Antiinflammatory activity of Anthurium cerrocampanense Croat in rats and mice

Aqueous (AE), ethanol (EE) and dichloromethane (DE) extracts from the whole plant of Anthurium cerrocampanense Croat, endemic to Panama, were assayed for antiinflammatory activity by carrageenan-induced rat paw edema and croton oil-induced mouse ear edema tests. The extracts were administered i.p. and topically, respectively. The best antiinflammatory activity in the carrageenan-induced rat paw edema test, was shown by DE (31% inhibition), which did not show any irritant effect in the peritoneal examination 4 h after administration of the extracts. Furthermore, the highest activity in the croton oil-induced mouse ear edema test was also exhibited by DE (93% inhibition). Since DE was the most effective of the extracts in both tests, it's activity was assessed in various inflammation models in rats. At 100 mg/kg, DE markedly inhibited inflammation produced by dextran (66.6% inhibition) and decreased weakly the edema induced by zymosan A, carrageenan and C16-platelet activation factor (C16-PAF) (33.2, 31.6 and 23.8%, respectively). At 50 mg/kg, DE only significantly reduced the swelling caused by dextran (36.2%). No effect was observed at the same doses in arachidonic acid-induced edema. A clear dose-related antiinflammatory activity of DE was seen in the croton oil-induced mouse ear edema test, and ED50 calculated was found to be 25.5 microg/ear. which was much lower than ED50 obtained for indomethacin (56.1 microg/ear).

H2O2 causes endothelial barrier dysfunction without disrupting the arginine-nitric oxide pathway

We have previously demonstrated that nitric oxide (.NO) donors attenuate and that inhibition of endogenous nitric oxide synthase (NOS) enhances hydrogen peroxide (H2O2)-mediated porcine pulmonary artery endothelial cell (PAEC) injury. The current study investigates the hypothesis that oxidant-mediated inhibition of NOS contributes to PAEC injury. PAEC barrier function, measured as the transmonolayer clearance of albumin, was significantly impaired by H2O2 (10-100 microM) in the absence of cytotoxicity. Treatment with H2O2 did not alter NOS activity, measured as the conversion of [3H]arginine to [3H]citrulline in PAEC lysates, either immediately after treatment with 0-250 microM H2O2 for 30 min or for up to 120 min after treatment with 100 microM H2O2. H2O2 had little effect on NOS activity in intact PAECs, measured as 1) the formation of [3H]citrulline in [3H]arginine-loaded PAECs, 2) PAEC guanosine 3',5'-cyclic monophosphate content, and 3) PAEC.NO release to the culture media. These results indicate that the arginine-.NO pathway remains intact after exposure to oxidant conditions sufficient to promote functional derangements of vascular endothelial cells.

Antifungal and larvicidal meroterpenoid naphthoquinones and a naphthoxirene from the roots of Cordia linnaei

Three new meroterpenoid naphthoquinones, the known cordiaquinone B and a new naphthoxirene have been isolated from the roots of Cordia linnaei. Their structures were established by spectrometric methods including EI, D/CI and FAB mass spectrometry, 1H, 13C and 2D NMR experiments. The naphthoquinones showed activity against Cladosporium cucumerinum, Candida albicans and the larvae of the yellow fever-transmitting mosquito Aedes aegypti, while the naphthoxirene derivative was found to be inactive in the same bioassays.

Role of 8-epi PGF2alpha, 8-isoprostane, in H2O2-induced derangements of pulmonary artery endothelial cell barrier function

