Volume 57, Issue 3-4

Two green algae (Ulva rigida and Cladophora coelothrix), the mussel Mytilus galloprovincialis and the snail Rapana thomasiana from the Bulgarian Black Sea shore have been treated with diesel fuel (100 mg l -1 ) in an aquarium with sea-water for three days. The lipids and their fatty acid changes have been examined. Significant changes have been observed mainly in the polar lipids and in the saturation of the fatty acids. These changes appeared to be bigger in the evolutionary less advanced species from both groups of marine organisms D algae and invertebrates (Ulva rigida and Mytilus galloprovincialis respectively). The data obtained could be used for a biomonitoring of the pollution

Two pyridine alkaloids were isolated from the derubberized resin of the hybrid Parthenium argentatum x P. tomentosa. These alkaloids are (±)-N-[4-(1-aminoethyl) phenyl]-4-[3-methylbutenylidine]- 1, 4-dihydropyridine (guayulamine A) and (±)-N-[4-(1-aminoethyl) phenyl]-4- [4-methylpentenylidine]-1, 4-dihydropyridine (guayulamine B). The structures were established by one- and two-dimensional NMR spectroscopy and mass spectrometry

A new flavonol triglycoside, rhamnocitrin-3-O-neohesperoside-4′-O-glucoside was isolated from the ethanol extract of Cadaba glandulosa together with two known diglycosides rhamnocitrin- 3-O-neohesperoside and rhamnetin-3-neohesperoside. Characterization of the three compounds was achieved by various spectroscopic methods

From the aerial parts of the plant Phlomis chimerae, a new neolignan glucoside, (-)-4-O-methyldihydrodehydrodiconiferyl alcohol-9′-O-β-ᴅ-glucopyranoside (1) was characterized along with the known neolignan glucosides, (D)-4-O-methyldehydrodiconiferyl alcohol-9′-O-β-ᴅ-glucopyranoside (= longifloroside A) (2) and (-)-dihydrodehydrodiconiferyl alcohol-9-O-β-ᴅ-glucopyranoside (3). The structure of the new compound was established on the basis of spectroscopic evidence

From 19 species of Galium, members of 6 European sections of the genus, 24 compounds were isolated, namely 16 iridoid glucosides, 2 secoiridoid glucosides and 6 triterpene saponins (the later found only in G. rivale (Sibth. & Sm. Griseb.) The iridoid content was analyzed by thin layer chromatography - densitometry. An effort was made to clarify interspecies relationships, based on the obtained results and previous data. Generally, a nearly uniform iridoid pattern in the studied species was observed. Nevertheless, some distinctions gave reason the following chemical characters to be treated as taxonomic markers: iridoids, secogalioside (characteristic of G. mollugo group), iridoids V1 and V2 (G. humifusum Bieb. and G. verum L.), 6-acetylscandoside (G. incurvum group and G. verum) and the triterpene saponins, rivalioside A and rivalioside C (characteristic of G. rivale). The studied species regarding to the iridoids could be attributed to three lines of evolutionary differentiation. One line is leading to the differentiation of G. rivale. It contains specific triterpenoids as well as iridoid acids, which show parallel development of both glyceraldehyde 3-phosphate/pyruvate and mevalonate biosynthetic routes in this species. A second line includes G. mollugo and G. incurvum species groups and the species G. humifusum and G. verum. Variety of iridoid esters, hydroxy and carboxy derivatives of iridoids and secoiridoids characterised this line. Third line comprises the remaining studied species, members of different sections and species groups. They posses a nearly identical iridoid pattern, which suggests a convergent evolution regarding to the iridoids

A new glycoside of salicylic aldehyde, paeonicluside, was isolated from the roots of the Greek endemic species Paeonia clusii subsp. clusii and identified as α-ʟ-arabinopyranosyl- (1→6)-O-β-ᴅ-glucopyranoside of salicylic aldehyde (1). In addition, one characteristic monoterpene and two monoterpene glycosides were identified as paeoniflorigenone, paeoniflorin and benzoyl paeoniflorin, respectively. The structure of 1 was elucidated on the basis of its spectroscopic data and chemical correlation. It is the first time that a derivative of salicylic aldehyde is isolated from the well-studied Paeonia genus

