Browsing by Author "Cardoso, Susana M."
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- Advances in analysis of phenolic compounds of salvia, thymus and lavandula plantsPublication . Pereira, Olívia R.; Afonso, Andrea Luísa Fernandes; Cardoso, Susana M.Salvia, Thymus and Lavandula are important genera belonging to the Lamiaceae family. Several species of these genera are widely used in culinary or in traditional medicine due to their claimed health-benefit properties. Notably, phenolic compounds are believed to be central constituents contributing for plant health properties and hence, they have been the focus of many investigations for the last decades. This chapter reviews the major and minor phenolic constituents found in Salvia, Thymus and Lavandula genera. Typically, plants of these genera are particular enriched in hydroxycinnamic acids, namely in distinct derivatives of caffeic. Moreover, they contain considerable amounts of flavones, which are mainly glycosidic forms of the flavonoids luteolin and apigenin. In turn, flavonols and flavanones are less abundant and/or widespread amongst Salvia, Thymus and Lavandula plants, although eriodictyol O-glycosidic derivatives can be frequently found in Thymus.
- Antioxidant activities of five Lamiaceae plantsPublication . Pereira, Olívia R.; Perez, María J.; Macias, Rócio I.R.; Marín, Jose J.G.; Cardoso, Susana M.In the last decades, oxidative stress has been recognized as a key process in the physiopathology of several diseases. Consequently, the search for new antioxidant compounds, as well as new antioxidant sources, has increased exponentially. The Lamiaceae family encloses many plant species which are potential sources of antioxidant compounds. The present study evaluates the antioxidant activity of phenolic enriched extracts of Lamium album, Leonurus cardiaca, Lavandula dentata, Mentha aquatica and Thymus citriodorus. The antioxidant activity of the hydroethanolic plant extracts was estimated by the in vitro measurement of their 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging potential and reducing power assays. Additionally, the protective effects of the extracts against the potassium dichromate (DK)-induced generation of reactive oxygen species (ROS) in human hepatoblastoma HepG2 cells were measured by flow cytometry, after a 48 h treatment period. The two chemical assays indicated that the extracts possess high antioxidant activity with the order of potency M. aquatica > L. album > L. dentata > T. citriodorus > L. cardiaca. EC50 values ranged from 8.1 to 18.3 μg/mL, and from 51.9 to 94.7 μg/mL for DPPH scavenging and reducing power assays, respectively. Moreover, with the exception of L. cardiaca, at 50 μg/mL, all the extracts induced an effective protection against the DK-induced generation of ROS in HepG2 cells. This protection was approximately 20% and 30%, for DK exposure at 5 and 25μM, respectively. The present data suggest that the herein studied plants can be applied as antioxidant agents.
- Antioxidant activities of five Lamiaceae plantsPublication . Pereira, Olívia R.; Perez, María J.; Macias, Rócio I.R.; Marín, Jose J.G.; Cardoso, Susana M.In the last decades, oxidative stress has been recognized as a key process in the physiopathology of several diseases. Consequently, the search for new antioxidant compounds, as well as new antioxidant sources, has increased exponentially. The Lamiaceae family encloses many plant species which are potential sources of antioxidant compounds. The present study evaluates the antioxidant activity of phenolic enriched extracts of Lamium album, Leonurus cardiaca, Lavandula dentata, Mentha aquatica and Thymus citriodorus. The antioxidant activity of the hydroethanolic plant extracts was estimated by the in vitro measurement of their 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging potential and reducing power assays. Additionally, the protective effects of the extracts against the potassium dichromate (DK)-induced generation of reactive oxygen species (ROS) in human hepatoblastoma HepG2 cells were measured by flow cytometry, after a 48 h treatment period. The two chemical assays indicated that the extracts possess high antioxidant activity with the order of potency M. aquatica > L. album > L. dentata > T. citriodorus > L. cardiaca. EC50 values ranged from 8.1 to 18.3 μg/mL, and from 51.9 to 94.7 μg/mL for DPPH scavenging and reducing power assays, respectively. Moreover, with the exception of L. cardiaca, at 50 μg/mL, all the extracts induced an effective protection against the DK-induced generation of ROS in HepG2 cells. This protection was approximately 20% and 30%, for DK exposure at 5 and 25μM, respectively. The present data suggest that the herein studied plants can be applied as antioxidant agents.
