Amélia Silva - Academia.edu (original) (raw)

Papers by Amélia Silva

International Journal of Molecular Sciences, Dec 2, 2022

Plants, 2019

Ginkgo biloba L. leaf extracts and herbal infusions are used worldwide due to the health benefits... more Ginkgo biloba L. leaf extracts and herbal infusions are used worldwide due to the health benefits that are attributed to its use, including anti-neoplastic, anti-aging, neuro-protection, antioxidant and others. The aim of this study was to evaluate the effect of an aqueous Ginkgo biloba extract on HepG2 cell viability, genotoxicity and DNA protection against paraquat-induced oxidative damage. Exposure to paraquat (PQ), over 24 h incubation at 1.0 and 1.5 µM, did not significantly reduce cell viability but induced concentration and time-dependent oxidative DNA damage. Ginkgo biloba leaf extract produced dose-dependent cytotoxicity (IC50 = 540.8 ± 40.5 µg/mL at 24 h exposure), and short incubations (1 h) produced basal and oxidative DNA damage (>750 and 1500 µg/mL, respectively). However, lower concentrations (e.g., 75 µg/mL) of Ginkgo biloba leaf extract were not cytotoxic and reduced basal DNA damage, indicating a protective effect at incubations up to 4 h. On the other hand, lon...

Journal of Applied Phycology, Jul 24, 2021

The red seaweeds Grateloupia turuturu and Porphyra umbilicalis are commonly used as human food, m... more The red seaweeds Grateloupia turuturu and Porphyra umbilicalis are commonly used as human food, mainly in East Asia, being valuable nutritional sources. However, studies focusing on their composition and bioactivities are scarce. Thus, G. turuturu and P. umbilicalis hydroethanolic and water (infusion and decoction) extracts were prepared to characterize their bioactive compounds; assess antioxidant activity against ABTS•+, •OH and •NO radicals and evaluate anti-proliferative and anti-inflammatory activities using mouse macrophage (RAW 264.7) cells. Folin–Ciocalteau results showed that G. turuturu and P. umbilicalis water extracts have fourfold and threefold, respectively, higher content in reducing compounds than hydroethanolic extracts, with the water decoctions on the richer ones (15.7 ± 0.3 and 11.9 ± 0.2 mg GAE g−1 dw, respectively; p 0.05) production inhibition capacity (~ 55%), however higher than water extracts (p < 0.05). Grateloupia turuturu water extracts produced the highest inhibition capacity against •NO production, 54–56%. RP-HPLC–DAD analysis revealed the presence of mycosporine-like amino acids (MAAs) shinorine, palythine, porphyra-334 and asterina-330 identified in both seaweeds. All extracts produced dose- and time-dependent anti-proliferative activity, being P. umbilicalis infusion extracts the most active (IC50 = 0.43 mg mL−1). At non-cytotoxic concentrations, dose-dependent anti-inflammatory activity was observed for all extracts, highlighting the P. umbilicalis hydroethanolic extract at 0.2 mg mL−1 that inhibited ~ 55% (of control) of lipopolysaccharide-induced NO release. In conclusion, G. turuturu and P. umbilicalis are rich in bioactive compounds, in particular MAAs, responsible for the bioactivities here reported, reinforcing their potential as functional food as well as sources of bioactive compounds to food and pharmaceutical industries.

Food Chemistry: X, Dec 1, 2021

Orange thyme (Thymus fragrantissimus) is becoming widely used in food as a condiment and herbal t... more Orange thyme (Thymus fragrantissimus) is becoming widely used in food as a condiment and herbal tea, nevertheless its chemical composition and potential bioactivities are largely unknown. Thus the objective of this work is to obtain a detailed phytochemical profile of T. fragrantissimus by exhaustive ethanolic extraction and by aqueous decoction mimicking its consumption. Extracts showed high content in rosmarinic acid, luteolin-Ohexuronide and eriodictyol-O-hexuronide; these were the main phenolic compounds present in orange thyme accounting for 85% of the total phenolic compounds. Orange thyme extracts presented high scavenging activity against nitric oxide and superoxide radicals. Both extracts presented significant inhibitory effect of tyrosinase activity and moderate anti-acetylcholinesterase activity. Both extracts showed a good in vitro anti-inflammatory activity and a weak anti-proliferative/cytotoxic activity against Caco-2 and HepG2 cell lines supporting its safe use. Orange thyme is a very good source of bioactive compounds with potential use in different food and nutraceutical industries.

