518 resultados para DIPHENYL DISELENIDE
Resumo:
Many bacterial and viral pathogens (or their toxins), including Pseudomonas aeruginosa exotoxin A, require processing by host pro-protein convertases such as furin to cause dis- ease. We report the development of a novel irreversible inhibitor of furin (QUB-F1) consist- ing of a diphenyl phosphonate electrophilic warhead coupled with a substrate-like peptide (RVKR), that also includes a biotin tag, to facilitate activity-based profiling/visualisation. QUB-F1 displays greater selectivity for furin, in comparison to a widely used exemplar com- pound (furin I) which has a chloromethylketone warhead coupled to RVKR, when tested against the serine trypsin-like proteases (trypsin, prostasin and matriptase), factor Xa and the cysteine protease cathepsin B. We demonstrate QUB-F1 does not prevent P. aerugi- nosa exotoxin A-induced airway epithelial cell toxicity; in contrast to furin I, despite inhibiting cell surface furin-like activity to a similar degree. This finding indicates additional proteases, which are sensitive to the more broad-spectrum furin I compound, may be involved in this process.
Resumo:
The Mediterranean species Cynara cardunculus L. is recognized in the traditional medicine, for their hepatoprotective and choleretic effects. Biomass of C. cardunculus L. var. altilis (DC), or cultivated cardoon, may be explored not only for the production of energy and pulp fibers, but also for the extraction of bioactive compounds. The chemical characterization of extractable components, namely terpenic and phenolic compounds, may valorize the cultivated cardoon plantation, due to their antioxidant, antitumoral and antimicrobial activities. In this study, the chemical composition of lipophilic and phenolic fractions of C. cardunculus L. var. altilis (DC), cultivated in the south of Portugal (Baixo Alentejo region) was characterized in detail, intending the integral valorization of its biomass. The biological activity of cultivated cardoon extracts was evaluated in terms of antioxidant, human tumor cell antiproliferative and antibacterial effects. Gas chromatography-mass spectrometry (GC-MS) was used for the chemical analysis of lipophilic compounds. Sixty-five lipophilic compounds were identified, from which 1 sesquiterpene lactone and 4 pentacyclic triterpenes were described, for the first time, as cultivated cardoon components, such as: deacylcynaropicrin, acetates of β- and α-amyrin, lupenyl acetate and ψ-taraxasteryl acetate. Sesquiterpene lactones were the major family of lipophilic components of leaves (≈94.5 g/kg), mostly represented by cynaropicrin (≈87.4 g/kg). Pentacyclic triterpenes were also detected, in considerably high contents, in the remaining parts of cultivated cardoon, especially in the florets (≈27.5 g/kg). Taraxasteryl acetate was the main pentacyclic triterpene (≈8.9 g/kg in florets). High pressure liquid chromatography-mass spectrometry (HPLC-MS) was utilized for the chemical analysis of phenolic compounds. Among the identified 28 phenolic compounds, eriodictyol hexoside was reported for the first time as C. cardunculus L. component, and 6 as cultivated cardoon components, namely 1,4-di-O-caffeoylquinic acid, naringenin 7-O-glucoside, naringenin rutinoside, naringenin, luteolin acetylhexoside and apigenin acetylhexoside. The highest content of the identified phenolic compounds was observed in the florets (≈12.6 g/kg). Stalks outer part contained the highest hydroxycinnamic acids abundance (≈10.3 g/kg), and florets presented the highest flavonoids content (≈10.3 g/kg). The antioxidant activity of phenolic fraction was examined through 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging assay. Stalks outer part, and receptacles and bracts extracts demonstrated the highest antioxidant effect on DPPH (IC50 of 34.35 μg/mL and 35.25 μg/mL, respectively). (cont.) abstract (cont.) The DPPH scavenging effect was linearly correlated with the total contents of hydroxycinnamic acids (r = -0.990). The in vitro antiproliferative activity of cultivated cardoon lipophilic and phenolic extracts was evaluated on a human tumor cells line of triple-negative breast cancer (MDA-MB-231), one of the most refractory human cancers to conventional therapeutics. After 48 h of exposition, leaves lipophilic extract showed higher inhibitory effect (IC50 = 10.39 μg/mL) than florets lipophilic extract (IC50 = 315.22 μg/mL), upon MDA-MB-231 cellular viability. Pure compound