Construction of luciferase-expressing Neospora caninum and drug screening.

BACKGROUND: Neospora caninum is an apicomplexan parasite that is particularly responsible for abortions in cattle and neuromuscular disease in dogs. Due to the limited effectiveness of currently available drugs, there is an urgent need for new therapeutic approaches to control neosporosis. Luciferase-based assays are potentially powerful tools in the search for antiprotozoal compounds, permitting the development of faster and more automated assays. The aim of this study was to construct a luciferase-expressing N. caninum and evaluate anti-N. caninum drugs. METHODS: Luciferase-expressing N. caninum (Nc1-Luc) was constructed using clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (CRISPR/Cas9). After testing the luciferase expression and phenotype of the Nc1-Luc strains, the drug sensitivity of Nc1-Luc strains was determined by treating them with known positive or negative drugs and calculating the half-maximal inhibitory concentration (IC50). The selective pan-rapidly accelerated fibrosarcoma (pan-RAF) inhibitor TAK-632 was then evaluated for anti-N. caninum effects using Nc1-Luc by luciferase activity reduction assay and other in vitro and in vivo studies. RESULTS: The phenotypes and drug sensitivity of Nc1-Luc strains were consistent with those of the parental strains Nc1, and Nc1-Luc strains can be used to determine the IC50 for anti-N. caninum drugs. Using the Nc1-Luc strains, TAK-632 showed promising activity against N. caninum, with an IC50 of 0.6131 µM and a selectivity index (SI) of 62.53. In vitro studies demonstrated that TAK-632 inhibited the invasion, proliferation, and division of N. caninum tachyzoites. In vivo studies showed that TAK-632 attenuated the virulence of N. caninum in mice and significantly reduced the parasite burden in the brain. CONCLUSIONS: In conclusion, a luciferase-expressing N. caninum strain was successfully constructed, which provides an effective tool for drug screening and related research on N. caninum. In addition, TAK-632 was found to inhibit the growth of N. caninum, which could be considered as a candidate lead compound for new therapeutics for neosporosis.

Garlic oil blocks tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumorigenesis by inducing phase II drug-metabolizing enzymes.

Lung cancer caused one-quarter of all cancer deaths that was more than other cancers. Chemoprevention is a potential strategy to reducing lung cancer incidence and death, and the effective chemopreventive agents are needed. We investigated the efficacy and mechanism of garlic oil (GO), the garlic product, in the chemoprevention of tobacco carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung cancer in A/J mice and MRC-5 cell models in the present study. As a result, it was demonstrated that GO significantly inhibited the NNK-induced lung cancer in vivo and protected MRC-5 cells from NNK-induced cell damage. GO could induce the expressions of the phase II drug-metabolizing enzymes, including NAD(P)H: quinone oxidoreductase 1 (NQO-1), glutathione S-transferase alpha 1 (GSTA1), and antioxidative enzymes heme oxygenase-1 (HO-1). These results supported the potential of GO as a novel candidate agent for the chemoprevention of tobacco carcinogens induced lung cancer.

In vitro and in vivo antioxidant potentials of the methanolic crude extract from Inula glomerata Oliv. & Hiern (Asteraceae) and Salacia kraussii (Harv) Harv (Celastraceae) / Potenciales antioxidantes in vitro e in vivo del extracto crudo metanólico de Inula glomerata Oliv. & Hiern. (Asteraceae) y Salacia kraussii (Harv) Harv (Celastraceae)

Reactive oxygen species are implicated in multiple pathological conditions including erectile dysfunction. This study evaluated the in vitro and in vivo antioxidant potential of the methanolic extracts of Inula glomerata and Salacia kraussii. The plant materials were pulverized and extracted with methanol. The phytochemical analysis, ability of the crude extracts to scavenge free radicals (ABTS, DPPH, NO.) in vitroas well as the total phenolic and flavonoid contents was investigated. In vivo, antioxidant potentials of the crude extracts (50/250 mg/kg body weight) were determined in an erectile dysfunction rat model. The phytochemical analysis revealed that both plants contain flavonoids, tannins, terpenoids, and alkaloids. The crude extracts at varying degree of efficiency, scavenged ABTS and DPPH radicals. The crude extracts at low concentrations (50 mg/kg b.w) significantly (p<0.05) diminished the level of malondialdehyde, augmented catalase activities and elevated glutathione levels. However, SOD activities were significantly boosted in a dose-dependent manner by the crude extracts. Therefore, I. glomerataand S. kraussiipossess antioxidant properties, hence, can serve as a therapeutic modality in the treatment of oxidative stress-induced erectile dysfunction.

