Involvement Of Flavonoids Research Articles

Antiseizure Activity of Mitragyna inermis in the Pentylenetetrazol-Induced Seizure Model in Mice: Involvement of Flavonoids and Alkaloids.

This study aimed to investigate whether Mitragyna inermis (Willd.) Otto Kuntze organic and aqueous extracts are able to control seizures induced by pentylenetetrazol (PTZ) in mice based on flavonoid fingerprints and alkaloidal contents. Ethanolic extract and decoction-derived fractions from roots, leaves, and stems were subjected to chromatographic fingerprinting using AlCl3 and screening for their antiseizure effects using PTZ-induced acute seizure model. From the fractions that showed potent bioactivities, plausible antiseizure alkaloids were isolated using thin layer chromatography, and their structures were elucidated using 1H NMR, 2D NMR, 13C NMR, and FAB-HR (+ve or -ve). All fractions, with the exception of the dichloromethane and hexane fractions, revealed remarkable flavonoid fingerprints. An acute PTZ-induced seizure test revealed that ethanolic extract of stem bark [500 mg/kg body weight (bw)], ethyl acetate extract of stem bark (500 mg/kg bw), and aqueous extract of leaves (300 mg/kg bw) significantly delayed the occurrence of hind limb tonic extension (HLTE); however, a non-significant delay was observed in the onset of first myoclonic jerk compared with control animals. Isolation yielded four main alkaloids: that are, pteropodine (1), isopteropodine (2), mitraphylline (3) and corynoxeine (4). Corynoxeine is a new compound derived from M. inermis. This study suggests that flavonoid fingerprints are tracers of M. inermis anticonvulsant ingredients. The stem bark ethanolic and ethyl acetate extracts and leaf aqueous extracts contain anticonvulsant bioactive principles that delay notifying the HLTE occurring in male naval medical research institute mice. Furthermore, alkaloidal contents also remain plausible bioactive anticonvulsant principles. All observations support the traditional use of M. inermis to manage epilepsy. However, further studies are needed to understand the effects of alkaloid fractions, flavonoids, and the isolated compounds as promising antiseizure agents derived from M. inermis in experimental animals.

Antiseizure Activity of Mitragyna inermis in the Pentylenetetrazol (PTZ) -Induced Seizure Model in Mice: Involvement of Flavonoids and Alkaloids

Antiseizure Activity of Mitragyna inermis in the Pentylenetetrazol (PTZ) -Induced Seizure Model in Mice: Involvement of Flavonoids and Alkaloids

Carissa carandas L. fruit mediated in vitro synthesis of silver nanoparticles and their antioxidant and antibacterial activities

Currently, we synthesized silver nanoparticles (AgNPs) from the aqueous fruit extract of Carissa carandas L. and evaluated their antioxidant and antibacterial properties. The UV-visible spectra showed a characteristic absorption peak at 412 nm. The Fourier transform infrared (FTIR) spectroscopy exhibits intense peaks at 3430.23cm-1 and 1625.67cm-1 which indicates the involvement of flavonoids and other functional groups in the biosynthesis, capping, and stabilization of AgNPs. From XRD analysis, the average size of AgNPs was estimated to be 45nm. The biogenic AgNPs were spherical in shape and average size range between 10 to 95nm confirmed by HR-TEM analysis. The fabricated AgNPs by fruit extract were monitored for antioxidant activity using DPPH method. The fruit extract of AgNPs (IC50= 946.22μg/ml) had the highest antioxidant activity against standard ascorbic acid. The antibacterial activity was done using Staphylococcus aureus and Escherichia coli bacterial strains. It was found from the results that the bacterial strain S. aureus had the highest antibacterial activity when compared to E. coli and aqueous fruit extract. Thus, the present study exhibits synergistic antioxidant and antibacterial activity which may explore in future clinical treatment.

Flavonoids-Macromolecules Interactions in Human Diseases with Focus on Alzheimer, Atherosclerosis and Cancer.