of cynaropicrin, representative of the main compound identified in leaves lipophilic extract, also prevented the cell proliferation of MDA-MB-231 (IC50 = 17.86 μM). MDA-MB-231 cells were much more resistant to the 48 h- treatment with phenolic extracts of stalks outer part (IC50 = 3341.20 μg/mL) and florets (IC50 > 4500 μg/mL), and also with the pure compound of 1,5-di-O-caffeoylquinic acid (IC50 = 1741.69 μM). MDA-MB-231 cells were exposed, for 48 h, to the respective IC50 concentrations of leaves lipophilic extract and pure compound of cynaropicrin, in order to understand their ability in modelling cellular responses, and consequently important potentially signaling pathways for the cellular viability decrease. Leaves lipophilic extract increased the caspase-3 enzymatic activity, contrarily to pure compound of cynaropicrin. Additionally, leaves lipophilic extract and pure compound of cynaropicrin caused G2 cell cycle arrest, possibly by upregulating the p21Waf1/Cip1 and the accumulation of phospho-Tyr15-CDK1 and cyclin B1. The inhibitory effects of leaves lipophilic extract and cynaropicrin pure compound, against the MDA-MB-231 cell proliferation, may also be related to the downregulation of phospho-Ser473-Akt. The antibacterial activity of cultivated cardoon lipophilic and phenolic extracts was assessed, for the first time, on two multidrug-resistant bacteria, such as the Gram-negative Pseudomonas aeruginosa PAO1 and the Gram-positive methicillin-resistant Staphylococcus aureus (MRSA), two of the main bacteria responsible for health care-associated infections. Accordingly, the minimum inhibitory concentrations (MIC) were determined. Lipophilic and phenolic extracts of florets did not have antibacterial activity on P. aeruginosa PAO1 and MRSA (MIC > 2048 μg/mL). Leaves lipophilic extract did not prevent the P. aeruginosa PAO1 growth, but pure compound of cynaropicrin was slightly active (MIC = 2048 μg/mL). Leaves lipophilic extract and pure compound of cynaropicrin blocked MRSA growth (MIC of 1024 and 256 μg/mL, respectively). The scientific knowledge revealed in this thesis, either by the chemical viewpoint, or by the biological viewpoint, contributes for the valorization of C. cardunculus L. var. altilis (DC) biomass. Cultivated cardoon has potential to be exploited as source of bioactive compounds, in conciliation with other valorization pathways, and Portuguese traditional cheeses manufacturing.
Resumo:
Isocyanates are included into a class with an extreme commercial importance because their use in the manufacture of polyurethanes. Polyurethanes are used in several applications such as adhesives, coatings, foams, thermoplastics resins, printing inks, foundry moulds and rubbers. Agglomerated cork stoppers are currently used for still wines, semi-sparkle and gaseous wines, beer and cider. Methylene diphenyl diisocyanate (MDI) is presently the isocyanate used in the production of polyurethane based adhesive in use due to its lowest toxicity comparing with toluene diisocyanate (TDI) previously employed. However, free monomeric TDI or MDI, depending on the based polyurethane, can migrate from agglomerated cork stoppers to beverages therefore it needs to be under control. The presence of these compounds are usually investigated by HPLC with Fluorescence or UV-Vis detector depending on the derivatising agent. Ultra Performance Liquid Chromatography with Diode Array Detector (UPLC-DAD) method is replacing HPLC. The objective of this study is to determine which method is better to analyze isocyanates from agglomerated cork stoppers, essentially TDI to quantify its monomer. A Design of Experiments (DOE) with three factors, column temperature, flow and solvent, at two levels was done. Eight experiments with three replications and two repetitions were developed. Through an ANOVA the significance of the factors was evaluated and the best level’s factors were selected. As the TDI has two isomers and in this method these two isomers were not always separated an ANOVA with results of resolution between peaks was performed. The Design of Experiments reveals to be a suitable statistical tool to determine the best conditions to quantified free isocyanates from agglomerated cork stoppers to real foodstuff. The best level’s factors to maximize area was column temperature at 30ºC, flow to 0,3 mL/min and solvent 0,1% Ammonium Acetate, to maximize resolution was the same except the solvent that was 0,01% Ammonium Acetate.
