with HEGK reduced the levels of MDA, mnPCEs, and increased the activities of antioxidant enzymes and restored GSH to levels comparable in control mice. Taken together, HEGK ameliorated CIS-toxicity via the activation of the antioxidative pathways and mitigated genotoxicity by mitigating mnPCEs formation in mice.

Cratoxylum formosum dyer extract alleviates testicular damage in hypertensive rats.

The effects of a Cratoxylum formosum (Jack) Dyer ssp. (CF) extract on testicular damage were assessed in hypertensive rats. Nω -nitro-L-arginine methyl ester hydrochloride (L-NAME; 40 mg kg-1  day-1 ) was administered for 5 weeks to induce hypertension in male Sprague-Dawley rats, and treated with CF extract (100, 300 or 500 mg kg-1  day-1 ) or sildenafil (5 mg kg-1  day-1 ) during the final 2 weeks (n = 8/group). Biochemical components of the CF extract were identified and mainly contained phenolic compounds. The CF extract significantly reduced systolic blood pressure and alleviated impaired sperm quality and seminiferous tubular morphology in hypertensive rats. CF extract restored reduced serum testosterone and protein expression of steroidogenic acute regulatory protein (StAR), nuclear factor erythroid-related factor 2 (Nrf2), and haem oxygenase 1 (HO-1) in L-NAME rats. Hypertensive rats presented decreased antioxidant enzyme activities, and increased testicular and plasma malondialdehyde (MDA) levels and superoxide production, all of which were normalised by CF extract. Furthermore, endothelial nitric oxide synthase (eNOS) expression in testicular tissue and plasma nitrate/nitrite levels were restored in hypertensive rats administered CF extract. Conclusion: CF extract alleviated testicular damage in hypertensive rats. Potential molecular mechanisms may involve suppression of oxidative stress and restoration of StAR, Nrf2, HO-1 and eNOS expression in hypertensive rats.

Inhibition of protein tyrosine phosphatase 1B (PTP1B) and α-glucosidase by xanthones from Cratoxylum cochinchinense, and their kinetic characterization.

Cratoxylum cochinchinense displayed significant inhibition against protein tyrosine phosphatase 1B (PTP1B) and α-glucosidase, both of which are key target enzymes to attenuate diabetes and obesity. The compounds responsible for both enzymes inhibition were identified as twelve xanthones (1-12) among which compounds 1 and 2 were found to be new ones. All of them simultaneously inhibited PTP1B with IC50s of (2.4-52.5 µM), and α-glucosidase with IC50 values of (1.7-72.7 µM), respectively. Cratoxanthone A (3) and γ-mangostin (7) were estimated to be most active inhibitors against both PTP1B (IC50 = 2.4 µM for 3, 2.8 µM for 7) and α-glucosidase (IC50 = 4.8 µM for 3, 1.7 µM for 7). In kinetic studies, all isolated xanthones emerged to be mixed inhibitors of α-glucosidase, whereas they behaved as competitive inhibitors of PTP1B. In time dependent experiments, compound 3 showed isomerization inhibitory behavior with following kinetic parameters: Kiapp = 2.4 µM; k5 = 0.05001 µM-1 S-1 and k6 = 0.02076 µM-1 S-1.

Mesua beccariana (Clusiaceae), a source of potential anti-cancer lead compounds in drug discovery.

An investigation on biologically active secondary metabolites from the stem bark of Mesua beccariana was carried out. A new cyclodione, mesuadione, along with several known constituents which are beccamarin, 2,5-dihydroxy-1,3,4-trimethoxy anthraquinone, 4-methoxy-1,3,5-trihydroxyanthraquinone, betulinic acid and stigmasterol were obtained from this ongoing research. Structures of these compounds were elucidated by extensive spectroscopic methods, including 1D and 2D-NMR, GC-MS, IR and UV techniques. Preliminary tests of the in vitro cytotoxic activities of all the isolated metabolites against a panel of human cancer cell lines Raji (lymphoma), SNU-1 (gastric carcinoma), K562 (erythroleukemia cells), LS-174T (colorectal adenocarcinoma), HeLa (cervical cells), SK-MEL-28 (malignant melanoma cells), NCI-H23 (lung adenocarcinoma), IMR-32 (neuroblastoma) and Hep-G2 (hepatocellular liver carcinoma) were carried out using an MTT assay. Mesuadione, beccamarin, betulinic acid and stigmasterol displayed strong inhibition of Raji cell proliferation, while the proliferation rate of SK-MEL-28 and HeLa were strongly inhibited by stigmasterol and beccamarin, indicating these secondary metabolites could be anti-cancer lead compounds in drug discovery.