Las especies reactivas de oxígeno están implicadas en múltiples condiciones patológicas, incluyendo la disfunción eréctil. Este estudio evaluó el potencial antioxidante in vitro e in vivo de extractos metanólicos de Inula glomeratay Salacia kraussii. Los materiales vegetales fueron pulverizados y extraídos con metanol. A estos extractos crudos se les llevó a cabo el análisis fitoquímico junto con el contenido total de fenólicos y flavonoides, así como se les investigó la capacidad in vitro para atrapar radicales (ABTS, DPPH, NO.). Los potenciales antioxidantes in vivo de los extractos crudos (50/250 mg/kg de peso corporal) se determinaron en un modelo en ratas con disfunción eréctil. El análisis fitoquímico reveló que ambas plantas contuvieron flavonoides, taninos, terpenoides y alcaloides. Los extractos crudos con un grado variable de eficiencia, atraparon a los radicales ABTS y DPPH. Los extractos crudos a bajas concentraciones (50 mg/kg p.c) significativamente (p<0.05) disminuyeron el nivel de malondialdehído, aumentaron las actividades de catalasa y elevaron los niveles de glutatión. Sin embargo, las actividades de SOD por los extractos crudos fueron significativamente dosis-dependientes. Así, los extractos de I. glomeratay S. kraussii mostraron propiedades antioxidantes, y por lo tanto, podrían servir como una alternativa terapéutica en el tratamiento de disfunción eréctil inducida por estrés oxidativo.

Antioxidant activity and polyphenol content in extracts from various parts of fresh and frozen mangosteen.

BACKGROUND: The search for new sources of natural antioxidants is very important because many diseases are caused by oxidative stress. Fruit which contain antioxidants are an important part of a healthy diet. The aim of this study was to evaluate the antioxidant activity of extracts of both the fresh and frozen peel and the flesh of Garcinia mangostana L. METHODS: The extracts from the fresh and frozen peel and the flesh of mangosteen were prepared by ultrasound-assisted extraction using 20%, 40%, 70% and 96% (v/v) ethanol for 15, 30 or 60 minutes. The antioxidant potential was evaluated by the DPPH, ABTS, CUPRAC, FRAP and FIC methods, whereas the total phenolic content was measured using the Folin-Ciocalteu (F-C) technique. The contents of anthocyanins and flavonoids in the peel extracts were also determined. RESULTS: In most cases, the highest antioxidant activity was observed in the fresh peel samples. It was higher than the antioxidant potential of the frozen peels and the fresh and frozen flesh. The ultrasound-assisted extraction, in particular those lasting 30 or 60 minutes and using ethanol in concentrations higher than 20% (v/v), seemed to be an effective extraction process. CONCLUSIONS: The obtained results suggest that G. mangostana, in particular its peels, could be a valuable source of antioxidants. The extraction parameters, such as the time or solvent concentration, as well as the type of plant material, had an impact on the tested properties of the extracts. However, more detailed studies on the antioxidant activity of the studied plants are required.

Anti-Amyloidogenic and Cyclooxygenase Inhibitory Activity of Guettarda speciosa.

Guettarda speciosa is known in traditional folk medicine for treating cough, cold, sore throat, fever, wounds, epilepsy, and headaches. To discover the scientific pharmacological potential of G. speciosa, we explore its anti-inflammatory, cytotoxicity, and inhibition of amyloid-beta (Aß) aggregation effects. Cyclooxygenase assay of the G. speciosa CHCl3 (GSC) extract and G. speciosa MeOH (GSM) extract are more selective to COX-1 inhibition with a 50% inhibitory concentration (IC50) of 3.56 µg/mL for the GSC extract and 4.98 µg/mL for the GSM extract. Neuroblastoma SH-SY5Y inhibition and thioflavin T assay amyloid-beta (Aß) aggregate inhibition of the GSM and GSC extracts showed their potential therapeutic effects against Alzheimer's disease. The putative compounds from the LC-MS analysis could be responsible for the observed activities. The results suggest that G. speciosa possesses anti-inflammatory and anti-neurodegenerative properties and a promising lead as a source of pharmacologically active compounds.

Protective effects of Camellia japonica flower extract against urban air pollutants.