The non-enzymatic peroxidation product of arachidonic acid, 8-epi-PGF2alpha or 8-isoprostane (8-IP) was measured in H2O2-exposed cultured pulmonary artery endothelial cell (PAEC) monolayers using a commercially-available enzyme immunoassay kit. H2O2 (50 microM for 1-30 min) significantly increased 8-IP production in a time-dependent fashion. Treatment with higher H2O2 concentrations (100 or 250 microM) failed to further increase 8-IP generation. Determinations of thiobarbituric acid reactive substances (TBARS) and lipid hydroperoxides (LOOH) were not sufficiently sensitive to detect lipid peroxidation in PAEC exposed to 50 microM H2O2 for 15 min. 8-IP (100 pM-500 nM for 2 h) caused PAEC monolayer barrier dysfunction measured as the transmonolayer clearance of albumin without causing significant PAEC cytotoxicity (measured as intracellular lactate dehydrogenase release). This is the first report to provide evidence that 8-IP generated in H2O2-exposed PAEC contributes to oxidant-mediated alterations in monolayer barrier function at non-cytotoxic concentrations.

Cardiac hypertrophy: old concepts, new perspectives

Growth of the heart in hypertrophy is accompanied by changes in the phenotypic expression of cardiac genes. To explore the molecular basis of cardiac hypertrophy, we have analyzed the regulation of myosin heavy chain gene (MHC) expression. In one set of experiments, pressure overload on the rat heart was produced by constriction of the abdominal aorta. Changes in the alpha and beta-MHC mRNA were then studied in overloaded hearts and following load removal. Pressure overload resulted in down-regulation of the alpha-MHC with corresponding up-regulation of the steady state level of beta-MHC mRNA. Load removal (debanding) resulted in regression of cardiac hypertrophy and a rapid return of alpha-MHC mRNA to normal values. In contrast, the recovery in beta-MHC mRNA was much slower to the extent that it remained substantially elevated compared to respective sham controls even after 7 weeks of post-debanding. These results suggest that putative load-related signals independently regulate two genes. Several lines of evidence indicate that adrenergic nervous system plays an important role in the induction and maintenance of cardiac hypertrophy and in the redistribution of myosin isoforms. We have analyzed the effect of cAMP inducing agents on the regulation of alpha-MHC gene in primary cultures of the fetal (18 day) rat cardiac myocyte. Inclusion of 8 Br-cAMP in the culture media increased the expression of alpha-MHC promoter/reporter construct comprising of 2.9 kb upstream sequence of the alpha-MHC gene. Several deletion mutations in the alpha-MHC gene promoter defined the cAMP responsive boundaries to be a 32 bp region comprising of -71 to -40 bp sequences. Deletion of this region resulted in loss of cAMP response as well as in basal expression of alpha-MHC promoter/reporter construct. These data suggest a role of beta-adrenergic pathway in the modulation of alpha-MHC gene expression.

Oleic acid reduces oxidant stress in cultured pulmonary artery endothelial cells

Altering the fatty acid composition of cultured porcine pulmonary artery endothelial cells (PAEC) modulates their susceptibility to oxidant stress. This study demonstrates that supplementing PAEC with oleic acid (18:1 omega 9), but not gamma-linolenic acid (18:3 omega 6), provided dose-dependent protection from hydrogen peroxide (H2O2)-induced cytotoxicity. It was hypothesized that 18:1 reduced PAEC susceptibility to oxidant stress by altering H2O2 metabolism. To test this hypothesis, confluent PAEC monolayers were treated with 100-200 microM H2O2 or control conditions 24 h after supplementation with 0.1 mM 18:1, 18:3, or vehicle for 3 h. Intracellular [H2O2] in control cells (14.4-29.0 pM), estimated from the rate of aminotriazole-mediated inactivation of endogenous catalase activity, increased following treatment with 200 microM H2O2 (19.0-37.3 pM). Supplementation with 18:1 attenuated increases in intracellular [H2O2] only in oxidant-exposed cells, whereas supplementation with 18:3 attenuated intracellular [H2O2] only in control cells. Supplementation with 18:1 or 18:3 tended to reduce or enhance PAEC lipid hydroperoxide content following H2O2 exposure, respectively, but did not alter PAEC reduced glutathione content, the activities of glutathione peroxidase or catalase, or H2O2 uptake and release. Alteration of H2O2 metabolism in cultured PAEC may contribute to the ability of fatty acids to modulate cellular oxidant susceptibility.

