A carregar...
32 resultados
Resultados da pesquisa
A mostrar 1 - 10 de 32
- Cytinus hypocistis (L.) L. extract effects in an animal model of papillomavirus-induced neoplasiaPublication . Medeiros, Catarina; Silva, Ana Rita; Ferreira, Tiago; Barros, Lillian; Neuparth, Maria João; Peixoto, Francisco P.; Bastos, Margarida M.S.M.; Medeiros, Rui; Costa, Rui Miguel Gil; Pires, Maria João; Faustino-Rocha, Ana; Gama, Adelina; Oliveira, Paula A.Infections with certain types of papillomavirus, such as the human papillomavirus 16 (HPV16), are associated with the development of preneoplastic lesions and cancers of the anogenital, and head and neck regions. Cytinus hypocistis (L.) L. extracts are composed of substances presenting antiproliferative, antioxidant, anti-inflammatory and antibacterial properties, which might be promising as new therapeutic compounds. This study analysed the influence of topical application of an extract obtained from C. hypocistis (CH) on K14-HPV16 and FVB/n mice to evaluate its therapeutic and toxicological properties. To achieve the study goals, 30 female mice, 33–37 weeks old, were divided into six groups (n=5/group): I (HPV+CH3.1); II (HPV+CH6.2); III (HPV+CH12.4); IV (FVB/ n+CH12.4); V (HPV+control) and VI (FVB/n+control). CH was applied topically to both ears for 28 days. After this period, all animals were sacrificed for samples collection. Skin lesions were classified histologically. Toxicological parameters included haematological and biochemical blood markers, and hepatic oxidative stress analysis. Transgenic animals showed a decrease in mean body weight regardless of the concentration of extract applied. The extract had no influence on physiological parameters, organ weight, or biochemical and oxidative stress parameters. Histology demonstrated the presence of proliferative epithelial lesions in the skin and oral mucosa of K14-HPV16 mice, with no association with the application of this extract. Overall, the application of CH extract had no influence on the skin lesions and was well tolerated by the animals in these concentrations.
- Metabolomic approach to assess the effect of the foraging year on the anti-elastase activity of Cytinus hypocistis (L.) L.Publication . Silva, Ana Rita; Ayuso, Manuel; García, Pablo A.; Barros, Lillian; Edrada-Ebel, RuAngelieCytinus hypocistis (L.) L. is a wild edible parasitic plant on numerous members of the Cistaceae family. Although its bioactive properties were potentially attributed to its hydrolysable tannin content, its chemical composition is largely unknown, and the bioactive substances have not yet been identified [1,2]. Thus, this work aimed to investigate its potential to inhibit human elastase, an important anti-ageing mechanism. The plant material was collected in Castro Daire, Portugal, from the host species Halimium lasianthum (Lam.) Greuter on the same calendar date in June for three consecutive years (2018, 2019, and 2020). Metabolomic- based analytical techniques were applied to disclose the discriminating features of the anti-elastase activity of nine hydroethanolic extracts (three per year). The discriminating features among samples were identified using a multivariate PLS-DA of the LC-HRMS data. Dereplication of the discriminating metabolites obtained from the loadings plot revealed that year-one had the best inhibitory activity with IC50s of 13 to 22 μg/mL and were comprised of high molecular weight compounds ranging between 500 and 950 Da. However, the second-year collection exhibited a significant decrease in the biological activity of 120 to 128 μg/mL indicating the occurrence of low molecular weight compounds between 150 and 300 Da. Year three gave IC50s of 74 to 109 μg/mL. This study offers an evidential hypothesis on the effect of annual environmental changes on the chemical profile of a parasitic plant. Albeit, the relative abundance of the discriminating features was minimal, it was significant enough to affect the anti-elastase bioactivity of the extracts