Resumo:
Pele, ossos, espinhas, entre outros, separados durante o processamento de produtos cárneos podem ser uma boa fonte de proteína, especialmente de colágeno. Para obtenção de colágeno nativo a partir de ossos é necessário um tratamento prévio de desproteinização e desmineralização. Portanto, o objetivo deste trabalho foi determinar os melhores parâmetros para a desmineralização de ossos de pescado e frango utilizando soluções de HCl e EDTA um complexante de íons metálicos. O melhor efeito da desmineralização foi obtido com solução de HCl 1,0 mol/L. Após 48 h de extração, 99,4 e 95,4% das substâncias minerais foram solubilizadas para os ossos de pescado e para ossos de frango, respectivamente. Paralelamente, a menor perda de colágeno também foi observada nessas condições. O processo realizado empregando soluções de EDTA foi menos eficaz do que com solução de HCl. Após 48 h de extração com EDTA 0,1 mol/L, 37,5 e 32,4% dos compostos minerais foram removidos dos ossos de pescado e dos ossos de frango, respectivamente. Uma maior eficiência foi alcançada com solução de EDTA 0,5 mol/L. O rendimento do processo foi de cerca de 66,6% a partir dos ossos de pescado e 70,6% a partir os ossos de frango. A desmineralização com EDTA não provocou perda de colágeno.
Resumo:
The southern region of Brazil, especially the states of Parana and Santa Catarina stand out for growing grapes and apples for fresh consumption and in order to add value to these products, process the material for the production of wine, juices and jellies . As a result large quantities of by-products, such as peels, seeds and pulp are produced becoming environmental problems. Studies reuse of these by-products have attracted interest because they have shown a high biological potential, due to the presence of high levels of phenolic compounds, which are associated with a lower incidence of disease caused by oxidative stress, due to its antioxidant, antiinflammatory and antibacterial properties. Currently, few studies are presented on the phenolic composition and biological potential of waste grape variety Bordô (Vitis labrusca) and apple (Malus domestica) Gala variety, cultivated in southern Brazil. Within this context, the objectives of this study were: compare the efficiency of solidliquid and liquid-liquid extraction, perform the optimization and validation of analytical methodology by HPLC-DAD for the separation, identification and quantification of multiclass phenolic compounds, evaluate the activity antioxidant by sequestering methods of free radical 2,2-diphenyl-1 picrilhidrazina (DPPH) and 2,2-azino-bis (3- ethyl-benzthiazoline-6-sulphonic acid) (ABTS) solution, reduction of Fe3+ in Fe2+ method (FRAP), ORAC, RP-HPLC-ABTS online, Rancimat and determination of total phenolics three agro-industrial byproducts, pomace and stems grape Bordô produced in Paraná Southwest region and Gala apple pomace coming from the Santa Catarina West. Optimization and validation of chromatographic method showed satisfactory quality parameters for the compounds of interest and the solidliquid extraction was more efficient in extracting phenolic evaluated. The three byproducts evaluated showed significant levels of phenolic compounds when analyzed by HPLC, especially flavonoids, catechin and epicatechin besides that showed significant antioxidant capacity. The grape stems extract had the highest sequestration capacity of DPPH and ABTS radical and reduced iron, and high content of phenolic compounds. The apple pomace extract showed the best response to the Rancimat method, which indicates a high potential to protect the oil from lipid oxidation, was no significant difference when compared to synthetic antioxidant TBHQ. The results of this study showed that the agro-industrial coproducts analyzed are rich in phenolic compounds of high antioxidant capacity and therefore must be better explored by the food and pharmaceutical industries.