Molecules, Nov 28, 2020

Vegetable oils obtained from different plants are known for their beneficial effects on prophylax... more Vegetable oils obtained from different plants are known for their beneficial effects on prophylaxis and supportive treatment of a great deal of inflammatory-mediated conditions. Their wide range of saturated and unsaturated fatty acids, and the presence of other ingredients (e.g., tocopherols, chlorophylls), provide them with anti-inflammatory, antioxidant and anticancer properties, which are worth being exploited. In this study, we have carried out the spectrofluorometric analysis of selected vegetable oils, namely apricot (Prunus armeniaca) kernel oil; blueberry (Vaccinium spp.) seed oil; argan (Argania spinosa) nut oil; kiwi (Actinidia deliciosa) seed oil; grape (Vitis vinifera) seed oil; evening primrose (Oenothera biennis) oil and meadowfoam (Limnanthes alba) seed oil, with the purpose to detect their fluorescent ingredients for further identification and bioactivity comparison. The obtained two-(2D) and three-dimensional (3D) emission spectra offered a complete description of the fluorescent components of the mixture and revealed different features for studied oils.

Journal of Biomedical Nanotechnology, Aug 1, 2009

Lipid-based Delivery Systems (LDS) has been the focus of potential strategies in drug delivery fo... more Lipid-based Delivery Systems (LDS) has been the focus of potential strategies in drug delivery for several years. A great deal of work has been invested on how to exploit their biocompatible and biodegradable nature, in combination with their nanosize range in a profitable way in the field of nanomedicines. A number of drugs loaded in LDS have been already tested in vivo successfully. However, in vivo behaviour of nanosized materials differs from their bulk counterparts (and also change drug properties), mainly depending on the particular LDS physicochemical characteristics. These may have huge impact on the toxicity of the system, despite the physiological nature of the lipid materials. This note on the regulatory concerns and toxicity assessment in LDS suggests that current knowledge of public and scientific communities is lacking, requiring intensive research and policy measures to provide a deep understanding on toxicological risks.

Journal of Thermal Analysis and Calorimetry, Sep 3, 2011

Praziquantel (PZQ) is the drug of choice for oral treatment of schistosomiasis and other fluke in... more Praziquantel (PZQ) is the drug of choice for oral treatment of schistosomiasis and other fluke infections that affect humans. Its low oral bioavailability demands the development of innovative strategies to overcome the first pass metabolism. In this article, solid lipid nanoparticles loaded with PZQ (PZQ-SLN) were prepared by a modified oil-in-water microemulsion method selecting stearic acid as lipid phase after solubility screening studies. The mean particle size (Z-Ave) and zeta potential (ZP) were 500 nm and-34.0 mV, respectively. Morphology and shape of PZQ-SLN were analysed by scanning electron microscopy revealing the presence of spherical particles with smooth surface. Differential scanning calorimetry suggested that SLN comprised a less ordered arrangement of crystals and the drug was molecularly dispersed in the lipid matrix. No supercooled melts were detected. The entrapment efficiency (EE) and loading capacity of PZQ, determined by high performance liquid chromatography, were 99.06 ± 0.3 and 17.48 ± 0.05, respectively. Effective incorporation of PZQ into the particles was confirmed by small angle X-ray scattering revealing the presence of a lipid lamellar structure. Stability parameters of PZQ-SLN stored at room temperature (25°C) and at 4°C were checked by analysing Z-Ave, ZP and the EE for a period of 60 days. Results showed a relatively long-term physical stability after storage at 4°C, without drug expulsion.

