Percorrer por autor "Varela, Carla"
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- Chemical Characterization and Differential Lipid-Modulating Effects of Selected Plant Extracts from Côa Valley (Portugal) in a Cell Model for Liver SteatosisPublication . Amorim, Ricardo; Marques, Mário Pedro; Melim, Catarina; Varela, Carla; Sardão, Vilma A.; Teixeira, José; Dias, Maria Inês; Barros, Lillian; Oliveira, Paulo J.; Cabral, CéliaCôa Valley, located in the northeast of Portugal, harbors more than 500 medicinal plant species. Among them, four species stand out due to their traditional uses: Equisetum ramosissimum Desf. (hemorrhages, urethritis, hepatitis), Rumex scutatus L. subsp. induratus (Boiss. and Reut.) Malag. (inflammation, constipation), Geranium purpureum Vill., and Geranium lucidum L. (pain relief, gastric issues). Given their rich ethnomedicinal history, we evaluated their protective effects on an in vitro model of metabolic dysfunction-associated steatotic liver disease (MASLD). Methods: Decoction (D) and hydroalcoholic (EtOH80%) extracts were prepared and chemically characterized. Their safety profile and effects on lipid accumulation were assessed in palmitic acid (PA)-treated HepG2 cells using resazurin, sulforhodamine B, and Nile Red assays. Results: Chemical analysis revealed diverse phenolic compounds, particularly kaempferol derivatives in E. ramosissimum. All extracts showed minimal cytotoxicity at 25–50 µg/mL. At 100 µg/mL, only E. ramosissimum extracts maintained high cell viability. In the lipotoxicity model, E. ramosissimum decoction demonstrated the most potent effect, significantly reducing PA-induced neutral lipid accumulation in a dose-dependent manner, while other extracts showed varying degrees of activity. Conclusions: These findings highlight E. ramosissimum’s decoction, rich in kaempferol derivatives, as particularly effective in reducing lipid accumulation in this MASLD cell model while also providing a comprehensive characterization of traditionally used plants from the Côa Valley region.
- Côa Valley’s medicinal plants as potential cosmetic ingredients: cytotoxic and antioxidant assessmentPublication . Marques, Mário Pedro; Landim, Euclides; Varela, Carla; Marques, Joana; Costa, Ricardo M.F. da; Carvalho, Luís A.E. Batista de; Carvalho, Aida; Oliveira, Paulo J.; Cabral, CéliaWhere is located and what is the importance of river Côa Valley? • The river Côa Valley is part of the Guarda District, in the Northeast of Portugal. The Valley comprises an Archeological Park, which is considered “the most important open-air Paleolithic rock art site” in the world, being classified as UNESCO World Heritage Site since 1998. What are the natural resources’ relevance of this region? • The flora of the Archeologic Park in river Côa Valley comprises approximately 500 to 600 different plant species, some Portuguese and/or Iberian endemic species, according to a botanical survey recently carried out by us. Even though, so far, little is known about the natural endogenous resources of this territory, namely concerning medicinal plants. What is the aim of this investigation? • The main aim is to assess the cytotoxicity in skin fibroblasts (NHDF cell line) and the antioxidant activity through cell-free methods, of hydroalcoholic extracts obtained from selected plant species (Figure 1). These extracts are meant to be incorporated into scientific-validated plantbased cosmetic formulations, hence creating an exclusive cosmetic brand for Côa Valley.