Resumo:
Mushrooms are known as a powerful source of bioactive compounds including antioxidants, inhibitors of human tumour cell lines growth, inducers of apoptosis and enhancers of immunity. Indeed, many pre-clinical studies have been conducted in human tumour cell lines and in some cases a number of compounds isolated from mushrooms have followed to clinical trials. The Northeast of Portugal is one of the European regions with higher wild mushrooms diversity. However, to our knowledge, no studies had been conducted so far to verify their bioactivities. The main aim of this work was the evaluation of the bioactive properties (antioxidant properties and growth inhibitory potential on human tumour cell lines) of wild edible mushrooms collected in the Northeast of Portugal. Once properly identified, methanolic, ethanolic and boiling water extracts were prepared from thirty eight wild mushroom species collected in that region. Chemical characterization was obtained by high performance liquid chromatography (HPLC) coupled to a photodiode array detector (DAD) or to a refraction index detector (RI). Antioxidant activity assays were carried out in those extracts, including evaluation of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals scavenging capacity, reducing power and inhibition of β-carotene bleaching. Extract-induced cell growth inhibition was assessed with the sulforhodamine B assay in four human tumour cell lines (NCI-H460 - lung cancer, MCF-7 -breast cancer, HCT-15 -colon cancer and AGS - gastric cancer). The effects on cell cycle profile and apoptosis were evaluated by flow cytometry and the effect on the expression levels of proteins related to cell cycle and apoptosis was further investigated by Western blotting. Three wild edible mushroom species revealed growth inhibitory activity in the studied human tumour cell lines: Clitocybe alexandri ethanolic extract, Lepista inversa methanolic extract and Suillus collinitus methanolic extract. C. alexandri ethanolic extract induced an S-phase cell cycle arrest and increased the percentage of apoptotic cells, in the NCI-H460 cell line. The analysed mushroom species also provided interesting antioxidant potential, mainly the boiling water extract of L. inversa which showed the highest DPPH radical scavenging activity, reducing power and β-carotene bleaching inhibition. S. collinitus methanolic extract induced a slight increase in the number of cells in G1, with a concomitant decrease in the percentage of cells in the S phase of the cell cycle and an increase in the percentage of apoptotic cells, in the MCF-7 cell line. The combined use of the S. collinitus methanolic extract and etoposide caused a greater decrease in the percentage of cell growth, when compared to either of them used individually, indicating the potential benefit of this combination. The tested extracts were chemically characterized and protocatechuic, p-hydroxybenzoic, p-coumaric and cinnamic acids were the main compounds identified on the phenolic (methanolic and ethanolic) extracts, while mannitol, trehalose and arabinose were the main sugars found in the polysaccharidic (boiling water) extracts after hydrolysis. The individual compounds identified in the extracts were submitted to a screening of tumour cells growth inhibitory activity, but only the phenolic acids and a related compound, cinnamic acid, presented activity. This compound was found to be the most potent one regarding cell growth inhibition in the NCI-H460 cell line. The effect of the individual and combined treatment with the identified compounds was also evaluated. Cinnamic and protochatequic acids caused a statistically significantly reduction in the number of viable cells. In addition, p-hydroxybenzoic acid did not show any significantly reduction in the viable cell number. Nevertheless, it was verified that the concomitant use of the three compounds provided the strongest decrease in the viable cell number, suggesting a possible concomitant effect of those compounds. Overall, the present work has contributed to further understand the bioactive potential of wild edible mushrooms from the Northeast of Portugal. This study allowed to identify some species with antioxidant or tumour cell growth inhibitory potential.
