Marine degradation and ecotoxicity of conventional, recycled and compostable plastic bags

Plastic bags are currently a major component of marine litter, causing aesthetical nuisance, and undesirable effects on marine fauna that ingest them or are entangled. Plastic litter also rises concern on the ecotoxicological effects due to the potential toxicity of the chemical additives leached in aquatic environments. Conventional plastic bags are made of polyethylene, either from first use or recycled, but regulations restricting single-use plastics and limiting lightweight carrier bags (<50 μm thickness) have fostered the replacement of thin PE bags by compostable materials advertised as safer for the environment. In this study, we assess the degradation of commercially available plastic bags in marine conditions at two scales: aquariums (60 days) and outdoors flow-through mesocosm (120 days). Strength at break point and other tensile strength parameters were used as ecologically relevant endpoints to track mechanical degradation. Ecotoxicity has been assessed along the incubation period using the sensitive Paracentrotus lividus embryo test. Whereas PE bags did not substantially lose their mechanical properties within the 60 d aquarium exposures, compostable bags showed remarkable weight loss and tensile strength decay, some of them fragmenting in the aquarium after 3-4 weeks. Sediment pore water inoculum promoted a more rapid degradation of compostable bags, while nutrient addition pattern did not affect the degradation rate. Longer-term mesocosms exposures supported these findings, as well as pointed out the influence of the microbial processes on the degradation efficiency of compostable/bioplastic bags. Compostable materials, in contrast toPE, showed moderate toxicity on sea-urchin larvae, partially associated to degradation of these materials, but the environmental implications of these findings remain to be assessed. These methods proved to be useful to classify plastic materials, according to their degradability in marine conditions, in a remarkably shorter time than current standard tests and promote new materials safer for the marine fauna.

Improving the 3D Printability and Mechanical Performance of Biorenewable Soybean Oil-Based Photocurable Resins

The general requirement of replacing petroleum-derived plastics with renewable resources is particularly challenging for new technologies such as the additive manufacturing of photocurable resins. In this work, the influence of mono- and bifunctional reactive diluents on the printability and performance of resins based on acrylated epoxidized soybean oil (AESO) was explored. Polyethylene glycol di(meth)acrylates of different molecular weights were selected as diluents based on the viscosity and mechanical properties of their binary mixtures with AESO. Ternary mixtures containing 60% AESO, polyethylene glycol diacrylate (PEGDA) and polyethyleneglycol dimethacrylate (PEG200DMA) further improved the mechanical properties, water resistance and printability of the resin. Specifically, the terpolymer AESO/PEG575/PEG200DMA 60/20/20 (wt.%) improved the modulus (16% increase), tensile strength (63% increase) and %deformation at the break (21% increase), with respect to pure AESO. The enhancement of the printability provided by the reactive diluents was proven by Jacobs working curves and the improved accuracy of printed patterns. The proposed formulation, with a biorenewable carbon content of 67%, can be used as the matrix of innovative resins with unrestricted applicability in the electronics and biomedical fields. However, much effort must be done to increase the array of bio-based raw materials.

Printability Study of a Conductive Polyaniline/Acrylic Formulation for 3D Printing

There is need for developing novel conductive polymers for Digital Light Processing (DLP) 3D printing. In this work, photorheology, in combination with Jacobs working curves, efficaciously predict the printability of polyaniline (PANI)/acrylate formulations with different contents of PANI and photoinitiator. The adjustment of the layer thickness according to cure depth values (C_d) allows printing of most formulations, except those with the highest gel point times determined by photorheology. In the working conditions, the maximum amount of PANI embedded within the resin was ≃3 wt% with a conductivity of 10^-5 S cm^-1, three orders of magnitude higher than the pure resin. Higher PANI loadings hinder printing quality without improving electrical conductivity. The optimal photoinitiator concentration was found between 6 and 7 wt%. The mechanical properties of the acrylic matrix are maintained in the composites, confirming the viability of these simple, low-cost, conductive composites for applications in flexible electronic devices.

Ethanolic extract of Artemisia campestris subsp. glutinosa (Besser) Batt. inhibits HIV-1 replication in vitro through the activity of terpenes and flavonoids on viral entry and NF-κB pathway

ETHNO-PHARMACOLOGICAL RELEVANCE

The genus Artemisia spp. is well known for its anti-infectious properties and its high content in anti-infectious compounds, like the well-known sweet wormwood (Artemisia annua L.). Another Artemisia species, Artemisia campestris subsp. glutinosa (Besser) Batt., field wormwood, has been traditionally used as medicinal plant in the Mediterranean region.

AIM OF THE STUDY

The aim of this study is to investigate the anti-HIV activity of field wormwood, to identify the compounds responsible for this activity and their structure and mechanism of action.

MATERIALS AND METHODS

Antiviral activity of isolated compounds and extracts was evaluated in HIV-1 infections of lymphoblastoid cells. We also evaluated the mechanism of action of isolated compounds. Viral entry was studied comparing the inhibitory effect of isolated compounds on wild type HIV-1 and VSV pseudotyped HIV-1. To assess the viral transcriptional effect, plasmids encoding luciferase reporter genes under the control of the whole genome of HIV-1 or NF-κB or Sp1 transcription factors were transfected in the presence of the compounds under evaluation. Finally, antioxidant activity was assessed by quantitation of reduced and total glutathione in treated cell cultures.