A GC-MS analysis of underivatized alkaloids from leaves of Crinum latifolium was performed. From the identified 15 alkaloids, 9 were found for the first time in this plant. Almost all alkaloids belonged to the crinane type. Substantial changes in the methylation and oxidation pattern of the alkaloids at and after flowering were observed

L. hintonii C. P. Smith grows in the Central Highland forests of Mexico at altitudes between 2800 m to 3200 m above see level. Members of the genus Lupinus produce quinolizidine alkaloids as main chemical defensive compounds against herbivores. Surprisingly alkaloid profiles are rather constant within this species, while substantial variation was found when compared to morphologically closely related other taxa. As part of a phytochemical project on Mexican wild lupins, we report on the alkaloid profiles of seeds and leaves of L. hintonii. 19 alkaloids could be identified by capillary GLC-MS. Six major alkaloids occurred in leaves and seeds: 13-hydroxylupanine (28% and 45% respectively), tetrahydrorhombifoline (31% and 23% respectively), angustifoline (2% and 4% respectively), lupanine (7% and 5% respectively), 13α-tigloyloxylupanine (19% and 5% respectively) and 4α-angeloyl-3β-hydroxylupanine (9% and 2%). This chemical pattern resembles that of the North American lupin L. floribundus

On the basis of qualitative and quantitative analysis with liquid chromatography - electrospray ionisation mass spectrometry, the foliage of dwarf birch (Betula nana L.), silver birch (B. pendula Roth) and mountain birch (B. pubescens ssp. czerepanovii (Orlova) Hamet- Ahti) were found, for the first time, to contain the same individual HTs that were described earlier for white birch (B. pubescens Ehrh.). In addition, one previously unidentified ellagitannin was preliminarily identified from the leaves of white and mountain birches, being totally absent from the foliage of the other two species. There were large variations in the contents of HTs between species. Seasonal variation affected significantly the contents of some individual HTs within species, and these changes were mainly in accordance with the biosynthetic pathway of HTs. All species converted galloylglucoses (GGs) into ellagitannins (ETs), dwarf birch being the only one that’s efficient ET synthesis resulted in seasonally increased contents of ETs and thereof total HTs as well. The presence of insoluble ETs as well as the absence of insoluble GGs was confirmed in all four birch species for the first time. Furthermore, the amounts of insoluble ETs per one birch leaf were found to accumulate during the growing season. These findings complemented our knowledge of the biosynthetic pathway of birch leaf HTs: from soluble GGs via soluble ETs into insoluble ETs. The possible role of HTs in the herbivore defence of these species is discussed

In a screening of basidiomycete cultures from Chile for the production of antibiotics we identified a Serpula himantoides strain as a producer of metabolites inhibiting the growth of bacteria and fungi. Bioactivity guided purification resulted in the isolation of four new antibiotics. Their structures were elucidated by spectroscopic methods. All four compounds are succinimide and maleimide derivatives, of which two are N-hydroxylated

Feeding experiments with specifically 13 C-labeled glucose disclosed that the diterpenoid part of the striatals/striatins is formed via the mevalonate pathway, whereas the pentose moiety originates either via glucuronic acid (70%) or the pentose phosphate cycle (30%). Application of radioactively labeled herical to cultures of Hericium ramosum demonstrates the pivotal role of this cyathane-xyloside in striatal biosynthesis. Herical inhibits a large spectrum of fungi and bacteria and shows cytotoxic and hemolytic properties

Screening of different extracts, fractions and compounds from Rubus imperialis Chum. Schl. (Rosaceae) has been conduced using the brine shrimp microwell cytotoxicity assay. Three parts of the plant (methanolic extract from leaves, roots and stems), three fractions from roots (hexane, ethyl acetate and butanol) and three isolated compounds (niga-ichigoside F1, 23-hydroxytormentic acid, ellagic acid derivative) were tested. The most promising material (LC 50 <1000 μg/ml) were the methanolic extract and ethyl acetate fraction from roots. However, there was little correlation observed in the degree of toxicities observed between the isolated compounds. On the other hand, the cytotoxicity and in vivo assays confirmed the hypoglycemic activity of methanolic extract and validated the Brazilian popular use of R. imperialis as an antidiabetic agent