Resumo:
Naturally-occurring phytochemicals have received a pivotal attention in the last years, due to the increasing evidences of biological activities. Equisetum giganteum L., commonly known as “giant horsetail”, is a native plant from Central and South America, being largely used in dietary supplements as diuretic, hemostatic, antiinflammatory and anti-rheumatic agents [1,2]. The aim of the present study was to evaluate the antioxidant (scavenging effects on 2,2-diphenyl-1-picrylhydrazyl radicals- RSA, reducing power- RP, β-carotene bleaching inhibition- CBI and lipid peroxidation inhibition- LPI), anti-inflammatory (inhibition of NO production in lipopolysaccharidestimulated RAW 264.7 macrophages) and cytotoxic (in a panel of four human tumor cell lines: MCF-7- breast adenocarcinoma, NCI-H460- non-small cell lung cancer, HeLa- cervical carcinoma and HepG2- hepatocellular carcinoma; and in non-tumor porcine liver primary cells- PLP2) properties of E. giganteum, providing a phytochemical characterization of its extract (ethanol/water, 80:20, v/v), by using highperformance liquid chromatography coupled to diode array detection and electrospray ionisation mass spectrometry (HPLC-DAD–ESI/MS). E. giganteum presented fourteen phenolic compounds, two phenolic acids and twelve flavonol glycoside derivatives, mainly kaempferol derivatives, accounting to 81% of the total phenolic content, being kaempferol-O-glucoside-O-rutinoside, the most abundant molecule (7.6 mg/g extract). The extract exhibited antioxidant (EC50 values = 123, 136, 202 and 57.4 μg/mL for RSA, RP, CBI and LPI, respectively), anti-inflammatory (EC50 value = 239 μg/mL) and cytotoxic (GI50 values = 250, 258, 268 and 239 μg/mL for MCF-7, NCI-H460, HeLa and HepG2, respectively) properties, which were positively correlated with its concentration in phenolic compounds. Furthermore, up to 400 μg/mL, it did not revealed toxicity in non-tumor liver cells. Thus, this study highlights the potential of E. giganteum extracts as rich sources of phenolic compounds that can be used in the food, pharmaceutical and cosmetic fields.
Resumo:
Mushrooms are very perishable foods due to their high susceptibility to moisture loss, changes in color and texture, or microbiological spoilage. Drying is considered as the most appropriate method to prevent these alterations, but it has some limitations, such as shrinkage, enzymatic and non-enzymatic browning reactions, and oxidation of lipids and vitamins. Irradiation might effectively attenuate the undesirable changes caused by drying process, ensuring also higher shelf-life of mushrooms and their decontamination [I]. In the present work, the combined effects of electron-beam irradiation (at 0, 0.5, 1 and 6 kGy doses) and storage time (at 0, 6 and 12 months) were evaluated and compared. Macrolepiota procera (Scop.) Singer wild samples were obtained in Tnis-os-Montes, in the Northeast of Portugal, and dried at 30 •c in an oven. Subsequently, the samples were divided in four groups: control (non-irradiated, 0 kGy); sample 1 (0.5 kGy); sample 2 (1 kGy) and sample 3 (6 kGy). The irradiation was performed at the lNCTInstitute of Nuclear Chemistry and Technology (lNCT), in Warsaw, Poland. Moisture, protein, fat, carbohydrates and ash were determined following standard procedures. Free sugars and tocopherols were determined by high performance liquid chromatography coupled to a refraction index detector (HPLC-RI) and a fluorescence detector, respectively; fatty acids were determined by gas-liquid chromatography with flame ionization detection (GC-FID). Antioxidant activity was evaluated in the methanolic extracts by in vitro assays measuring DPPH (1,1-diphenyl-2- picrylhydrazyl) radical scavenging activity, reducing power, inhibition of ~-carotene bleaching and inhibition oflipid peroxidation using thiobarbituric acid reactive substances (TBARS) assay. Total phenolics were also determined by the Folin-Ciocalteu assay. All the parameters showed a decrease tendency with storage time. Trehalose and y-tocopherol were preserved with 1 kGy dose. Electron-beam irradiation did not impart additional changes to most of the chemical and antioxidant parameters of M. procera dried samples. This is a very promising result, since electron-beam irradiation might attenuate most unwanted changes caused by drying, maintaining its long-term effectiveness.