BACKGROUND: Exposure of skin to urban air pollutants is closely related to skin aging and inflammatory responses such as wrinkles formation, pigmentation spot, atopic dermatitis, and acne. Thus, a great deal of interest has been focused on the development of natural resources that can provide a protective effect to skin from pollutants. METHODS: The antioxidative activity of Camellia japonica flower extract (CJFE) was evaluated by 1,2-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) assay, and the inhibitory effect of CJFE by urban air pollutants-induced reactive oxygen species (ROS) production was determined in cultured normal human dermal fibroblasts (NHDFs). We additionally investigated the protective effects of CJFE against urban air pollutant using in vitro and ex vivo model. RESULTS: CJFE with high phenolic concentration showed antioxidative activity on scavenging capacity of 1,2-diphenyl-2-picrylhydrazyl (DPPH) radicals and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical cation in a concentration dependent manner. CJFE inhibited urban air pollutants-induced ROS generation, matrixmetalloproteinase-1 (MMP-1) production and a xenobiotic response element (XRE)-luciferase activity indicating the aryl hydrocarbon receptor (AhR) transactivation. In addition, CJFE showed an excellent protective activity against pollutants-induced deteriorating effect in ex vivo model. CJFE reduced the level of pollutants-induced malondialdehyde (MDA), lipid peroxidation marker, inhibited MMP-1 expression and increased collagen synthesis. It also reduced the cell numbers with pyknotic nuclei (mainly occurring in apoptosis) and detachment of dermo-epidermal junction (DEJ) induced by pollutants. CONCLUSIONS: Apparently, it is proposed that CJFE can be used as a protective material against pollutant-induced skin damages.

In Vitro Assay for Studying the Aggregation of Tau Protein and Drug Screening.

Aggregation of tau protein and formation of paired helical filaments is a hallmark of Alzheimer's disease and other tauopathies. Compared to other proteins associated with neurodegenerative diseases, the reported in vitro aggregation kinetics for tau protein are less consistent presenting a relatively high variability. Here we describe the development of an in vitro aggregation assay that mimics the expected steps associated with tau misfolding and aggregation in vivo. The assay uses the longest tau isoform (huTau441) which contains both N-terminal acidic inserts as well as four microtubule binding domains (MBD). The in vitro aggregation is triggered by addition of heparin and followed continuously by thioflavin T fluorescence in a 96 well microplate format. The tau aggregation assay is highly reproducible between different wells, experimental runs and batches of the protein. The aggregation leads to tau PHF-like morphology which is very efficient in seeding the formation of de novo fibrillar structures. In addition to its application in studying the mechanism of tau misfolding and aggregation, the current assay is a robust tool for screening drugs that could interfere with the pathogenesis of tau.

Antiplasmodial, anti-chikungunya virus and antioxidant activities of 64 endemic plants from the Mascarene Islands.

Vector-borne diseases cause more than 1 million deaths annually. The research into new medicines is urgent, especially as there is currently no specific treatment. In this study, the authors have selected 64 endemic plants from the Mascarene Islands based on their endemism, their medicinal use and their registration in the French Pharmacopeia to evaluate the antiplasmodial, anti-chikungunya and antioxidant activities. The list of these 64 plants including their local name, population, data of collection and voucher number are available in the Supporting Information. Forty active extracts were identified from the 38 species: 22 responded positively to the antiplasmodial activity, 8 to the anti-chikungunya activity and 8 to the antioxidant activity. Six plants demonstrated high antiplasmodial activity (concentration inhibiting 50% of parasitic growth (IC50) <5 µg/mL): Casearia coriaceae, Monimia rotundifolia, Poupartia borbonica, Psiadia retusa, Vernonia fimbrillifera and Zanthoxylum heterophyllum; and five showed high anti-chikungunya activity (IC50<20 µg/mL): Aphloia theiformis, Stillingia lineata, Croton mauritianus, Indigofera ammoxylum, and Securinega durissima. Eight plants displayed an important antioxidant activity, with values of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), ferric reducing antioxidant power (FRAP) or oxygen Radical Absorbance Capacity (ORAC) >2000 µM of Trolox equivalent per mg/mL of extract: Bertiera borbonica, Erythroxylon laurifolium, Erythroxylon sideroxyloides, I. ammoxylum, P. borbonica, Scolopia heterophylla, Sophora denudata, and Terminalia bentzoe. Some data obtained tend to corroborate the reported traditional use of the plant, such as Z. heterophyllum (antiplasmodial), A. theiformis (anti-chikungunya), and E. laurifolium (antioxidant).

