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Mechanical Engineering and Resource Sustainability Center
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Quality, Safety and Biological Studies on Campylanthus glaber Aerial Parts
Publication . Lima, Katelene; Malmir, Maryam; Camões, Sérgio P.; Hasan, Kamrul; Gomes, Samuel; Moreira da Silva, Isabel; Figueira, Maria Eduardo; Miranda, Joana P.; Serrano, Rita; Duarte, Maria Paula; Silva, Olga; MEtRICS - Centro de Engenharia Mecânica e Sustentabilidade de Recursos; Molecular Diversity Preservation International (MDPI)
In Cabo Verde, several endemic species are used in traditional medicine. However, no scientific studies have been conducted on the quality, efficacy, and safety of most of these plants. This study focused on establishing the botanical and chemical identification parameters required for a quality monograph of Campylanthus glaber Benth. aerial parts, a medicinal plant of Cabo Verde traditionally used to treat fever and muscular pain. In addition, in vitro antioxidant and antihyperglycemic activity, cytotoxicity, and genotoxicity were assessed for this medicinal plant. Optical microscopy, LC/UV-DAD-ESI/MS, and colorimetric assays were used for botanical, chemical, and biological studies, respectively. Cytotoxicity was assessed by the MTT assay with HepG2 cells, and genotoxicity by the Ames test. Microscopically, the xeromorphic leaf of C. glaber presents a thick cuticle (13.6–25.5 µm), thick-walled epidermal cells, anomocytic-type stomata, glandular trichomes (stalk length = 49.4–120.8 µm), and idioblasts containing calcium oxalate microcrystals. The chemical screening of aqueous and hydroethanolic extracts of this medicinal plant revealed the presence of organic acids, iridoids, phenylethanoids, and flavonoids as the main classes of marker compounds, with malic acid, citric acid, and verbascoside being the main marker compounds identified. Both extracts showed similar LC/UV-DAD/ESI-MS qualitative profiles and DPPH radical scavenger activity (IC50 = 130.9 ± 1.4; 134.3 ± 3.1 µg/mL). The hydroethanolic extract inhibited both α-amylase and α-glucosidase enzymes in a dose-dependent manner. Both extracts showed no cytotoxicity (up to 1000 µg/mL) by the MTT assay and no genotoxic potential with or without metabolic activation up to 5 mg /plate. The results obtained are an important contribution to the monographic quality assessment of C. glaber aerial parts and suggest that this medicinal plant may be safe and potentially used as an herbal drug raw material for pharmaceutical purposes.
Citrus By-Products
Publication . Andrade, Mariana A.; Barbosa, Cássia H.; Shah, Muhammad Ajmal; Ahmad, Nazir; Vilarinho, Fernanda; Khwaldia, Khaoula; Silva, Ana Sanches; Ramos, Fernando; DQ - Departamento de Química; MDPI - Multidisciplinary Digital Publishing Institute
Citrus production produces about 15 million tons of by-products/waste worldwide every year. Due to their high content of bioactive compounds, several extraction techniques can be applied to obtain extracts rich in valuable compounds and further application into food applications. Distillation and solvent extraction continues to be the most used and applied extraction techniques, followed by newer techniques such as microwave-assisted extraction and pulsed electric field extraction. Although the composition of these extracts and essential oils directly depends on the edaphoclimatic conditions to which the fruit/plant was exposed, the main active compounds are D-limonene, carotenoids, and carbohydrates. Pectin, one of the most abundant carbohydrates present in Citrus peels, can be used as a biodegradable polymer to develop new food packaging, and the extracted bioactive compounds can be easily added directly or indirectly to foods to increase their shelf-life. One of the applications is their incorporation in active food packaging for microbiological and/or oxidation inhibition, prolonging foods’ shelf-life and, consequently, contributing to reducing food spoilage. This review highlights some of the most used and effective extraction techniques and the application of the obtained essential oils and extracts directly or indirectly (through active packaging) to foods.
Effects of Periploca chevalieri Browicz on Postprandial Glycemia and Carbohydrate-Hydrolyzing Enzymes
Publication . Lima, Katelene; Malmir, Maryam; Sabiha, Shabnam; Pinto, Rui; Silva, Isabel Moreira da; Figueira, Maria Eduardo; Rocha, João; Duarte, Maria Paula; Silva, Olga; DQ - Departamento de Química; MEtRICS - Centro de Engenharia Mecânica e Sustentabilidade de Recursos; Molecular Diversity Preservation International (MDPI)
Background/Objectives: Periploca chevalieri Browicz (Apocynaceae), an endemic species of the Cabo Verde archipelago, is commonly used in traditional medicine for the treatment of diabetes. The aim of this study was to characterize the chemical profiles of the aqueous and hydroethanolic (70%) extracts of the P. chevalieri dried aerial parts (PcAE and PcEE) and evaluate their potential to modulate postprandial glycemia and inhibit key carbohydrate-hydrolyzing enzymes. Methods: The chemical characterization was performed by LC/UV-DAD-ESI/MS/MS. An in vivo evaluation of postprandial glycemia modulation was conducted on healthy CD1 mice submitted to an oral sucrose tolerance test. In vitro enzymatic inhibition was performed for the α-amylase, α-glucosidase, and DPP4 enzymes. Additionally, antioxidant and antiglycation activities were also assessed. Results: Phenolic acid derivatives, flavanols, proanthocyanidins, and flavonols were the major classes of secondary metabolites identified. PcEE at 170 mg/kg of body weight significantly (p < 0.05) reduced the postprandial glycemia peak in CD1 mice submitted to sucrose overload. Regarding the enzymatic inhibition, both extracts showed concentration-dependent inhibitory potential against the α-amylase, α-glucosidase, and DPP4 enzymes. Both extracts inhibited α-glucosidase more effectively than acarbose. Conclusions: The obtained results supports the traditional use of P. chevalieri and suggest the potential for further pharmacological investigation.