1,3,5,6-Tetrahydroxyxanthone, a natural xanthone, induces diuresis and saluresis in normotensive and hypertensive rats.

The aim of the present study was to evaluate the diuretic effect of 1,3,5,6-tetrahydroxyxanthone (THX), isolated from preparations of Garcinia achachairu Rusby (Clusiaceae) branches, in rats. Wistar normotensive (NTR) and spontaneously hypertensive rats (SHR) received a single oral treatment with THX, hydrochlorothiazide (HCTZ) or just vehicle (VEH). The effects of THX in combination with diuretics of clinical use, as well as with l-NAME, atropine, and indomethacin were also explored. Cumulative urine volume and urinary parameters were measured at the end of the 8-h or 24-h experiment. THX was able to stimulate 8-h and 24-h diuresis in both NTR and SHR, as well as urinary Na+ and K+ excretion, at a dose of 0.1 mg/kg; while 8-h urinary Cl- levels were only significantly increased in the group of animals treated with THX at the dose of 0.3 mg/kg. In addition, Ca2+ content was reduced in the 24-h urine of THX-treated NTR and SHR, like that obtained in the HCTZ (10 mg/kg) group. The combination with HCTZ or furosemide, but not with amiloride, significantly enhanced THX-induced diuresis. The diuretic effect with HCTZ plus THX treatment was accompanied by an increase of the urinary Na+, K+, and Cl- excretion. On the other hand, when given THX in combination with amiloride, there was a significant increase in Na+ and a decrease in K+ excretion, an effect characteristic of this class of diuretics. Moreover, the diuretic effect of THX was heightened after pretreatment with l-NAME, and its ability to induce diuresis was prevented neither in the presence of indomethacin nor in the presence of atropine. However, the pretreatment with atropine completely avoided the saluretic effect stimulated by THX, suggesting, at least in part, the role of muscarinic receptors in the renal effects of THX disclosed in this study.

Novel anticancer agents, kayeassamins A and B from the flower of Kayea assamica of Myanmar.

The CHCl(3)-soluble fraction of 70% EtOH extract of the flower of Kayea assamica completely killed human pancreatic PANC-1 cancer cells preferentially under nutrient-deprived conditions at 1 microg/mL. Bioassay-guided fractionation and isolation afforded two novel compounds, kayeassamins A (1) and B (2). Their structures were elucidated using extensive spectroscopic methods and the modified Mosher method. Each compound showed 100% preferential cytotoxicity (PC(100)) against PANC-1 cells under nutrient-deprived conditions at 1 microM. Furthermore, both compounds inhibited the migration of PANC-1 cells in the wound closure assay.

Proteic and phenolics compounds contents in Bacupari callus cultured with glutamine and nitrogen sources.

In this study was evaluated the influence of glutamine supplementation on the endogenous content of amino acids, proteins, total phenolics, flavonoids and proanthocyanidins in Bacupari callus. The explants were inoculated in MS medium, MS with half concentration of the nitrogen salts (MS½) and nitrogen-free MS, supplemented with glutamine (5, 10, 30 and 60mM) named as Gln5, Gln10, Gln30 and Gln60. Amino acids and proteins were analyzed after 20, 80 and 140 days and the secondary metabolites on the 140th day. There was no difference in the amino acids on the 20th day. On the 80th day the treatments MS and MS½ presented the lowest levels. On the 140th day MS and MS½ presented the lowest amino acid concentration and Gln10 the highest. Concerning proteins, there was difference only on the 140th day, being the highest concentrations observed in Gln5, and the lowest in MS½ treatment. Total phenolics content was higher in the treatment Gln60 and lowest in MS. Treatments Gln5, Gln10, Gln30 and MS½ were statistically equal. For flavonoids, the highest values occurred in the treatments Gln30, Gln60 and MS½ and the lowest in Gln5, Gln10 and MS. Similarly, for the proanthocyanidins the highest concentrations were observed in treatment Gln60 and the lowest in Gln5 and MS. In conclusion, the treatment with 60mM of glutamine favors the protein accumulation and production of secondary metabolites in Bacupari callus.