Evaluation of Antioxidant Properties, Phenolic Compounds, Anthelmintic, and Cytotoxic Activities of Various Extracts Isolated from Nepeta cadmea: An Endemic Plant for Turkey.

Nepeta cadmea Boiss. is a species endemic to Turkey that belongs to the Nepeta genus. Several species of this genus are used in folk medicine. This study was designed to investigate the phenolic compounds, antioxidant, anthelmintic, and cytotoxic activities of various extracts (ethanol, methanol, acetone, and water) of N. cadmea. The antioxidant activities of these extracts were analyzed using scavenging methods (DPPH, ABTS, and H2 O2 scavenging activity), the ß-carotene/linoleic acid test system, the phosphomolybdenum method, and metal chelating activity. Among the 4 different extracts of N. cadmea that were evaluated, the water extract showed the highest amount of radical scavenging (DPPH, 25.54 µg/mL and ABTS, 14.51 µg/mL) and antioxidant activities (ß-carotene, 86.91%). In the metal chelating and H2 O2 scavenging activities, the acetone extract was statistically different from the other extracts. For the phosphomolybdenum method, the antioxidant capacity of the extracts was in the range of 8.15 to 80.40 µg/mg. The phenolic content of the ethanol extract was examined using HPLC and determined some phenolics: epicatechin, chlorogenic, and caffeic acids. With regard to the anthelmintic properties, dose-dependent activity was observed in each of the extracts of N. cadmea. All the extracts exhibited high cytotoxic activities. The results will provide additional information for further studies on the biological activities of N. cadmea, while also helping us to understand the importance of this species. Furthermore, based on the results obtained, N. cadmea may be considered as a potentially useful supplement for the human diet, as well as a natural antioxidant for medicinal applications. PRACTICAL APPLICATION: The plants of the Nepeta genus have been extensively used as traditional herbal medicines. Nepeta cadmea Boiss., one of the species belonging to the Nepeta genus, is a species endemic to Turkey. In our study, we demonstrated the antioxidant capacities, total phenolic, flavonoid, tannin content, anthelmintic, and cytotoxic activities of various extracts of Nepeta cadmea. The present study could well supply valuable data for future investigations and further information on the potential use of this endemic plant for humans, in both dietary and pharmacological applications.

Sessein and isosessein with anti-inflammatory, antibacterial and antioxidant activity isolated from Salvia sessei Benth.

ETHNOPHARMACOLOGICAL RELEVANCE: Salvia sessei Benth, popularly known as "pipilolxochitl" or "sabanito", is a plant utilized in Mexico in traditional medicine for the treatment of erysipela. To date, only one report, to our knowledge, has been found in which a royleanone-type diterpene of the aerial parts of the species was isolated but, again to our knowledge, studies have not been conducted on the pharmacological activity of extracts and compounds isolated from this plant. AIM OF THE STUDY: The objective of the study was to evaluate the anti-inflammatory, antibacterial and antioxidant activity of the organic extracts of the aerial parts of Salvia sessei Benth and sessein and isosessein isomers isolated from this. MATERIALS AND METHODS: Anti-inflammatory activity was evaluated in a model of edema in mouse ear at 1 mg/ear of the isolated extracts and compounds (1 and 2), a dose-response curve was performed on these latter and one-half of the effective dose (ED50) was determined; antibacterial activity was determined through minimal inhibitory concentration (MIC) by microdilution at 100, 50, 25, and 12.5 µg/mL, and antioxidant capacity, by means of DPPH, ABTS, and FRAP assays where, for the first two assays noted, the inhibitory concentration 50% (IC50) was calculated for the extracts as well as for the compounds isolated. RESULTS: The hexanic extracts (40.55 ±â€¯0.5%), dichloromethanic (56.01 ±â€¯1.1%) and methanolic (66.05 ±â€¯0.3%), as well as isolated compounds 1 (79.85 ±â€¯3.5%) and 2 (54.36 ±â€¯1.7%), demonstrated anti-inflammatory activity; the methanolic extract presented the greatest percentage of inhibition, while isolated compounds 1 and 2 did not present a difference in their ED50; additionally, compound 1 exerted a similar effect to that of the drug-of-reference at the same dose (75.24 ±â€¯2.4%). The antibacterial activity of the extracts and compounds was principally against Gram-positive bacteria: the hexanic extract presented activity against Staphylococcus hominis and the methanolic and dichloromethanic extracts, and compound 1 exhibited activity against Staphylococcus haemolyticus, S. hominis, E. faecalis, in addition to that Escherichia coli was sensitive to compound 1, while isomer 2 showed activity against Staphylococcus aureus, Staphylococcus haemolyticus, Staphylococcus epidermis and Streptococcus pyogenes bacteria related to erysipela. In the three assays, the extract demonstrating greatest antioxidant capacity was the methanolic extract, while that of the isolated compounds was compound 1. CONCLUSIONS: The results show that the three extracts evaluated in the three models presented activity and the chromatographic separation of the dichloromethanic extract permitted the isolation of compounds 1 and 2 royleanone-type isomers, which also presented significant activities such as anti-inflammatory, antibacterial and antioxidant, thus validate the use of this species in traditional medicine.