Transcription enhancer factor 1 interacts with a basic helix-loop-helix zipper protein, Max, for positive regulation of cardiac alpha-myosin heavy-chain gene expression

The M-CAT binding factor transcription enhancer factor 1 (TEF-1) has been implicated in the regulation of several cardiac and skeletal muscle genes. Previously, we identified an E-box-M-CAT hybrid (EM) motif that is responsible for the basal and cyclic AMP-inducible expression of the rat cardiac alpha-myosin heavy chain (alpha-MHC) gene in cardiac myocytes. In this study, we report that two factors, TEF-1 and a basic helix-loop-helix leucine zipper protein, Max, bind to the alpha-MHC EM motif. We also found that Max was a part of the cardiac troponin T M-CAT-TEF-1 complex even when the DNA template did not contain an apparent E-box binding site. In the protein-protein interaction assay, a stable association of Max with TEF-1 was observed when glutathione S-transferase (GST)-TEF-1 or GST-Max was used to pull down in vitro-translated Max or TEF-1, respectively. In addition, Max was coimmunoprecipitated with TEF-1, thus documenting an in vivo TEF-1-Max interaction. In the transient transcription assay, overexpression of either Max or TEF-1 resulted a mild activation of the alpha-MHC-chloramphenicol acetyltransferase (CAT) reporter gene at lower concentrations and repression of this gene at higher concentrations. However, when Max and TEF-1 expression plasmids were transfected together, the repression mediated by a single expression plasmid was alleviated and a three- to fourfold transactivation of the alpha-MHC-CAT reporter gene was observed. This effect was abolished once the EM motif in the promoter-reporter construct was mutated, thus suggesting that the synergistic transactivation function of the TEF-1-Max heterotypic complex is mediated through binding of the complex to the EM motif. These results demonstrate a novel association between Max and TEF-1 and indicate a positive cooperation between these two factors in alpha-MHC gene regulation.

Nitric oxide attenuates hydrogen peroxide-mediated injury to porcine pulmonary artery endothelial cells

To examine the role of nitric oxide (.NO) in vascular endothelial cell injury, cultured porcine pulmonary artery endothelial cells (PAEC) were treated with H2O2 (100-500 microM) for 30 min in the presence or absence of the .NO donors (+/-)S-nitroso-N-acetylpenicillamine (SNAP) or diethylamine nitric oxide (DEANO). H2O2 caused dose-dependent PAEC cytotoxicity detected 2 h after H2O2 treatment as the release of lactate dehydrogenase. SNAP (100 microM) and DEANO (100 microM) attenuated H2O2-induced cytotoxicity if present during H2O2 treatment. In contrast, restricting treatment with .NO donors to periods before (30 min) or after (2 h) incubation with H2O2 did not prevent PAEC injury. Furthermore, the .NO synthase inhibitor NG-nitro-L-arginine methyl ester (1 mM) sensitized PAEC to H2O2-induced injury. SNAP also attenuated H2O2-induced PAEC lipid peroxidation even if restricted to periods before or after exposure to H2O2. Thus, although .NO effectively attenuated H2O2-mediated PAEC lipid peroxidation and cytotoxicity, these effects were clearly dissociated, suggesting that the antiperoxidative effects of .NO are not sufficient to account for its cytoprotective properties.