Prenylated ß-diketones, two new additions to the family of biologically active Hypericum perforatum L. (Hypericaceae) secondary metabolites.

Two novel ß-diketones, 2,6,9-trimethyl-8-decene-3,5-dione (A) and 3,7,10-trimethyl-9-undecene-4,6-dione (B), were identified from the renowned medicinal plant Hypericum perforatum L. The structures of ß-diketones A and B were corroborated by syntheses (4 steps starting from methyl acetoacetate, overall yields 30% and 23%, respectively). In solution, these ß-diketones predominantly exist as two rapidly interconverting ß-keto-enol tautomers. The structures of A and B show some common fragments with the molecules of hyperforin and adhyperforin, respectively, the acknowledged multi-target secondary metabolites from St. John's wort. It is therefore not surprising that A displayed a noteworthy biological activity profile as well (including brine shrimp toxicity, antinociceptive, antidepressant and acetylcholinesterase inhibitory activity). ß-Diketone A manifested the most outstanding potency as an acetylcholinesterase inhibitor with IC50 value of 1.51 µM pointing again to the ß-keto-enol moiety as a promising lead structure for the development of drugs that could lessen symptoms of Alzheimer's disease (such as dementia, depression and pain).

Synthesis of (+/-)-clusianone: high-yielding bridgehead and diketone substitutions by regioselective lithiation of enol ether derivatives of bicyclo[3.3.1]nonane-2,4,9-triones.

[Structure: see text] A concise synthesis of the polyprenylated acylphloroglucinol natural product, clusianone, in racemic form, is described. An Effenburger cyclization generated a core bicyclo[3.3.1]nonane-trione structure, which was then elaborated by means of regioselective lithiation reactions.

Effect of Mesua ferrea Linn. flower extract on Salmonella.

Based on its traditional uses in folk medicine, the whole flower extract of Mesua ferrea Linn. was tested for its in vitro antimicrobial efficacy against five different strains of Salmonella spp. All the strains were found to be highly sensitive to the extract, MIC of the extract against each organism being 50 microg/ml. The extract was tested in vitro for its mode of antibacterial activity against S. Typhimurium NCTC 74 and it was found to be bactericidal in action. In vivo studies of this extract offered significant protection to Swiss albino mice at doses approximately 2 and 4 mg/mouse when challenged with 50 median lethal dose of S. Typhimurium NCTC 74. Further, the extract caused statistically significant reduction in viable count of the strain in liver, spleen and heart blood of challenged mice.

Differential responses of C3 and CAM native Brazilian plant species to a SO2- and SPMFe-contaminated Restinga.

Aiming to evaluate responses in terms of growth rates, physiological parameters, and degree of sensitivity to SO2 and SPMFe in Eugenia uniflora L. (Myrtaceae, a C3 species) and Clusia hilariana Schlecht (Clusiaceae, a CAM species); saplings were exposed to emissions from a pelletizing factory for 7 months. The species were distributed along a transect (200, 500, 800, 1400, and 1700 m away from the emission source), and analyses were performed after 71, 118, and 211 days of exposure to the pollutants. E. uniflora received higher superficial deposition of particulate iron. The highest total iron foliar contents were observed 200 m away from the emission source in both plant species, while the highest total sulfur foliar contents were observed 200 m away in C. hilariana and 800 m away in E. uniflora. E. uniflora presented decreased values of height growth rate, number of necrotic leaves, chlorophyll analysis (SPAD index) and transpiration, in relation to the distances from the emission source. C. hilariana showed decreased values of height growth rate, number of leaves, number of necrotic leaves, total ionic permeability, stomatal conductance, transpiration, net CO2 assimilation, and total dry matter, in relation to distances from the emission source. In relation to the days of exposure, both species presented increased number of necrotic leaves and foliar phytotoxicity index, and decreased values in the chlorophyll analysis. The two native plant species, both of which occur in the Brazilian Restinga, showed damage when exposed to emissions from an iron ore pelletizing factory. C. hilariana was considered the most sensitive species due to the decreased values in a higher number of variables after exposition.