Resumo:
Mushrooms are rich in several bioactive metabolites among them are phenolic compounds, terpenoids, polysaccharides, lectins, and steroids including mycosterols, namely ergosterol [1]. Ethanolic extracts prepared by maceration of several mushroom species have been recently described as having antiinflammatory properties [2]. In the present work, ethanolic extracts of Agaricus bisporus L., Lentinus edodes (Berk.) Pegler and Pleurotus ostreatus (Jacq. ex Fr.) P.Kumm., purchased from a local supermarket in the Northeast of Portugal, were obtained by Soxhlet and chemically characterized in terms of ergosterol content by HPLC-UV. The antioxidant properties of these extracts were evaluated through DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity (RSA), reducing power (RP), p. carotene bleaching inhibition (CBI) and lipid peroxidation inhibition in TBARS (thiobarbituric acid reactive substances) assay (LPI); the antioxidant activity of ergosterol was also evaluated by the DPPH assay. The anti-inflammatory activity of the same extracts and ergosterol was evaluated in LPS (lipopolysaccharide) stimulated RAW 264.7 macrophages, through the inhibition of NO production. A. bisporus revealed the highest content in ergosterol (44.8 ± 0.4 mg/ g extract) followed by P. ostreatus (34 ± 3 mg/ g extract) and finally L. edodes (8.9 ± 0.1 mg/ g extract). A. bisporus showed the highest RSA, RP and CBI (EC50 values= 7.0 ± 0.8, 2.3 ± 0.1 and 1.4 ± 0.1 mg/mL, respectively), while L. edodes presented the highest LPI (2.5 ± 0.1 mg/mL ); ergosterol revealed higher RSA (0.46±0. 0 I mg/mL) than the extracts. Concerning the anti-inflammatory potential, the most efficient species was L. edodes (lC50 value = 164 ± 16 J.lg/mL), followed by A. bisporus (185 ± 16 J.lg/mL) and finally P. ostreatus (290 ± 10 J.lg/mL). However, ergosterol presented lower activity (338 ± 23 J.lg/mL) due to its low solubility in the culture medium. The higher antioxidant properties displayed by A. bisporus can be related with its higher ergosterol content, while in the anti-inflammatory activity this relation cannot be established also due to the low solubility of ergosterol in the cells culture medium, decreasing the ergosterol availability. More studies are being conducted regarding the ergosterol solubility. Several compounds have been implicated in the bioactivity of mushrooms and in this study we have found that ergosterol can give an important contribution.
Resumo:
Boletus edulis Bull: Fr. is an edible mushroom quite appreciated for its organoleptic and nutritional properties. However, the seasonality and perishability cause some difficulties in its distribution and marketing in fresh form; losses associated with this type of food during marketing can reach 40% [1]. Irradiation is recognized as a safe and effective method for food preservation, being used worldwide to increase shelf life of fresh and dehydrated products (e.g. fruits, vegetables and spices) [2]. In particular, gamma irradiation has already been applied to cultivated mushrooms (especially Agaricus, Lentinula and Pleurotus Genus) and proved to be an interesting conservation technology [3]. However, the studies with added-value wild species are scarce. In this work, the effects of gamma irradiation on chemical and antioxidant properties of wild B. edulis, were evaluated. Fruiting bodies were obtained in Trás-os-Montes, in the Northeast of Portugal, in November 2012. The irradiation was performed in experimental equipment with 60Co sources at 1 and 2 kGy. All the results were compared with nonirradiated samples (control). Macronutrients and energy value were determined following official procedures of food analysis; fatty acids were analyzed by gas-chromatography coupled to flame ionization detection (GC-FID), while sugars and tocopherols were determined by high performance liquid chromatography (HPLC) coupled to refraction index (RI) and fluorescence detectors, respectively. Antioxidant activity was evaluated in the methanolic extracts by in vitro assays measuring DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, reducing power, inhibition of β- carotene bleaching and inhibition of lipid peroxidation using thiobarbituric acid reactive substances (TBARS) assay. Total phenolics were also determined by the Folin-Ciocalteu assay. The nutritional profiles were not affected in high extension. Fatty acids and sugars were slightly affected, decreasing with the increasing doses. The performed assays for antioxidant activity, indicate that irradiated samples tended to have lower scavenging activity and reducing power, but higher lipid peroxidation inhibition. Despite the detected differences in individual compounds, the results of nutritional parameters, the most relevant in terms of mushroom acceptability by consumers, were less affected, indicating an interesting potential of gamma-irradiation to be used as an effective conservation technology for the studied mushrooms.
