Browsing by Author "Moreira, Manuela M."
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- Antioxidant, photoprotective and inhibitory activity of tyrosinase in extracts of Dalbergia ecastaphyllumPublication . Morais, Daniel Vieira; Costa, Maria Angélica Carvalho; Bárbara, Marivalda; Silva, Fabiane de Lima; Moreira, Manuela M.; Delerue-Matos, Cristina; Dias, L.G.; Estevinho, Leticia M.; Carvalho, Carlos Alfredo Lopes deDalbergia ecastaphyllum is a native Brazil plant with importance for beekeeping, and widely used in folk medicine. For the first time, the extracts of this plant were assessed for the presence of hydrophilic and lipophilic antioxidants, as well as inhibition of tyrosinase, free radicals scavenging and sunscreen protection. The antioxidant activity was evaluated by free radical scavenging (DPPH) andβ-carotene bleaching assay. The tyrosinase inhibitory activity was evaluated and calculated the EC50. The photoprotective activity was measured using different concentrations of D. ecastaphyllum extracts. The Sun Protection Factor (SPF) of the samples was higher than 6, and the sample from Ilhe ´us showed the most pronounced photoprotective effect. Sample from Canavieiras presented the highest antioxidant activity by free radical scavenging DPPH andβ-carotene bleaching method, with 92.41% and 48.34%, respectively. All samples inhibited the tyrosinase, especially the sample from Prado that was most effective (124.62μg.mL-1). Significant negative correlation was found between flavonoid contents and inhibition of tyrosinase. The overall results provide relevant information about the Dalbergia ecastaphyllum species, indicating as potential material to cosmetic and pharmaceutical industry.
- Dalbergia ecastaphyllum leaf extracts: in vitro inhibitory against enzymes related to metabolic syndrome, inflammation and neurodegenerative diseasesPublication . Morais, Daniel Vieira; Moreira, Manuela M.; Silva, Fabiane de Lima; Costa, Maria Angélica Carvalho; Delerue-Matos, Cristina; Carvalho, Carlos Alfredo Lopes de; Estevinho, Leticia M.For the first time, the anti-hemolytic activity and the enzyme inhibitory activities of Dalbergia ecastaphyllum leaves extracts were tested against α-amylase, α-glucosidase, lipase, acetylcholinesterase, butyrylcholinesterase, tyrosinase and hyaluronidase. The phenolic profile of the obtained extracts was also investigated by high-performance liquid chromatography with photodiode array detection (HPLC-PAD). The extracts showed inhibitory activity against all enzymes evaluated, with the highest inhibitory activity reported for the enzyme hyaluronidase (28.28 ± 2.43 to 72.19 ± 1.40 μg mL-1). The obtained extracts also demonstrate anti-hemolytic activity (52.22 ± 1.62 to 71.17 ± 1.82%). Among the phenolic compounds identified, protocatechuic, vanillic and β-resorcylic acids were the most abundant (1.13 ± 0.06 to 2.53 ± 0.06, 0.90 ± 0.06 to 2.19 ± 0.06 and 1.03 ± 1.62 to 22.11 ± 1.62 mg L-1, respectively). In the statistical analysis, a significant correlation was found between the flavonoids content and all enzymes inhibitory activities. The present study showed that D. ecastaphyllum leaves extracts may have the potential to be used in the therapeutic treatment of several diseases such as Alzheimer, Parkinson, type 2 diabetes mellitus, hyperglycemia, and pigmentation, as well as those associated with oxidative stress.
