Browsing by Author "Chahdoura, Hassiba"
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- Bioactivity and chemical characterization of Opuntia macrorhiza Engelm. seed oil: potential food and pharmaceutical applicationsPublication . Chahdoura, Hassiba; Barreira, João C.M.; Adouni, Khawla; Mhadhebi, Lamia; Calhelha, Ricardo C.; Snoussi, Mejdi; Majdoub, Hatem; Flamini, Guido; Ferreira, Isabel C.F.R.; Achour, LotfiIn the food industry, there is a continuous search for ingredients that might provide advantageous properties to food products, either considering their nutritional value or bioactivity, as well as flavouring and technological aspects. Crude oils are good examples of this type of ingredient, especially if obtained from nonconventional sources. Accordingly, the Opuntia macrorhiza Engelm. seed oil (OMSO) was chemically characterized and evaluated for different in vitro and in vivo bioactivities. OMSO presented physicochemical characteristics appropriate to be considered as an edible oil, namely low acidity value, stability to oxidation (high peroxide value and low K 232 and K 270 values), and high contents of unsaturated fatty acids (as shown by the iodine value) and saponifiable matter. Furthermore, this natural oil, owing to its rich phytochemical profile, showed relevant antioxidant activity (especially in lipid peroxidation inhibition assays), a-glucosidase inhibitory activity, cytotoxicity against human tumour cell lines, antibacterial (mainly against Gram positive species) and antifungal properties, as well as anti-inflammatory and analgesic activities. Furthermore, OMSO did not show any sign of acute toxicity on animals, highlighting its possible use in different applications, considering that this natural product is not expected to induce the adverse effects typically associated with synthetic bioactive agents (e.g., ampicillin, amphotericin B, or lysine acetylsalicilate).
- Bioactivity, hydrophilic, lipophilic and volatile compounds in pulps and skins of Opuntia macrorhiza and Opuntia microdasys fruitsPublication . Chahdoura, Hassiba; Barreira, João C.M.; Barros, Lillian; Dias, Maria Inês; Calhelha, Ricardo C.; Flamini, Guido; Soković, Marina; Achour, Lotfi; Ferreira, Isabel C.F.R.Opuntia genus includes several species able to grow in arid regions and known for producing delicate fruits, which are far from being thoroughly characterized. Herein, fruits from O. macrorhiza and O. microdasys were divided in skins and pulps (without including seeds) and studied for chemical composition, individual phytochemicals and bioactivity. The major volatiles were camphor and ethyl acetate, while citric acid was the main organic acid. The fatty acids detected in highest percentages were linoleic acid (skins) and lauric acid (pulps); α- tocopherol was the major isoform of vitamin E. Quercetin-3-O-rutinoside and quercetin-O-(deoxyhexoside-rutinoside) were the main phenolics in fruit skins of O. macrorhiza and O. microdasys (respectively), similarly to piscidic acid in O. macrorhiza pulp (O. microdasys pulp showed no quantifiable compounds). Betanin and isobetanin were the major betalains. All samples were antioxidant (particularly O. macrorhiza), but antimicrobial activity was only detected in skins. Cytotoxicity was low in all cases. Overall, these fruits proved to be potential new ingredients for food or pharmaceutical related applications, adding value to these natural species able to grow in arid environments.
- Bioactivity, proximate, mineral and volatile profiles along the flowering stages of Opuntia microdasys (Lehm.): defining potential applicationsPublication . Chahdoura, Hassiba; Barreira, João C.M.; Fernández-Ruiz, Virginia; Morales, Patricia; Calhelha, Ricardo C.; Flamini, Guido; Soković, Marina; Ferreira, Isabel C.F.R.; Achour, LotfiOpuntia spp. flowers have been traditionally used for medical purposes, mostly because of their diversity in bioactive molecules with health promoting properties. The proximate, mineral and volatile compound profiles, together with the cytotoxic and antimicrobial properties were characterized in O. microdasys flowers at different maturity stages, revealing several statistically significant differences. O. microdasys stood out mainly for its high contents of dietary fiber, potassium and camphor, and its high activities against HCT15 cells, Staphylococcus aureus, Aspergillus versicolor and Penicillium funiculosum. The vegetative stage showed the highest cytotoxic and antifungal activities, whilst the full flowering stage was particularly active against bacterial species. The complete dataset has been classified by principal component analysis, achieving clearly identifiable groups for each flowering stage, elucidating also the most distinctive features, and comprehensively profiling each of the assayed stages. The results might be useful to define the best flowering stage considering practical application purposes.