Exogenous fatty acids modulate the functional and cytotoxic responses of cultured pulmonary artery endothelial cells to oxidant stress

We previously reported that supplementation with exogenous fatty acids modulated the susceptibility of cultured pulmonary artery endothelial cells (PAEC) to oxidant-mediated cytotoxicity. The current study investigates the effects of fatty acids with increasing degrees of unsaturation on oxidant-mediated dysfunction and cytotoxicity in cultured porcine pulmonary artery and aortic endothelial cells (AEC). Monolayers supplemented with 0.1 mmol/L oleic (18:1), linoleic (18:2), or gamma-linolenic (18:3) acids were exposed to oxidant stress (100 mumol/L hydrogen peroxide (H2O2)) or to control conditions for 30 minutes. Gas chromatographic analysis of the PAEC fatty acids confirmed incorporation of supplemental fatty acids into PAEC lipids. Cytotoxicity, measured as the release of intracellular lactate dehydrogenase (LDH), and PAEC monolayer barrier function, assessed by measuring the monolayer clearance of Evans blue dye bound to albumin, were determined for 1 to 3 hours after oxidant stress. The PAEC and AEC demonstrated comparable responses to H2O2. Hydrogen peroxide caused increases in monolayer permeability and detachment of cells from the monolayer that were most attenuated by supplementation with 18:2 or 18:3, and to a lesser degree with 18:1. In contrast, H2O2-mediated LDH release was attenuated by supplementation with 18:1, whereas 18:2 and 18:3 potentiated cytotoxicity after exposure to H2O2. These results indicate that the relationship between PAEC lipid composition and oxidant susceptibility is complex and that the extent of fatty acid unsaturation does not predict the functional or cytotoxic responses of PAEC to oxidant stress. Furthermore, these results suggest that functional derangements may not correlate with traditional assays of cytotoxicity induced by oxidant injury in cultured endothelium.

Catecholamines and cardiac growth

The present knowledge concerning the alpha- and beta-adrenergic systems in the regulation of cardiac growth and gene expression is reviewed. To investigate the mechanism by which cAMP regulates the expression of cardiac genes we have used cultured myocytes derived from fetal rat hearts. We have shown previously that the addition of Br cAMP to the culture medium produced an increase in alpha-myosin heavy chain (alpha-MHC) mRNA level, in its rate of transcription as well as in the amount of V1 isomyosin. To characterize the promoter element(s) involved in cAMP responsive regulation of alpha-MHC expression we performed transient transfection analysis with a series of alpha-MHC gene promoter-CAT constructs. We have identified a 13 bp E-box/M-CAT hybrid motif (EM element) which conferred a basal muscle specific and cAMP inducible expression of the alpha-MHC gene. Using mobility shift assay we have documented that one of the EM element binding protein is TEF-1. Moreover, by incubating cardiac nuclear extracts with the catalytic subunit of PK-A we have found that factor(s) binding to the EM element is a substrate for cAMP dependent phosphorylation.

Sympathetic control of cardiac myosin heavy chain gene expression

Several neuroendocrine factors have been shown to influence the muscle phenotype. Various physiological reports have suggested the role of adrenergic nervous system for cardiac myosin heavy chain (MHC) expression. We have used cultured fetal rat heart myocytes to investigate the role of cAMP on the alpha- and beta-MHC gene expression. In low density cultures, addition of 1 mM 8 Br cAMP resulted in up regulation of alpha-MHC and down regulation of beta-MHC mRNA. This antithetic effect of cAMP depends on the basal expression of both expression of both MHC transcripts. In transient transfection analysis employing a series of alpha-MHC gene promoter/reporter constructs, we identified a 13 bp E-box M-CAT hybrid motif (EM element) which conferred a basal muscle specific and cAMP-inducible expression of the alpha-MHC gene. Data obtained from the mobility gel-shift analysis indicated that one of the factor(s) binding to the EM element is related to troponin T M-CAT binding factor (TEF-1). To test whether the protein binding to this sequence could be a substrate for cAMP-dependent phosphorylation, the cardiac nuclear proteins were preincubated in a kinase reaction buffer either with a catalytic subunit of PKA (CatPKA) or with cAMP, and binding activity of proteins to the EM element was evaluated by mobility gel shift assay. In a concentration dependent manner, a twofold increase in the intensity of the retarded band was observed. Furthermore, at 100 units of CatPKA, an additional band of faster mobility was observed which was not present either when phosphorylated nuclear extract was incubated with alkaline phosphatase or when ATP was absent in kinase reaction buffer. These results strongly suggest that factor(s) binding to the EM element is a substrate for cAMP dependent phosphorylation.