- Antioxidant activities of plants enriched in rosmarinic acidPublication . Pereira, Olívia R.; Perez, María J.; Macias, Rócio I.R.; Domingues, Maria R.M.; Marín, Jose J.G.; Cardoso, Susana M.The present study aims to evaluate the in vitro antioxidant potential of Lavandula dentata and Mentha aquatica plant extracts. For that, ethanolic extracts of the two plants were prepared and their phenolic composition was determined through combined methods of HPLC-DAD and ESI-MS. Moreover, the antioxidant activity of the plant extracts was estimated by: i) evaluation of DPPH scavenging potential and ii) monitoring the protective effects against the generation of reactive oxygen species (ROS) induced by potassium dichromate in human hepatoblastoma HepG2 cells. M. aquatica ethanolic extract was much enriched in phenolic compounds, in comparison with that of L. dentata. Both extracts contained rosmarinic acid in similar concentrations but M. aquatica also contained significant amounts of other phenolics, including rutinoside derivatives of eriodictyol and luteolin. The plant extracts showed high radical scavenging activity against DPPH radical and significantly diminished intracellular ROS production under oxidative stress conditions. The latter protection was mostly evidenced in the L. dentata extract and was also observed for the rosmarinic acid used as reference. Attending that rosmarinic acid is a major phenolic component of L. dentata and M. aquatica ethanolic extracts, the present results suggest that this phenolic compound can be involved in the antioxidant properties of both plants.
- Antioxidant activities of plants enriched in rosmarinic acidPublication . Pereira, Olívia R.; Perez, María J.; Macias, Rócio I.R.; Domingues, Maria R.M.; Marín, Jose J.G.; Cardoso, Susana M.The present study aims to evaluate the in vitro antioxidant potential of Lavandula dentata and Mentha aquatica plant extracts. For that, ethanolic extracts of the two plants were prepared and their phenolic composition was determined through combined methods of HPLC-DAD and ESI-MS. Moreover, the antioxidant activity of the plant extracts was estimated by: i) evaluation of DPPH scavenging potential and ii) monitoring the protective effects against the generation of reactive oxygen species (ROS) induced by potassium dichromate in human hepatoblastoma HepG2 cells. M. aquatica ethanolic extract was much enriched in phenolic compounds, in comparison with that of L. dentata. Both extracts contained rosmarinic acid in similar concentrations but M. aquatica also contained significant amounts of other phenolics, including rutinoside derivatives of eriodictyol and luteolin. The plant extracts showed high radical scavenging activity against DPPH radical and significantly diminished intracellular ROS production under oxidative stress conditions. The latter protection was mostly evidenced in the L. dentata extract and was also observed for the rosmarinic acid used as reference. Attending that rosmarinic acid is a major phenolic component of L. dentata and M. aquatica ethanolic extracts, the present results suggest that this phenolic compound can be involved in the antioxidant properties of both plants.
- Antioxidant activities of plants enriched in rosmarinic acidPublication . Pereira, Olívia R.; Perez, María J.; Macias, Rócio I.R.; Domingues, Maria R.M.; Marín, Jose J.G.; Cardoso, Susana M.The present study aims to evaluate the in vitro antioxidant potential of Lavandula dentata and Mentha aquatica plant extracts. For that, ethanolic extracts of the two plants were prepared and their phenolic composition was determined through combined methods of HPLC-DAD and ESI-MS. Moreover, the antioxidant activity of the plant extracts was estimated by: i) evaluation of DPPH scavenging potential and ii) monitoring the protective effects against the generation of reactive oxygen species (ROS) induced by potassium dichromate in human hepatoblastoma HepG2 cells. M. aquatica ethanolic extract was much enriched in phenolic compounds, in comparison with that of L. dentata. Both extracts contained rosmarinic acid in similar concentrations but M. aquatica also contained significant amounts of other phenolics, including rutinoside derivatives of eriodictyol and luteolin. The plant extracts showed high radical scavenging activity against DPPH radical and significantly diminished intracellular ROS production under oxidative stress conditions. The latter protection was mostly evidenced in the L. dentata extract and was also observed for the rosmarinic acid used as reference. Attending that rosmarinic acid is a major phenolic component of L. dentata and M. aquatica ethanolic extracts, the present results suggest that this phenolic compound can be involved in the antioxidant properties of both plants.
- Antioxidant activity of thymus citriodorusPublication . Pereira, Olívia R.; Perez, María J.; Macias, Rócio I.R.; Marín, Jose J.G.; Cardoso, Susana M.
