An In Vitro Study on the Cytotoxic, Antioxidant, and Antimicrobial Properties of Yamogenin-A Plant Steroidal Saponin and Evaluation of Its Mechanism of Action in Gastric Cancer Cells.

Yamogenin is a steroidal saponin occurring in plant species such as Asparagus officinalis, Dioscorea collettii, Trigonella foenum-graecum, and Agave sp. In this study, we evaluated in vitro cytotoxic, antioxidant, and antimicrobial properties of yamogenin. The cytotoxic activity was estimated on human colon cancer HCT116, gastric cancer AGS, squamous carcinoma UM-SCC-6 cells, and human normal fibroblasts with MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. The amount of apoptotic and dead AGS cells after treatment with yamogenin was estimated with flow cytometry. Also, in yamogenin-treated AGS cells we investigated the reactive oxygen species (ROS) production, mitochondrial membrane depolarization, activity level of caspase-8 and -9, and gene expression at mRNA level with flow cytometry, luminometry, and RT-PCR, respectively. The antioxidant properties of yamogenin were assessed with DPPH (2,2-diphenyl-1-picrylhydrazyl) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) assays. The antimicrobial potential of the compound was estimated on Staphylococcus aureus, Bacillus cereus, Klebsiella pneumoniae, Escherichia coli, Salmonella enterica, Helicobacter pylori, Campylobacter coli, Campylobacter jejuni, Listeria monocytogenes, Lactobacillus paracasei, and Lactobacillus acidophilus bacteria strains. Yamogenin showed the strongest cytotoxic effect on AGS cells (IC50 18.50 ± 1.24 µg/mL) among the tested cell lines. This effect was significantly stronger in combinations of yamogenin with oxaliplatin or capecitabine than for the single compounds. Furthermore, yamogenin induced ROS production, depolarized mitochondrial membrane, and increased the activity level of caspase-8 and -9 in AGS cells. RT-PCR analysis revealed that this sapogenin strongly up-regulated TNFRSF25 expression at the mRNA level. These results indicate that yamogenin induced cell death via the extrinsic and intrinsic way of apoptosis. Antioxidant study showed that yamogenin had moderate in vitro potential (IC50 704.7 ± 5.9 µg/mL in DPPH and 631.09 ± 3.51 µg/mL in ABTS assay) as well as the inhibition of protein denaturation properties (with IC50 1421.92 ± 6.06 µg/mL). Antimicrobial test revealed a weak effect of yamogenin on bacteria strains, the strongest one being against S. aureus (with MIC value of 350 µg/mL). In conclusion, yamogenin may be a potential candidate for the treatment and prevention of gastric cancers.

Anti-Helicobacter pylori Biofilm Extracts from Rubus idaeus and Rubus occidentalis.

Helicobacter pylori infections are still an important health problem and are directly related to the development of gastric ulcer, gastric adenocarcinoma, mucosal lymphoid tissue lymphoma, and diabetes. At the same time, the number of substances/drugs effective against these bacteria is limited due to increasing resistance. Raw plant materials from various species of the Rubus genus-fruits and shoots-have shown antimicrobial activity in numerous studies against different bacteria, including H. pylori in a planktonic form. Research carried out on a model using fragments of intravenous infusions and triphenyl tetrazolium chloride (TTC) as a dye showed that the shoot extract of Rubus idaeus 'Willamette', the fruit extract of R. idaeus 'Poranna Rosa', R. idaeus and R. idaeus 'Laszka', and R. occidentalis Litacz' prevent the formation of biofilm by H. pylori. Active concentrations inhibiting biofilm formation were 6.65 mg/mL for shoots and 16.65 mg/mL for fruits. However, in the resulting biofilm, the extract from the shoots of R. idaeus 'Willamette' and the fruit of R. idaeus 'Poranna Rosa' at a concentration of 16.65 mg/mL was active against living bacteria, and the remaining extracts showed such activity at a concentration of 33.3 mg/mL. In studies on the interaction of the extract with antibiotics on biofilm, the extract from the shoots of R. idaeus 'Willamette' showed synergy with doxycycline and levofloxacin, additivity with amoxicillin and clarithromycin, and neutrality with metronidazole. H. pylori biofilm research was carried out in a newly elaborated research model-culture on fragments of intravenous infusions with the addition of TTC as a marker of living bacterial cells. The research results may constitute the basis for the development of new combination therapies for the treatment of H. pylori infections, including its resistant strains. The proposed new biofilm research model, which is cheap and effective, may allow testing of new substances that are potentially more effective against H. pylori and other biofilm-forming bacterial strains.