Flavonoids, a class of polyphenols, consumed daily in our diet, are associated with a reduced risk for oxidative stress (OS)-related chronic diseases, such as cardiovascular disease, neurodegenerative diseases, cancer, and inflammation. The involvement of flavonoids with OS-related chronic diseases have been traditionally attributed to their antioxidant activity. However, evidence from recent studies indicate that flavonoids’ beneficial impact may be assigned to their interaction with cellular macromolecules, rather than exerting a direct antioxidant effect. This review provides an overview of the recent evolving research on interactions between the flavonoids and lipoproteins, proteins, chromatin, DNA, and cell-signaling molecules that are involved in the OS-related chronic diseases; it focuses on the mechanisms by which flavonoids attenuate the development of the aforementioned chronic diseases via direct and indirect effects on gene expression and cellular functions. The current review summarizes data from the literature and from our recent research and then compares specific flavonoids’ interactions with their targets, focusing on flavonoid structure–activity relationships. In addition, the various methods of evaluating flavonoid–protein and flavonoid–DNA interactions are presented. Our aim is to shed light on flavonoids action in the body, beyond their well-established, direct antioxidant activity, and to provide insights into the mechanisms by which these small molecules, consumed daily, influence cellular functions.

Possible involvement of flavonoids in response of mulberry (Morus alba L.) to infection with Ralstonia solanacearum (Smith 1896) Yabuuchi et al., 1996

Possible involvement of flavonoids in response of mulberry (Morus alba L.) to infection with Ralstonia solanacearum (Smith 1896) Yabuuchi et al., 1996

Sardinian plants with antimicrobial potential. Biological screening with multivariate data treatment of thirty-six extracts

In this paper, thirty-six extracts from Sardinian plants were evaluated in vitro for their antimicrobial activity towards a panel of reference strains, Staphylococcus aureus, S. epidermidis, Klebsiella pneumoniae and Escherichia coli, and for their cytotoxicity on mammalian cells. The biological data, together with total phenolic and flavonoid content of the extracts, were treated by PCA (Principal Components Analysis), which highlighted the positive correlation among total phenolic content and increasing antibacterial activities, and a possible involvement of flavonoids in mitigate the cytotoxicity. Thirteen extracts displayed relevant IC50 values (half maximal inhibitory concentration) on S. aureus (IC50 from 1.4 to 153.6 μg/mL), ten out of them were active also against S. epidermidis (IC50 from 3.9 to 150 μg/mL), seven against K. pneumoniae (IC50 from 28.5 to 97.5 μg/mL), and two against E. coli (IC50 74.9 and 156.3 μg/mL). In particular, three extracts obtained from Pistacia terebinthus ssp. terebinthus, Cytinus hypocistis and Limonium morisianum emerged as promising antibacterial candidates. They exhibited remarkable inhibitory activity towards bacterial strains from clinical specimens and presenting different antibiotic-resistance profiles.

Involvement of Flavonoids from the Leaves of Carya cathayensis Sarg. in Sirtuin 1 Expression in HUVEC Senescence.

Atherosclerosis is the commonest cause of death in the world and one of the most important processes that occurs with increasing age because it is accompanied by progressive endothelial dysfunction. Recent studies demonstrated that Sirtuin 1 (SIRT1) might potentially affect cell senescence. However, the effect of SIRT1 on the regulation of human umbilical vein endothelial cell (HUVEC) senescence with total flavonoids (TFs) has not been addressed previously. This study investigated how SIRT1 functions in the process of HUVEC senescence when TFs are present and identified the potential molecular mechanisms involved. Using a model of HUVEC senescence induced by angiotensin II, TFs pretreatment reduced the percentage of senescence-associated β-galactosidase (SA-β-gal) cells and p53 mRNA expression. The level of SIRT1 protein and E2F1 decreased during HUVEC senescence and could be partially recovered when cells were coincubated with TFs, while the levels of proteins p53 and p21 increased during cell senescence and diminished in response to the TFs treatment. When coincubated with 20 mM nicotinamide, the results with SA-β-gal-positive cells and the expression of SIRT1, E2F1, p53, and p21 were contrary to that obtained with only TFs pretreatment. The data indicate that the TFs exert their effect on HUVEC senescence through SIRT1.

Bioavailability, bioactivity and impact on health of dietary flavonoids and related compounds: an update.

