Profily fenolického obsahu a antivolonoradikálová aktivita kořenů druhů Glycyrrhiza

8. ABSTRAKT 8.1. Profily fenolického obsahu a antivolnoradikálová aktivita kořenů druhů Glycyrrhiza V této studii byla určena antivolnoradikálová aktivita 80% metanolových extraktů kořenů z rostlin G. glabra, G. uralensis, G. echinata a G. pallidiflora za použití DPPH antivolnoradikálové a antisuperoxidové anionové zkoušky. Celkový obsah fenolů (TP), flavonoidů (TF) a taninů (TT) byl také změřen. Z výsledků je zřejmé, že G. glabra prokázala nejvyšší DPPH antivolnoradikálovou aktivitu (DRSA), zatímco G. echinata prokázala nejnižší hodnoty DRSA. Extrakty z G. uralensis, G. echinata a G. pallidiflora ukázaly nejvyšší superoxidovou antivolnoradikálovou aktivitu (SRSA). Nejvyšší TP obsah byl nalezen v G. uralensis a G.echinata (4.71 a 4.70 mg ekvivalentů kyseliny galové /100 mg extraktu, respektive). Nejvyšší obsah TF (1.84 mg kercetinových ekvivalentů (QE)/100 mg extraktu) byl pozorován v rostlině G. glabra, zatímco nejnižší hodnota (0.53 mg QE/100 mg extraktu) byla naměřena v rostlině G. pallidiflora. Extrakty z G. uralensis a G. pallidiflora prokázaly nejvyšší obsah TT. Byly zde pozitivní a významné korelace mezi TP a SRSA (r = 0.6881, p < 0.05) a mezi TT a SRSA (r = 0.7754, p < 0.05). Obsah TF byl významně korelován pouze s DRSA (r = 0.8804, p < 0.05). Tyto výsledky ukazují, že flavonoidy a taniny byly...7. ABSTRACT 7.1. Phenolic content profiles and free radical-scavenging activity of roots of Glycyrrhiza species In this study, the free radical-scavenging activity of 80% methanolic extracts from G. glabra, G. uralensis, G. echinata, and G. pallidiflora roots was assessed using DPPH free radical and superoxide anion radical scavenging assays. The total contents of phenolics (TP), flavonoids (TF), and tannins (TT) were also measured. From the results, G. glabra showed the highest DPPH radical scavenging activity (DRSA), whereas G. echinata exhibited the lowest values of DRSA. Extracts from G. uralensis, G. echinata, and G. pallidiflora showed the highest superoxide radical scavenging activity (SRSA). The highest TP content was found out in G. uralensis and G. echinata (4.71 and 4.70 mg gallic acid equivalents/100 mg of extract, respectively). The highest TF content (1.84 mg quercetin equivalents (QE)/100 mg of extract) was observed in G. glabra, whereas the lowest value (0.53 mg QE/100 mg of extract) was measured in G. pallidiflora. Extracts from G. uralensis and G. pallidiflora showed the highest TT content. There were positive and significant correlations between TP and SRSA (r = 0.6881, p < 0.05) and between TT and SRSA (r = 0.7754, p < 0.05). The TF content was significantly correlated only with DRSA (r...Katedra farmakognozieDepartment of PharmacognosyFaculty of Pharmacy in Hradec KrálovéFarmaceutická fakulta v Hradci Králov

Atrapadores de radicales libres y antioxidantes de Cymbopogon citratus, Populus TMxTM y frutos de Fragaria chiloensis ssp. chiloensis (f. chiloensis)