RESULTS

Ethanolic and aqueous extracts of Artemisia campestris subsp. glutinosa (Besser) Batt. subsp. glutinosa displayed anti-HIV activity in vitro, although ethanolic extract was more powerful (IC₅₀ 14.62 μg/mL). Bio-guided ethanolic extract fractionation leads to the isolation and characterization of two terpenes, damsin and canrenone, and four flavonoids, 6, 2', 4'-trimethoxyflavone, acerosin, cardamonin and xanthomicrol. All the isolated compounds inhibited HIV-1 replication in vitro with IC₅₀ values between the middle nanomolar and the low micromolar range. Their anti-HIV mechanism of action is due to the bloking of viral entry and/or transcription inhibition, without correlation with the antioxidant activity, through interference with the cellular transcription factors NF-κB and Sp1, which are targets that are not currently reached by antiretroviral therapy.

CONCLUSION

We describe here the anti-HIV activity of field wormwood, Artemisia campestris subsp. glutinosa (Besser) Batt., and the isolation and study of the mechanism of action of two terpenes and four flavonoids, responsible, at least in part, for its activity, through the inhibition of two different cellular targets affecting the HIV replication cycle. The activity of these compounds in cellular targets could explain why plant extracts can be used in the treatment of different diseases. Besides, the presence of several compounds with dual and different mechanisms of action could prove useful in the treatment of HIV-1 infection, since it could aid to overcome drug resistances and simplify drug therapy. This work is a further step in understanding the anti-infectious activity of wormwood species and their use in treating infectious diseases.

Chitosan and Kappa-Carrageenan Vaginal Acyclovir Formulations for Prevention of Genital Herpes. In Vitro and Ex Vivo Evaluation

Vaginal formulations for the prevention of sexually transmitted infections are currently gaining importance in drug development. Polysaccharides, such as chitosan and carrageenan, which have good binding capacity with mucosal tissues, are now included in vaginal delivery systems. Marine polymer-based vaginal mucoadhesive solid formulations have been developed for the controlled release of acyclovir, which may prevent the sexual transmission of the herpes simplex virus. Drug release studies were carried out in two media: simulated vaginal fluid and simulated vaginal fluid/simulated seminal fluid mixture. The bioadhesive capacity and permanence time of the bioadhesion, the prepared compacts, and compacted granules were determined ex vivo using bovine vaginal mucosa as substrate. Swelling processes were quantified to confirm the release data. Biocompatibility was evaluated through in vitro cellular toxicity assays, and the results showed that acyclovir and the rest of the materials had no cytotoxicity at the maximum concentration tested. The mixture of hydroxyl-propyl-methyl-cellulose with chitosan- or kappa-carrageenan-originated mucoadhesive systems that presented a complete and sustained release of acyclovir for a period of 8–9 days in both media. Swelling data revealed the formation of optimal mixed chitosan/hydroxyl-propyl-methyl-cellulose gels which could be appropriated for the prevention of sexual transmission of HSV.

A mouse model to study the alterations in haemostatic and inflammatory parameters induced by Lonomia achelous caterpillar haemolymph

A mouse model was established to reproduce the haemorrhagic syndrome which occurs in humans after accidental contact with the hairs of the caterpillar Lonomia achelous (LA) and measures the haemostatic and inflammatory alterations that occur as a result of this contact. Mice were injected intradermally with different doses (0.4, 0.8 and 1.6 mg/animal) of L. achelous haemolymph (LAH). Haematological (haemoglobin, haematocrit, platelet count, differential leukocyte count), haemostatic (fibrinogen, plasminogen, factor XIII [FXIII], fibrinolytic activity) and inflammatory parameters (tumour necrosis factor alpha [TNF-α], nitric oxide [NO]) were measured at different times up to 48 h. C57BL/6 mice responded to LAH injection, in terms of these parameters, in a manner similar to that seen in humans, whereas the BALB/c mice were unresponsive. In C57BL/6 mice injected with LAH, time course measurements showed: a) a reduction in the haemoglobin, haematocrit, fibrinogen, FXIII and plasminogen levels, b) no effect on the platelet count and c) immediate leukocytosis and an increase in the fibrinolytic activity in plasma. An inflammatory response (TNF-α) was observed within 1 h post-injection, followed by a more persistent increase in serum NO. These findings suggest that C57BL/6 mice represent a useful model of the haemorrhagic syndrome observed in humans who have suffered contact with the caterpillar, permitting a deeper understanding of the role of the inflammatory response in the haematological and haemostatic manifestations of this syndrome.