Characterization of antioxidant and antiglycation properties and isolation of active ingredients from traditional chinese medicines.

There is considerable interest in the isolation of more potent antioxidant compounds to treat diseases involving oxidative stress. Thirty-three traditional Chinese medicine (TCM) extracts were examined for their antioxidant activity using the 2,2'-azinobis[3-ethylbenzothiazoline-6-sulfonate] (ABTS) assay. Five extracts with high activity (Cratoxylum cochinchinense, Cortex magnoliae officinalis, Psoralea corylifolia L, Curculigo orchioides Gaertn, and Glycyrrhiza uralensis Fisch.) were selected for further characterization. C. cochinchinense outperformed other extracts in most of the assays tested except phospholipid peroxidation inhibition, where P. corylifolia L showed higher activity. C. cochinchinense was particularly potent in inhibiting the formation of advanced glycation end products on proteins and strongly inhibited hypochlorous acid-induced DNA damage. We attempted to isolate the active ingredients from C. cochinchinense and obtained an extract (YCT) containing at least 90% mangiferin as identified by HPLC and mass spectrometry. However, YCT showed significantly higher activity in assays of phospholipid peroxidation, inhibition of protein glycation, and superoxide (O(2)(?-)) and peroxynitrite (ONOO(-)) scavenging, as compared with mangiferin, suggesting that the nonmangiferin constituents of YCT contribute to its additional antioxidant activities.

Mechanism of cell death induced by an antioxidant extract of Cratoxylum cochinchinense (YCT) in Jurkat T cells: the role of reactive oxygen species and calcium.

YCT is a semipurified extract from Cratoxylum cochinchinense that has antioxidant properties and contains mostly mangiferin. We show here that YCT is selectively toxic to certain cell types and investigate the mechanisms of this toxicity in Jurkat T cells. By flow cytometric analyses, we show that YCT causes intense oxidative stress and a rise in cytosolic Ca(2+). This is followed by a rise in mitochondrial Ca(2+), release of cytochrome c, collapse of Deltapsi(m), a fall in ATP levels, and eventually cell death. The mechanism(s) of intense oxidative stress may involve a plasma membrane redox system, as cell death is inhibited by potassium ferricyanide. Cell death has some features of apoptosis (propidium iodide staining, externalization of phosphatidylserine, limited caspase-3 and -9 activities), but there was no internucleosomal DNA fragmentation.

Proteic and phenolics compounds contents in Bacupari callus cultured with glutamine and nitrogen sources / Conteúdo de proteínas e compostos fenólicos em calos de Bacupari cultivados com glutamina e fontes de nitrogênio

Abstract In this study was evaluated the influence of glutamine supplementation on the endogenous content of amino acids, proteins, total phenolics, flavonoids and proanthocyanidins in Bacupari callus. The explants were inoculated in MS medium, MS with half concentration of the nitrogen salts (MS½) and nitrogen-free MS, supplemented with glutamine (5, 10, 30 and 60mM) named as Gln5, Gln10, Gln30 and Gln60. Amino acids and proteins were analyzed after 20, 80 and 140 days and the secondary metabolites on the 140th day. There was no difference in the amino acids on the 20th day. On the 80th day the treatments MS and MS½ presented the lowest levels. On the 140th day MS and MS½ presented the lowest amino acid concentration and Gln10 the highest. Concerning proteins, there was difference only on the 140th day, being the highest concentrations observed in Gln5, and the lowest in MS½ treatment. Total phenolics content was higher in the treatment Gln60 and lowest in MS. Treatments Gln5, Gln10, Gln30 and MS½ were statistically equal. For flavonoids, the highest values occurred in the treatments Gln30, Gln60 and MS½ and the lowest in Gln5, Gln10 and MS. Similarly, for the proanthocyanidins the highest concentrations were observed in treatment Gln60 and the lowest in Gln5 and MS. In conclusion, the treatment with 60mM of glutamine favors the protein accumulation and production of secondary metabolites in Bacupari callus.