In vitro antiplasmodial activities of extracts from Albizia saman, Fabaceae, Calea tenuifolia (C. zacatechichi), Asteraceae, Hymenaea courbaril, Fabaceae, Jatropha curcas, Euphorbiaceae, Momordica charantia, Cucurbitaceae, and Moringa oleifera, Moringaceae were evaluated. From the lipophilic extract of C. tenuifolia five active flavones were obtained. 4′,5- Dihydroxy-7-methoxyflavone [genkwanin] and 5-hydroxy-4′,7-dimethoxyflavone [apigenin 4′,7-dimethylether] exhibited the strongest antiplasmodial activity against a chloroquine-sensitive strain (poW) and a chloroquine-resistant strain (Dd2) of Plasmodium falciparum (IC 50 values: 17.1 - 28.5 μm). Furthermore octadeca-9,12-dienoic acid [linoleic acid] {IC 50 values of 21.8 μm (poW) and 31.1 μm (Dd2)} and octadeca-9,12,15-trienoic acid (α-linolenic acid) were isolated

Eupatorium semialatum is a member of the Asteraceae, which occurs in Guatemala. Previously, we reported the occurrence of sesquiterpene lactones of the eudesmanolide type as main constituents in the leaves. This paper deals with the isolation and identification of the first guaianolide found in E. semialatum. Since this plant is used against malaria and other diseases in the Guatemalan folk medicine, the main sesquiterpene lactones were tested for their activities against Plasmodium falciparum in vitro

The chemical composition of the essential oils of Achillea holosericea, Achillea taygetea, Achillea fraasii was determined by GC/MS analysis. Among the ninety-five assayed constituents, camphor, borneol and 1,8-cineol were found to be the major components. The in-vitro antimicrobial activity of these essential oils was evaluated against six bacteria indicating that the first is totally inactive, while the other two possess moderate to strong activities mainly against the Gram negative strains. The essential oil of A. fraasii was also active against the tested pathogenic fungi

Two new garcinia acid derivatives, 2-(butoxycarbonylmethyl)-3-butoxycarbonyl-2-hydroxy- 3-propanolide and 1′,1′-dibutyl methyl hydroxycitrate, were isolated from the fruits of Garcinia atroviridis guided by TLC bioautography against the fungus Cladosporium herbarum. The structures of these compounds were established by spectral analysis. The former compound represents a unique β-lactone structure and the latter compound is most likely an artefact of garcinia acid (= hydroxycitric acid). Both compounds showed selective antifungal activity comparable to that of cycloheximide (MID: 0.5 μg/spot) only against C. herbarum at the MIDs of 0.4 and 0.8 μg/spot but were inactive against bacteria (Bacillus subtilis, methicillin- resistant Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli), other fungi (Alternaria sp., Fusarium moniliforme and Aspergillus ochraceous) including the yeast Candida albicans

The study was aimed at the quantitative evaluation of the temporal and spatial partitioning of non-structural carbohydrates and needle biomass in a canopy of Scots pine (Pinus sylvestris L.) growing in a Myrtillus site type forest stand (predominant in Estonia). The tree canopy was divided into ten equal layers and the material for the spatial partitioning of the investigated characteristics was sampled from all layers. Our findings revealed a significant variation in morphology and in the partitioning of carbohydrates in needles in different layers of the canopy. The study of the temporal dynamics of carbohydrates showed that starch content in needles started to increase in early spring before budbreak, which was accompanied by a decline in soluble carbohydrates. In October, the starch content of needles was low, but the concentration of soluble sugars started to increase attaining a maximum in winter. Regression analysis indicated that before budbreak, the partitioning of soluble sugars in different canopy layers was relatively weakly correlated with the height of the layer; however, a strong correlation was observed for starch. In autumn, when the growth of trees stopped and daily temperatures decreased, the allocation of soluble sugars was correlated with the height of the canopy layer

(-)-α-Pinene (1), a major constituent of many aromatic plants was biotransformed by the plant pathogenic fungus, Botrytis cinerea to afford three new metabolites, characterized as 3 β-hydroxy-(-)- β-pinene (10%) (3), 9-hydroxy-(-)-α-pinene (12%) (4), 4 β-hydroxy-(-)-α- pinene-6-one (16%) (5) by physical and spectroscopic methods. A known metabolite verbenone (2) was also obtained