Quality Preservation and Shelf-Life Extension of Prickly Pear (Opuntia ficus-indica L. Mill) Using Edible Coatings
Publication . Rodrigues, Carolina; Polesca, Cariny; Bicalho, Isabela; Souza, Victor Gomes Lauriano; Coelhoso, Isabel; Fernando, Ana Luísa; DQ - Departamento de Química; MEtRICS - Centro de Engenharia Mecânica e Sustentabilidade de Recursos; LAQV@REQUIMTE
Prickly pear consumption is increasing across the world due to its rich variety of nutrients and bioactive compounds. Yet, it is a seasonal and highly perishable fruit, and the application of edible coatings emerges as an alternative to extend its shelf life. In this work, the effects of alginate, starch, chitosan, and pectin as coatings on the physicochemical, bioactive, microbiological, and textural properties of two prickly pear varieties (orange and red), kept under refrigeration (5 ± 2 °C) were evaluated for 6 weeks. Coatings proved to be helpful in the maintenance of the fruits’ color and textural properties, especially when pectin was applied. Overall, starch and chitosan can be considered the most effective coatings in preserving the quality of prickly pears among the options studied. A lower weight loss (8–10%) in fruits was achieved when starch and chitosan were applied, while in control fruits (without coating), the loss was 18–23%. Starch and chitosan also contributed to preserving the bioactivity of red fruits and showed good results in the preservation of total phenolic content in the orange fruits. In addition, starch and chitosan coatings also presented the best performance for the reduction of microbial contamination (both yeasts and molds and total mesophilic aerobic microorganisms). These findings highlight the role of edible coatings in preserving prickly pears, for a longer period, meeting consumers’ demand for fresh fruit.
Identification of Marker Compounds and In Vitro Toxicity Evaluation of Two Portuguese Asphodelus Leaf Extracts
Publication . Malmir, Maryam; Lima, Katelene; Póvoas Camões, Sérgio; Manageiro, Vera; Duarte, Maria Paula; Paiva Miranda, Joana; Serrano, Rita; Moreira da Silva, Isabel; Silva Lima, Beatriz; Caniça, Manuela; Silva, Olga; DQ - Departamento de Química; MEtRICS - Centro de Engenharia Mecânica e Sustentabilidade de Recursos; MDPI - Multidisciplinary Digital Publishing Institute
The leaves of Asphodelus bento-rainhae subsp. bento-rainhae, an endemic Portuguese species, and Asphodelus macrocarpus subsp. macrocarpus have been used as food, and traditionally as medicine, for treating ulcers, urinary tract, and inflammatory disorders. The present study aims to establish the phytochemical profile of the main secondary metabolites, together with the antimicrobial, antioxidant and toxicity assessments of both Asphodelus leaf 70% ethanol extracts. Phytochemical screenings were conducted by the TLC and LC-UV/DAD-ESI/MS chromatographic technique, and quantification of the leading chemical classes was performed by spectrophotometric methods. Liquid-liquid partitions of crude extracts were obtained using ethyl ether, ethyl acetate, and water. For in vitro evaluations of antimicrobial activity, the broth microdilution method, and for the antioxidant activity, the FRAP and DPPH methods were used. Genotoxicity and cytotoxicity were assessed by Ames and MTT tests, respectively. Twelve known compounds including neochlorogenic acid, chlorogenic acid, caffeic acid, isoorientin, p-coumaric acid, isovitexin, ferulic acid, luteolin, aloe-emodin, diosmetin, chrysophanol, and β-sitosterol were identified as the main marker compounds, and terpenoids and condensed tannins were found to be the major class of secondary metabolites of both medicinal plants. The ethyl ether fractions demonstrated the highest antibacterial activity against all the Gram-positive microorganisms, (MIC value of 62 to 1000 µg/mL), with aloe-emodin as one of the main marker compounds highly active against Staphylococcus epidermidis (MIC value of 0.8 to 1.6 µg/mL). Ethyl acetate fractions exhibited the highest antioxidant activity (IC50 of 800 to 1200 µg/mL, respectively). No cytotoxicity (up to 1000 µg/mL) or genotoxicity/mutagenicity (up to 5 mg/plate, with/without metabolic activation) were detected. The obtained results contribute to the knowledge of the value and safety of the studied species as herbal medicines.
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Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
6817 - DCRRNI ID
Número da atribuição
UIDP/04077/2020