HPLC-DAD finger printing, antioxidant, cholinesterase, and α-glucosidase inhibitory potentials of a novel plant Olax nana.

BACKGROUND: The medicinal importance of a novel plant Olax nana Wall. ex Benth. (family: Olacaceae) was revealed for the first time via HPLC-DAD finger printing, qualitative phytochemical analysis, antioxidant, cholinesterase, and α-glucosidase inhibitory assays. METHODS: The crude methanolic extract of O. nana (ON-Cr) was subjected to qualitative phytochemical analysis and HPLC-DAD finger printing. The antioxidant potential of ON-Cr was assessed via 1,1-diphenyl,2-picrylhydrazyl (DPPH), 2,2-azinobis[3-ethylbenzthiazoline]-6-sulfonic acid (ABTS) and hydrogen peroxide (H2O2) free radical scavenging assays. Furthermore, acetylcholinesterase (AChE) & butyrylcholinesterase (BChE) inhibitory activities were performed using Ellman's assay, while α- glucosidase inhibitory assay was carried out using a standard protocol. RESULTS: The qualitative phytochemical analysis of ON-Cr revealed the presence of secondary metabolites like alkaloids, flavonoids, tannins, sterols, saponins and terpenoids. The HPLC-DAD finger printing revealed the presence of 40 potential compounds in ON-Cr. Considerable anti-radical activities was revealed by ON-Cr in the DPPH, ABTS and H2O2 free radical scavenging assays with IC50 values of 71.46, 72.55 and 92.33 µg/mL, respectively. Furthermore, ON-Cr showed potent AChE and BChE inhibitory potentials as indicated by their IC50 values of 33.2 and 55.36 µg/mL, respectively. In the α-glucosidase inhibition assay, ON-Cr exhibited moderate inhibitory propensity with an IC50 value of 639.89 µg/mL. CONCLUSIONS: This study investigated Olax nana for the first time for detailed qualitative phytochemical tests, HPLC-DAD finger printing analysis, antioxidant, anticholinesterase and α-glucosidase inhibition assays. The antioxidant and cholinesterase inhibitory results were considerable and can provide scientific basis for further studies on the neuroprotective and anti-Alzheimer's potentials of this plant. ON-Cr may further be subjected to fractionation and polarity guided fractionation to narrow down the search for isolation of bioactive compounds.

LC-MS/MS profiling of polyphenol-enriched leaf, stem and root extracts of Korean Humulus japonicus Siebold & Zucc and determination of their antioxidant effects.

Polyphenols from ethyl acetate extracts from the leaves, stems and roots of Korean Humulus japonicus were comprehensively profiled using liquid chromatography-electrospray ionization-tandem mass spectrometry. A total of 36 polyphenols were detected, of which 26 were structurally characterized based on their [M - H]- peak, tandem mass spectrometry fragmentation pattern, UV-vis absorption and published data. Validation data provided satisfactory results for the evaluated parameters. The determination coefficients were ≥0.9812. The limits of detection and quantification were 0.017-0.573 and 0.056-1.834 mg/L, respectively, indicating good performance limits. The accuracy (expressed as percentage recovery) at 50 and 100 mg/L was 71.4-99.7 and 75.1-105.1%, with precisions (expressed as relative standard deviation) of 1.5-7.3 and 0.8-4.1%, respectively, indicating acceptable accuracy and precision values. The leaves were rich in total polyphenols (3089.9 ± 6.4 mg/kg of fresh sample) followed by the stems (1313.9 ± 6.4 mg/kg of fresh sample) and roots (655.2 ± 2.7 mg/kg of fresh sample). Antioxidant activity, determined by α,α-diphenyl-ß-picrylhydrazyl, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) scavenging activity and ferric reducing antioxidant power assay, revealed the lowest EC50 value for the leaf extracts, indicating a higher scavenging activity in this tissue followed by the roots and stems. Overall, the results indicated that H. japonicus is rich in polyphenols and could be a potential alternative to Humulus lupulus (hop plant) in the brewery industry.