- HPLC- MS Flavonoid determination and antioxidant capacity of Brazilian dehydrated bee pollenPublication . De-Melo, Adriane A.M.; Estevinho, Leticia M.; Moreira, Manuela M.; Delerue-Matos, Cristina; Almeida-Muradian, Ligia BicudoBee-pollen, produced by Apis mellifera bees, is an important source of proteins, lipids, vitamins and minerals for the hive, being considered one of nature's most completely nourishing foods. Its composition may vary according to the geographical region and its quality is influenced by harvest method and processing conditions. Although it has good nutritional components, beepollen contains significant amounts of polyphenols with recognized health benefits, including antioxidant activity. The present study aimed to evaluate the flavonoid composition, using HPLC-MS technique; and the antioxidant activity, using two different methods (DPPH and ORAC), of eight dehydrated bee-pollen samples collected in different Brazilian apiaries. The sample with the highest antioxidant capacity using DPPH method was produced in Rio Grande do Sul State (110.85 mol TE/g) while the sample with the least antioxidant capacity was collected in Bahia State (9.97 mol TE/g). The same sample from Rio Grande do Sul State presented the highest antioxidant capacity using ORAC method (542.00 mol TE/g), while the lowest value was observed in a sample from Mato Grosso State (133.70 mol TE/g). The flavonoid analysis using HPLC-MS revealed the following variations: catechin (0.69 to 0.75 mg/100 g); naringenine (4.57 to 18.36 mg/100 g); rutin (3.36 to 46.80 mg/100 g); quercetin (1.86 to 67.91 mg/100 g) and kaempferol (5.50 to 44.97 mg/100 g). In the sample with the highest antioxidant capacity (Rio Grande do Sul State) was observed 40 peaks in the HPLC-MS, while the samples with the lowest antioxidant capacities the number of peaks were 25 (Mato Grosso State) and 22 (Bahia State); therefore, the variety of compounds may have influenced the antioxidant capacity of the samples.
- HPLC/DAD analysis of phenolic compounds from lavender and its application to quality controlPublication . Areias, Filipe M.; Valentão, Patrícia; Andrade, Paula B.; Moreira, Manuela M.; Amaral, Joana S.; Seabra, Rosa M.A reversed phase HPLC procedure is proposed for the determination of eight phenolic compounds (2-O-glucosilcoumaric acid, o-coumaric acid, rosmarinic acid, apigenin-7-O-glucoside, coumarin, herniarin, luteolin, and apigenin) in lavender. The chromatographic separation was achieved using a reversed–phase Spherisorb ODS 2 (5 μm particle size: 25.0 x 0.46 cm) column. From the several extractive solvents assayed, only ethanol was able to extract all the mentioned compounds. Best resolution was obtained using a gradient of water-formic acid (19:1) and acetonitrile. Ten samples were subjected to quantification, all of them showing a common composition pattern.
- A multivariate approach based on physicochemical parameters and biological potential for the botanical and geographical discrimination of Brazilian bee pollenPublication . De-Melo, Adriane A.M.; Estevinho, Leticia M.; Moreira, Manuela M.; Delerue-Matos, Cristina; Freitas, Alex da Silva; Barth, Ortrud M.; Almeida-Muradian, Ligia BicudoFifty six Brazilian bee pollen samples were characterised, and their botanical and geographical origins were studied. The samples were also classified based on physicochemical and biological properties. The characterisation was done using Soxhlet extraction and micro-Kjeldahl methods, ashing at 550°C, transmittance, microscopy, spectrophotometry, inductively coupled plasma optical emission spectrometry and high-performance liquid chromatography. As expected, the values of proteins (7.9–32.2g/100g), lipids (3.2–13.5g/100g), ash (1.9–3.6g/100g), carbohydrates (54.9–82.8g/100g), K (3.4–9.8g/kg), Ca (0.9–4.1g/kg), Mg (0.6–2.4g/kg), Fe (46–1180mg/kg), Na (20–374mg/kg), Mn (25–215mg/kg), Zn (30–101mg/kg), Cu (7.4–19.7mg/kg), total phenolics (6.5–29.2mgGAE/g)and flavonoids(0.3–17.5mgQE/g)as well as the phenolic profiles varied among the samples. In general, the products had high antioxidant capacity (ORAC: 133–563 μmol TE/g; DPPH: 9.4–155μmolTE/g) and the antimicrobial capacity varied according to the sample and microorganism tested. The instrumental colour parameters could be used as indicators of some minerals. Based on multivariate approaches, bee pollen from Southern Brazil seemed to have a higher biological potential, whereas products from the Northeast region had higher calcium and magnesium levels. Similarities were identified in bee pollen containing C. nucifera or Brassica, and monofloral bee pollen seemed to have higher mineral content than heterofloral bee pollen.