Numerous data accumulated during the last decade have shown that the Shine-Dalgarno (SD) sequence is not a unique initiator of translation for Escherichia coli. Several other sequences, mostly of viral origin, have demonstrated their capability of either enhancing or initiating translation in vivo. A phage T7 gene 10 sequence, called “epsilon” (ε), has shown its high enhancing activity on translation in both Escherichia coli and Agrobacterium tumefaciens cells. In this study the ε, together with three other nucleotide sequences derived from the 5′ non-translated regions of tobacco mosaic virus (TMV), papaya mosaic virus (PMV) and clover yellow mosaic virus (CYMV) RNAs are tested for translation initiation activity in A. tumefaciens cells. The obtained results indicate that none of them was capable of initiating translation in vivo of chloramphenicol acetyltransferase (CAT) mRNA. To determine whether their inactivity was related with structural differences in the ribosomal protein S1, the rpsA gene (coding for S1 protein in E. coli) was co-expressed in A. tumefaciens together with the cat gene placed under the translational control of the above sequences. Our results showed that the rpsA gene product did not make any of the four viral enhancers active in A. tumefaciens cells. The inability of A. tumefaciens ribosomes to translate mRNAs devoid of SDsequences indicates for a substantial difference in the ribosome structure of the two Gram negative bacteria E. coli and A. tumefaciens

Hansenula polymorpha CBS 4732 was studied during cultivation on methanol and different glucose concentrations. Activities of Cu/Zn and Mn superoxide dismutase, catalase and methanol oxidase were investigated. During cultivation on methanol, increased superoxide dismutase and catalase activities and an induced methanol oxidase were achieved. Transfer of a methanol grown culture to medium with a high glucose concentration caused growth inhibition, low consumption of carbon, nitrogen and phosphate substrates, methanol oxidase inactivation as well as decrease of catalase activity (21.8 ± 0.61 ΔE 240 × min -1 × mg protein -1 ). At the same time, a high value for superoxide dismutase enzyme was found (42.9 ± 0.98 U × mg protein -1 , 25% of which was represented by Mn superoxide dismutase and 75% - by the Cu/Zn type). During derepression methanol oxidase was negligible (0.005 ± 0.0001 U × mg protein -1 ), catalase tended to be the same as in the repressed culture, while superoxide dismutase activity increased considerably (63.67 ± 1.72 U × mg protein -1 , 69% belonging to the Cu/Zn containing enzyme). Apparently, the cycle of growth inhibition and reactivation of Hansenula polymorpha CBS 4732 cells is strongly connected with the activity of the enzyme superoxide dismutase

The influence of copper (II) ions on the growth, accumulation properties and superoxide dismutase (SOD) activity of a growing culture of Aspergillus niger B-77 were studied. Microbial growth, the level of copper (II) accumulation and SOD activity depended on the initial copper (II) concentration. Aspergillus niger is able to accumulate large amounts of copper (II) from the nutrient medium with 200 mg.l -1 copper (II) ions without loosing its biological activities. Addition of copper (II) ions increased the SOD activity in the growing cell cultures. The changes in enzyme activity induced by heavy metal ions might be used as an indicator of intracellular oxy-intermediate generation in a cell culture growing under stress conditions

In a survey of plant secondary metabolites regulating the behavior of phytopathogenic Aphanomyces cochlioides zoospores, we found that leaf extracts of Amaranthus gangeticus and cotyledon extracts of pea (Pisum sativum) remarkably halted the motility of zoospores. Bioassay-directed fractionation of A. gangeticus and pea constituents revealed that the halting activity was dependent on a single chemical factor (halting factor). The active principle was identified as nicotinamide (1) by comparing its biological activity and spectroscopic properties with those of the authentic compound. Nicotinamide (1) showed potent halting activity toward the zoospores of A. cochlioides and A. euteiches, but it exhibited very less activity against other Oomycetes, Pythium aphanidermatum and Phytophthora infestans zoospores. Interestingly, the zoospores halted by nicotinamide (1) encysted within 10-15 min and then the resulting cystospores regenerated zoospores instead of germination. Nicotinamide (1) and related compounds were subjected to the halting activity bioassay to elucidate the structure- activity relationships. These bioassays revealed that part structures of (A) the aromatic ring containing at least one nitrogen atom, (B) carbonyl-like group adjacent to the aromatic ring and (C) hydrogen atoms on the amide group are responsible for the strong activity. So far, this is the first report of halting activity of nicotinamide (1) against fungal zoospores