Activity of Cinnamic Acid Derivatives with 4-Chloro-2-mercaptobenzenesulfonamide Moiety against Clinical HLAR and VRE Enterococcus spp.

The rapid increase in strains that are resistant to antibiotics requires new active compounds to be found whose mechanism of action on bacteria is different to those that are currently known. Of particular interest are compounds that occur in plants as secondary metabolites. The focus of this study concerns the examination of the effects of synthetic cinnamic acid derivatives, with 4-chloro-2-mercaptobenzenesulfonamide moiety on Enterococcus spp. with HLAR (high-level aminoglycoside resistance) and VRE (vancomycin-resistant Enterococcus) mechanisms. The minimum inhibitory concentration (MIC) values of the tested compounds were determined using the serial dilution method for Enterococcus spp. groups, and the most active compounds were as follows: 16d, 17c, 16a, 16c and 16f (2-4 µg/mL). These compounds, at a concentration of 4 × MIC, inhibited the biofilm formation of HLAR strains (70 to 94%). At concentrations of 2 × MIC and 4 × MIC, they also inhibited the growth of VRE strains (42 to 96%). The best effect produced on the formed biofilm was demonstrated by compound 16f (from 62% MIC concentration to 89% 4 × MIC concentration) on the tested HLAR strains. In vitro studies, using the peripheral blood of domestic sheep, demonstrated the stable bacteriostatic activity of the tested compounds against Enterococcus spp. The compounds 16a, 16c, 16d, 16f and 17c showed synergism and additivity with ampicillin, streptomycin, gentamicin and vancomycin against resistant strains of Enterococcus spp. The tested compounds, when combined, reduce the MIC for antibiotics by 800 to 10,000 times for HLAR strains and by 8 to 10,000 times for VRE strains. The MIC of the tested compounds, in combination with antibiotics, is reduced 2-16-fold for HLAR strains and 2-32-fold for VRE strains. These studies demonstrate the potential for the therapeutic use of synthetic, cinnamic acid derivatives, with 4-chloro-2-mercaptobenzenesulfonamide moiety, to work against clinical strains of Enterococcus spp.

Application of tris-(4,7-Diphenyl-1,10 phenanthroline)ruthenium(II) Dichloride to Detection of Microorganisms in Pharmaceutical Products.

tris-[(4,7-diphenyl-1,10-phenanthroline)ruthenium(II)] dichloride (Ru(DPP)3Cl2), a fluorescent sensor which is sensitive to the amount of oxygen in the sample, was applied using the fluorescent optical respirometry (FOR) technique. The oxygen in the samples quenches the fluorescence. The fluorescence intensity depends on the metabolic rate of the viable microorganisms. The effect of DMSO and plant extracts on bacteria was determined by FOR. It was shown that the MIC values obtained by FOR were consistent with the results of the MIC determinations using the method of serial dilutions; at the same time, the effects of concentrations lower than the growth-inhibitory concentrations on microbial cells were demonstrated. The FOR method enables the detection of multiplying bacteria in sterile and non-sterile pharmaceutical preparations in real time, which significantly shortens the time required to obtain results and allows the introduction of repair processes in the production. This method also allows for quick, unambiguous detection and the counting of the viable cells of aerobic microorganisms in non-sterile pharmaceuticals.

Kalanchoe sp. Extracts-Phytochemistry, Cytotoxic, and Antimicrobial Activities.