Ellagitannins from Tuberaria lignosa as entry inhibitors of HIV

Screening of plants from the Iberian Peninsula for anti-human immunodeficiency virus (-HIV) activity revealed that aqueous extract of Tuberaria lignosa gave positive results. Following an activity-guided procedure, the crude extract was counterextracted, and the subsequent fractions obtained tested for their anti-HIV activity in vitro. The bioassay-guided fractionation of the extract afforded an ellagitannin enriched fraction (EEF) isolated for the first time from this species. This EEF exhibited antiviral activity against HIV in MT-2 infected cells, with an IC(50) value of 2.33mug/ml (selectivity index greater than 21). Inhibition of HIV infection by EEF appears to be mediated by CD4 down-regulation, the main receptor for HIV entry. CXCR4 and CCR5 receptors were not affected by EEF, explaining why EEF is able to inhibit R5 and X4 infections.

Preliminary study of the anti-inflammatory activity of hexane extract and fractions from Bursera simaruba (Linneo) Sarg. (Burseraceae) leaves

Bursera simaruba (L.) Sarg. leaves hexane extracts display anti-inflammatory activity on the adjuvant-carrageenan-induced inflammation in rats. In order to isolate and identify the active compounds of the hexane extract, we performed a preliminary phytochemical study and a bioassay-directed fractionation using the carrageenan-induced paw oedema test in mice. From the nine fractions (A-I) obtained, of an initial chromatographic separation, fractions A and E (doses equivalents to 1.50 g dry plant/kg body weight) showed the strongest anti-inflammatory activity comparable to that of the reference drug phenylbutazone (80 mg/kg). The isolation and characterization of 3-methylene-7,11,15-trimethylhexadec-1-ene (neophytadiene) (1), ergost-5-en-3beta-ol (2), 24S-stigmast-5,22E-dien-3beta-ol (3), 24S-stigmast-5-en-3beta-ol (4) and alpha-amyrin (5), from these fractions is reported.

COX-2 and sPLA2 inhibitory activity of aqueous extract and polyphenols of Rhizophora mangle (red mangrove)

The aqueous extract of Rhizophora mangle bark and its polyphenolic fractions showed remarkable in vitro antiinflammatory activity in a preliminary study. The low molecular weight fraction exhibited cyclooxygenase-2 inhibitory activity while the total aqueous extract and the low molecular weight fraction showed secretory phospholipase A(2) inhibitory activity.

Anti-inflammatory activity of four Bolivian Baccharis species (Compositae)

Hexanic, dichloromethanic, ethanolic and aqueous extracts from Baccharis obtusifolia HBK, Baccharis latifolia (R. et P.) Pers., Baccharis pentlandii D.C. and Baccharis subulata Wedd., plants used in the traditional medicine of South America have been studied for their in vitro anti-inflammatory activity in cellular systems. Calcium ionophore A23187-stimulated mouse peritoneal macrophages were validated as a source of cyclooxygenase-1 (COX-1) (prostaglandin E2, PGE2) and 5-lipoxygenase (5-LOX) (leukotriene C4, LTC4), and mouse peritoneal macrophages stimulated with Escherichia coli lipopolysaccharide (LPS) were used for testing cyclooxygenase-2 (COX-2) (PGE2), nitric oxide (NO) and tumour necrosis factor-alpha (TNF-alpha) activity. Most of the extracts tested were active in all assays.

Screening of selected plant extracts for in vitro inhibitory activity on human immunodeficiency virus

As part of our screening of anti-AIDS agents from natural sources, extracts of 15 medicinal plants widely used in the folk medicines of North America and Europe were evaluated in vitro. Most of the extracts tested were relatively nontoxic to human lymphocytic MT-2 cells, but only the extracts of Hysopp officinalis and Dittrichia viscosa exhibited anti-HIV activity in an in vitro MTT assay. The 50% hydroalcohol extract of Hysopp officinalis and the aqueous extract of Dittrichia viscosa showed inhibitory effects against HIV-1 induced infections in MT-2 cells at concentrations ranging from 50 to 100 microg/mL and 25 to 400 microg/mL, respectively. Both extracts showed no appreciable cytotoxicity at these concentrations.

Effects of six diterpenes on macrophage eicosanoid biosynthesis

Six diterpenes (three clerodanes, two abietanes and one rosane) were tested for interactions with the cyclooxygenase and 5-lipoxygenase pathways of arachidonate metabolism and for effects of nitric oxide production. Two abietane diterpenes, aethiopinone and 11,12-dihydroxy-6-oxo-8,11,13-abietatriene and the rosane lagascatriol showed a remarkable effect on COX-1 pathway of PGE2 release in calcium ionophore A23187-stimulated peritoneal macrophages. Only the two latter diterpenes showed inhibition on COX-2 pathway of PGE2 release in E. coli LPS-stimulated peritoneal macrophages. In addition, all compounds assayed were inhibitors of LTC4 release with IC50 < or = 10 microM. Clerodane diterpenes were inactive in COX assay. None of the diterpenes assayed, except 11,12-dihydroxy-6-oxo-8,11,13-abietatriene, affected NO production. The results obtained suggest that the cellular mechanisms of action of some of these substances may involve inhibition of cyclooxygenase/lipoxygenase pathways and nitric oxide production.