- Côa Valley’s medicinal plants as potential cosmetic ingredients: cytotoxic and antioxidant screeningPublication . Marques, Mário Pedro; Landim, Euclides; Varela, Carla; Marques, Joana; Costa, Ricardo; Carvalho, Luís de; Carvalho, Aida; Oliveira, Paulo; Cabral, CéliaCôa Valley is a Northeast region of Portugal, classified as a UNESCO World Her- itage Site since 1998, and recognised as “the most important open-air Paleo- lithic rock art site”. So far, little is known about the natural endogenous resourc- es of this territory, namely medicinal plants. According to a preliminary ethnobotanical survey in this region, several medicinal plants were mentioned to have skin-beneficial effects. However, many of them still lacking scientific validation. Taking into account the results gathered during the survey carried in the CôaMedPlants project, the main goal of this investigation is to assess the cytotoxicity and antioxidant activity of selected species to incorporate them into scientific-validated plant- based cosmetic formulations and create an ex- clusive cosmetic brand for Côa Valley. Therefore, nine species were selected and their hydroalcoholic extracts (EtOH 80 %) were prepared. Their non-cyto- toxic concentrations were determined in vitro using the Normal Human Dermal Fibroblasts (NHDF) cell line, by the evaluation of metabolic activity through the Alamar Blue assay, and cell mass estimation according to the sulforhodamine B (SRB) assay. Most of the extracts revealed non-toxic concentrations ≤ 0.2 mg/mL using the NHDF cell model. Afterwards, non-cellular techniques were used to screen the antioxidant activity of these ethanolic extracts, through DPPH, ABTS, CUPRAC and FRAP assays. From the 9 species studied, the most promising so far are: Arbutus unedo L., Cistus albidus L., Cistus salviifolius L., Lavandula pedunculata (Mill.) Cav. and Pistacia terebinthus L., which will be further investigated in- depth, to characterise their antioxidant potential using in vitro cell models.
- Essential oils from coa valley lamiaceae species: cytotoxicity and antiproliferative effect on glioblastoma cellsPublication . Marques, Mário Pedro; Neves, Beatriz Guapo; Varela, Carla; Zuzarte, Mónica; Goncalves, Ana Cristina; Dias, Maria Inês; Amaral, Joana S.; Barros, Lillian; Magalhães, Mariana; Cabral, CéliaLavandula pedunculata (Mill.) Cav., Mentha cervina L. and Thymus mastichina (L.) L. subsp. mastichina are representative species of the Coa Valley's flora, a Portuguese UNESCO World Heritage Site. L. pedunculata and T. mastichina are traditionally used to preserve olives and to aromatize bonfires on Saint John's Eve, while M. cervina is mainly used as a spice for river fish dishes. Despite their traditional uses, these aromatic plants are still undervalued, and literature regarding their bioactivity, especially anticancer, is scarce. In this work, the morphology of secretory structures was assessed by scanning electron microscopy (SEM), and the composition of essential oils (EOs) was characterized by gas chromatography-mass spectrometry (GC-MS). The study proceeded with cytotoxic evaluation of EOs in tumor and non-tumor cells with the cell death mechanism explored in glioblastoma (GB) cells. L. pedunculata EO presented the most pronounced cytotoxic/antiproliferative activity against tumor cells, with moderate cytotoxicity against non-tumor cells. Whereas, M. cervina EO exhibited a slightly lower cytotoxic effect against tumor cells and did not affect the viability of non-tumor cells. Meanwhile, T. mastichina EO did not induce a strong cytotoxic effect against GB cells. L. pedunculata and M. cervina EOs lead to cell death by inducing apoptosis in a dose-dependent manner. The present study suggests that L. pedunculata and M. cervina EOs have a strong cytotoxic and antiproliferative potential to be further studied as efficient antitumor agents.