- Biological activities evaluation of enantiopure isoxazolidine derivatives: in vitro, in vivo and in silico studiesPublication . Mosbah, Habib; Chahdoura, Hassiba; Mannai, Asma; Snoussi, Mejdi; Aouadi, Kaïss; Abreu, Rui M.V.; Bouslama, Ali; Achour, Lotfi; Selmi, BoulbabaA series of enantiopure isoxazolidines (3a–c) were synthesized by 1,3-dipolar cycloaddition between a (−)-menthone-derived nitrone and various terminal alkenes. The screened compounds were evaluated for their antioxidant activity by two in vitro antioxidant assays, including β-carotene/linoleic acid bleaching, and inhibition of lipid peroxidation (thiobarbituric acid reactive species, TBARS). The results revealed that compound 3b (EC50 = 0.55 ± 0.09 mM) was the most potent antioxidant as compared to the standard drug (EC50 = 2.73 ± 0.07 mM) using the TBARS assay. Furthermore, the antimicrobial activity was assessed using disc diffusion and microdilution methods. Among the synthesized compounds, 3c was found to be the most potent antimicrobial agent as compared to the standard drug. Subsequently, the acute toxicity study has also been carried out for the newly synthesized compounds and the experimental studies revealed that all compounds were safe up to 500 mg/kg and no death of animals were recorded. The cytotoxicity of these compounds was assessed by the MTT cell proliferation assay against the continuous human cell lines HeLa and compound 3c (GI50 = 46.2 ± 1.2 μM) appeared to be more active than compound 3a (GI50 = 200 ± 2.8 μM) and 3b (GI50 = 1400 ± 7.8 μM). Interestingly, all tested compounds displayed a good α-amylase inhibitory activity in competitive manner with IC50 values ranging between 23.7 and 64.35 μM when compared to the standard drug acarbose (IC50 = 282.12 μM). In addition, molecular docking studies were performed to understand the possible binding and the interaction of the most active compounds to the α-amylase pocket.
- Chemical and antioxidant parameters of dried forms of ginger rhizomesPublication . Jelled, Aicha; Fernandes, Ângela; Barros, Lillian; Chahdoura, Hassiba; Achour, Lotfi; Ferreira, Isabel C.F.R.; Cheikh, Hassen BenThere are various products that can be obtained from ginger (Zingiber officinale Roscoe) rhizomes, such as dried products, being difficult to choose the best option for antioxidant purposes. In this study, three different dried forms of ginger rhizomes (freshly dried, dried and powder dried) were characterized in terms of chemical composition including individual profiles in sugars, organic acids, fatty acids, tocopherols, and antioxidants (phenolics and flavonoids). The in vitro antioxidant properties (free radicals scavenging activity, reducing power and lipid peroxidation inhibition) of their methanolic extracts were also evaluated. The results of this study indicate that the ginger form has significant influence in chemical and antioxidant parameters of the plant; dried ginger (DG) proved to be the best choice. Overall, this study could help the consumer in the selection of the most suitable option regarding antioxidant purposes.