Anti-HIV activity of medicinal plant extracts

As part of our screening of anti-AIDS agents from natural sources, ethanolic and aqueous extracts of 15 medicinal plants widely used in the folk medicine of the Iberian Peninsula were evaluated in vitro. Most of the extracts tested were relatively nontoxic to human lymphocytic MT-2 cells, but only the extracts of Tuberaria lignosa and Sanguisorba minor magnolii exhibited anti-HIV activity in an in vitro MTT assay. The aqueous extracts of these plants showed inhibitory effects against HIV-1 induced infections in MT-2 cells at concentrations ranging from 12.5 to 50 microg/ml and 50 microg/ml, respectively. Both extracts showed no appreciable cytotoxicity at these concentrations.

Effects of furocoumarins from Cachrys trifida on some macrophage functions

Phytochemical and biological studies aimed at the discovery and development of novel antiinflammatory agents from natural sources have been conducted in our laboratory for a number of years. In this communication, three naturally occurring furocoumarins (imperatorin, isoimperatorin and prantschimgin) were evaluated as potential inhibitors of some macrophage functions involved in the inflammatory process. These furocoumarins have been tested in two experimental systems: ionophore-stimulated mouse peritoneal macrophages serve as a source of cyclooxygenase-1 and 5-lipoxygenase, and mouse peritoneal macrophages stimulated with E. coli lipopolysaccharide are the means of testing for anti-cyclooxygenase-2 and nitric-oxidesynthase activity. All above-mentioned furocoumarins showed significant effect on 5-lipoxygenase (leukotriene C4) with IC50 values of < 15 microM. Imperatorin and isoimperatorin exhibited strong-to-medium inhibition on cyclooxygenase-1- and cyclooxygenase-2-catalysed prostaglandin E2 release, with inhibition percentages similar to those of the reference drugs, indometacin and nimesulide, respectively. Of the three furocoumarins, only imperatorin caused a significant reduction of nitric oxide generation. Imperatorin and isoimperatorin can be classified as dual inhibitors, since it was evident that both cyclooxygenase and lipoxygenase pathways of arachidonate metabolism were inhibited by these compounds. However, selective inhibition of the 5-lipoxygenase pathway is suggested to be the primary target of action of prantschimgin.

Influence of prime-probe stimulus onset asynchrony and prime precuing manipulations on semantic priming effects with words in a lexical-decision task

The present research examines semantic priming from attended and unattended parafoveal words. Participants made a lexical decision in response to a single central target. The target was preceded by two parafoveal prime words, with one of them (the attended prime) being precued by a peripheral cue. The main variables manipulated across experiments were cue informativeness (valid vs. neutral cues) and stimulus onset asynchrony (SOA) between prime and probe (200, 300, 600, or 1,000 ms). The results showed (a) reliable semantic priming from both attended and ignored prime words and (b) that the ignored priming effects were either negative or positive, depending on both the prime-probe SOA and cue informativeness. The present findings are discussed in relation to inhibitory versus episodic retrieval models of negative priming.

Search for antiviral activity in higher plant extracts

In the course of our search for plant natural products as antiviral agents, extracts of ten plants from the Iberian Peninsula were tested for antiviral activity against herpes simplex type I (HSV-1), vesicular stomatitis virus (VSV) and poliovirus type 1. Aqueous extracts of five of these medicinal plants, namely Nepeta nepetella (150-500 microg/mL), Nepeta coerulea (150-500 microg/mL), Nepeta tuberosa (150-500 microg/mL), Dittrichia viscosa (50-125 microg/mL) and Sanguisorba minor magnolii (50-125 microg/mL), showed a clear antiviral activity against two different DNA and RNA viruses, i.e. HSV-1 and VSV. Only the medicinal plant Dittrichia viscosa was active against an additional virus, poliovirus type 1.

In vitro anti-inflammatory activity of iridoids and triterpenoid compounds isolated from Phillyrea latifolia L

Two iridoids, oleuropeoside and ligustroside, and two triterpenoid compounds, oleanolic acid and ursolic acid, have been isolated from the leaves of Phillyrea latifolia L. (Oleaceae). These compounds were tested for interactions with the cyclooxygenase (COX) and 5-lipoxygenase (5-LOX) pathways of arachidonate metabolism in calcium ionophore-stimulated mouse peritoneal macrophages and human platelets, and for their effect on cell viability. Structure-activity relationships obtained for in vitro screening results were discussed. These compounds are capable of exerting inhibitory actions on enzymes of the arachidonate cascade. All compounds assayed showed a significant effect on prostaglandin E2 (PGE2)-release, with inhibition percentages similar to the reference drug indomethacin (IC50 = 0.95 microM). The IC50 values of the active compounds are: oleuropeoside 47 microM, ligustroside 48.53 microM, oleanolic acid 23.51 microM and ursolic acid 60.91 microM. In the leukotriene C4 (LTC4)-assay, only oleanolic acid showed a significant effect (IC50 = 16.79 microM). We also investigated the action of compounds on thromboxane B2 (TXB2)-release induced by calcium ionophore in human platelets. Of all the tested compounds, only ligustroside (IC50 = 122.63 microM) and ursolic acid (IC50 = 50.21 microM) showed a significant effect, although with less potency than the reference drug ibuprofen (IC50 = 1.27 microM). Thus, our compounds possess an array of potentially beneficial anti-inflammatory properties which may, alongside other constituents, contribute to the claimed therapeutic properties of the plant from which they are derived.

