Browsing by Author "García, Pablo A."
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- Chemical and Bioactive Properties of Red Rice with Potential Pharmaceutical UsePublication . Baptista, Eugénia; Liberal, Ângela; Cardoso, Rossana V.C.; Fernandes, Ângela; Dias, Maria Inês; Pires, Tânia C.S.P.; Calhelha, Ricardo C.; García, Pablo A.; Ferreira, Isabel C.F.R.; Barreira, João C.M.Red rice has been proposed as a super-food. Accordingly, the nutritional properties (AOAC), as well as its chemical composition, including sugars (HPLC-RI), organic acids (UFLC-PDA), tocopherols (HPLD-FD), and phenolic compounds (LC-DAD-ESI/MSn), together with the main bioactive properties (antioxidant, cytotoxic, antiproliferative, and antibacterial activities), were evaluated to access its nutritional benefits and health improvement potential. The most abundant macronutrients found were carbohydrates (87.2 g/100 g dw), proceeded by proteins (9.1 g/100 g dw), fat (2.6 g/100 g dw), and ash (1.1 g/100 g dw). Sucrose and raffinose were the only detected sugars, with sucrose presenting the maximum concentration (0.74 g/100 g dw). MUFAs and PUFAs were the predominant fatty acids (40.7% and 31%, respectively). Among the two detected tocopherol isoforms, γ-tocopherol (0.67 mg/100 g dw) predominated over α-tocopherol. The phenolic compounds profile, majorly composed of flavan-3-ols, should be associated with the detected bioactivities, which may provide biological benefits to human health beyond the primary nutritional effect. Overall, the bioactive potential of red rice was comprehensively accessed.
- Combined action of dietary-based approaches and therapeutic agents on cholesterol metabolism and main related diseasesPublication . Baptista, Eugénia; Pereira, Cláudia S.G.P.; García, Pablo A.; Ferreira, Isabel C.F.R.; Barreira, João C.M.Dyslipidaemia is among the major causes of severe diseases and, despite being wellestablished, the hypocholesterolaemic therapies still face significant concerns about potential side effects (such as myopathy, myalgia, liver injury digestive problems, or mental fuzziness in some people taking statins), interaction with other drugs or specific foods. Accordingly, this review describes the latest developments in the most effective therapies to control and regulate dyslipidaemia. Scope and approach: Herein, the metabolic dynamics of cholesterol and their integration with the current therapies: statins, bile acid sequestrants, fibrates, niacin, proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, reconstituted high-density lipoprotein (rHDL), or anti-inflammatory and immunemodulating therapies), were compared focusing their effectiveness, patients’ adhesion and typical side-effects. Likewise, the interaction of these therapies with recommended dietary habits, focusing functional foods and nutraceuticals uptake were also considered. Key findings and conclusions: Since none of the current therapeutic alternatives represent an ideal solution (mainly due to side-effects or patients’ tolerance), the potential adjuvant action of selected diets (and other healthy habits) was proposed as a way to improve the cholesterol-lowering effectiveness, while reducing the adverse effects caused by dose-increase or continuous uptake of alternating therapeutic agents. In general, the relevance of well-adapted diets must be acknowledged and their potential effects must be exhorted among patients, who need to be aware of the associated multifactorial advantages.
- Comparative analysis on parasite and host bioactive properties - a Cytinus hypocistis (L.) L. case studyPublication . Silva, Ana Rita; Pereira, Carla; Calhelha, Ricardo C.; García, Pablo A.; Ferreira, Isabel C.F.R.; Barros, LillianCytinus hypocistis (L.) L. is a rootless, stemless, and leafless holoparasite with a vegetative body reduced to an endophytic system that only grows inside the host [1,2]. Although to date, most studies on plant parasitism were focused on nutrient transfer from host to the parasite and the influence of parasites on host plants, a growing number of studies have documented the transfer of non-nutrient molecules. The transference of phytohormones, secondary metabolites, RNAs, and proteins suggests that hosts may significantly impact parasite physiology and ecology [3].
- Cromatografia em Camada Fina e Cromatografia em Coluna utilizadas na síntese química de derivados do ergosterolPublication . Francisco, Cristhian Rafael Lopes; Heleno, Sandrina A.; Calhelha, Ricardo C.; Gonçalves, Odinei Hess; Barreiro, M.F.; García, Pablo A.; Ferreira, Isabel C.F.R.O ergosterol é o esteroide mais abundante nos fungos e apresenta diversas propriedades bioativas, nomeadamente atividade hipocolesterolémica, que o tornam um agente funcionalizante interessante para a área alimentar. Contudo, este é insolúvel em água e apresenta solubilidade limitada em meios apolares, sendo a via da modificação química utilizada frequentemente para ultrapassar este problema. A cromatografia revela-se essencial no acompanhamento das reações de modificação química e na purificação dos produtos obtidos. Este trabalho teve como objetivo proceder a reações de acetilação [1], esterificação [2] e metilação [3] da molécula de ergosterol. A conversão do ergosterol no decorrer das reações foi avaliada por Cromatografia em Camada Fina (TLC, placas DC-Fertigfolien Alugram® Xtra SIL G/UV254; éter de petróleo/acetato de etilo (9:1, v/v) como eluente). A mistura obtida no final de cada reação foi diluída em éter de petróleo/acetato de etilo e aplicada numa coluna cromatográfica contendo sílica em gel (14x230 mm, Geduran® Si 60). O eluente foi recolhido e a pureza do produto monitorizada por TLC por comparação com os fatores de retenção dos reagentes iniciais. As frações contendo os produtos de interesse foram separadas e avaliadas em relação às propriedades citotóxicas em linhas tumorais (MCF-7, NCI-H460, HeLa, HepG2) e não-tumorais (PLP2). Após isolamento, os compostos foram caracterizados por ressonância magnética nuclear de protão (1H RMN, CDCl3). Estes apresentaram menor atividade citotóxica do que a molécula de ergosterol parental, em todas as linhas celulares tumorais. No entanto, ao contrário desta que apresentou toxicidade em células não-tumorais (GI50 = 89 𝜇g/mL), nenhum dos compostos sintetizados apresentou toxicidade para células normais à concentração máxima testada (400 𝜇g/mL). Assim, as moléculas obtidas por modificação química poderão ser utilizadas em matrizes alimentares lipofílicas.