Kalanchoe species are succulents occurring in tropical regions. They have many biological and pharmacological properties. In this study, the cytotoxic and antimicrobial activities of water and dichloromethane Kalanchoe fractions obtained from ethanol extracts of three Kalanchoe species-K. daigremontiana, K. pinnata, and K. blossfeldiana were estimated. The cytotoxic effect was assessed on human cancer cell lines-ovarian SKOV-3, cervical HeLa, breast MCF-7, and melanoma A375-by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The antimicrobial activity was estimated on selected Gram-positive and Gram-negative bacteria strains and on Candida albicans. The phytochemical analysis of selected Kalanchoe extracts was conducted by LC-QTOF-MS. The obtained results showed that the water fraction of K. blossfeldiana was active both on the tested cancer cells (IC50 values were 28.28 ± 2.76 and 32.51 ± 0.69 µg/mL on HeLa and SKOV-3, respectively) and bacteria strains (MIC values were 16 and 32 µg/mL on S. epidermidis and S. aureus, respectively). The water fraction of K. pinnata also had a significant effect on S. epidermidis and S. aureus, with MIC values of 32 and 64 µg/mL, respectively. The water fraction of K. blossfeldiana triggered a decrease in mitochondrial membrane potential (MMP) and induced cell cycle arrest in the G2/M phase in the SKOV-3 and HeLa cells. This fraction did not significantly increase cellular oxidative stress level. The DPPH and ABTS assays revealed that the water fraction of K. blossfeldiana had a strong antioxidant effect (IC50 was 9.44 ± 0.06 and 3.17 ± 0.1 µg/mL, respectively). The phytochemical analysis of the extracts of K. blossfeldiana and K. pinnata revealed the presence of at least 218 main components. The most frequently occurring were flavonol glycosides (31 metabolites), phenylpropanoids (13 metabolites), gallic acid derivatives (13 compounds), benzoic acid derived compounds (14 metabolites), and acyclic alcohol glycosides (16 compounds). In addition, proanthocyanidins were detected mainly in K. blossfeldiana. The study indicates that the water fraction of K. blossfeldiana has significant biological potential and can be further investigated towards anticancer and antimicrobial application.

Ru(II) Oxygen Sensors for Co(III) Complexes and Amphotericin B Antifungal Activity Detection by Phosphorescence Optical Respirometry.

The measurement of oxygen consumption is an important element in the understanding of an organism's metabolic state. Oxygen is also a phosphorescence quencher, which allows the evaluation of phosphorescence emitted by oxygen sensors. Two Ru(II)-based oxygen-sensitive sensors were used to study the effect of chemical compounds [(1) = [CoCl2(dap)2]Cl, and (2) = [CoCl2(en)2]Cl (AmB = amphotericin B) against reference and clinical strains of Candida albicans. The tris-[(4,7-diphenyl-1,10-phenanthroline)ruthenium(II)] chloride ([Ru(DPP)3]Cl2) (Box) adsorbed onto the DavisilTM silica gel was embedded in the silicone rubber Lactite NuvaSil® 5091 and the coating on the bottom of 96-well plates. The water-soluble oxygen sensor (BsOx = tris-[(4,7-diphenyl-1,10-phenanthrolinedisulphonic acid disodium)ruthenium(II)] chloride 'x' hydrate = {Ru[DPP(SO3Na)2]3}Cl2 = water molecules were omitted in the BsOx formula) was synthesized and characterized by RP-UHPLC, LCMS, MALDI, elemental analysis, ATR, UV-Vis, 1H NMR, and TG/IR techniques. The microbiological studies were performed in the environment of RPMI broth and blood serum. Both Ru(II)-based sensors turned out to be useful in the study of the activity of Co(III) complexes and the commercial antifungal drug amphotericin B. In addition, a new activity of the oxygen sensor, the soluble Ru(II) complex BsOx, was demonstrated, which is a mixture with amphotericin B that caused a significant increase in its antifungal activity. Thus, it is also possible to demonstrate the synergistic effect of compounds active against the microorganisms under study.

Mangiferin Affects Melanin Synthesis by an Influence on Tyrosinase: Inhibition, Mechanism of Action and Molecular Docking Studies.

Mangiferin is a strong antioxidant that presents a wide range of biological activities. The aim of this study was to evaluate, for the first time, the influence of mangiferin on tyrosinase, an enzyme responsible for melanin synthesis and the unwanted browning process of food. The research included both the kinetics and molecular interactions between tyrosinase and mangiferin. The research proved that mangiferin inhibits tyrosinase activity in a dose-dependent manner with IC50 290 +/- 6.04 µM, which was found comparable with the standard kojic acid (IC50 217.45 +/- 2.54 µM). The mechanism of inhibition was described as mixed inhibition. The interaction between tyrosinase enzyme and mangiferin was confirmed with capillary electrophoresis (CE). The analysis indicated the formation of two main, and four less significant complexes. These results have also been supported by the molecular docking studies. It was indicated that mangiferin binds to tyrosinase, similarly to L-DOPA molecule, both in the active center and peripheral site. As it was presented in molecular docking studies, mangiferin and L-DOPA molecules can interact in a similar way with surrounding amino acid residues of tyrosinase. Additionally, hydroxyl groups of mangiferin may interact with amino acids on the tyrosinase external surface causing non-specific interaction.

