PHYTONUTRIENT SCREENING BY GAS CHROMATOGRAPHY–MASS SPECTROMETRY AND ANTI-AGING PROPERTIES OF GLYCOSMIS PENTAPHYLLA (RETZ.) DC. (SOM-CHUEN) EXTRACTS

Objective: The aims of this study were to screen the phytonutrient constituents and investigate their anti-aging property of leaves and bark ofGlycosmis pentaphylla (Retz.) DC. (GP).Methods: GP is the medicinal plant which used as traditional medicine. Glycosmis pentaphylla leaves (GPL) and Glycosmis pentaphylla bark (GPB) ofGP were extracted with ethanol. The gas chromatography–mass spectrometry was used for phytonutrients analysis. The anti-aging properties wereperformed using ABTS assay, deoxyribose degradation assay, bovine serum albumin (BSA)-fructose model, and matrix metalloproteinase 1 (MMP-1)inhibitory activity.Results: The important phytonutrients of GPL were α-tocopherol, linolenic acid, squalene, stigmasterol, and β-amyrin and for GPB were α-tocopherol,phytol, campesterol, stigmasterol, dictamine, and γ-sitosterol. The percentage inhibition of GPL and GPB extracts at various concentrations wasbetween 16.57–76.05 and 20.66-78.81 by ABTS assay, 68.24–90.06 and 73.83–96.64% by deoxyribose degradation assay, 4.24–99.98 and 54.81–99.94 by BSA-fructose model, and 6.31–81.55 and 1.06–74.45 by MMP-1 inhibitory activity, respectively.Conclusion: Leaves and bark extracts of GP (Retz.) DC. are good sources of important phytonutrients and have the potential in anti-aging property.

In Vitro Evaluation of Pro- and Antioxidant Effects of Flavonoid Tricetin in Comparison to Myricetin

Flavonoids are rather common plant phenolic constituents that are known for potent antioxidant effects and can be beneficial for human health. Flavonoids with a pyrogallol moiety are highly efficient reducing agents with possible pro- and antioxidant effects, depending on the reaction milieu. Therefore, the redox properties of myricetin and tricetin were investigated by differential pulse voltammetry and deoxyribose degradation assay. Tricetin proved to be a good antioxidant but only showed negligible pro-oxidant activity in one of the deoxyribose degradation assay variants. Compared to tricetin, myricetin showed pro- and antioxidant effects. The more efficient reducing properties of myricetin are probably caused by the positive mesomeric effect of the enolic 3-hydroxy group on ring C. It is evident that the antioxidant properties of structurally similar flavonoids can be converted to apparent pro-oxidant effects by relatively small structural changes, such as hydroxylation. Since reactive oxygen species (ROS) often serve as secondary messengers in pathological and physiological processes in animal and plant cells, the pro- and antioxidant properties of flavonoids are an important part of controlling mechanisms of tissue signal cascades.

Evaluation of antioxidant, cytotoxic and apoptotic activities of methanolic extract of momordica cymbalaria hook f. unripe fruit

Natural products gain more attention nowadays because of their compatibility with mankind, safe and economic feasible. The main purpose of this study was to evaluate antioxidant, cytotoxic and apoptotic activities of methanolic extract of Momordica cymbalaria Hook F. unripe fruit (UF). A considerable DPPH, hydroxyl radical scavenging and metal ion chelating activities and significant inhibitory effect on lipid peroxidation and least activity on deoxyribose degradation was observed for methanolic UF extract. Cytotoxic activity of UF extract on HeLa cells was observed and its inhibitory concentration fifty percent was calculated as 17.69±0.01µg/mL. Apoptosis inducing ability of UF extract on HeLa cells was also observed by Propidium iodide and acridine orange/ethidium bromide (AO/EtBr) dual staining. This is the first report on antioxidant, cytotoxic and apoptotic inducing ability of methanolic UF extract of Momordica cymbalaria collected from Sattur, Virudhunagar district, Tamilnadu, India.