Resumo:
Background: Vernonia cinerea (L.) Less is used in folk medicine as a remedy for various diseases. Objectives: The present study reports antioxidant and antimicrobial activities of solvent fractions of Vernonia cinerea. Methods: The antioxidant properties of solvent fractions of V. cinerea were evaluated by determining radicals scavenging activity, total flavonoid and phenolic contents measured with the 2,2-diphenyl-1-picryl hydrazyl (DPPH) test, the aluminum chloride and the Folin-ciocalteau methods, respectively. Antimicrobial activities were tested against human pathogenic microorganisms using agar diffusion method. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of each active extract were determined. Results: The ethyl acetate fraction having the IC50 value of 6.50 μg/mL demonstrated comparable DPPH radical-scavenging activity with standard antioxidants, gallic acid and quercetin included in the study. All fractions displayed moderate antimicrobial potential against the tested pathogens with the zone of inhibition that ranged from 9.0 to 13.5 mm. The MIC (1.56 mg/mL) and MBC (3.13 mg/mL) indicated highest susceptibility of Candida albicans in all fractions. Conclusion: The results of this study showed that the solvent fractions of V. cinerea possess antioxidant and antimicrobial activities, hence justifying the folkloric use of the plant for the treatment of various ailments in traditional medicine.
Resumo:
Food industry is focused on the development of novel functional foods containing health promoting natural ingredients. Natural antioxidants present important health benefits like the prevention of several diseases related to oxidative stress [1,2]. Foeniculum vulgare Mill. (fennel) is a source of those compounds with proved antioxidant potential [3]. Herein, after evaluation of 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity and reducing power of fennel (provided by Américo Duarte Paixão Lda.) decoction, we propose its incorporation into cottage cheese (produced by Queijos Casa Matias Lda.). Three groups of cottage cheese samples were prepared: control; samples with fennel decoction (incorporated at EC25 value=0.35 mg/mL, previously determined by DPPH assay); and samples with fennel powder (incorporated at 1.75 mg/mL, considering the decoction yield=20%). The samples were submitted to an evaluation of DPPH scavenging activity and reducing power immediately after the incorporations, and after 7 and 14 days of storage, at 4 ºC. The incorporation of fennel improved the antioxidant activity of cottage cheese. Samples incorporated with plant powder revealed higher antioxidant properties than samples incorporated with decoction, either in 0 or 7 days of storage. After 14 days, cottage cheese incorporated with fennel decoction gave the highest DPPH scavenging activity (46.72±0.09 mg/mL). A decrease in the antioxidant potential of the cottage cheese with fennel was observed along the shelf life. Nevertheless, it is important to highlight that the samples still display antioxidant properties. Studies regarding the effects of the incorporation of these natural ingredients on nutritional and chemical composition of cottage cheese are in course
Resumo:
Elephant foot yam (Amorphophallus paeoniifolius (Dennst.) Nicolson) is an underground, unbranched deciduous plant that produces a large tubercle (rhizome) with recognized health effects. In this study, the influence of solvent nature (water, water/etanol (1:1) and absolute ethanol) and processing type (fresh, lyophilized and boiled) on the antioxidant activity and bioactive compounds extractability of elephant foot yam was evaluated. Extracts were compared for their contents in total phenolics, flavonoids and tannins. Moreover, their antioxidant capacity was assessed by the ferric reducing antioxidant power (FRAP) and the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH▪) scavenging capacity assays. Phenolics (154 mg GAE/L) and tannins (109 mg GAE/L) were maximized in lyophilized samples extracted with the hydroalcoholic solvent, which attained also the highest FRAP value (711 mg FSE/L). In turn, flavonoids reached the highest yields in lyophilized samples (95 mg ECE/L) extracted with pure ethanol, as well as the highest DPPH▪ scavenging activity. These findings might have practical applications to define the best processing methodology regarding the enhancement of elephant foot yam, either for prompt consumption, as well as to develop food supplements or pharmaceutical related products.