156 p.En el marco de esta investigacion se logro aislar, identificar y evaluar los principales compuestos antioxidantes y atrapadores de radicales libres de las hojas de “yerba Luisa” Cymbopogon citratus (DC.) Stapf. (Gramineae), Alamo Populus TMxTM y “frutilla blanca” Fragaria chiloensis ssp. chiloensis (f. chiloensis). Se determino la capacidad atrapadora de radicales libres y el efecto antioxidante de la infusion, decoccion y extractos MeOH:H2O 7:3 y 1:1, MeOH de hojas de Yerba Luisa y Alamo. El extracto MeOH para la yerba Luisa y el extracto MeOH:H2O 7:3 para el Alamo, mostraron la mayor actividad antioxidante y atrapadora de radicales libres. El fraccionamiento y aislamiento guiado del extracto MeOH de yerba Luisa permitio aislar 5 flavonoides C-glicosidos, acido clorogenico y acido cafeico, los cuales mostraron fuerte actividad antioxidante / atrapadora de radicales libres. La presencia de estos compuestos en C. citratus pudo ser relacionada con algunos de sus beneficios indicados por la medicina tradicional, ademas permitio sentar la bases para un sistema de control de calidad de la droga cruda basado en la identidad, contenido y actividad antioxidante. El fraccionamiento y aislamiento guiado del extracto MeOH:H2O 7:3 de hojas del Alamo permitio aislar cuatro flavonoles glicosidados con fuerte actividad antioxidante atrapadora de radicales libres. La presencia de metabolitos antioxidantes y atrapadores de radicales libres en las hojas de este hibrido valoro su potencial uso como fuente de antioxidantes naturales para aplicacion industrial proporcionando un valor agregado a desechos de la industria forestal. A partir de la “frutilla blanca” se logro aislar cianidina 3-O-glucosido, triptofano, tres derivados del acido trans-cinamico y acido elagico identificado por HPLC-DAD. La actividad antioxidante y atrapadora de radicales libres de frutilla blanca pudo se

Fatty Acid Substitutions Modulate the Cytotoxicity of Puwainaphycins/Minutissamides Isolated from the Baltic Sea Cyanobacterium Nodularia harveyana UHCC-0300

Puwainaphycins (PUW) and minutissamides (MIN) are structurally homologous cyclic lipopeptides that exhibit high structural variability and possess antifungal and cytotoxic activities. While only a minor variation can be found in the amino acid composition of the peptide cycle, the fatty acid (FA) moiety varies largely. The effect of FA functionalization on the bioactivity of PUW/MIN chemical variants is poorly understood. A rapid and selective liquid chromatography-mass spectrometry-based method led us to identify 13 PUW/MIN (1-13) chemical variants from the benthic cyanobacterium Nodularia harveyana strain UHCC-0300 from the Baltic Sea. Five new variants identified were designated as PUW H (1), PUW I (2), PUW J (4), PUW K (10), and PUW L (13) and varied slightly in the peptidic core composition, but a larger variation was observed in the oxo-, chloro-, and hydroxy-substitutions on the FA moiety. To address the effect of FA substitution on the cytotoxic effect, the major variants (3 and 5-11) together with four other PUW/MIN variants (14-17) previously isolated were included in the study. The data obtained showed that hydroxylation of the FA moiety abolishes the cytotoxicity or significantly reduces it when compared with the oxo-substituted C-18-FA (compounds 5-8). The oxo-substitution had only a minor effect on the cytotoxicity of the compound when compared to variants bearing no substitution. The activity of PUW/ MIN variants with chlorinated FA moieties varied depending on the position of the chlorine atom on the FA chain. This study also shows that variation in the amino acids distant from the FA moiety (position 4-8 of the peptide cycle) does not play an important role in determining the cytotoxicity of the compound. These findings confirmed that the lipophilicity of FA is essential to maintain the cytotoxicity of PUW/MIN lipopeptides. Further, a 63 kb puwainaphycin biosynthetic gene cluster from a draft genome of the N. harveyana strain UHCC-0300 was identified. This pathway encoded two specific lipoinitiation mechanisms as well as enzymes needed for the modification of the FA moiety. Examination on biosynthetic gene clusters and the structural variability of the produced PUW/MIN suggested different mechanisms of fatty-aryl-AMP ligase cooperation with accessory enzymes leading to a new set of PUW/MIN variants bearing differently substituted FA.Peer reviewe

Semi-synthetic puwainaphycin/minutissamide cyclic lipopeptides with improved antifungal activity and limited cytotoxicity