Inhibition of prostaglandin E2 and leukotriene C4 in mouse peritoneal macrophages and thromboxane B2 production in human platelets by flavonoids from Stachys chrysantha and Stachys candida

Seven flavonoids of Stachys chrysantha and Stachys candida have been isolated. The structures of the compounds were elucidated by spectroscopic methods, particularly highfield NMR spectroscopy. The effects of the methanol extracts of these two endemic Greek Stachys sp. and their main flavonoids were examined on arachidonic acid (AA) metabolism in the cellular system (mouse peritoneal macrophages and human platelets). Their cytotoxicity on cells was also investigated. Most samples assayed did not exhibit any significant effect on prostaglandin E2 (PGE2)-release from calcium ionophore-stimulated mouse peritoneal macrophages. Only chrysoeriol-7-O-beta-(3''-E-p-coumaroyl)-glucopyranoside, at the highest non-cytotoxic dose (50 microM), inhibited the release of PGE2, but this effect is not statistically significant. The release of leukotriene C4 (LTC4) by mouse peritoneal macrophages stimulated with calcium ionophore was inhibited by a crude extract of S. chrysantha, with an IC50 value of 34.3 microg/ml. Xanthomicrol (IC50 = 29.2 microM) and chrysoeriol-7-O-beta-D-(3''-E-p-coumaroyl)-glucopyranoside (IC50 = 11.1 microM) also inhibited the release of LTC4, although it showed less potency than the reference compound nordihydroguaiaretic acid (NDGA) (IC50 = 2 microM). However, most samples assayed showed a significant effect on thromboxane B2 (TXB2)-release from calcium ionophore-stimulated human platelets, with inhibition percentages slightly lower than the reference drug ibuprofen (IC50 = 7 microM). The IC50 values are: crude extract of S. candida 23.3 microg/ml; crude extract of S. chrysantha 23.1 microg/ml; xanthomicrol 28.8 microM; calcycopterin 2.66 microM and chrysoeriol-7-O-beta-D-(3''-E-p-coumaroyl)-glucopyranoside 8.8 microM. Our results indicate that the selective inhibition of TX-synthase enzyme may be the primary target of action of most of these samples, and one of the mechanisms through which thus exert their antiinflammatory effects.

Antiviral activity of Bolivian plant extracts

Ethanolic and aqueous extracts of seven plant species used in the traditional medicine of Bolivia have been tested for their antiviral activity against herpes simplex type I (HSV-1), vesicular stomatitis virus (VSV), and poliovirus type 1. The aqueous extracts of most of the species investigated showed antiviral activity. Two of these plants-namely, Satureja boliviana and Baccharis genistelloides-were active against two different viruses-HSV-1 and VSV.

Antiviral activity of some South American medicinal plants

Folk medicinal plants are potential sources of useful therapeutic compounds including some with antiviral activities. Extracts prepared from 10 South American medicinal plants (Baccharis trinervis, Baccharis teindalensis, Eupatorium articulatum, Eupatorium glutinosum, Tagetes pusilla, Neurolaena lobata, Conyza floribunda, Phytolacca bogotensis, Phytolacca rivinoides and Heisteria acuminata) were screened for in vitro antiviral activity against herpes simplex type I (HSV-1), vesicular stomatitis virus (VSV) and poliovirus type 1. The most potent inhibition was observed with an aqueous extract of B. trinervis, which inhibited HSV-1 replication by 100% at 50-200 micrograms/mL, without showing cytotoxic effects. Good activities were also found with the ethanol extract of H. acuminata and the aqueous extract of E. articulatum, which exhibited antiviral effects against both DNA and RNA viruses (HSV-1 and VSV, respectively) at 125-250 micrograms/mL. The aqueous extracts of T. pusilla (100-250 micrograms/mL), B. teindalensis (50-125 micrograms/mL) and E. glutinosum (50-125 micrograms/mL) also inhibited the replication of VSV, but none of the extracts tested had any effect on poliovirus replication.

Effects of compounds extracted from Santolina oblongifolia on TXB2 release in human platelets

A group of compounds isolated from the medicinal plant, Santolina oblongifolia, have been investigated for their effects on the release of platelet cyclo-oxygenase metabolite thromboxane A(2) (measured as thromboxane B(2)) from ionophore-stimulated human platelets. These compounds, which are dual inhibitors of cyclo-oxygenase (prostaglandin E(2)) and lipoxygenase (leukotriene C(4)) activity in vitro, are: apigenin, luteolin, quercetin, herniarin, scopoletin, scopolin and aesculetin. All compounds assayed presented a dose-related response to thromboxane B(2) release, with the percentages of inhibition being slightly lower than the reference drug, ibuprofen. Inhibition was more evident with the flavonoids. Our data support the inhibition of arachidonic acid metabolism as one of the mechanisms for which flavonoids and coumarins from S. oblongifolia exert their anti-inflammatory effect.