- Cytinus hypocistis (L.) L. SubSp. Macranthus Wettst.: Nutritional characterizationPublication . Silva, Ana Rita; Fernandes, Ângela; García, Pablo A.; Barros, Lillian; Ferreira, Isabel C.F.R.The habit of eating wild plants in Europe is often associated with times of famine; an example of such is the nectar of Cytinus hypocistis (L.) L., a parasitic plant. To the authors’ best knowledge, there are no studies on its nutritional and chemical composition; thus, the whole C. hypocistis (L.) L. subsp. macranthus Wettst. plant (CH) and its nectar (NCH) were nutritionally and chemically characterized. The proximate composition of CH and NCH were very similar in terms of energy, ash, and carbohydrate content. Protein and fat were approximately 2-fold higher in NCH, and crude fiber was 4.6-fold higher in CH compared to NCH. Fructose, glucose, sucrose, and trehalose were the free sugars present in both samples. Oxalic, malic, and citric acids were the identified organic acids in both samples, with citric acid as the most abundant molecule. For both samples, polyunsaturated and saturated fatty acids (PUFA and SFA, respectively) predominate over monounsaturated fatty acids (MUFA) due to the significant contribution of linoleic and palmitic acids, respectively. However, unsaturated fatty acids (UFA) prevail over SFA in CH and NCH. Therefore, CH proved to be an excellent source of nutritional compounds, which supports its use during past periods of scarcity.
- Morphometric measurements in HPV-transgenic mice after topical application of Cytinus hypocistis (L.) extractPublication . Silva, Ana Rita; Medeiros, Catarina; Ferreira, Teresa; Barros, Lillian; Ferreira, Isabel C.F.R.; Pires, Maria João; Costa, Rui Miguel Gil; Gama, Ana; Oliveira, Paula A.Human papillomavirus (HPV) infections are associated with the development of several anogenital cancers. K14HPV16 transgenic model is an animal model that mimics HPV-induced lesions. Cytinus hypocistis (L.) is an endophytic parasitic plant that has been shown to possess several antibacterial and antiproliferative properties1. During antiproliferative studies in animal models, the toxicological analysis is also required. Therefore, the present research aims to study the toxic effects of applying a topical formulation enriched with Cytinus hypocistis extracts (FCH) on K14HPV16 mice. Three different concentrations of FCH were used to enrich a base cream, the phenolic compounds were analyzed by HPLC-DAD-ESI/MS and were applied to the animal’s ears for 28 days. Thirty female mice were equally divided into six groups (G) (n=5): G1 (HPV16+-C1); G2 (HPV16+-C2); G3 (HPV16+-C3); G4 (HPVC3); G5 (HPV+-control); and G6 (HPV-control). The animals were kept under controlled conditions and biological variables were registered throughout the study. In the end, animals were sacrificed, and the organs collected and weighed. The main phenolic compound present in the base cream enriched with C. hypocistis was galloyl-bis-HHDPglucose. Food and water intake were constant throughout the trial. G3 presented a higher relative weight of the liver and lungs than the control animals, and a significant difference in body weight relatively to G4 (p<0.05). The body weight loss and the increase in liver weight observed in HPV+ mice treated with they may reflect a negative impact of the extract on these already fragile animals. However, overall, the FCH was well tolerated by the animals. Although the highest concentration of the extract had a negative impact on the evaluated morphometric parameters, this does not necessarily imply that the extract is toxic, which can be corroborated with histological analysis. Further studies are needed to understand whether different doses of this extract would cause distinct effects.