An In Vitro Antimicrobial, Anticancer and Antioxidant Activity of N-[(2-Arylmethylthio)phenylsulfonyl]cinnamamide Derivatives.

Cinnamic acid is a plant metabolite with antimicrobial, anticancer, and antioxidant properties. Its synthetic derivatives are often more effective in vitro than parent compounds due to stronger biological activities. In our study, we synthesized ten new N-(4-chloro-2-mercapto-5-methylphenylsulfonyl)cinnamamide derivatives, containing two pharmacophore groups: cinnamic acid moiety and benzenesulfonamide. The antimicrobial activity of the obtained compounds was estimated using different types of Gram-positive and Gram-negative bacteria, fungus species of Candida albicans, as well as clinical strains. The compounds were evaluated on biofilm formation and biofilm formed by Staphylococcus clinical strains (methicillin-resistance S. aureus MRSA and methicillin-resistance coagulase-negative Staphylococcus MRCNS). Furthermore, blood bacteriostatic activity test was performed using S. aureus and S. epidermidis. In cytotoxic study, we performed in vitro hemolysis assay on domestic sheep peripheral blood and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay on human cervical HeLa, ovarian SKOV-3, and breast MCF-7 cancer cell lines. We also estimated antioxidant activity of ten compounds with 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) assays. Our results showed a significant antimicrobial activity of the compounds. All of them were active on Staphylococcus and Enterococcus species (MIC was 1-4 µg/mL). The compounds 16d and 16e were the most active on staphylococci clinical strains and efficiently inhibited the biofilm formation and biofilm already formed by the clinical staphylococci. Moreover, the hemolytic properties of the tested compounds occurred in higher quantities (>32.5 µg/mL) than the concentrations that inhibited both the growth of bacteria in the blood and the formation and growth of biofilm. The results of MTT assay showed that compounds 16c, 16d, 17a, and 17d demonstrated the best activity on the cancer cells (the IC50 values were below 10 µg/mL). Compound 16f was the least active on the cancer cells (IC50 was > 60 µg/mL). Antiradical tests revealed that compounds 16f and 17d had the strongest antioxidant properties within the tested group (IC50 was 310.50 ± 0.73 and 574.41 ± 1.34 µg/mL in DPPH, respectively, and 597.53 ± 1.3 and 419.18 ± 2.72 µg/mL in ABTS assay, respectively). Our study showed that the obtained cinnamamide derivatives can be used as potential antimicrobial therapeutic agents.

New Chalcone Derivatives Containing 2,4-Dichlorobenzenesulfonamide Moiety with Anticancer and Antioxidant Properties.

Chalcones and their derivatives, both natural and synthetic, exhibit diverse biological activities. In this study, we focused on designing and synthesizing (E)-2,4-dichloro-N-(4-cinnamoylphenyl)-5-methylbenzenesulfonamides 4-8 with the following two pharmacophore groups: 2,4-dichlorobenzenesulfonamide and chalcone. The obtained compounds displayed notable anticancer effects on various human cancer cells, such as cervical HeLa, acute promyelocytic leukemia HL-60, and gastric adenocarcinoma AGS, when assessed with the MTT test. The activity of all compounds against cancer cells was significant, and the obtained IC50 values were in the range of 0.89-9.63 µg/mL. Among all the tested compounds, derivative 5 showed the highest activity on the AGS cell line. Therefore, it was tested for cell cycle inhibition, induction of mitochondrial membrane depolarization, and activation of caspase-8 and -9. These results showed that this compound strongly arrested the cell cycle in the subG0 phase, depolarized the mitochondrial membrane, and activated caspase-8 and -9. Similar to the anticancer effects, all the obtained compounds 4-8 were also assessed for their antioxidant activity. The highest antiradical effect was demonstrated for derivative 5, which was able to inhibit DPPH and ABTS radicals. All examined compounds showed dose-dependent activity against neutrophil elastase. Notably, derivatives 7 and 8 demonstrated inhibitory properties similar to oleanolic acid, with IC50 values of 25.61 ± 0.58 and 25.73 ± 0.39 µg/mL, respectively. To determine the antibacterial activity of derivatives 4-8, the minimum bacteriostatic concentration (MIC) values were estimated (>500 µg/mL for all the tested bacterial strains). The findings demonstrate the substantial potential of sulfonamide-based chalcone 5 as a promising drug in anticancer therapy.