- Antioxidant activity of thymus citriodorusPublication . Pereira, Olívia R.; Perez, María J.; Macias, Rócio I.R.; Marín, Jose J.G.; Cardoso, Susana M.Background and aims: Thymus citriodorus, or lemon thyme, is used as a medicinal plant in the treatment of asthma and other respiratory diseases, although the mechanism of its beneficial properties is poorly understood. The aim of the present study was to determine the antioxidant ability of the polyphenols present in this plant. Methods: An ethanolic extract was prepared and its antioxidant activity was determined by in vitro measurement of its 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) scavenging potential, reducing power, and protective effects against the generation of reactive oxygen species (ROS) induced by potassium dichromate (5 and 25 μM) in hepatoblastoma HepG2 cells. The non-toxic range of extract concentrations was determined by MTT test, after exposure of HepG2 cells to the extract (1–200 µg/mL) for 72 h. ROS generation was measured by flow cytometry using dichlorofluorescein diacetate after 48 h of incubation with the extract. Results and discussion: Concentrations of extract able to decrease to 50% (EC50) DPPH absorbance and reducing power were 0.32±0.05 mg/mL and 0.77±0.15 mg/mL, respectively. These findings indicate that the components of the extract have a relevant radical scavenging ability towards nitrogen free radicals and high reducing capacity. As revealed the MTT test, maximal non-toxic concentration of the extract was 50 µg/mL. This concentration was further used to treat HepG2 cells resulting in a decreased rate of ROS production, both under basal conditions or when oxidative stress was induced by potassium dichromate. Antioxidant protection was approximately 60%. Conclusion: Our results suggest that, since luteolin-7-O-glucoside, apigenin-7-O-glucuronide and rosmarinic acid are major components of Thymus citriodorus ethanolic extract [1], these phenolic constituents may be involved in its antioxidant properties. Accordingly, further investigations to elucidate the actual contribution of each compound to the overall protective effect are needed.
- Antioxidant and anti-inflammatory activities of cytisus multiflorusPublication . Saraiva, Susana C.; Pereira, Olívia R.; Liberal, Joana; Batista, Maria T.; Domingues, Maria R.M.; Cruz, Maria T.; Cardoso, Susana M.Cytisus multiflorus(white spanish broom) is a plant used in folk medicine in the Iberian Peninsula, where it is claimed to have various health benefits. However, the usage is totally based on the available ethnopharmacological information, as no scientific data regarding its biological effects has been delivered. In this sense, is the aim of this work to contribute to the scientific knowledge of the antioxidant and anti-inflammatory properties of C. multiflorus. The extract was rich in phenolic compounds mainly chrysin-7-O-glycopyranoside and a dihydroxyflavone isomer of chrysin which accounted for 49.4±7.3 mg/g and 21.8±3.8 mg/g, respectively. The low EC50 values, determined by DPPH and reducing power assays, indicated that the C. multiflorus purified ethanolic extract has a high antioxidant capacity. Moreover, the extract did not cause cytotoxicity against RAW 264.7 macrophages for high concentrations and the treatment of this cell line with purified extract induced a significant decrease in the levels of NO. Overall, the gathered data suggests that C. multiflorus is in fact a good antioxidant and anti-inflammatory plant, as believed by the folk knowledge.
- Antioxidant and antimicrobial activities of aqueous extracts of Anthemis nobilisPublication . Pereira, Sara I.; Cardoso, Susana M.; Pereira, Olívia R.; Domingues, Maria R.M.; Ferreira, Fernanda M.Introduction: Anthemis nobilis L. (roman chamomille) is an autochthonous plant, very common in North America and in Iberian Peninsula territory. The yellow flower buttons of this plant are widely used in traditional medicine and thus, they are commonly found in herbal stores. Anthemis nobilis L. is used as a potential therapeutic agent for all body illnesses, in particular for fever, inflammatory processes, skin infections and as a tranquilizer (1). In accordance, the main goal of this work was the evaluation of A. nobilis therapeutic potential, with focus on its antioxidant and antimicrobial activities. Methodology: Aqueous extracts of A. nobilis button flowers were prepared by maceration with water at room temperature during 2 hours or by decoction. Both extracts were analysed by electrospray mass spectrometry in the negative mode and their phenolic content was determined by the Folin–Ciocalteu method (2). Antioxidant activity was evaluated through ABTS radical-scavenging activity (3),TBARS method (4) and red blood cells haemolysis (5). Potential antibacterial action of the two extracts was evaluated as the antibiogram potential, analyzing Staphyllococcus aureus and Escherichia coli growth. Results: The aqueous extracts (crude and decoccion) of A. nobilis button flowers showed high antioxidant activity, as evaluated by ABTS, TBARS and haemolysis of red blood cells assays. Moreover, this activity was higher for the decoction extract, in good agreement with its greater phenolic content. As revealed by the mass spectrometry analysis, the potent antioxidant ability of aqueous A. nobilis extracts can result from the presence of quinic acid and caffeic acid derivatives. In opposition, the two aqueous extracts of A. nobilis button flowers showed no inhibitory effect on the growth of S. aureus and E. coli (common Gram+ and Gram- bacteria), thus indicating that this plant is not is not suitable for the treatment of health problems associated to those microorganisms.