- Chemical characterization of Opuntia sp. by-productsPublication . Chahdoura, Hassiba; Barreira, João C.M.; Barros, Lillian; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.; Achour, LotfiThe species from the Cactaceae family are important invaders in the Mediterranean. The seeds are usually discarded and proper utilisation of these waste products could lead to an important source of bioactive compounds. The seeds have been described to be rich in health-promoting polyunsaturated fatty acids and may potentially be included in animal and human diets [1]. Moreover, seeds could also be recovered for their high nutritional value, as sources of sugars, tocopherols, dietary fiber and polyphenols instead of being discarded, as it currently occurs. In this study, the composition in soluble sugars, fatty acids, organic acids, tocopherols and phenolic composition were determined in seeds of Opuntia macrorhiza (Engelm.) and Opuntia microdasys (Lehm.). The individual sugars profile was determined by HPLC-RI, fatty acids by GC-FID, organic acids by HPLC-DAD, tocopherols by HPLC-fluorescence and phenolic compounds by HPLC-DAD-ESI/MS. In both cases, the overall concentrations of soluble sugars in seeds were quite lower than those detected in other Opuntia sp. parts. Quinic (0.30 g/100 g dw) and oxalic (0.32 g/100 g dw) acids were the major organic acids detected in O. microdasys and O. macrorhiza, respectively. The fatty acid profiles detected in the seeds of both species were similar, with linoleic acid (C18:2n6) as the major fatty acid (71% in O. microdasys; 74% in O. macrorhiza). γ-Tocopherol was the most abundant tocopherol vitamer in both species (7.4 mg/100 g dw in O. microdasys; 5.8 mg/100 g dw in O. macrorhiza). Regarding the phenolic profile, eight compounds were identified: seven phenolic acid derivatives and one flavonoid, and O. macrorhiza seeds (1016 μg/g extract) revealed a higher concentration than O. microdasys (450 μg/g extract). Feruloyl di-hexoside was the most abundant phenolic acid in both species (225 μg/g extract in O. microdasys and 718 μg/g extract in O. macrorhiza). The seeds of Opuntia sp. presented several bioactive phytochemicals, which may allow considering this botanical part as highly interesting by-products.
- Chemical composition, nutritional value, and biological evaluation of tunisian okra pods (abelmoschus esculentus L. moench)Publication . Romdhane, Mariem Haj; Chahdoura, Hassiba; Barros, Lillian; Dias, Maria Inês; Corrêa, Rúbia C.G.; Morales, Patricia; Ciudad-Mulero, María; Flamini, Guido; Majdoub, Hatem; Ferreira, Isabel C.F.R.The aim of this work was to perform an unprecedented in-depth study on the bioactive phytochemicals of Abelmoschus esculentus L. Moench Tunisian landrace (Marsaouia). For this purpose, its nutritional, aroma volatile, and phenolic profiles were characterized, and sundry biological activities were assessed in vitro. The approximate composition revealed that total dietary fiber as the most abundant macronutrient, mainly insoluble dietary fiber, followed by total carbohydrates and proteins. In addition, okra pods were rich in K, Ca, Mg, organic acids, tocopherols, and chlorophylls. Gas Chromatography-Electron Impact Mass Spectrometry (GC-EIMS) analysis showed that oxygenated monoterpenes, sesquiterpene hydrocarbons, and phenylpropanoids were the predominant essential volatile components in A. esculentus pods. A total of eight flavonols were detected by High-Performance Liquid Chromatography coupled to a DAD detector and mass spectrometry by electrospray ionization (HPLC-DAD-MS/ESI); with quercetin-3-O-glucoside being the majority phenolic component, followed by quercetin-O-pentosyl-hexoside and quercetin-dihexoside. This pioneering study, evidences that Tunisian okra display promising antioxidant and cytotoxic actions, in addition to relevant inhibitory effects against α-amylase and α-glucosidase enzymes, and interesting analgesic activity.