Microbial cyclic lipopeptides are an important class of antifungal compounds with applications in pharmacology and biotechnology. However, the cytotoxicity of many cyclic lipopeptides limits their potential as antifungal drugs. Here we present a structure-activity relationship study on the puwainaphycin/minutissamide (PUW/MIN) family of cyclic lipopeptides isolated from cyanobacteria. PUWs/MINs with variable fatty acid chain lengths differed in the dynamic of their cytotoxic effect despite their similar IC50 after 48 hours (2.8 mu M for MIN A and 3.2 mu M for PUW F). Furthermore, they exhibited different antifungal potency with the lowest MIC values obtained for MIN A and PUW F against the facultative human pathogen Aspergillus fumigatus (37 mu M) and the plant pathogen Alternaria alternata (0.6 mu M), respectively. We used a Grignard-reaction with alkylmagnesium halides to lengthen the lipopeptide FA moiety as well as the Steglich esterification on the free hydroxyl substituents to prepare semi-synthetic lipopeptide variants possessing multiple fatty acid tails. Cyclic lipopeptides with extended and branched FA tails showed improved strain-specific antifungal activity against A. fumigatus (MIC = 0.5-3.8 mu M) and A. alternata (MIC = 0.1-0.5 mu M), but with partial retention of the cytotoxic effect (similar to 10-20 mu M). However, lipopeptides with esterified free hydroxyl groups possessed substantially higher antifungal potencies, especially against A. alternata (MIC = 0.2-0.6 mu M), and greatly reduced or abolished cytotoxic activity (>20 mu M). Our findings pave the way for a generation of semi-synthetic variants of lipopeptides with improved and selective antifungal activities.Peer reviewe

Anti-Proliferative Activity of Meroditerpenoids Isolated from the Brown Alga Stypopodium flabelliforme against Several Cancer Cell Lines

The sea constitutes one of the most promising sources of novel compounds with potential application in human therapeutics. In particular, algae have proved to be an interesting source of new bioactive compounds. In this work, six meroditerpenoids (epitaondiol, epitaondiol diacetate, epitaondiol monoacetate, stypotriol triacetate, 14-ketostypodiol diacetate and stypodiol) isolated from the brown alga Stypopodium flabelliforme were tested for their cell proliferation inhibitory activity in five cell lines. Cell lines tested included human colon adenocarcinoma (Caco-2), human neuroblastoma (SH-SY5Y), rat basophilic leukemia (RBL-2H3), murine macrophages (RAW.267) and Chinese hamster fibroblasts (V79). Antimicrobial activity of the compounds was also evaluated against Staphylococcus aureus, Salmonella typhimurium, Proteus mirabilis, Bacillus cereus, Enterococcus faecalis and Micrococcus luteus. Overall, the compounds showed good activity against all cell lines, with SH-SY5Y and RAW.267 being the most susceptible. Antimicrobial capacity was observed for epitaondiol monoacetate, stypotriol triacetate and stypodiol, with the first being the most active. The results suggest that these molecules deserve further studies in order to evaluate their potential as therapeutic agents

The use of plants in the traditional management of diabetes in Nigeria: Pharmacological and toxicological considerations

Ethnopharmacological relevance: The prevalence of diabetes is on a steady increase worldwide and it is now identified as one of the main threats to human health in the 21st century. In Nigeria, the use of herbal medicine alone or alongside prescription drugs for its management is quite common. We hereby carry out a review of medicinal plants traditionally used for diabetes management in Nigeria. Based on the available evidence on the species׳ pharmacology and safety, we highlight ways in which their therapeutic potential can be properly harnessed for possible integration into the country׳s healthcare system. Materials and methods: Ethnobotanical information was obtained from a literature search of electronic databases such as Google Scholar, Pubmed and Scopus up to 2013 for publications on medicinal plants used in diabetes management, in which the place of use and/or sample collection was identified as Nigeria. ‘Diabetes’ and ‘Nigeria’ were used as keywords for the primary searches; and then ‘Plant name – accepted or synonyms’, ‘Constituents’, ‘Drug interaction’ and/or ‘Toxicity’ for the secondary searches. Results: The hypoglycemic effect of over a hundred out of the 115 plants reviewed in this paper is backed by preclinical experimental evidence, either in vivo or in vitro. One-third of the plants have been studied for their mechanism of action, while isolation of the bioactive constituent(s) has been accomplished for twenty three plants. Some plants showed specific organ toxicity, mostly nephrotoxic or hepatotoxic, with direct effects on the levels of some liver function enzymes. Twenty eight plants have been identified as in vitro modulators of P-glycoprotein and/or one or more of the cytochrome P450 enzymes, while eleven plants altered the levels of phase 2 metabolic enzymes, chiefly glutathione, with the potential to alter the pharmacokinetics of co-administered drugs. Conclusion: This review, therefore, provides a useful resource to enable a thorough assessment of the profile of plants used in diabetes management so as to ensure a more rational use. By anticipating potential toxicities or possible herb–drug interactions, significant risks which would otherwise represent a burden on the country׳s healthcare system can be avoided