Forty-two extracts of folk medicinal plant organs from Pakistan were tested in competition binding assays for their interaction with the specific ligand recognition sites on the human α 2 -adrenoceptor subtypes α 2A , α 2B and α 2C . Strong binding of the extracts (40 mg/ml) from Acacia nilotica (L.) Delile leaves (88-98% displacement of radiolabel) and Peganum harmala seeds (89-96% displacement) on three subtypes prompted us to extract these plant materials with 40% and 80% methanol, ethanol, and acetone. The extraction results indicated an absence of α 2 -adrenoceptor binding activity in the stalk of A. nilotica and A. tortils, whereas the leaves of both plants contained activity. The extracts of A. nilotica leaves showed a slight, but consistent, preference for the α 2C -adrenoceptor, whereas the leaves of A. tortils were slightly more active on the α 2B subtype. The extract of P. harmala stalks was less active than that of its seeds. The binding activities of A. nilotica leaves and P. harmala seeds were mainly concentrated in the water and 30% methanol fractions and further sub-fractions. In a functional activity assay, the active fractions inhibited epinephrine-stimulated 35 S-GTPγS binding, thus indicating a predominantly antagonistic nature of the compounds with α 2 -adrenoceptor affinity in these fractions. Among the known major alkaloids of P. harmala (demissidine, harmaline, harmine, 6-methoxyharmalan, and norharmane), only 6-methoxyharmalan showed moderate affinity (dissociation constant (K i ) of 530 ± 40 nᴍ for α 2A subtype). This study is a first systematic attempt towards the discovery of potential drug candidates from these plant materials for treating α 2 -adrenoceptor related diseases

Two series of pyrrolidinium (PYA-n) and piperidinium (PPPA-n) bromides with incorporated antioxidant function were synthesized. Both have hydrocarbon chains with odd number of the carbon atoms (n) ranging between 7 and 15. Pig erythrocytes (RBC) were used to study antioxidant activity of these compounds. They were incorporated into RBC membranes in sublytic (micromolar) concentrations and RBC were then subjected to UV radiation. It was found that all the salts used protected erythrocyte membranes against oxidation of membrane lipids. This protection increased with hydrocarbon chain length. Such effect may be the result of an incorporation of particular compounds to different depths into the lipid phase of RBC membrane depending on their chain length. Such possibility was checked by studies on fluidity changes induced by the compounds studied in ghost membranes by fluorimetric measurements. The measurements showed that pyrrolidinium bromides were slightly more effective in a protection of erythrocytes than the corresponding piperidinium ones. The possible reason of such behaviour may be the difference in lipophilicity between piperidine and pyrrolidine rings

We established a methodology to analyze radioligand binding to the recombinant type 1a metabotropic glutamate receptor (mGluR1a). A full-length ᴄDNA encoding mGluR1a, which was isolated from a λ gt 11 ᴄDNA library of human cerebellar origin, was expressed in a baculovirus/Sf9 insect cell system. Membrane fractions with recombinant receptor expression were analyzed for the binding of [ 3 H]L-quisqualic acid (ʟ-QA), which is known to be a potent agonist of mGluR1a. Efficient binding of the radioligand to the human receptor was observed in a saturable manner, giving an apparent Kd= 0.091 μᴍ. [ 3 H]ʟ-QA bound to the human mGluR1a was displaced by known ligands such as ʟ-QA, ʟ-Glu, t-ACPD(( ±)-1- aminocyclopentane-trans-1,3-dicarboxylic acid) with IC 50 s = 0.056, 0.97 and 4.0 μᴍ, respectively. MCPG (α-methyl-4-carboxyphenylglycine) displaced the radioligand binding with lower potency. Using this binding protocol, we then evaluated the ligand ability of synthetic dipeptides. Among peptides tested, only Glu-containing dipeptides inhibited the radioligand binding, e.g. IC 50 of ʟ-Met-ʟ-Glu was 4.3 μᴍ. When phosphatidyl inositol turnover was assayed in mGluR1a-expressing CHO cells, ʟ-Met-ʟ-Glu was partially agonistic. We further expanded this [ 3 H]ʟ-QA binding protocol to type 5a mGluR, another member of group I mGluRs, as well as to AMPA receptor, a member of ionotropic glutamate receptors, since ʟ-QA is also known to be a potent ligand for these receptors. Data shown here will provide a novel system not only to search for ligands for the glutamate receptors, but also to biochemically analyze the interaction modes between glutamate receptors and their ligands