- Phenolic profile and antioxidant capacity from 56 brazilian dehydrated bee-pollenPublication . De-Melo, Adriane A.M.; Estevinho, Leticia M.; Moreira, Manuela M.; Delerue-Matos, Cristina; Almeida-Muradian, Ligia BicudoBee-pollen is a food produced by bees from the flower pollen, to be a source of proteins, lipids, vitamins and minerals for the hive [1]. Its composition varies according to the region where it is produced, and its quality is influenced by the collection and processing conditions [2, 3]. Besides nutritional substances, bee-pollen contains significant amounts of polyphenols with recognized health benefits, including antioxidant activity [4]. The present study aimed to evaluate the polyphenolic profile and antioxidant activity of 56 dehydrated bee-pollen samples by high performance liquid chromatography and in vitro assays. Bee-pollens samples, collected during November 2011 to December 2013 from apiaries located in different Brazilian regions, were extracted with stirring for 30 minutes with ethanol 70% at 70 ºC and analyzed. The total phenolic content ranged from 6.5 ± 0.2 to 29.2 ± 0.3 mg gallic acid equivalent/g dry sample and flavonoid content ranged from 0.35 ± 0.01 to 17.5 ± 0.1 mg quercetin equivalent/g dry sample. The antioxidant activity assays, with values of 9.4 ± 0.4 to 155 ± 5 mol Trolox equivalent/g dry sample for DPPH and 133 ± 2 to 563 ± 15 mol TE/g for ORAC methods, revealed the antioxidant capacity of bee-pollen extracts. Regarding, the characterization of the phenolic composition from the several extracts by HPLC-PAD it was possible to observe that rutin, quercetin and vanillic acid were the main phenolic compounds found in the Brazilian dehydrated bee-pollen analyzed. On the other hand, caffeic acid was found in less amounts in the majority of samples studied. Among the identified polyphenols, only quercetin seems to have influenced positively in the antioxidant capacity of the samples. The Pearson’s Correlation analysis indicated high correlation between quercetin and ORAC values (r=0.6570, p=0.000) and medium correlation between quercetin and DPPH values (r=0.4873, p=0.000). In conclusion, bee-pollen characteristics vary according to the botanical origin and the Brazilian region where the sample was produced. This is a product with high antioxidant potential, therefore other tests, especially bioavailability assays, should be performed.
- Phenolic profile by HPLC-MS, biological potential, and nutritional value of a promising food: Monofloral bee pollenPublication . De-Melo, Adriane A.M.; Estevinho, Leticia M.; Moreira, Manuela M.; Delerue-Matos, Cristina; Freitas, Alex da Silva; Barth, Ortrud M.; Almeida-Muradian, Ligia BicudoThe objective of this study was to determine physicochemical and phenolic profiles as well the antioxidant and antimicrobial capacities of monofloral bee pollen samples from Brazil. Traditional methods were used. The phenolic profile was determined by high-performance liquid chromatography-mass spectrometry (HPLC-MS). The protein (10.6–33.9 g/100g), lipids (3.2–8.3 g/ 100g), ashes (2.6–3.8 g/100g), total phenolic (5.6–29.7 mg GAE/g), and total flavonoid (0.3– 19.0 mg QE/g) values were variable, even between products with the same botanical origin. The minerals analyzed were found in amounts varying between 10 mg/kg and 9.1 g/kg. Each product presented specific color parameters. Myrcia bee pollen presented the greater antioxidant capacity, and Mimosa scabrella bee pollen from Santa Catarina state was the most efficient in inhibiting bacteria and yeasts. Among the compounds identified by HPLC-MS, flavonoid 3-O-glycosides predominated. The physicochemical and phenolic profiles of each sample were distinct, and there was no pattern between monofloral products of the same pollen type.
- Potential of Portuguese vine shoot wastes as natural resources of bioactive compoundsPublication . Moreira, Manuela M.; Barroso, M. Fátima; Porto, João Vasconcellos; Ramalhosa, M.J.; Švarc-Gajić, Jaroslava; Estevinho, Leticia M.; Morais, Simone; Delerue-Matos, CristinaSince annually a high amount of wastes is produced in vine pruning, the aimof this studywas to evaluate the potential of vine shoots fromtwo Portuguese grape varieties (Touriga Nacional - TNand Tinta Roriz - TR) to be used as a natural source of phenolic compounds. To reach this goal, three techniques were explored, namely microwave-assisted extraction (MAE), subcritical water extraction (SWE) and conventional extraction (CE). The phenolic composition of the extracts, antioxidant and biological activities were evaluated by spectrophotometry and chromatography. MAE and SWE produced the highest concentrated extracts. TR vine shoot variety had the highest antioxidant activity and total phenolic (32.1±0.9mggallic acid equivalents/g dry sample), as well as flavonoid content (18.7±1.2mg epicatechin equivalents/g dry sample). For the first time, the biological activity of the vine shoot extracts was tested. Results demonstrated that all of them had antimicrobial potential against different bacteria and yeasts, and the ability of inhibiting α-amylase and acetylcholinesterase enzymes, with MAE TR extracts being the most efficient. HPLC analysis enabled the identification of different phenolic compounds, with gallic acid, catechin, myricetin and kaempferol-3-O-rutinoside being the main contributors to the phenolic composition. Portuguese vine shootwastes could serve as easily accessible source of natural antioxidants for the food or pharmaceutical industries.