- Dietary fiber, mineral elements profile and macronutrients composition in different edible parts of Opuntia microdasys (Lehm.) Pfeiff and Opuntia macrorhiza (Engelm.)Publication . Chahdoura, Hassiba; Morales, Patricia; Barreira, João C.M.; Barros, Lillian; Fernández-Ruiz, Virginia; Ferreira, Isabel C.F.R.; Achour, LotfiNowadays, we are living in the era of functional foods. People are constantly seeking for new healthier food products, mainly derived from plants, with bioactive components such as fiber and/or mineral elements, in suitable and healthy ratios. Cactus (Opuntia spp.), which includes more than 1500 species, presents high potential to be considered as a functional food, as it was revealed by the phytochemical profiles and antioxidant activity previously demonstrated in different botanical parts of Opuntia microdasys (Lehm.) Pfeiff and Opuntia macrorhiza (Engelm.). In this follow-up work, morphological characters, nutritional composition, and particularly fiber and mineral elements profiles of these two species were characterized in the cladodes, pulp and seeds. Most of these parameters were also studied in their juice. Both species presented similar chemical profiles, but each of the different studied botanical parts presented great differences, as revealed by principal component analysis. Accordingly, the obtained results reinforce Opuntia spp. as a potential functional food, indicating also the botanical parts with highest adequacy to act as source of a specific constituent.
- Phytochemical characterization and antioxidant activity of Opuntia microdasys (Lehm.) Pfeiff flowers in different stages of maturityPublication . Chahdoura, Hassiba; Barreira, João C.M.; Barros, Lillian; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.; Achour, LotfiChemical composition and antioxidant activity of Opuntia microdasys flowers in different maturity stages was evaluated. Fructose, glucose, sucrose and trehalose were found; oxalic, quinic, malic, and citric acids were also detected; five hydroxycinnamoyl, two kaempferol and six isorhamnetin derivatives; 23 fatty acids were quantified in all stages, except C20:2, which was only found in post flowering stage (F3); alpha-, beta-, gamma-, and delta-tocopherols were quantified in all samples. The highest contents in soluble sugars and phenolic compounds were detected in full flowering stage (F2), while organic acids and tocopherols were predominant in vegetative stage (F1). The highest levels of saturated, monounsaturated and polyunsaturated fatty acids were found in F3, F2 and F1, respectively. F1 gave the highest antioxidant activity. Principal components analysis showed clearly individualized groups corresponding to each flowering stage, identifying the most distinctive features, which might be useful to select a flowering stage for incorporation in functional foods. (C) 2014
- Phytochemical characterization and antioxidant activity of the cladodes of Opuntia macrorhiza (Engelm.) and Opuntia microdasys (Lehm.)Publication . Chahdoura, Hassiba; Barreira, João C.M.; Barros, Lillian; Santos-Buelga, Celestino; Ferreira, Isabel C.F.R.; Achour, LotfiThe genus Opuntia (Cactaceae) includes different plants well adapted to arid and semi-arid zones. These species are cultivated under restricted growth conditions, not suitable for the growth of other fruits/vegetables. The cactus pear is a well-known example inside Opuntia genus. Its young cladodes, also known as nopalitos, are frequently consumed and used in folk medicine due to their beneficial effects and phytochemical composition. Herein, hydrophilic and lipophilic extracts from cladodes of Opuntia microdasys and Opuntia macrorhiza were characterized. Furthermore, their antioxidant properties were compared to the corresponding phytochemical profile. Despite the phylogenetic proximity and similar geographical origin O. microdasys and O. macrorhiza showed significant differences in sugars, organic acids, phenolic compounds, fatty acids and tocopherols profiles. In particular, O. microdasys distinguished for having high contents in fructose, glucose, C6:0, C8:0, C12:0, C14:0, C14:1, C16:0, C18:3, C20:0, C22:0, C23:0, C24:0, SFA and tocopherols, and also for its higher DPPH EC50 values. O. microdasys by its side proved to have significantly higher amounts of trehalose, organic acids, C13:0, C16:1, C17:0, C18:0, C18:1, C20:1, C20:2 and MUFA. The obtained phytochemical profiles might be considered as useful information to select the best Opuntia species regarding a determined application of its natural extracts/isolated compounds.