- Essential oils from Côa Valley Lamiaceae species: cytotoxicity on glioblastoma cellsPublication . Marques, Mário Pedro; Delgado, Jéssica; Zuzarte, Mónica; Varela, Carla; Dias, Maria Inês; Barros, Lillian; Magalhães, Mariana; Cabral, CéliaLavandula pedunculata (Mill.) Cav., Mentha cervina L. and Thymus mastichina (L) L. subsp. mastichina are widely used and fairly representative species of the flora and traditional uses of the Côa Valley, a Portuguese UNESCO World Heritage Site. L. pedunculata and T. mastichina are used by local populations to preserve olives, as a condiment in traditional cuisine and to aromatize bonfires on Saint John's Eve, while M. cervina is mainly used as a spice for river fish dishes. However, despite their popularity among the population and prevalence in the territory of Côa Valley, these aromatic plants are still undervalued and scientific literature on their potential as anti-cancer agents is scarce. Therefore, in this work we aim to study the therapeutic potential of the essential oils (EO) obtained from these three species, by assessing their chemical composition, secretory structures morphology and cytotoxic effect against glioblastoma cell lines
- A Spectrochemically Driven Study: Identifying Phenolic-Rich Extracts from Helichrysum stoechas, Lavandula pedunculata, and Thymus mastichina with Potential to Revert Skin Aging EffectsPublication . Marques, Mário Pedro; Landim, Euclides; Varela, Carla; Costa, Ricardo M. F. da; Marques, Joana; Carvalho, Luís A. E. Batista de; Silva, Ana; Cruz, Maria Teresa; André, Rebeca; Rijo, Patrícia; Dias, Maria Inês; Carvalho, Aida; Oliveira, Paulo J.; Cabral, CéliaPlants inhabiting mediterranean-influenced climatic zones, like Helichrysum stoechas (L.) Moench subsp. stoechas, Lavandula pedunculata (Mill.) Cav., and Thymus mastichina (L.) L. subsp. mastichina, have been scarcely investigated regarding their richness in phenolic compounds, herein explored as sources of skin anti-aging compounds. In this investigation, Fourier transform infrared spectroscopy (FTIR) in attenuated total reflectance (ATR) mode and high-performance liquid chromatography coupled with diode-array detection and electrospray ionization tandem mass spectrometry (HPLC-DAD-ESI/MSn) were employed to chemically characterize the hydroethanolic extracts (HEs), and their cell-free antioxidant potential was screened. Thereafter, non-toxic concentrations of HEs were determined in human skin cells using Alamar blue® and Sulforhodamine B assays. The cytoprotective and antioxidant effects of HEs were assessed in tert-butyl hydroperoxide-stimulated fibroblasts, their anti-inflammatory potential was studied in lipopolysaccharide-injured macrophages, and enzymatic inhibition assays were performed. Notably, the irritant effects of HEs were tested according to Test Guideline No. 439 of the Organization for Economic Co-operation and Development (OECD). The major compounds identified in the T. mastichina and L. pedunculata HEs were rosmarinic and salvianolic acid derivatives, while H. stoechas HE was mainly composed of caffeoyl and feruloyl derivatives, and O-glycosylated flavonoids. T. mastichina (≤0.4 mg/mL) exhibited significant cytoprotective, anti-inflammatory, and antioxidant effects, as well as remarkable anti-hyaluronidase activity. Shedding light on the quantitative and qualitative chemical picture of these HEs highlighted T. mastichina as a promising candidate to target skin aging effects, which correlates with its phenolic content. Further investigation is warranted regarding its anti-aging pharmacological activity, which could lead to the development of plant-based skin anti-aging products.
- Study of the edible Rumex induratus from Côa Valley in hepaticocarcinoma cellsPublication . Varela, Carla; Farinha, Diana; Jorge, Joana; Alves, Raquel de Oliveira; Dias, Maria Inês; Barros, Lillian; Oliveira, Paulo; Gonçalves, Ana Cristina; Cabral, CéliaHepatocellular carcinoma (HCC) is the most common form of liver cancer (about 90%) which remains a worldwide health challenge due to its incidence growth and yet scarce and not specific treatments.HCC is characterized by a metabolic and oxidative stress which induces a prolonged pathological inflammation and cell damage, and also an evident increase in the production of reactive oxygen species (ROS) which will lead to an increase of cellular lipid peroxidation and of hepatic enzymes. Available treatments are not very effective being usually adapted from other illnesses. Plants are considered very important sources for the discovery of new compounds to prevent and treat diseases (1). There are several natural drug leads presently used in chemotherapy including in HCC. Rumex induratus is native in Iberian Peninsula and spontaneous in northwest Portugal where it is used in local cuisine. Its extracts have significative antioxidant activity (2). This work aimed to add value to this species focused on the evaluation of the antitumoral activity of different extracts. Extractions of Rumex induratus (collected in Vale do Côa, Portugal, between March and May 2021) were made in water, ethanol 80% and ethanol 100% and tested in HCC in vitro models using HepG2, HuH7 and Hep3B cells lines. Metabolic activity, cellular morphology, cellular death and the quantification of reactive oxygen species (ROS) (superoxide anion and hydrogen peroxide) were assayed. A reduction in the metabolic activity was dependent on the extract and its concentration: it was observed that the infusion was more cytotoxic and Hep3B the most sensitive cell line. As for cellular morphology, in HuH7 was observed the condensation of the nucleus after treatment with infusion, and in Hep3B the hydroethanolic extract led to cellular contraction. Cellular death evaluated by the membrane potential revealed that HepG2 and HuH7 suffered from exposure to infusion and hydroethanolic extracts, while Hep3B was not so sensitive. As for ROS quantification, a growth pattern in the concentration of the superoxide anion and a decrease in peroxides were detected with an increase in the concentration of R. induratus extracts. Although not so robust, results of this study still revealed an evident influence of R. induratus extracts in the cellular activity and intracellular ROS production in the studied hepatocellular carcinoma cell lines. It is understandable that these biologic activities are directly associated to the existent phenolic compounds which antioxidant potential allows the understanding that the extracts led to an increase in membrane potential in all cell lines, with HepG2 presenting the highest values. In conclusion, the plant extract provides intracellular differences that can lead to the triggering of apoptosis in tumor cells. Nevertheless, future assays will allow to understand the mechanism of action of R. induratus extracts in HCC and to potentiate its use.
- Targeting Skin Aging Hallmarks In Vitro: Antioxidant, Anti-Inflammatory, and Anti-Senescence Effects of Phenolic-Rich Extracts from Cistus L. SpeciesPublication . Marques, Mário Pedro; Landim, Euclides; Varela, Carla; Costa, Ricardo M. F. da; Marques, Joana; Carvalho, Luís A. E. Batista de; Silva, Ana; Cruz, Maria Teresa; André, Rebeca; Rijo, Patrícia; Dias, Maria Inês; Carvalho, Aida; Oliveira, Paulo J.; Cabral, CéliaPlant-based extracts are rich sources of phenolic compounds, which may act as skin antiaging mediators. Herein, Cistus albidus L. (Ca), Cistus ladanifer L. subsp. ladanifer (Cl) and Cistus salviifolius L. (Cs) were selected to test whether their phytochemical profile and bioactive potential align to target human skin aging. Hydroethanolic extracts (HEs) were prepared and characterized using infrared vibrational spectroscopy (FTIR-ATR) and liquid chromatography-mass spectrometry (LC-MS). Non-toxic concentrations were screened, and cytoprotective and antioxidant effects were studied in tert-butyl hydroperoxide-stimulated normal human dermal fibroblasts (NHDFs). Lipopolysaccharide-stimulated RAW 264.7 macrophages were used to assess anti-inflammatory activity, the Organization for Economic Co-operation and Development (OECD) Test Guideline No. 439 was used to assess irritant effects, and the anti-senescence potential was assessed in etoposide-stimulated NHDFs. A series of enzymatic inhibition assays was performed. All extracts comprised ellagic acid derivatives, as well as myricetin and quercetin derivatives in Cs and Ca. The HE of Cs was also markedly composed of ligstroside. At non-toxic concentrations, cytoprotective effects were observed in NHDFs. However, only Cs and Cl exhibited significant antioxidant activity in these cells (p < 0.001 and p < 0.0001, respectively). In addition to that, Cl demonstrated highly significant anti-inflammatory (p < 0.0001) and anti-senescence (p < 0.0001) effects. Cs and Cl showed a remarkable potential to inhibit elastase; in addition, Cs also showed anti-hyaluronidase and anti-tyrosinase activities. Meaningfully, Cs and Cl extracts did not exhibit skin irritant effects. The unveiled potential of Cl in skin aging offset highlights the need to elucidate the detailed mechanisms of action, paving the way for the development of skin anti-aging formulations.