Antiinflammatory and antioxidant activity of plants used in traditional medicine in Ecuador

Ethanolic extracts from 15 plant species, representing eight different families, used in traditional medicine in Ecuador were evaluated for antiinflammatory and antioxidant activities. Conyza floribunda, Eupatorium articulatum, Bonafousia longituba, Bonafousia sananho, Tagetes pusilla and Piper lenticellosum extracts showed a significant antiinflammatory activity in vivo in the carrageenan-induced paw oedema model in mice. The extracts were also tested in vitro for their ability to inhibit lipid peroxidation and to scavenge superoxide and hydroxyl radicals. E. articulatum extract possesses both activities. Baccharis trinervis, E. articulatum and Phytolacca rivinoides extracts were active as antioxidants.

Effects of compounds extracted from Tanacetum microphyllum on arachidonic acid metabolism in cellular systems

In the present study, the effects of compounds extracted from Tanacetum microphyllum, four flavonoids and one sesquiterpene lactone, on arachidonic acid metabolism in cellular systems were examined. In the PGE2- and LTC4-release assay, most compounds did not exhibit any significant effect. Only hydroxyachillin, and the flavonoids centaureidin and 5,3'-dihydroxy-4'-methoxy-7-methoxycarbonylflavonol showed a significant effect, although with less potency than the reference drugs, indomethacin and NDGA. However, all compounds inhibited the release of TXB2 from ionophore-stimulated human platelets. The action is more marked with the flavonoids santin and ermanin.

Effect of Santolina oblongifolia on ACII-immunized animals

The therapeutic effect of organic extracts of Santolina oblongifolia in adjuvant-carrageenan-induced inflammation (ACII) in Wistar rats was investigated. The present study concerns the effect of the extracts on serum copper (Cu) and zinc (Zn) levels, and on hindpaw swelling and ankle joint widths of arthritic animals. Compared with controls, the arthritic animals showed an increase in serum Cu levels, while serum Zn was decreased. The altered levels of trace elements in arthritic animals were significantly normalized in the chronic phase of the disease after treatment with most of the extracts of S. oblongifolia. Additionally, administration of the extracts significantly decreased the clinical signs of inflammation. The results of the present investigation indicated that these extracts could offer a partial protective action against changes induced by ACII in Wistar rats.

Cell lines susceptible to infection are permeabilized by cleaved and solubilized outer layer proteins of rotavirus

It has previously been shown that trypsinized triple-layered particles of rotavirus induce destabilization of liposomes and membrane vesicles in the absence of Ca2+, a condition which leads to solubilization of the outer capsid proteins of the virus. In this work, we have studied the relationship between outer capsid solubilization and permeabilization of membrane vesicles, monitoring particle and vesicle size simultaneously by changes in light scattering. Permeabilization of intact cells induced by solubilized outer capsid proteins was monitored by following the rate of entry of ethidium bromide into the cells. Solubilized outer capsid proteins separated from double-layered particles induced vesicle permeabilization. Solubilization of the outer capsid preceded and was required for vesicle or cell permeabilization. Membrane damage induced by rotaviral outer proteins was not repaired upon addition of 1 mM Ca2+ to the medium. Rotavirus infection and cell permeabilization were correlated in six different cell lines tested. This phenomenon might be related to the mechanism of virus entry into the cell. We propose a new model for rotavirus internalization based on the permeabilizing ability of outer capsid proteins and the cycling of trapped calcium in the endosomal compartment.

Adjuvant-carrageenan-induced inflammation in mice

1. A study was conducted to evaluate the optimum conditions for the induction of adjuvant-carrageenan-induced inflammation (ACII) in Swiss and DBA/1 mice. 2. ACII was induced in mice under experimental conditions similar to those known to be effective in rats. Mice were immunized by subdermal injection of Freund's complete adjuvant (CFA), followed by a subplantar inoculation of carrageenan at different times. 3. The diversities of the responses on ACII between both strains of mice and rats were observed. Data obtained indicate that DBA/1 mice showed an increase in hindpaw and ankle joint swelling, which was more evident on day 21 after carrageenan injection, independently of the time of application of this phlogistic agent. At this time, the histopathological changes were similar to those seen in rats, and were characterized by epidermal hyperplasia, with leukocyte infiltration and granuloma formation. 4. We found that DBA/1 mice, instead of rats, can be used for the evaluation of anti-inflammatory drug activity. However, it is advisable also to consult the histological data to establish whether the synovial changes revert.