- Quantifying the Impact of High‐Pressure Processing on the Phenolic Profile, Antioxidant Activity, and Pollen Morphology in HoneyPublication . Scepankova, Hana; Majtan, Juraj; Pospiech, Matej; Moreira, Manuela M.; Pinto, Carlos A.; Dias, Luís G.; Estevinho, Letícia M.; Delerue‐Matos, Cristina; Saraiva, Jorge A.Honey can benefit from non‐thermal processing techniques such as high‐pressure processing (HPP) to improve its quality and bioactivity. This study investigated the impact of HPP (600 MPa for 5, 10, and 15 min) on honey's quality, including the levels of hydroxymethylfurfural (HMF), antioxidant activity, total phenolic content (TPC), and phenolic profile. HPP treatment did not significantly affect HMF or TPC levels but led to selective changes in the phenolic profile. Despite a reduction in certain phenolic compound content, HPP for 5 and 15 min caused a significant increase in the antioxidant activity (2,2‐diphenyl‐1‐picrylhydrazyl [DPPH]) of honey from the mean value of 41.8% to values of 45.4% and 49.6%, respectively. On the other hand, HPP for 10 min did not change the antioxidant activity of tested honey. A 27.5% reduction in the equatorial diameter of pollen grains was observed after HPP combined with temperature at 75°C, suggesting an improved release of bioactive compounds. The content of specific phenolic compounds, including caffeic acid, p‐coumaric acid, sinapic acid, naringin, kaempferol, and the TPC, significantly affected the DPPH activity. The increment in the antioxidant activity of HPP honey may be attributed to selective changes in the content of certain phenolic compounds and improved their extraction from pollen grains.
- Storage methods, phenolic composition, and bioactive properties of Apis mellifera and Trigona spinipes pollenPublication . Santa Bárbara, Marivalda F.; Moreira, Manuela M.; Machado, Cerilene Santiago; Chambó, Emerson Dechechi; Pascoal, Ananias; Carvalho, Carlos Alfredo Lopes de; Sodré, Geni da Silva; Delerue-Matos, Cristina; Estevinho, Leticia M.The aim of this study was to evaluate the influence of lyophilization and drying in stove on phenolic compounds content and the biological activity of Apis mellifera and Trigona spinipes pollens produced in Brazil. In general, the bee pollen produced by T. spinipes presented highest antioxidant activity in dried and fresh samples assessed either by test of plasma ferric reduction capacity (FRAP) and free radical scavenging assay (DPPH) methods. For A. mellifera bee pollen the antioxidant activity was higher on the fresh samples. Nevertheless, b-carotene bleaching assay (BCB) and linoleic acid content were higher in T. spinipes samples, mainly in the fresh ones. Higher antioxidant activity was owing to higher content in phenolic compounds. Lyophilization method was the best for phenolic compounds’ conservation for both species. The bee pollen of both species has a high amount of flavonoids: kaempferol-3-O-glucoside was the most abundant in A. mellifera while for T. spinipes the most prevalent was resorcylic acidþepicatechin. All extracts presented antibacterial activity against Saphylococcus aureus (ATCC 43300)TM, (ESA 83138150), (ESA 32), Pseudomonas aeruginosa (ATCC 15442)TM, Pseudomonas aeruginosa (MRC.4) and (MRC.10). The methods used for storage influenced the biological properties of bee pollen from both species. Regarding the content of phenolic compounds, differences were observed amongst the pollen types: for A. mellifera these were best preserved with lyophilization, while for T. spinipes the three storage methods were equivalent.