Substituted quinazolinones and their anti-inflammatory activity

6-Substituted-2-alkyl-3-(4-aminobenzene sulphonamido)quinazolin-4-(3H) ones (1a-b) were converted either to 2-methyl 3-[(N-aminoacylbenzoate)benzenes sulphonamido]quinazolin-4 (3H) ones (2a-c) or to 6-substituted-2-alkyl-3-(N-arylidene benzene sulphonamido)-quinazolin-4- (3H) ones (3a-h). 3 on reduction, yielded 6-substituted-2-alkyl-3-(N-arylmethyl sulphonamido)-quinazolin-4(3H)ones (4a-l). Reaction of 3a-h with thioglycolic acid afforded 2-alkyl-3-[4'-(5'-arylthiazolidin-3'-one)benzene sulphonamido]quinazolin-4(3H)ones (5a-h). All these compounds were evaluated for their anti-inflammatory activity against carrageenin induced rat's paw oedema. Active compounds were also evaluated for ulcerogenic liability and ALD50 values.

Natural product drug discovery and development: new perspectives on international collaboration

Until recently, the prevailing attitude in developed nations regarded the world's genetic resources, which are mainly concentrated in the developing world, as a common resource of humankind, to be exploited freely irrespective of national origin. With the devastation being wreaked in the tropical rainforests and the resurgence in interest in recent years in the discovery of novel drugs from natural sources, particularly plants and marine organisms, the international scientific community has realized that the conservation of these global genetic resources and the indigenous knowledge associated with their use are of primary importance if their potential is to be fully explored. With this realization has come a recognition that these goals must be achieved through collaboration with, and fair and equitable compensation of, the scientists and communities of the genetically rich source countries. The signing of the United Nations Convention on Biological Diversity by nearly all of the World's nations has emphasized the need for the implementation of such policies. In this review, the articles of the Convention of relevance to the activities and practices of the natural products scientific community are briefly discussed. This discussion is followed by a summary of policies for international collaboration and compensation being implemented by several developed country organizations, and the perspectives on the current developments given by representatives of some of the source countries located in the regions of greatest biodiversity.

Cytotoxic biflavonoids from Selaginella willdenowii

Bioactivity-guided fractionation of the leaves of Selaginella willdenowii afforded three known biflavones, 4',7"-di-O-methylamentoflavone, isocryptomerin and 7"-O-methylrobustaflavone, that were significantly cytotoxic against a panel of human cancer cell lines. Non-cytotoxic isolates were also obtained, namely, amentoflavone, bilobetin, robustaflavone and 2",3"-dihydroisocryptomerin, a new dihydrobiflavone. The structure for the new biflavonoid was unambiguously assigned by a combination of spectroscopic methods.

Antifungal principles of Baccharis pedunculata

Four compounds including a flavone, an acetylenic lactone, a prenylated coumarin, and a 3-methyl ether flavone were isolated from the dichloromethane leaf extract of Baccharis pedunculata (Mill.) Cabr. (Asteraceae). The latter three compounds were identified to be responsible for the antifungal activity against some human pathogenic and phytopathogenic fungi. The most active compound, lachnophyllum lactone, an acetylenic lactone, showed a very high toxicity (LD50 2 micrograms/ml) against human keratinocytes.

Dynamics of educational development in the Chhattisgarh region, India

"The aim of this paper is to analyse the spatial patterns of the level of educational development along with the decennial change in the literacy rate in the Chhattisgarh region of Madhya Pradesh State [India]. Eleven variables...have been considered to find out the index of educational development in the tahsils [divisions] of the region. The eighty two tahsils...are grouped into four categories...on the basis of decennial growth rate in literacy during 1981-91 and the level of educational development...."