Solubilized and cleaved VP7, the outer glycoprotein of rotavirus, induces permeabilization of cell membrane vesicles

It has been previously shown that rotavirus triple-layered particles induce permeabilization of liposomes and membrane vesicles. These effects were mediated by one or both of the solubilized outer-capsid proteins, VP4 and VP7. Permeabilization was dependent on trypsin treatment of the viral particles, suggesting that VP4 was involved. To analyse the respective roles of the outer-capsid proteins in this permeabilization process, we have used membrane vesicles loaded with carboxyfluorescein and virus-like particles derived from insect cells co-expressing various sets of capsid proteins. Virus-like particles containing VP2, VP6 and VP7 (VLP2/6/7) are as efficient in permeabilizing vesicles as triple-layered particles. As with double-layered particles, virus-like particles made of VP2 and VP6 had no effect on vesicle permeabilization. Permeabilization of membrane vesicles required trypsinization of the VP7 solubilized from VLP2/6/7. These results show that solubilized and trypsinized VP7 is able to induce membrane permeabilization, independently of the presence of VP4.

Isolation of two flavonoids from Tanacetum microphyllum as PMA-induced ear edema inhibitors

The CH2Cl2 extract of Tanacetum microphyllum exhibited antiinflammatory activity on PMA-mouse ear model. Two antiinflammatory flavonoids, 5,7-dihydroxy-3,6,4'-trimethoxyflavone (santin) (1) and 5,7-dihydroxy-3,4'-dimethoxyflavone (ermanin) (2), were isolated.

Antiinflammatory activity of coumarins from Santolina oblongifolia

Four coumarins were isolated from the EtOAc extract of the flower-tops of Santolina oblongifolia Boiss. (Compositae). They were identified as 7-methoxycoumarin (herniarin) (1), 6,7-dihydroxycoumarin (aesculetin) (2), 6-methoxy-7-glucosidylcoumarin (scopolin) (3), and 6-hydroxy-7-methoxycoumarin (scopoletin) (4). This is the first report of the isolation of aesculetin and scopolin from the genus Santolina. The isolated coumarins showed marked activity as inhibitors of eicosanoid-release from ionophore-stimulated mouse peritoneal macrophages.

Antiinflammatory activity of some medicinal plant extracts form Venezuela

Six medicinal plant extracts from Venezuela, used in traditional medicine, were investigated for their anti-inflammatory potential against adjuvant-carrageenan-induced inflammation (ACII). All doses expressed here are equivalents of dried starting plant materials (1.50 g dry plant/kg body wt.). The most interesting plant extracts were Synedrella nodiflora, and the hexane leaf extract of Bursera simaruba. In ACII, orally administered extracts (at doses 40 and 80 mg/kg, respectively), inhibited both the acute and chronic phases of this experimental model of inflammation, mainly the chronic phase. These extracts exhibited potent anti-inflammatory activity daily throughout the experiment, and were as effective as reference drugs, phenylbutazone (80 mg/kg) and indomethacin (3 mg/kg).

Aggravation of adjuvant arthritis by carrageenan

1. We have studied the optimum conditions for the induction of adjuvant carrageenan-induced inflammation (ACII) in male Wistar rats with limited susceptibility to adjuvant arthritis (AA). 2. ACII was induced by intradermal injection of Freund's complete adjuvant (CFA), containing 10 mg/ml Mycobacterium tuberculosis, followed by a subplantar inoculation of the nonspecific inflammatory stimulus carrageenan at different times. 3. Data obtained indicate that the arthritis of rats inoculated with CFA is significantly increased by carrageenan, particularly when it is injected 14 days after the adjuvant. Arthritis enhancement was more evident in the joints of the leg that had been previously injected with carrageenan, and remained stable around the peak level for some weeks. The development of joint inflammation was associated histologically with the appearance of inflammatory cells in the synovial membrane of those animals. 4. We found that the injection of carrageenan aggravated the course of AA in general, but very significantly when administered at the moment of the appearance of arthritis (day + 14). This aggravation affected both the intensity of inflammation and the chronicity of the disease.

Inhibition by hydroxyachillin, sesquiterpene lactone from Tanacetum microphyllum, of PMA-induced mouse ear oedema

4-beta-phorbol 12-myristate 13-acetate (PMA), when administered topically to mouse ear, induces a pronounced inflammatory response mediated by protein kinase C (PKC). Activation of PKC is implicated in the pathogenesis of inflammation, with phospholipase A2-dependent arachidonic acid release and eicosanoid production. We have investigated the effects of hydroxyachillin, a sesquiterpene lactone from Tanacetum microphyllum DC., on mouse ear oedema induced by PMA. The effects of this compound on swelling and other inflammatory parameters are described. Hydroxyachillin significantly (p < or = 0.01) inhibited ear swelling in a dose-dependent manner, and was as effective as the reference drugs. The PMA-induced vascular permeability was significantly (p < or = 0.05) reduced by hydroxyachillin at the highest dose (3 mg/ear). Histologically, the signs of inflammation were greatly reduced in the hydroxyachillin-treated ear lesions. These data suggest that hydroxyachillin is an effective anti-inflammatory agent in this model, and that the inhibition of PKC may be one of the mechanisms of hydroxyachillin's effect.