Observation of both tensio-active and emulsifying activities indicated that biosurfactants were produced by the newly isolated and promising strain Pseudomonas putida 21BN. The biosurfactants were identified as rhamnolipids, the amphiphilic surface-active glycolipids usually secreted by Pseudomonas spp. Their production was observed when the strain was grown on soluble substrates, such as glucose or on poorly soluble substrates, such as hexadecane, reaching values of 1.2 g l -1 . When grown on hexadecane as the sole carbon source the biosurfactant lowered the surface tension of the medium to 29 mN m -1 and formed stable and compact emulsions with emulsifying activity of 69%

The influence of lipid peroxidation (LP) on the rate of disruption of rat liver and kidney subcellular structures was studied under two experimental conditions. Damage to cell organelles was found only when peroxidation process carried out into large granule fraction suspensions. Exogenous thiobarbituric acid positive products were noneffective as membrane labilizers. Age, organ and cell organelle-linked differences in the response towards LP produced damage were observed. Rat liver peroxisomes showed higher stability than those of kidney with respect to injury induced by peroxidation process. In addition, in rat kidney and neonatal rat liver samples the lysosomes were found to be more sensitive than mitochondria to the damaging effect of this process. Thiourea, an inhibitor of diene conjugate formation as well as manitol and ethanol known as hydroxyl radical scavengers were tested as terminators of LP and as membrane protectors. Effectiveness was demonstrated only for thiourea

The aim of the study was to monitor urokinase plasminogen activator antigen concentrations and its type 1 (PAI-1) and type 2 (PAI-2) inhibitors in histologically defined forms of primary breast cancer and a comparison with these antigens levels in normal tissue. Another goal was a search for a relationship /or its lack/ between the occurrence of the new generation markers of neoplastic disease and a presence /or absence/ of lymph node metastases. UPA, PAI-1 and PAI-2 antigen levels were determined by ELISA tests in protein extracts of breast cancer tissues. Among the studied breast tumors 32 specimens were ductal carcinomas, 15 specimens were lobular carcinomas and the remaining 13 were other rare histological forms. In comparison to the obtained values of u-PA antigen levels in normal tissue, the values in neoplastic tissues were elevated several times: 11-fold, 6-fold and 15-fold in ductal c., lobular c. and other rare neoplasms. The values of PAI-1 antigen levels were about 20- fold higher for all studied, histologically defined primary breast cancers. The greatest differences of PAI-2 antigen levels growth was observed in histologically defined primary breast cancer forms. It was augmented 10-fold, 40-fold and 20-fold, respectively, for ductal carcinoma, lobular carcinoma and rare forms of neoplasms. In various forms of invasive breast cancer and those without lymph node metastases the content of u-PA, PAI-1 and PAI-2 were also significantly elevated. Among the new generation of independent markers of the neoplastic process, PAI-2 seems to be the most reliable marker for the identification of primary breast cancer. The goal of the present study was to evaluate a possible combined prognostic value of the three major components of the u-PA system (u-PA, PAI-1 and PAI-2) in patients with defined histopathological forms of primary breast cancer

The Copey tree (Clusia rosea) has a large distribution in Cuba and its floral resin is a rich source of polyisoprenylated benzophenones. To determine the presence of these natural products, we carried out a study by HPLC of 21 propolis samples produced by honey bees (Apis mellifera) from different provinces of Cuba. Nemorosone resulted to be the most abundant polyisoprenylated benzophenone and the mixture of xanthochymol and guttiferone E was also observed, but in minor proportion. We studied the biological activity of the pure natural product nemorosone and its methyl derivatives. We found that nemorosone has cytotoxic activity against epitheloid carcinoma (HeLa), epidermoid carcinoma (Hep-2), prostate cancer (PC-3) and central nervous system cancer (U251). It also exhibited antioxidant capacity. Methylated nemorosone exhibited less biological activity than the natural product