Enhancing the Antioxidant Activities of Wines by Addition of White Rose Extract.

White rose petal extract (WRE) contains large amounts of phenolic compounds and is considered edible. In this study, red and white wines were prepared by the addition of WRE (0.10% or 0.25% (w/v)), followed by fermentation at 25°C for 15 days. The fermentation profiles, colors, sensory test results, and antioxidant activities of the wines were compared. As reported herein, the fermentation profiles of the pH, CO2 production rate, and final ethanol concentration were not affected by the addition of WRE, but a slow consumption rate of sugar was observed in 0.25% WRE-added wine. In contrast, the total polyphenol concentrations in WRE-added wines increased significantly (p < 0.05) in a dose-dependent manner, resulting in appreciable enhancement of the antioxidant activities of the wines. Chromaticity tests showed slight changes in the redness and yellowness, but sensory tests showed that the overall flavor qualities of the WRE-added wines were acceptable to the panels. This study demonstrates that addition of WRE to wine confers beneficial health effects and this treatment results in better outcome in white wine.

ANTIOXIDANT ACTIVITY AND A-AMYLASE INHIBITORY POTENTIAL OF ROSA CANINA L.

BACKGROUND: Diabetes mellitus is one of the most common endocrinal disorders and medicinal plants continue to play an important role in the management of this disease. In this study, Rosa canina was investigated for the antioxidant and α-amylase inhibition activities. MATERIALS AND METHODS: Methanolic extract of Rosa canina was investigated for its potential antioxidant activity. The extracts' total phenolic and flavonoid contents and scavenging capacity for free radicals were evaluated. The α-amylase inhibition assay was also carried. RESULTS: Rosa canina extract exhibits a total Phenolic and flavonoid levels respectively (21.918 mg GAE/g and 2.647mg ER/g). The free radical scavenging activity was found to be prominent against DPPH with an IC50 of 0.668 mg/ml and against ABTS with an IC50 of 0.467 mg/ml. Extract showed a significant ferric ion reducing activities with an IC50 of4.962 mg/ml. CONCLUSION: Rosa canina exerted a higher inhibitory activity against α-amylase. The obtained results support the antidiabetic use of rosa canina.

Lyophilized aqueous extracts of Mori Fructus and Mori Ramulus protect Mesenchymal stem cells from •OH-treated damage: bioassay and antioxidant mechanism.

BACKGROUND: Mori Fructus and Mori Ramulus are two traditional Chinese herbal medicines from mulberries. The present work explores their beneficial effects on •OH-treated mesenchymal stem cells (MSCs) and discusses possible mechanisms. METHODS: Lyophilized aqueous extracts of Mori Fructus (LAMF) and Mori Ramulus (LAMR) were prepared and analyzed using HPLC. LAMF and LAMR (along with morin) were further investigated for their effects on •OH-treated MSCs using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl (MTT) assay. The direct antioxidation mechanisms were studied using 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO•)-scavenging, 2,2'-azino-bis (3-ethylbenzo-thiazoline-6-sulfonic acid (ABTS+•)-scavenging and 1,1-diphenyl-2-picryl-hydrazl (DPPH•)-scavenging, as well as Cu2+-reducing and Fe3+-reducing antioxidant power. Finally, the indirect antioxidant mechanism was investigated based on the UV-vis spectra of Fe2+-chelation. RESULTS: In each LAMF and LAMR, seven phytophenols were successfully measured by HPLC, including five flavonoids (morin, rutin, astragalin, isoquercitrin and luteolin) and two non-flavonoids (chlorogenic acid and maclurin). MTT assays revealed that LAMF, LAMR and morin could effectively increase the survival of •OH-treated MSCs at 10-100 µg/mL, and could effectively scavenge PTIO• (IC 50 6609.7 ± 756.6, 4286.9 ± 84.9 and 103.4 ± 0.9 µg/mL, respectively), DPPH• (IC 50 208.7 ± 3.0, 97.3 ± 3.1 and 8.2 ± 0.7 µg/mL, respectively) and ABTS+• (IC 50 73.5 ± 5.8, 34.4 ± 0.1 and 4.2 ± 0.2 µg/mL, respectively), and reduce Cu2+ (IC 50 212.5 ± 7.0, 123.2 ± 0.9 and 14.1 ± 0.04 µg/mL, respectively) & Fe3+ (IC 50 277.0 ± 3.1, 191.9 ± 5.2 and 5.0 ± 0.2 µg/mL, respectively). In the Fe2+-chelating assay, the five flavonoids produced much stronger shoulder-peaks than the two non-flavonoids within 420-850 nm. CONCLUSION: Mori Fructus and Mori Ramulus, can protect MSCs from •OH-induced damage. Such beneficial effects can mainly be attributed to the antioxidant action of phytophenols, which occurs via direct (ROS-scavenging) and indirect mechanism (Fe2+-chelating). The ROS-scavenging mechanism, however, include at least a H+-transfer and an electron-transfer (ET), and possibly includes a hydrogen-atom-transfer (HAT). In the Fe2+-chelating, flavonoids are more effective than non-flavonoids. This can be attributed to several adjacent planar chelating-sites between the 3-OH and 4-C = O, between the 4-C = O and 5-OH, or between the 3'-OH and 4'-OH in flavonoids. Such multiple-Fe2+-chelating reactions cause overlap in the UV-vis absorptions to deepen the complex color, enhance the peak strength, and form shoulder-peaks. By comparison, two non-flavonoids with catechol moiety produce only a weak single peak.