There is substantial interest in the role of plant secondary metabolites as protective dietary agents. In particular, the involvement of flavonoids and related compounds has become a major topic in human nutrition research. Evidence from epidemiological and human intervention studies is emerging regarding the protective effects of various (poly)phenol-rich foods against several chronic diseases, including neurodegeneration, cancer and cardiovascular diseases. In recent years, the use of HPLC-MS for the analysis of flavonoids and related compounds in foods and biological samples has significantly enhanced our understanding of (poly)phenol bioavailability. These advancements have also led to improvements in the available food composition and metabolomic databases, and consequently in the development of biomarkers of (poly)phenol intake to use in epidemiological studies. Efforts to create adequate standardised materials and well-matched controls to use in randomised controlled trials have also improved the quality of the available data. In vitro investigations using physiologically achievable concentrations of (poly)phenol metabolites and catabolites with appropriate model test systems have provided new and interesting insights on potential mechanisms of actions. This article will summarise recent findings on the bioavailability and biological activity of (poly)phenols, focusing on the epidemiological and clinical evidence of beneficial effects of flavonoids and related compounds on urinary tract infections, cognitive function and age-related cognitive decline, cancer and cardiovascular disease.

Plant flavonoids--biosynthesis, transport and involvement in stress responses.

This paper aims at analysing the synthesis of flavonoids, their import and export in plant cell compartments, as well as their involvement in the response to stress, with particular reference to grapevine (Vitis vinifera L.). A multidrug and toxic compound extrusion (MATE) as well as ABC transporters have been demonstrated in the tonoplast of grape berry, where they perform a flavonoid transport. The involvement of a glutathione S-transferase (GST) gene has also been inferred. Recently, a putative flavonoid carrier, similar to mammalian bilitranslocase (BTL), has been identified in both grape berry skin and pulp. In skin the pattern of BTL expression increases from véraison to harvest, while in the pulp its expression reaches the maximum at the early ripening stage. Moreover, the presence of BTL in vascular bundles suggests its participation in long distance transport of flavonoids. In addition, the presence of a vesicular trafficking in plants responsible for flavonoid transport is discussed. Finally, the involvement of flavonoids in the response to stress is described.

Quercetin Regulates the Inhibitory Effect of Monoclonal Non-Specific Suppressor Factor β on Tumor Necrosis Factor-α Production in LPS-Stimulated Macrophages

Monoclonal non-specific suppressor factor beta (MNSFbeta) is a member of the ubiquitin-like family that has been implicated in various biological functions. Previous studies have demonstrated that MNSFbeta regulates the ERK1/2-MAPK cascade in the macrophage cell line Raw 264.7. In this study, we found evidence that the flavonol quercetin regulates the effect of MNSFbeta on TNFalpha production in LPS-stimulated Raw264.7 cells. Quercetin inhibited MNSFbeta siRNA-mediated enhancement of both TNFalpha production and ERK1/2 phosphorylation in LPS-stimulated Raw264.7 cells. Quercetin decreased the expression of 33.5-kDa MNSFbeta adduct, which is important to the regulation of ERK1/2 activity, in unstimulated Raw264.7 cells. The various flavonoids tested, including other flavonols, did not affect the formation of this adduct. Collectively, MNSFbeta and quercetin might share a common pathway in regulating the ERK1/2 pathway in macrophages. This is the first report describing the involvement of flavonoids in the action of ubiquitin-like proteins.

Involvement of flavonoids in the resistance of two poplar cultivars to mistletoe (Viscum album L.)

Flavonoid compounds were studied in healthy and parasitized poplar branches following mistletoe (Viscum album L.) attack. Two poplar cultivars showing different degrees of resistance to mistletoe: sensitive “Fritzi Pauley” (FPL) and resistant “Vereecken” (VER) were used. Flavonoids were detected and localized using histofluorescence after treating frozen sections with two specific reagents. Total amounts of flavonoids were determined spectrophotometrically. Defence mechanisms were induced during penetration of the primary haustorium. They consisted of inner periderm development and flavonoid accumulation. These reactions were weaker in the FPL cultivar than in the VER one. In the latter, growth of the primary haustorium and the establishment of direct connections between the living host cells and parasite failed. The resistance of poplar cultivars to mistletoe was dependent on the production of defensive mechanisms against the pathogen.