Polyphenolic Characterization, Antioxidant, Antihyaluronidase and Antimicrobial Activity of Young Leaves and Stem Extracts from Rubus caesius L.

Fruits are the main food part of the European dewberry (Rubus caesius L.), known as a source of polyphenols and antioxidants, while very little attention is paid to leaves and stems, especially young first-year stems. The purpose of this work was to analyze for the first time water and ethanol extracts obtained from young, freshly developed, leaves and stems of the European dewberry to determine their antioxidant and biological activity, whereas most of the papers describe biological properties of leaves collected during summer or autumn. As the phytochemical profile changes during the growing season, the quantitative and qualitative content of flavonoid glycosides and flavonoid aglycones was analyzed using reversed phase liquid chromatography/electrospray ionization triple quadrupole mass spectrometry (LC-ESI-MS/MS) with multiple reaction monitoring (MRM). The ability to inhibit hyaluronidase as well as antioxidant activity (2,2 diphenyl-1-picrylhydrazyl: DPPH and ferric antioxidant power: FRAP) were estimated. Extracts were also analyzed against Gram-positive and Gram-negative bacteria. The results of the qualitative phytochemical analysis indicated the presence of flavonoid aglycones and flavonoid glycosides, with the highest amount of tiliroside, hyperoside, isoquercetin, astragalin, rutin and catechin in ethanol extracts. DPPH and FRAP tests proved the high antioxidant activity of the extracts from leaves or stems and the antihyaluronidase assay revealed for the first time that water and ethanol extracts obtained from the stems exhibited the ability to inhibit hyaluronidase activity resulting in an IC50 of 55.24 ± 3.21 and 68.7 ± 1.61 µg/mL, respectively. The antimicrobial activity has never been analyzed for European dewberry and was the highest for Clostridium bifermentans and Clostridium sporogenes-anaerobic sporulation rods as well as Enterococcus faecalis for both water and ethanol extracts.

2D LC as a tool for standardization of Foenugraeci semen extracts containing compounds with anti-Helicobacter pylori activity.

The on-line heart-cutting two-dimensional liquid chromatography method with the use of a diode array detector and a mass spectrometer (LC-LC-DAD-ESI-MS) was established and validated for quantitation of C-glycosylflavones in fenugreek seeds (Foenugraeci semen, Trigonella foenum-graecum L.). The first- (1D) and second- (2D) dimensional separations were performed on Kinetex C-18 columns with different diameters, respectively, and gradient (1D) and isocratic elution (2D). Finally, 17 compounds were separated, 13 of which were quantified by 1D separation and 4 compounds by 2D separation. As a result, it was pointed out that fenugreek seeds of Polish origin can be considered as a rich source of C-glycosylflavones. Antibacterial activity against Helicobacter pylori of standardized 70% methanol extract from fenugreek seeds has been demonstrated, in contrast to the inactive aqueous extract. Anti-H. pylori activity of the 70% methanol extract can be related to a higher concentration of C-glycosylflavones. This is the first report on the bactericidal activity of vitexin, diosgenin, tigogenin and sarsasapogenin against H. pylori and the bacteriostatic activity of orientin against this bacterium.

Inhibition of Neutrophil Functions and Antibacterial Effects of Tarragon (Artemisia dracunculus L.) Infusion-Phytochemical Characterization.

The aim of the study was to characterize phytochemicals in an infusion of the aerial parts of tarragon (Artemisia dracunculus L.) using ultra-high-performance liquid chromatography diode array detector electrospray ionisation tandem mass spectrometry UHPLC-DAD-ESI-MS/MS method, as well as an evaluation of its effects on mediators of the inflammation in an in vitro model of human neutrophils, and antimicrobial activity on selected pathogens. Flavonoids and caffeoylquinic acids were the main phenolic components of the extract of tarragon's aerial parts. The infusion was able to inhibit reactive oxygen species (ROS), interleukin 8 (IL-8), and tumour necrosis factor α (TNF-α) production. The antimicrobial assay was performed with the use of nine strains of bacteria, both Gram-negative and Gram-positive. Three human pathogens, Staphylococcus aureus ATCC6538, Staphylococcus epidermidis ATCC14990, and Staphylococcus aureus MRSA (methicyllin-resistant Staphylococcus aureus) ATCC43300, proved to be the most sensitive to tarragon infusion. Our study demonstrated the antiinflammatory and antimicrobial properties of tarragon (Artemisia dracunculus L.), meaning the common spice may be a prospective source of health-promoting constituents.