Volatile organic compounds produced by a soil-isolate, Bacillus subtilis FA26 induce adverse ultra-structural changes to the cells of Clavibacter michiganensis ssp. sepedonicus, the causal agent of bacterial ring rot of potato.

Rhizobacterial volatile organic compounds (VOCs) play an important role in the suppression of soil-borne phytopathogens. In this study, the VOCs produced by a soil-isolate, Bacillus subtilis FA26, were evaluated in vitro for their antibacterial activity against Clavibacter michiganensis ssp. sepedonicus (Cms), the causal agent of bacterial ring rot of potato. The VOCs emitted by FA26 inhibited the growth of Cms significantly compared with the control. Scanning and transmission electron microscopy analyses revealed distorted colony morphology and a wide range of abnormalities in Cms cells exposed to the VOCs of FA26. Varying the inoculation strategy and inoculum size showed that the production and activity of the antibacterial VOCs of FA26 were dependent on the culture conditions. Headspace solid-phase microextraction/gas chromatography-mass spectrometry analyses revealed that FA26 produced 11 VOCs. Four VOCs (benzaldehyde, nonanal, benzothiazole and acetophenone) were associated with the antibacterial activity against Cms. The results suggested that the VOCs produced by FA26 could control the causal agent of bacterial ring rot of potato. This information will increase our understanding of the microbial interactions mediated by VOCs in nature and aid the development of safer strategies for controlling plant disease.

Phenolic compounds from Citrus leaves: antioxidant activity and enzymatic browning inhibition.

Background Phenolic compounds from Citrus are known to be a topic of many studies due to their biological properties including antioxidant activity. Methods Methanolic and aqueous extracts were isolated from Citrus leaves of different species (C. clementina, C. limon, C. hamlin, C. navel, C. aurantifolia, C. aurantium and C. grandis) harvested in Algeria. Results The results showed that aqueous extracts of all species are rich in total phenolic compounds and flavonoids (from 68.23 to 125.28 mg GAE/g DM) and (from 11.99 to 46.25 mg QE/g DM) respectively. The methanolic and aqueous extracts were examined for in vitro antioxidant properties using various antioxidant assays. For aqueous extracts, C. limon showed an important DPPH radical scavenging activity (IC50 35.35 µg/mL), and C. clementina exerted the highest ABTS radical scavenging activity (1,174.43 µM ET/g DM) and a significant ferric reducing potential (30.60 mg BHAE/g DM). For methanolic extracts, C. clementina showed the highest antioxidant activity for all the realized assays (IC50 41.85 µg/mL, 378.63 µM ET/g DM and 13.85 mg BHAE/g DM) for DPPH, ABTS radicals scavenging activities and ferric reducing potential respectively. Antiperoxidase and antipolyphenol oxidase activities of these samples were also evaluated. Conclusions In this investigation, the assessment of antiperoxidase activity proved that the leaves extracts of different species were able to inhibit peroxidase activity. However, this inhibition varied with the species and the source of these enzymes. On the other hand, the aqueous extracts of different species showed moderate inhibition of polyphenol oxidase, while no effect on these enzymes was obtained with methanolic extracts.