- Cytinus hypocistis (L.) L. extract as a source of anti-aging cosmeceutical ingredientsPublication . Silva, Ana Rita; Taofiq, Oludemi; Pinela, José; Dias, Maria Inês; Calhelha, Ricardo C.; Alves, Maria José; Mocan, Andrei; García, Pablo A.; Barros, Lillian; Ferreira, Isabel C.F.R.Plant-derived compounds have been extensively used for cosmeceutical applications, especially because humans have once again turned to Nature to mitigate the relative void of combinatorial chemistry, to find new molecules and the toxicological effects associated with the synthetic ones [1]. Cytinus hypocistis (L.) L. is a wild edible parasitic plant on various members of the Cistaceae family. Although its biological properties were potentially attributed to its hydrolysable tannins content, to the author's best knowledge, its chemical composition is largely unknown, and active biomolecules are not yet identified [2]. According to a semi-quantitative study, where 100 extracts obtained from plants collected in India, Africa, and the Mediterranean area, C. hypocistis figures on the top 10 group of plants that potently inhibited both elastase and tyrosinase, two main enzymes involved in skin aging [3]. Thus, studying the bioative properties and chemical composition of C. hypocistis plant will give comprehensive clues on its potential cosmeceutical applications. Plant specimens of C. hypocistis were collected in June 2018 in Castro Daire, Portugal. After lyophilisation, the phenolic compounds were analysed in the hydroethanolic extracts of four different parts of C. hypocistis (whole plant, nectar chamber of the flower, petals, and stalks) using a HPLC-DAD-ESI/MSn system. The antioxidant activity of the four extracts were evaluated using OxHLIA and TBARS methodology. Anti-tyrosinase enzyme inhibitory assay was performed using L-DOPA as substract and kojic acid as standard. C. hypocistis extracts were also tested for their antibacterial activity based on minimum inhibitory and bactericidal concentrations and the anti-inflammatory activity was evaluated through NO inhibition, in LPS-activated murine macrophage (RAW 264.7). A total of 17 phenolic compounds were identified, being galloyl-bis-HHDP-glucose, digalloyl-bis-HHDP-glucopyranose, and pedunculagin the most abundant. UV radiation generates oxidative stress, being mainly responsible for cell membrane oxidation and, although through different mechanisms, OxHLIA and TBARS are equally a consequence of lipid peroxidation. All the tested extracts showed high antioxidant capacity, with the petals exhibiting the most promising results for both OxHLIA (IC50 = 279 ± 5 ng/mL) and TBARS (IC50 = 342 ± 2 ng/mL) assays. Considering the anti-tyrosinase inhibitory assay, the main enzyme involved in skin pigmentation, the stalks presented the lowest IC50 values, 0.09 ± 0.02 mg/mL. All tested extracts displayed a broad-spectrum microbial inhibition against both Gram-positive and Gram-negative bacteria. Moreover, being chronic inflammation one of the molecular mechanisms behind skin aging, the petals result for NO inhibition (IC50: 127 ± 8 μg/mL) is an important evidence on the versatile profile of this plant. Although for the four studied samples the 17 identified phenolic compounds were the same, its concentration was higher in the petals extract, followed by the stalks, being these two plant parts of C. hypocistis unveiling the strongest bioactive potential. These results point a potential correlation between the phenolic profile of C. hypocistis and its properties. For its bioactivity validation and mechanism investigation, further studies on fractionation, isolation and characterization of compounds of the extracts of C. hypocistis are currently ongoing.