Biological activities of leaf extracts from selected Kalanchoe species and their relationship with bufadienolides content.

CONTEXT: Kalanchoe species (Crassulaceae) are widely used in traditional medicine as remedies in infectious diseases and cancer treatment. OBJECTIVE: Cytotoxic and antimicrobial activities of Kalanchoe daigremontiana Raym.-Hamet & H. Perrier, K. pinnata (Lam.) Pers., and K. blossfeldiana Poelln. extracts were determined. The relationship between biological activities and the extracts bufadienolides content was also investigated. MATERIALS AND METHODS: Fresh leaves of Kalanchoe species were macerated with 95% ethanol or water. The quantitative analysis of bufadienolides in the extracts was carried out with mass spectrometry. Cytotoxicity tests were performed on human cancer cell lines - HeLa, SKOV-3, MCF-7, and A375 by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay and Real-Time Cell Analysis system. The microbiological study was done using a few bacteria strains (ß-hemolytic Streptococcus, Corynebacterium diphtheriae, Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus hirae, Escherichia coli) and Candida albicans. RESULTS: The K. blossfeldiana ethanol extract and K. daigremontiana water extract exhibited the most potent cytotoxic activity (IC50 < 19 µg/mL for HeLa and SKOV-3 cells). The strongest antibacterial effects showed ethanol extract of K. blossfeldiana and K. pinnata (MIC values were 8.45, 8.45, 0.25 and <33.75 µg/mL for S. aureus, S. epidermidis, and E. hirae, respectively). The highest total amount of bufadienolides was in K. daigremontiana ethanol extract. In contrast, K. blossfeldiana ethanol extract did not show the presence of these compounds. CONCLUSIONS: Kalanchoe blossfeldiana ethanol extract is a potential candidate for cancer and bacterial infection treatment. Additionally, the biological effects of Kalanchoe extracts are not dependent on the presence and amount of bufadienolides in the plant extracts.

Antibacterial and anti-inflammatory activity of bistort (Bistorta officinalis) aqueous extract and its major components. Justification of the usage of the medicinal plant material as a traditional topical agent.

ETHNOPHARMACOLOGICAL RELEVANCE: Bistort rhizome (Bistorta officinalis) is a traditionally used plant material popular in Europe and Asia in the treatment of diarrhea and as a topical agent for skin conditions. It contains tannins mostly condensed flavan-3-ol derivatives. However, the in-depth phytochemical investigation of infusions from this plant materials is still lacking. Additionally, the scientific reports supporting the traditional topical application of bistort rhizome are scarce. AIM OF THE STUDY: The major objective of the present study was to comprehensively investigate the chemical composition of infusion from subterranean parts of common bistort both using hyphenated chromatographic technique and isolation approach. Additionally, the influence of water extract on pro-inflammatory functions of human neutrophils was performed. As bacterial infections play a crucial role in the generation of skin inflammations the antimicrobial activity of the infusion and its major components was established. MATERIAL AND METHODS: The chemical composition of the infusion was established using UHPLC-DAD-MS3 method. Major compounds which could not be identified using chromatographic analysis were isolated by column chromatography and preparative HPLC. Obtained pure phytochemicals were identified by NMR analysis. The influence of the extract and compounds on the cell viability and apoptosis was evaluated by flow cytometry. The release of pro-inflammatory cytokines after LPS stimulation was established by ELISA. Finally, the antimicrobial assays were performed by establishing MIC and MBC values using several bacterial strains. RESULTS: The UHPLC analysis revealed the infusion contained mainly, galloyl glucose derivatives, procyanidins and chlorogenic acid. Several compounds were isolated and identified for the first time from the investigated plant material. It was shown that the infusion and its constituents influenced the release of proinflammatory cytokines such as IL-1ß, TNF-α and IL-8 and also affected the viability and apoptosis of healthy cells. Both extract and isolated natural products displayed antimicrobial activity against skin pathogens. CONCLUSIONS: The results obtained in the present study support that the infusions from common bistort influence key biological processes are crucial for skin conditions with the inflammatory background. The study justifies the traditional topical application of common bistort.