Resumo:
People of Western Kordofan (Sudan) are endowed with a deep knowledge concerning the use of wild plants. Tubers of Raphionacme splendens Schl. subspecies splendens Flickr (family Apocynaceae), locally known as Elfayo, are used as a food reserve during times of famine or poor harvest. The aim of this study was to analyze the nutritional composition and antioxidant capacity of root tubers of R. splendens. Samples were collected from South-West Kordofan. Analyses included determination of moisture, carbohydrate, crude protein, fat, fibre, ash, minerals, vitamin C, amino acids and fatty acids composition. Antioxidant activity was determined by the DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2.2’-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) assays. The total phenolic content was also assessed. The results, which are referred to as (%) dry weight, showed that the tubers contained 3.2% protein, 18% carbohydrate, 0.5% lipid, 2.4% crude fibre, 3.5% ash, 79.2% moisture and gross energy 101.7 kJ/g. The total amino acids were 10776 mg/100g where the essential amino acids represented 28.2%. The more abundant essential amino acids were leucine (792mg/100g), isoleucine (712mg/100g) and threonine (536mg/100g). Methionine and lysine were the limiting amino acids. Minerals were potassium (259mg/100g), calcium (183mg/100g), magnesium (64mg/100g), phosphorus (37mg/100g), copper (3.6mg/100g), manganese (2.4mg/100g), zinc (1.8mg/100g) and iron (1.2mg/100g). Total saturated fatty acids were 45.6% whereas total unsaturated fatty acids were 54.4%. Oleic acid (32.56%) and palmitic acid (30.23%) were the most abundant fatty acids. Tubers displayed good antioxidant activity with IC50 values 0.987 and 1.559mg/mL against DPPH and ABTS radicals respectively. Vitamin C was 31.5mg/100g and total phenolic content was 60mg gallic acid equivalent (GAE) per 100g dry sample and they could be the main contributor to the antioxidant capacity of the tubers. In conclusion, the results of this study suggested that tubers of R. splendens could have beneficial effect for food and/or nutraceutical application for normal growth and adequate protection against diseases associated with reactions of free radicals.
Resumo:
Environmental indicators have been proposed as a means to assess ecological integrity, monitoring both chemical and biological stressors. In this study, we used nestling bald eagles as indicators to quantify direct or indirect tertiary-level contaminant exposure. The spatial and temporal trends of polychlorinated biphenyl (PCB) congeners were evaluated in nestling plasma from 1999–2014. Two hexa-chlorinated congeners, PCB-138 and 153, were detected with the highest frequency and greatest concentrations throughout Michigan. Less-chlorinated congeners such as PCB-52 and 66 however, comprised a greater percentage of total PCB concentrations in nestlings proximate to urbanized areas, such as along the shorelines of Lake Erie. Toxic equivalents were greatest in the samples collected from nestlings located on Lake Erie, followed by the other Great Lakes spatial regions. Nestling plasma samples were also used to measure concentrations of the most heavily-used group of flame retardants, brominated diphenyl ethers (BDEs), and three groups of alternative flame retardants, non-BDE Brominated Flame Retardants (NBFRS), Dechloranes, and organophosphate esters (OPs). BDE-47, 99 and 100 contributed the greatest to total BDE concentrations. Concentrations of structurally similar NBFRs found in this study and recent atmospheric studies indicate that they are largely used as replacements to previously used BDE mixtures. A variety of Dechloranes, or derivatives of Mirex and Dechlorane Plus, were measured. Although, measured at lesser concentrations, environmental behavior of these compounds may be similar to mirex and warrant future research in aquatic species. Concentrations of OPs in nestling plasma were two to three orders of magnitude greater than all other groups of flame retardants. In addition to chemical indicators, bald eagles have also been proposed as indicators to identify ecological stressors using population measures that are tied to the fitness of individuals and populations. Using mortality as a population vitality rate, vehicle collisions were found to be the main source of mortality with a greater incidence for females during white-tailed deer (Odocoileus virginianus) hunting months and spring snow-melt. Lead poisoning was the second greatest source of mortality, with sources likely due to unretrieved hunter-killed, white-tailed deer carcasses, and possibly exacerbated by density-dependent effects due to the growing population in Michigan.