- Cosmeceutical properties of p-hydroxybenzoic acid and use of microencapsulation technique to ensure controlled releasePublication . Taofiq, Oludemi; Heleno, Sandrina A.; Silva, Ana Rita; Calhelha, Ricardo C.; Fernandes, Isabel P.; Alves, Maria José; González-Paramás, Ana María; Barros, Lillian; Barreiro, M.F.; Ferreira, Isabel C.F.R.Topical formulations are designed to exert multifunctional benefits to the skin, and the interest on natural bioactive compounds as cosmeceutical ingredients have recently received increased attention [1]. However, the utilization of natural ingredients can present constraints related to their stability (e.g. against pH and temperature), being microencapsulation a useful strategy to overcome some of these limitations [2]. The present work describes p-hydroxybenzoic acids anti-inflammatory, anti-tyrosinase, and antimicrobial activity. The compound was further microencapsulated using the atomization/coagulation method, with sodium alginate coagulated with calcium chloride. The obtained microspheres were characterized in terms of morphology, particle size distribution, and encapsulation efficiency. Free and microencapsulated forms were then incorporated into a semisolid cosmetic base formulation and HPLC-DAD was used to screen the presence of the compound in the final formulation. p-Hydroxybenzoic acid showed anti-inflammatory (EC50 = 195 ± 9 μg/mL), anti-tyrosinase (EC50 = 1.86 ± 0.01 mg/mL), and antimicrobial activity against a panel of Gram positive and Gram negative bacteria, and also Candida albicans. The microparticles showed spherical morphology, with various sizes (D10, D50 and D90 representing 20.5, 74.6, and 206 μm, respectively), little agglomeration, and a unimodal and bimodal particle size distribution (number and volume, respectively). Encapsulation efficiency and yield were 88.3% and 57.8%, respectively. After incorporation, the formulation containing free forms of the compound maintained some of its bioactive properties, while the encapsulated forms preserved the bioactivity showing a slow release profile of the compounds. In conclusion, the studied compound showed interesting bioactive properties and can be used in the development of multifunctional cosmeceutical formulation. The adopted encapsulation strategy also provides a suitable alternative to prolong retention of bioactive compounds for subsequent release (sustained release), thereby preserving its bioactivity over time.
- Response surface methodology and artificial neural network modeling as predictive tools for phenolic compounds recovery from olive pomacePublication . Silva, Ana Rita; Ayuso, Manuel; Oludemi, Taofiq; Gonçalves, Alexandre; Melgar Castañeda, Bruno; Barros, LillianThis study optimized the extraction of three major phenolic compounds (oleuropein, tyrosol, and verbascoside) from olive pomace using microwave- and ultrasonic-assisted methods. Screening factorial design (SFD) and central composite design (CCD) were employed, and response surface methodology (RSM) and artificial neural networks (ANN) were used for data modeling. The microwave-assisted method in the SFD yielded higher compound amounts, with verbascoside showing a four-fold increase compared to the ultrasonic-assisted method. Factors like vessel diameter, ultrasonic power using UAE, and solvent acidity in both techniques had minimally impacted extractability. CCD-RSM revealed temperaturés significantly affect on oleuropein, but improved tyrosol recovery, with the effect on verbascoside being influenced by the temperature range. RSM and ANN integration enhanced understanding and prediction of factor behavior. Microwave-assisted extraction at 113 ◦C for 26 min, with minimum ramp time of 7.7 min, yielded 67.4, 57, and 5.1 mg of oleuropein, tyrosol, and verbascoside per gram of extract, respectively, with a prediction error ranging from 0.83 to 15.19.
- Eco-sustainable recovery of ergosterol-rich bioactive extracts from Pleurotus eryngii (DC.) QuélPublication . Taofiq, Oludemi; Silva, Ana Rita; Caleja, Cristina; Barros, Joana; Ferreira, Inês; Nunes, João; Prieto Lage, Miguel A.; Barros, Lillian; Ferreira, Isabel C.F.R.Pleurotus eryngii (DC.) Quél. is widely recognized for its organoleptic qualities and health benefits, being commercially produced in great extent in Asia, Europe, and North America [1]. Depending on the size of the mushroom industry, an expressive volume (20 to 35% in weight of fresh mushrooms) of bio-residues are often discarded, even though their content in biomolecules is not necessarily compromised [2]. Hence, there are major opportunities to turn these outcomes into high-value products through the recovery of bioactive compounds, such as ergosterol rich extracts. Ergosterol, one of the main sterols in mushrooms, has been reported to be the major contributor in P. eryngii bio-functionalities [2]. In the present work, P. eryngii bio-residues (PER) and intact mushrooms (PEG) were compared for their ergosterol content. Response Surface Methodology (RSM) was applied using heat-assisted extraction methodology. The combined effect of time (10-150 min) and temperature (30-90°C) was performed using a circumscribed central composite design (CCCD), and the response criteria were extraction yield and ergosterol content using HPLC-UV. The global optimum conditions predicted by the model were 112.7 min, 90°C, and 150 min, 61.8°C for PER and PEG, respectively. Under these conditions, 190.14 and 360.58 mg of ergosterol per 100 g of dry weight sample were recovered from PER and PEG, correspondingly. Even though P. eryngii bio-residues presented up to 53% of PEG ergosterol yield, PER offers sustainable and economic advantages. These results confirm the enormous potential of the under-exploited P. eryingii bio-residues as a valuable source of ergosterol-rich extracts.