Biological Activities and Chemical Content of Glycyrrhiza Species

7. ABSTRACT 7.1. Phenolic content profiles and free radical-scavenging activity of roots of Glycyrrhiza species In this study, the free radical-scavenging activity of 80% methanolic extracts from G. glabra, G. uralensis, G. echinata, and G. pallidiflora roots was assessed using DPPH free radical and superoxide anion radical scavenging assays. The total contents of phenolics (TP), flavonoids (TF), and tannins (TT) were also measured. From the results, G. glabra showed the highest DPPH radical scavenging activity (DRSA), whereas G. echinata exhibited the lowest values of DRSA. Extracts from G. uralensis, G. echinata, and G. pallidiflora showed the highest superoxide radical scavenging activity (SRSA). The highest TP content was found out in G. uralensis and G. echinata (4.71 and 4.70 mg gallic acid equivalents/100 mg of extract, respectively). The highest TF content (1.84 mg quercetin equivalents (QE)/100 mg of extract) was observed in G. glabra, whereas the lowest value (0.53 mg QE/100 mg of extract) was measured in G. pallidiflora. Extracts from G. uralensis and G. pallidiflora showed the highest TT content. There were positive and significant correlations between TP and SRSA (r = 0.6881, p < 0.05) and between TT and SRSA (r = 0.7754, p < 0.05). The TF content was significantly correlated only with DRSA (r..

Free radical-scavenging, antioxidant and immunostimulating effects of a licorice infusion (Glycyrrhiza glabra L.)

To contribute to the understanding of the mechanisms underlying the beneficial effects of licorice, the antioxidant, free radical-scavenging and immunostimulating effects of a licorice infusion (LI) were investigated, and its chemical profile was determined. Two major components of LI were identified as (1) liquiritin and (2) glycyrrhizin. LI weakly scavenged DPPH{radical dot}, and compounds 1 and 2 showed negligible effects. Both LI and 2 substantially scavenged superoxide radicals. The β-carotene bleaching was inhibited by LI, but compounds 1 and 2 showed no effect. The LI, 1, and 2 exhibited no meaningful activities against HOCl, and they showed pro-oxidant effects in the MPO-chlorinating system. Granulocytes and NK cells were markedly activated by LI, whereas 1 and 2 were inactive. The LI, 1, and 2 showed no effects on the lymphocyte cell cycle. These results support, in part, the traditional use of licorice to treat and prevent diseases in which oxidants or free radicals are implicated and suggest that LI could be used as a potential non-specific immune stimulator. © 2010 Elsevier Ltd. All rights reserved.info:eu-repo/semantics/publishe

Variations in the chemical profile and biological activities of licorice (Glycyrrhiza glabra L.), as influenced by harvest times

This study investigates the variations in the chemical profile, free radical scavenging, antioxidant and gastroprotective activities of licorice extracts (LE) from plants harvested during the months of February to November. Correlations between biological properties and the chemical composition of LE were also investigated. The results showed that the total contents of phenols, flavonoids and tannins in LE varied at different harvest times. Liquiritin and glycyrrhizin, the major components of LE, varied in the range of 28.65–62.80 and 41.84–114.33 mg g−1, respectively. The relative proportion of glycyrrhizin derivative (3), glabridin (4), glabrene (5) and liquiritigenin derivative (6), varied in the range of 0.88–11.38 %, 1.86–10.03 %, 1.80–18.40 % and 5.53–16.31 %, respectively. These fluctuations correlated positively with changes in the antioxidant and free radical scavenging activities of licorice. In general, the samples from May and November showed the most favorable free radical scavenging and antioxidant effects, whereas the best gastroprotective effect was in May. Liquiritin and glycyrrhizin, the major constituents in the February and May LE, appeared to contribute to the superoxide radical scavenging and gastroprotective effects. Glabridin and glabrene, the compounds with the highest relative proportion in the November LE, accounted for the antioxidant and DPPH scavenging activities of licorice. It is concluded that the chemical profile of licorice quantitatively varied at different harvest times and these fluctuations determined changes in its bioactivities. These data could pave the way to optimize harvesting protocols for licorice in relation with its health-promoting properties.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Variations in the chemical profile, free radical scavenging, antioxidant and gastroprotective activities of licorice (Glycyrrhiza glabra L.): as influenced by harvest times

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