- Cytinus hypocistis (L.) L. and its great bioactive potentialPublication . Silva, Ana Rita; García, Pablo A.; Ferreira, Isabel C.F.R.; Barros, LillianPlant-derived compounds have been extensively investigated to find novel active compounds as templates to mitigate the relative void of combinatorial chemistry, offering the potential to discover innovative structures that can lead to effective agents for various purposes [1]. Cytinus hypocistis (L.) L. is a wild edible parasitic plant on numerous members of the Cistaceae family. Although its biological properties were potentially attributed to its hydrolysable tannin content, its chemical composition was largely unknown, and the active substances not yet identified [2,3]. Thus, to decipher its potential applications, this work aimed at studying the bioactive properties and chemical composition of C. hypocistis. The plant material was collected in Castro Daire, Portugal. After lyophilisation, four different hydroethanolic extracts (whole plant, nectar chamber of the flower, petals, and stalks) were prepared and used for further analysis. The proximate composition was evaluated by AOAC official procedures; free sugars were determined using HPLC-RI, while organic acids were determined using UPLC-DAD [4]. Phenolic compounds were analysed by HPLC-DAD/ESI-MSn [4-6]. C. hypocistis extracts were tested for their antioxidant (OxHLIA and TBARS), antibacterial (MIC and MBC), anti-inflammatory (murine macrophage - RAW64.7), and wound healing (migration capacity of HaCaT cells) properties. Enzyme inhibitory properties for α-amylase, SARSCoV- 2 chymotrypsin-like protease, and tyrosinase were also evaluated. C. hypocistis study unveiled its nectar as a balanced source of nutrients. A correlation between its hydrolysable tannin content and bioactive properties was also established. Extracts exhibited broad-spectrum antibacterial activity and good antiinflammatory, antioxidant, and wound healing properties, together with the capacity to inhibit tyrosinase, α-amylase, and SARS-CoV-2 chymotrypsin-like protease. These results are significant evidence of the versatile profile of this plant. For bioactivity validation and mechanism investigation, further studies on fractionation, isolation, and compound characterisation are required.
- 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.
- 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.
- 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.
- Cytotoxic Terphenyl Neolignans from Fungus Terana coerulea: New Natural Corticins D and E, and Revised Structure for Corticin APublication . Maisterra Udi, Maitane; Castro, María Ángeles; Muñoz-Centeno, Luz M.; Calhelha, Ricardo C.; Ferreira, Isabel C.F.R.; García, Pablo A.The cobalt crust fungus Terana coerulea (Phanerochaetaceae family) was selected for a bio-guided study after an ethnobotanical survey at the Irati's Forest (Navarra, Spain) for its local use as antibiotic. Six extracts of increasing polarity, from hexane to hot water, were obtained from powdered dry fungi and tested for cytotoxicity against four human tumour cell lines and one non-tumour primary cell culture. From the most cytotoxic, EtOAc extract, we isolated and identified three terphenyl neolignans: two of them new natural products, named corticins D and E, and one previously described as corticin A, whose earlier structure has been revised. Their structural elucidation and biological evaluation as cytotoxic agents are described.
- Disacáridos cianogénicos y benzoilados en hojas de Psydrax LocuplesPublication . Castro, María Ángeles; Zimba, Amandio D.; García, Pablo A.; Corral Santana, José María Miguel del; Ferreira, Isabel C.F.R.; Munyemana, FrançoisLas plantas del género Psydrax y otras Rubiaceas relacionadas son usadas en la medicina popular africana frente a malaria, fiebre, dolores de cabeza, reumatismos, diarrea, conjuntivitis, micosis y otros cuadros infecciosos. Apenas existe bibliografía fitoquímica sobre este género: únicamente tres compuestos en la especie Psydrax livida [1]. Recientemente hemos comunicado las propiedades antioxidantes y citotóxicas de los extractos obtenidos de hojas de Psydrax locuples, planta arbórea utilizada particularmente en Mozambique para tratar la “doença da lua” en niños y recién nacidos, un síndrome relacionado con la epilepsia caracterizado por fiebre, vómitos, diarrea, dolor de cabeza y cólicos abdominales [2]. A partir del extracto de acetato de etilo de sus hojas se han aislado, mediante sucesivas cromatografías en columna y cromatografías en capa fina preparativas, varios disacáridos acetilados con estructura de (2R)-β-D-apiofuranosil-(1→6)-β-Dglucopiranosa. Estos disacáridos se pueden clasificar en dos familias en función de si el hidroxilo de la posición 1 de la β-D-glucopiranosa se encuentra benzoilado o si se encuentra unido a un residuo de mandelonitrilo formando glicósidos cianogénicos relacionados con la oxyanthina presente en Psydrax livida [1].Estos disacáridos son prácticamente desconocidos en el reino vegetal, tanto los benzoilados como los cianogénicos, siendo la mayoría nuevos productos naturales.
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