Propolis has been extensively used in folk medicine for the management of a wide spectrum of disorders. In a previous study, we demonstrated the protective effect of the aqueous propolis extract (APE) against the injurious effects of carbon tetrachloride (CCl 4 ) on hepatocytes in vitro. The present investigation was carried out to show whether the hepatoprotective effect of the extract could also be manifested in vivo. Rats were given APE orally for 14 consecutive days, before being subjected to a single intraperitoneal injection of CCl 4 . One day after the CCl 4 injection, the animals were sacrificed, hepatocytes were isolated and liver homogenates were prepared for the assessment of liver injury. In isolated hepatocytes, APE afforded protection against CCl 4 -induced injury as manifested by a decrease in the leakage of the cytosolic enzyme lactate dehydrogenase (LDH), decreased generation of lipid peroxide and maintenance of cellular reduced glutathione (GSH) content. In principle, similar findings were observed in liver homogenates. The present findings show that APE has in vivo hepatoprotective potential which could be attributed at least in part to the maintenance of cellular GSH content. The latter effect seems to play an important role in conserving the integrity of biomembranes as it was associated with a decrease in lipid peroxidation and reduced leakage of cytosolic LDH

Three propolis samples from East Nile Delta, Egypt were collected. Propolis samples were investigated by GC/MS,103 compounds were identified, 20 being new for propolis. Dakahlia propolis was a typical poplar propolis but it contained two new caffeate esters and two new triterpenoids. Ismailia propolis was characterized by the presence of new triterpenic acid methyl esters and it did not contain any aromatic acids, esters and flavonoids. Sharkia propolis was characterized by the presence of caffeate esters only, some di- and triterpenoids. The antiviral (Infectious Bursal Disease Virus and Reo-Virus) and antimicrobial (Staphylococcus aureus; Escherichia coli and Candida albicans) activities of propolis samples were investigated. Dakahlia propolis showed the highest antiviral activity against Infectious Bursal Disease Virus (IBDV) and the highest antibacterial activity against Escherichia coli and the highest antifungal activity against Candida albicans. While Ismailia propolis had the highest antiviral activity against Reo-virus. Sharkia propolis showed the highest antibacterial activity against Staphylococcus aureus and moderate antiviral activity against infectious bursal disease virus and reovirus

The free radical scavenging effect of two propolis samples collected from reclaimed land, Egypt as well as of vitamin C and caffeic acid in 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical system was determined. The antimicrobial (Staphylococcus aureus; Escherichia coli and Candida albicans) activity was also investigated. The results of the free radical scavenging effect of El-Saff and Ismailia propolis showed a concentration-dependent activity. The antioxidant activity was varied according to the examined material. It was obvious that caffeic acid and vitamin C showed the highest activity if compared with the propolis samples. El- Saff propolis had a higher antioxidant activity than Ismailia propolis, it showed a higher antibacterial activity against Staphylococcus aureus and a higher anti-fungal activity against Candida albicans. While the Ismailia propolis had a higher antibacterial activity against Escherichia coli, than El-Saff propolis. The chemical composition of propolis samples was investigated by GC/MS, where 75 compounds were identified, 22 being new for propolis. The Ismailia propolis was characterized by the presence of a highly significant amount of aromatic acid esters (47.3%) and triterpenoids (17.3%), while El-Saff propolis contained 3% and 1.9% respectively. The new esters belonged to 4-methoxyhydrocinnamic acid, hydroferulic acid and ferulic acid. El-Saff propolis had a very high significant amount (27%) of 2,6-bis-(pentanyloxy)-4-pentanylphenethanol, which is also a new compound for propolis

An investigation of the MeOH extract from the roots of Peritassa campestris (Hippocrateaceae) afforded two isomeric seco-A-ring quinonemethide triterpenoids, campestrine-I (1) and -II (2). This appears to be the first report of a C 26 -type triterpene carbon skeleton from the Celastraceae or Hippocrateaceae families. The structures were elucidated on the basis of spectral data, particularly HMQC, HMBC and NOE experiments

The induction of HSP90 in murine erythroleukemia cells, clone F4 N, by cisplatin (DDP) was examined using indirect immunofluorescence and avidin-biotin technique, and compared with cisplatin cytotoxicity. A reverse dependence of HSP90 induction time was found on a wide range of cisplatin concentrations (0.5D10 μᴍ), which proved to be cytostatic up to 48 h of continuous treatment. Thus, the observed induction pattern of HSP90 in F4 N cells strictly correlated with their high tolerance toward DDP. This indicates that HSP90 might be responsible, at least in part, for cisplatin resistance of F4 N cells