Coordination Complex Formation and Redox Properties of Kynurenic and Xanthurenic Acid Can Affect Brain Tissue Homeodynamics

Reactive oxygen species (ROS) are known for their participation in various physiological and pathological processes in organisms, including ageing or degeneration. Kynurenine pathway metabolites, such as kynurenic (KYNA) or xanthurenic (XA) acid, can affect neurodegenerative diseases due to their ROS scavenging and Fe ion coordination complex formation but insights are still incomplete. Therefore, we investigated the formation and antioxidant capabilities of KYNA– and XA–Fe complexes by nano-electrospray−mass spectrometry, differential pulse voltammetry, deoxyribose degradation and FeII autoxidation assays. XA formed coordination complexes with FeII or FeIII ions and was an effective antioxidant. By contrast, only FeII–KYNA complexes could be detected. Moreover, KYNA showed no antioxidant effects in the FeCl3/ascorbic acid deoxyribose degradation assay variant and only negligible activities in the FeII autoxidation assay. Coordination complexes of Fe ions with KYNA probably stabilize KYNA in its keto tautomer form. Nevertheless, both KYNA and XA exhibited sufficient antioxidant activities in some of the employed assay variants. The results provide evidence that both have the potential to alleviate neurodegenerative diseases by helping to maintain tissue redox homeodynamics.

Phenolic Imidazole Derivatives with Dual Antioxidant/Antifungal Activity: Synthesis and Structure-Activity Relationship

Background: Previous publications show that the addition of a phenolic antioxidant to an antifungal agent, considerably enhances the antifungal activity. Objective: Synthesis of novel compounds combining phenolic units with linear or cyclic nitrogencontaining organic molecules with antioxidant/antifungal activity using methodologies previously developed in the group. Methods: Several N- [1,2-dicyano-2- (arylidenamino) vinyl]-O-alkylformamidoximes 3 were synthesized and cyclized to 4,5-dicyano-N- (N´-alcoxyformimidoyl)-2-arylimidazoles 4 upon reflux in DMF, in the presence of manganese dioxide or to 6-cyano-8-arylpurines 5 when the reagent was refluxed in acetonitrile with an excess of triethylamine. These compounds were tested for their antioxidant activity by cyclic voltammetry, DPPH radical (DPPH•) assay and deoxyribose degradation assay. The minimum inhibitory concentration (MIC) of all compounds was evaluated against two yeast species, Saccharomyces cerevisiae and Candida albicans, and against bacteria Bacillus subtilis (Gram-positive) and Escherichia coli (Gram negative). Their cytotoxicity was evaluated in fibroblasts. Results: Among the synthetised compounds, five presented higher antioxidant activity than reference antioxidant Trolox and from these compounds, four presented antifungal activity without toxic effects in fibroblasts and bacteria. Conclusion: Four novel compounds presented dual antioxidant/antifungal activity at concentrations that are not toxic to bacteria and fibroblasts. The active molecules can be used as an inspiration for further studies in this area.

New Nitrogen Compounds Coupled to Phenolic Units with Antioxidant and Antifungal Activities: Synthesis and Structure–Activity Relationship

A selection of 1-amino-2-arylidenamine-1,2-(dicyano)ethenes 3 was synthesized and cyclized to 2-aryl-4,5-dicyano-1H-imidazoles 4 upon reflux in ethyl acetate/acetonitrile, in the presence of manganese dioxide. These compounds were tested for their antioxidant capacity by cyclic voltammetry, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and deoxyribose degradation assays. The minimum inhibitory concentration of all compounds was evaluated against two yeast species, Saccharomyces cerevisiae and Candida albicans. Their toxicity was tested in mammal fibroblasts. Among the synthesised compounds, two presented dual antioxidant/antifungal activity without toxic effects in fibroblasts. The new compounds synthesized in this work are potential biochemical tools and/or therapeutic drugs.

Antioxidant and Antimutagenic Activities of Different Fractions from the Leaves of Rhododendron arboreum Sm. and Their GC-MS Profiling

In this era of urbanization and environmental pollution, antioxidants and antimutagens derived from plants are promising safeguards for human health. In the current investigation, we analyzed the antioxidant and antimutagenic effects of the hexane, chloroform, and ethyl acetate fractions of Rhododendron arboreum Sm. leaves and determined their chemical composition. The different fractions inhibited lipid peroxidation, repressed the production of nitric oxide radicals, and prevented deoxyribose degradation. The antimutagenic activity of the leaf fractions was analyzed against 4-nitro-O-phenylenediamine, sodium azide and 2-aminofluorene mutagens in two test strains (TA-98 and TA-100) of Salmonella typhimurium. The experiment was conducted using pre- and co-incubation modes. The best results were obtained in the pre-incubation mode, and against indirect acting mutagen. The presence of a number of bioactive constituents was confirmed in the different fractions by GC-MS analysis. The study reveals the strong antioxidant and antimutagenic activity of R. arboreum leaves. We propose that those activities of R. arboreum might correspond to the combined effect of the phytochemicals identified by GC-MS analysis. To the best of our knowledge, this is the first report on the antimutagenic activity of R. arboreum leaves.