- A literacia financeira dos gestores/empresários como um dos determinantes da estrutura de capitais na indústria têxtil e no setor da hotelaria e na restauração do norte de PortugalPublication . Silva, Ana Rita; Monte, Ana Paula; Fernandes, António B.A tomada de decisões financeiras, nomeadamente sobre financiamento e performance da empresa, será potenciada pelo conhecimento das diversas ferramentas financeiras disponíveis, pelo que a alfabetização financeira dos empresários e gestores poderá ser uma ferramenta essencial para o sucesso das empresas. O objetivo do presente trabalho é investigar se a literacia financeira dos gestores/empresários é um dos fatores determinantes da estrutura de capitais das empresas e se há determinantes diferenciados em função dos setores de atividade, usando como estudo de caso o setor têxtil e o setor da hotelaria e restauração do norte de Portugal. Especificamente pretende-se ainda (i) medir o nível de literacia financeira (NLF) dos gestores/empresários; (ii) apurar se o NLF dos gestores é influenciado pelas caraterísticas sociodemográficas (idade, género e nível de educação formal); (iii) testar as teorias trade off e pecking order na estruturação de capitais das empresas da indústria têxtil e do setor da hotelaria e restauração; e (iv) verificar se a dimensão e o setor de atividade das empresas influenciam a estruturação de capitais, além do NLF. No presente estudo, apurou-se que, em relação ao NLF, nenhum dos indivíduos possui NLF muito baixo, mas ainda assim, há 8% dos inquiridos que evidenciaram um NLF baixo e 22% um nível médio. Relativamente ao estudo dos determinantes de estrutura de capitais, apenas duas variáveis se apresentam como estatisticamente significativas para o modelo, rendibilidade e dimensão apresentando-se com relação negativa, o que indicia que as empresas, em análise, seguem a teoria pecking order.
- Cytinus hypocistis (L.) L.: optimised heat/ultrasound-assisted extraction of tannins by response surface methodologyPublication . Silva, Ana Rita; Pinela, José; García, Pablo A.; Ferreira, Isabel C.F.R.; Barros, LillianTannins are a class of phenolic compounds commonly found in plants and studied for their bioactive and inhibitory enzyme properties. Cytinus hypocistis (L.) L. is a wild edible parasitic plant whose biological properties have been correlated with its high tannin content. Thus, studying the extraction of tannins from C. hypocistis will give comprehensive clues to enhance the recovery of these high added-value bioactive compounds. The present work applied Response Surface Methodology (RSM) to optimise tannins extraction using Heat-Assisted (HAE) and Ultrasound-Assisted (UAE) methods. Two three-factor Rotatable Central Composite Designs were used to assess the linear, quadratic, and interaction effects of the independent variables on the target responses. The obtained results from both extraction systems revealed high ethanol percentages as the critical factor in increasing tannin content. The optimum global processing conditions predicted by the polynomial models were 95.1 min, 46.4 ◦C, and 74.3% ethanol for HAE; and 18.7 min, 327.4 W, and 69.3% ethanol for UAE. Following these conditions, 200 mg and 178 mg of total tannins per g of extract were recovered using HAE and UAE, correspondingly. Although HAE presented a higher final response, the UAE stood out as a time-saving technique.