Chemical composition and biological activity of Rubus idaeus shoots--a traditional herbal remedy of Eastern Europe.

BACKGROUND: The young shoots of Rubus idaeus are traditionally used as a herbal remedy in common cold, fever and flu-like infections yet there is no research concerning this plant material. The aim of the study was to evaluate the chemical composition and biological properties of raspberry shoots from 11 cultivar varieties. METHODS: The methanol extracts were subjected to chromatographic analysis using HPLC-DAD-ESI-MS, and two-dimensional 'comprehensive' LCxLC techniques. The biological activity of the shoot extract from the 'Willamette' cultivar variety was evaluated. Antioxidant activity was tested using DPPH and phosphomolybdenum assay. Antimicrobial activity was estimated towards 15 strains of human pathogenic bacteria using broth microdilution method. Cytotoxic activity was tested using MTT cell viability assay. RESULTS: The dominating compounds identified in the shoots of R. idaeus were ellagic acid (26.1 - 106.8 mg/100 g) and sanguiin H-6 (139.2 - 633.1 mg/100 g). The best separation of compounds present in the analysed polyphenol complex, was achieved by 'comprehensive' LCxLC method using Nucleodur Sphinx RP column in the first dimension and Chromolith Performance column in the second dimension. The shoot extract was found to be a strong antioxidant (EC50 19.4 µg/ml, AAE 427.94 mg/g) and displayed the strongest bactericidal properties towards Corynebacterium diphtheriae. The extract revealed higher cytotoxic activity towards the HL-60 cells (IC50 110 µg/ml) than HeLa (IC50 300 µg/ml). CONCLUSIONS: The shoots of R. idaeus stand out as a valuable source of sanguiin H-6 and ellagic acid and possess a number of biological properties including antioxidative, antimicrobial and cytotoxic.

Structure-activity relationships of novel heteroaryl-acrylonitriles as cytotoxic and antibacterial agents.

Eighteen new 2,6-disubstituted acrylonitriles and two new (benzimidazol-1-yl)-acetamide derivatives were prepared and screened for antibacterial and cytotoxic activities on 12 human cancer cell lines. Based on the lead structure 2-(benzimidazol-2-yl)-3-(5-nitrothiophen-2-yl) acrylonitrile it was found that placement of methyl groups at the 5,6 positions of the benzimidazole ring lead to a 3-fold increase in overall cytotoxic activity. Replacing the nitrothiophene for pyridine reduced cytotoxic activity as did replacing the nitro group for a methoxy group. Cytotoxic activity was only slightly reduced when the benzimidazole ring was replaced by a imidazo[4,5-b]pyridine or a benzthiazole ring but replacement by benzoxazole led to a substantial decrease in activity. Moving the acrylonitrile group from position 2 to position 1 of the benzimidazole ring also resulted in moderately active compounds. (Benzimidazol-1-yl)acetamides showed only modest activity. The structure-activity relationships found in the cytotoxicity studies are mirrored in the results of the antibacterial experiments.

Synthesis and biological activity of new 2-amino-8-chloro-5,5-dioxo[1,2,4]triazolo[2,3-b][1,4,2]benzodithiazines.

Two series of 1-(6-chloro-1,1-dioxo-1,4,2-benzodithiazin-3-yl)-4-arylsemicarbazides 6-17 and 2-arylamino-8-chloro-5,5-dioxo[1,2,4]triazolo[2,3-b][1,4,2]benzodithiazines 18-26 were prepared in order to evaluate their biological activity. Compounds 6 and 18-26 were tested for their in vitro cytotoxic potency against 12 human cancer cell lines. The compounds 6 and 19 were inactive, whereas triazolobenzodithiazines 18, 20-26 possess tumor growth inhibitory properties. The prominent methyl 8-chloro-2-(4-chlorophenylamino)-5,5-dioxo[1,2,4]triazolo[2,3-b][1,4,2]benzodithiazine-7-carboxylate (21) exhibited potency higher or comparable to cisplatin. Moreover, compounds 6, 9, 19 and 23-25 with structure similar to other chemotherapeutic agents were tested for their antibacterial activity and exhibited MIC and MBC against Staphylococcus aureus (3.9-31.5 microg ml).