The activity of flavonoids extracted from Tanacetum microphyllum DC. (Compositae) on soybean lipoxygenase and prostaglandin synthetase

1. The in vitro effects of centaureidin and 5,3'-dihydroxy-4'-methoxy-7-carbomethoxyflavonol (Fig. 1), two anti-inflammatory flavonoids extracted from Tanacetum microphyllum DC., have been examined on both cyclooxygenase and lipoxygenase activity. 2. These flavonoids produced an inhibition of soybean lipoxygenase activity in a dose-dependent manner, with IC50 values (20 and 29 microM respectively) similar to the reference drug. 3. The IC50 values for the in vitro inhibition of cyclooxygenase activity by these flavonoids, were higher than those that produced lipoxygenase activity (318 and 60 microM respectively). 4. These results suggest that the anti-inflammatory activity of our flavonoids may, at least in part, be due to the inhibition of leukotriene synthesis. 5. This is the first report of the biological activity in vitro of these compounds.

Anti-inflammatory activity of hydroxyachillin, a sesquiterpene lactone from Tanacetum microphyllum

The aerial parts of Tanacetum microphyllum D.C. (Compositae), used in folk medicine as an anti-inflammatory and anti-ulcer agent, were studied, the active principle hydroxyachillin (1) was isolated, and its pharmacological properties were analyzed. Hydroxyachillin showed marked anti-inflammatory activity in carrageenan-induced paw edema in mice. In the experimental models in vitro, hydroxyachillin has been reported to be a dual inhibitor of cyclooxygenase and soybean lipoxygenase. In this study, inhibition of prostaglandin synthetase (bovine seminal vesicular microsomes) by hydroxyachillin required concentrations more than twice those which inhibited soybean lipoxygenase (ED50 values = 10(-4) M and 2.6 x 10(-5) M, respectively). Therefore, an inhibition of leukotriene synthesis might be involved in the anti-inflammatory activity of hydroxyachillin in vivo.

Nonparallel secretion of pepsinogen and acid by gastric oxyntopeptic cells of the toad (Bufo marinus)

Pepsinogen and HCl secretion in the amphibian stomach are performed by a single cell type, the oxyntopeptic cell. These functions were studied in gastric mucosae of toads (Bufo marinus) mounted in Ussing-type chambers. HCl and peptic activity of luminal fluid were measured by titration and proteolysis of albumin, respectively. Distribution of pepsinogen in the gastric mucosa was heterogeneous, activity being highest in the proximal part of the stomach. Zymogen granules in the oxyntopeptic cell were more abundant in the deeper cells of the glands and in the fundus. On stimulation, the granules were released into the lumen of the glands by exocytosis. Histamine, forskolin, or carbachol alone each induced an increase in HCl and pepsinogen secretion. Carbachol after maximal histamine or forskolin stimulation produced an extra increase in both secretions that was greater for pepsinogen response. Similarly, joint addition of carbachol and histamine was more potent than histamine alone for both parameters; however, the effect was greater on pepsinogen release. Pretreatment with cimetidine blocked HCl and pepsinogen responses to carbachol but did not affect responses to forskolin. Addition of omeprazole to forskolin-stimulated mucosae uncoupled the two secretions, inducing a total inhibition of HCl secretion with a slight reduction in pepsinogen secretion. Thus pepsinogen release, similar to HCl secretion, is sensitive to cAMP and Ca(2+)-dependent secretagogues. However, the action of Ca2+ would require the previous elevation of cAMP induced by the different secretagogues. In such a case, the increase in intracellular Ca2+ would result in a nonparallel activation of the two secretions.

Anti-inflammatory activity of two flavonoids from Tanacetum microphyllum

The CH2Cl2 extract of Tanacetum microphyllum aerial parts exhibited anti-inflammatory activity and yielded two anti-inflammatory flavonoids: 5,7,3'-trihydroxy-3,6,4'-trimethoxyflavone (centaureidin) [1], and 5,3'-dihydroxy-4'-methoxy-7-carbomethoxyflavonol [2]. This is the first report of the chemical composition of Ta. microphyllum and of the isolation of centaureidin from the genus Tanacetum.

A T cell clone defining a common DP/DR determinant in strong linkage disequilibrium with HLA-A9

Clone F-7 was generated by limiting dilution of lymphocytes stimulated by allogeneic PBL on MLC. Priming against the A23, Cw6, B45, DR7, DRw53, DQw2 haplotype was performed between two HLA haploidentical first degree relatives. The clone was tested for its ability to proliferate in response to a panel of 38 homozygous B lymphoblastoid cell lines plus three local T cell lines. It showed a pattern of reactivity corresponding to HLA-A9 specificity (r = 1) and presented a concomitant cytotoxic activity. Phenotypically, this clone consisted entirely of CD4 cells, as determined by indirect immunofluorescence. Its reactivity was completely blocked by anti-DR (GSP4.1, PL8, L243) and anti-DP (B7/21, PL15) Mo-Abs, whereas anti-DQ (1A3, TU22) and anti-class I (w6/32, BB7.7) Mo-Abs and anti-A9 antibodies did not inhibit its reactivity. These results may suggest that clone F-7 could recognize a DP specificity sharing common determinants with DR, which occurs in linkage disequilibrium with HLA-A9.