Multimodal near-infrared-emitting PluS Silica nanoparticles with fluorescent, photoacoustic, and photothermal capabilities.

PURPOSE: The aim of the present study was to develop nanoprobes with theranostic features, including - at the same time - photoacoustic, near-infrared (NIR) optical imaging, and photothermal properties, in a versatile and stable core-shell silica-polyethylene glycol (PEG) nanoparticle architecture. MATERIALS AND METHODS: We synthesized core-shell silica-PEG nanoparticles by a one-pot direct micelles approach. Fluorescence emission and photoacoustic and photothermal properties were obtained at the same time by appropriate doping with triethoxysilane-derivatized cyanine 5.5 (Cy5.5) and cyanine 7 (Cy7) dyes. The performances of these nanoprobes were measured in vitro, using nanoparticle suspensions in phosphate-buffered saline and blood, dedicated phantoms, and after incubation with MDA-MB-231 cells. RESULTS: We obtained core-shell silica-PEG nanoparticles endowed with very high colloidal stability in water and in biological environment, with absorption and fluorescence emission in the NIR field. The presence of Cy5.5 and Cy7 dyes made it possible to reach a more reproducible and higher doping regime, producing fluorescence emission at a single excitation wavelength in two different channels, owing to the energy transfer processes within the nanoparticle. The nanoarchitecture and the presence of both Cy5.5 and Cy7 dyes provided a favorable agreement between fluorescence emission and quenching, to achieve optical imaging and photoacoustic and photothermal properties. CONCLUSION: We obtained rationally designed nanoparticles with outstanding stability in biological environment. At appropriate doping regimes, the presence of Cy5.5 and Cy7 dyes allowed us to tune fluorescence emission in the NIR for optical imaging and to exploit quenching processes for photoacoustic and photothermal capabilities. These nanostructures are promising in vivo theranostic tools for the near future.

Riboflavin Phototransformation on the Changes of Antioxidant Capacities in Phenolic Compounds.

Eight phenolic compounds including: p-coumaric acid, vanillic acid, caffeic acid, chlorogenic acid, trolox, quercetin, curcumin, and resveratrol were treated with riboflavin (RF) photosensitization and in vitro antioxidant capacities of the mixtures were determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2' azino bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and ferric reducing antioxidant power (FRAP) assays. Mixtures containing p-coumaric acid and vanillic acid under RF photosensitization showed increases in ferric ion reducing ability and radical scavenging activity of DPPH, whereas mixtures of other compounds had decreases in both radical scavenging ability and ferric reducing antioxidant power. Hydroxycoumaric acid and conjugated hydroxycoumaric and coumaric acids were tentatively identified from RF photosensitized p-coumaric acid, whereas dimmers of vanillic acid were tentatively identified from RF photosensitized vanillic acid. RF photosensitization may be a useful method to enhance antioxidant properties like ferric ion reducing abilities of some selected phenolic compounds.

Antioxidative activities of 62 wild mushrooms from Nepal and the phenolic profile of some selected species.

Mushrooms have garnered immense popularity for their nutritional as well as medicinal values. The therapeutic potential of mushrooms in Nepal, a country well known for its biodiversity and natural medicinal resources, remains largely unstudied. Therefore, this study attempts to unveil the antioxidative properties of Nepalese wild mushrooms. Sixty-two wild mushroom samples were collected from several forests in different parts of Nepal. Ethanol and water extracts of the dried samples were tested for their antioxidative activities using total phenolic content (TPC), oxygen radical absorbance capacity (ORAC) assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and reducing power (RP) assays. Ethanol extracts of samples belonging to the order Hymenochaetales showed significantly high activity in all the assays. Inonotus clemensiae had an exceptionally high TPC of 643.2 mg gallic acid equivalent (GAE)/g extract and also exhibited the lowest EC50 values in DPPH (0.081 mg/mL), ABTS (0.409 mg/mL), and EC0.5 value in reducing power (RP; 0.031 mg/mL) assays. High-performance liquid chromatography (HPLC) analysis of the top ten samples with the highest TPC was done to identify the phenolic compounds in the extracts, followed by liquid chromatography-mass spectrometry (LC-MS) analysis for some unknown compounds. These findings highlight the very strong antioxidative activity of Nepalese mushrooms, and paves the way for further research to explore their economic potential.