Xanthine oxidase inhibitory activity of some Panamanian plants from Celastraceae and Lamiaceae

Thirty four crude extracts of Panamanian plants, from nine species of Celastraceae and Lamiaceae, were assayed for xanthine oxidase (XO) inhibitory activity. The enzymatic activity was estimated by measuring the increase in absorbance at 290 nm due to uric acid formation. Eighty five percent of the crude extracts were found to possess XO inhibitory activity at 50 micrograms/ml and all the extracts of the species from Lamiaceae were active even at 1 micrograms/ml. The ethanol extracts of Hyptis obtusiflora Presl ex Benth. (Lamiaceae) and H. lantanaefolia Poit. (Lamiaceae) exhibited the highest activity with an inhibition of approximately 40% at 1 micrograms/ml.

Bio-active compounds from Psychotria camponutans

A new benzoquinone (1-hydroxybenzoisochromanquinone) and benz [g]isoquinoline-5, 10-dione have been isolated from the woody parts of Psychotria camponutans, as a result of bioactivity-guided fractionation. The compounds were characterized by UV, IR, EI-mass, 1H-, and 13C-NMR, and HETCOR NMR spectroscopy. Both compounds, together with acetylbenzoisochromanquinone, showed in vitro strong activity against brine shrimp, KB cells, and chloroquine-resistant P. falciparum.

Bioactive anthraquinone glycosides from Picramnia antidesma spp. fessonia

A bioactivity guided fractionation, using KB cells and brine shrimp assays, of the methanolic extract from the leaves of Picramnia antidesma yielded two known anthraquinones, aloe-emodin and aloe-emodin anthrone, and three new aloe-emodin C-glycosides, named picramnioside A, picramnioside B and picramnioside C. Structures were established by spectroscopic methods (UV, IR, mass spectrometry, 1H and 13C and 2D NMR including COSY 45, HMQC, HMBC and ROESY). CD was used to establish the absolute configuration of the picramniosides.

Demonstration of glutathione peroxidase in rat liver peroxisomes and its intraorganellar distribution

Earlier, we reported that rat liver peroxisomes contain Cu-Zn superoxide dismutase (J. Biol. Chem. 267, 6870), thereby suggesting a new antioxidant role for this organelle in free radical metabolism. In this study, we report for the first time that mammalian peroxisomes also contain glutathione peroxidase. Using highly purified rat liver peroxisomes isolated by Nycodenz gradient, we found that peroxisomes contain glutathione peroxidase which shows enzymatic activity with different substrates such as hydrogen peroxide, cumene hydroperoxide, and t-butyl hydroperoxide. This activity could be inhibited in vitro by mercaptosuccinate. Western blot analysis revealed that peroxisomes from control and ciprofibrate-treated livers show immunoreactive bands with antibodies raised against glutathione peroxidase. The intraperoxisomal distribution of glutathione peroxidase was investigated by using peroxisomal membrane and matrix proteins. The results revealed that glutathione peroxidase is a matrix enzyme. The presence of glutathione peroxidase in peroxisomes provides an alternate enzyme system responsible for the degradation of organic peroxides and the degradation of H2O2 under conditions in which catalase is inactivated (e.g., ischemia-reperfusion and endotoxemia). These findings suggest that glutathione peroxidase in peroxisomes may play a novel role in the cellular antioxidant responses to various oxidative stress conditions.

Pharmacological and phytochemical studies of Cephäelis axillaris

The most significant effect, observed in the preliminary pharmacological evaluation of the whole ethanol extract and the alkaloidal fraction of Cephäelis axillaris, was the hyperemia of ears and external mucosas which was most probably due to an alpha-adrenergic blocking activity. In addition, both samples also induced a marked hypotension in normotensive as well as hypertensive (SHR) rats and inhibited the increases of blood pressure induced by i.v. administration of noradrenaline in pithed rats. The structures of the major alkaloidal components of the extract were elucidated on the basis of chemical characterization assays and IR, UV, 1H and 13C one and two-dimensional NMR analyses.