Resumo Nesse estudo foi avaliado o efeito da suplementação com glutamina no conteúdo endógeno de aminoácidos, proteínas, fenólicos totais, flavonoides e proantocianidinas em calos de Bacupari. Os explantes foram inoculados em meio MS, meio MS com metade da concentração de dos sais de nitrogênio (MS½) e meio MS sem nitrogênio suplementado com glutamina (5, 10, 30 e 60mM) denominados como Gln5, Gln10, Gln30 e Gln60. Os aminoácidos e as proteínas foram analisados após 20, 80 e 140 dias e os metabólitos secundários no 140° dia. Não houve diferença nos aminoácidos no 20° dia. No 80° dia os tratamentos MS e MS½ apresentaram os menores níveis. No 140° dia, MS e MS½ apresentaram as menores concentrações de aminoácidos e o Gln10 as maiores. A respeito das proteínas, houve diferença apenas no 140° dia, sendo as maiores concentrações observadas nos tratamentos Gln, e as menores no MS½. O conteúdo de fenólicos totais foi maior no tratamento Gln60 e menor no MS. Os tratamentos Gln5, Gln10, Gln30 e MS½ foram estatisticamente iguais. Para os flavonóides, os maiores valores ocorreram nos tratamentos Gln30, Gln60 e MS½ e os menores no Gln5, Gln10 e MS. Da mesma forma, para as proantocianidinas, as maiores concentrações foram observadas no tratamento Gln60 os menores no Gln5 e MS. Em conclusão, o tratamento com 60 mM de glutamina favorece o acúmulo de proteínas e a produção de metabólitos secundários em calos de Bacupari.

Patchy stomatal behavior during midday depression of leaf CO2 exchange in tropical trees.

We investigated effects of heterogeneous stomatal behavior on diurnal patterns of leaf gas exchange in 10 tree species. Observations were made in middle and upper canopy layers of potted tropical rainforest trees in a nursery at the Forest Research Institute Malaysia. Measurements were taken from 29 January to 3 February 2010. We measured in situ diurnal changes in net photosynthetic rate and stomatal conductance in three leaves of each species under natural light. In both top-canopy and sub-canopy species, midday depression of net assimilation rate occurred in late morning. Numerical analysis showed that patchy bimodal stomatal behavior occurred only during midday depression, suggesting that the distribution pattern of stomatal apertures (either uniform or non-uniform stomatal behavior) varies flexibly within single days. Direct observation of stomatal aperture using Suzuki's Universal Micro-Printing (SUMP) method demonstrated midday patchy stomatal closure that fits a bimodal pattern in Shorea leprosula Miq., Shorea macrantha Brandis. and Dipterocarpus tempehes V.Sl. Inhibition of net assimilation rate and stomatal conductance appears to be a response to changes in vapor pressure deficit (VPD). Variable stomatal closure with increasing VPD is a mechanism used by a range of species to prevent excess water loss from leaves through evapotranspiration (viz., inhibition of midday leaf gas exchange). Bimodal stomatal closure may occur among adjacent stomata within a single patch, rather than among patches on a single leaf. Our results suggest the occurrence of patches at several scales within single leaves. Further analysis should consider variable spatial scales in heterogeneous stomatal behavior between and within patches and within single leaves.

Effect of Mesua ferrea Linn. flower extract on Salmonella.

Based on its traditional uses in folk medicine, the whole flower extract of Mesua ferrea Linn. was tested for its in vitro antimicrobial efficacy against five different strains of Salmonella spp. All the strains were found to be highly sensitive to the extract, MIC of the extract against each organism being 50 microg/ml. The extract was tested in vitro for its mode of antibacterial activity against S. Typhimurium NCTC 74 and it was found to be bactericidal in action. In vivo studies of this extract offered significant protection to Swiss albino mice at doses approximately 2 and 4 mg/mouse when challenged with 50 median lethal dose of S. Typhimurium NCTC 74. Further, the extract caused statistically significant reduction in viable count of the strain in liver, spleen and heart blood of challenged mice.