Antioxidants, Jun 3, 2020

Thymus zygis subsp. zygis is an endemic Portuguese plant belonging to the Thymus zygis species. A... more Thymus zygis subsp. zygis is an endemic Portuguese plant belonging to the Thymus zygis species. Although T. zygis is commonly used as a condiment and as a medicinal herb, a detailed description of the polyphenol composition of hydroethanolic (HE) and aqueous decoction (AD) extracts is not available. In this work, we describe for the first time a detailed phenolic composition of Thymus zygis subsp. zygis HE and AD extracts, together with their antioxidant, anti-proliferative and anti-inflammatory activities. Unlike other Thymus species, T. zygis subsp. zygis extracts contain higher amounts of luteolin-(?)-O-hexoside. However, the major phenolic compound is rosmarinic acid, and high amounts of salvianolic acids K and I were also detected. T. zygis subsp. zygis extracts exhibited significant scavenging activity of ABTS + , hydroxyl (• OH), and nitric oxide (NO) radicals. Regarding the anti-proliferative/cytotoxic effect, tested against Caco-2 and HepG2 cells, the AD extract only slightly reduced cell viability at higher concentrations (IC 50 > 600 µg/mL, 48 h exposure), denoting very low toxicity, while the HE extract showed a high anti-proliferative effect, especially at 48 h exposure (IC 50 of 85.01 ± 15.10 µg/mL and 82.19 ± 2.46 µg/mL, for Caco-2 and HepG2, respectively). At non-cytotoxic concentrations, both extracts reduced the nitric oxide (NO) release by lipopolysaccharide (LPS)-stimulated RAW 264.7 cells (at 50 µg/mL, HE and AD extracts inhibited NO release in~89% and 48%, respectively). In conclusion, the results highlight the non-toxic effect of aqueous extracts, both resembling the consumption of antioxidants in foodstuff or in functional food. Furthermore, the HE extract of T. zygis subsp. zygis is a source of promising molecules with antioxidant, anti-inflammatory and anticancer activities, highlighting its potential as a source of bioactive ingredients for nutraceutical and pharmaceutical industries.

Journal of Applied Toxicology, Nov 15, 2013

Cationic solid lipid nanoparticles (cSLN) are colloidal carriers for genes or drugs, particularly... more Cationic solid lipid nanoparticles (cSLN) are colloidal carriers for genes or drugs, particularly lipophilic drugs. Several reports exist on their high efficiency, but only a few studies report the effect of cSLNs on living cells. In the present work, internalization, cell viability (alamar blue assay) and genotoxic potential (alkaline comet assay) of three cSLN formulations (A-C) were evaluated in HepG2 and Caco-2 cells. cSLN showed an average hydrodynamic diameter (z-ave) of 141-222 nm, zeta-potential of 55.0-72.5 mV and polidispersity indices (PdI) of 0.336-0.421. Dispersion in physiological buffers increased z-ave and PdI. 0.01 mg ml-1 cSLN unaffected cell viability, but 1.0 mg ml-1 significantly decreased it, being cSLN-C (Compritol-based) the most toxic and HepG2 the most affected. DNA damage was not significantly increased by 0.1 mg ml-1 cSLN but damage was observed at 1.0 mg ml-1 cSLN-C. Thus, no genotoxicity is to be expected at concentrations that do not reduce cell viability.

International Journal of Molecular Sciences

In this work, three pesticides of different physicochemical properties: glyphosate (GLY, herbicid... more In this work, three pesticides of different physicochemical properties: glyphosate (GLY, herbicide), imidacloprid (IMD, insecticide), and imazalil (IMZ, fungicide), were selected to assess their cytotoxicity against Caco-2 and HepG2 cells. Cell viability was assessed by the Alamar Blue assay, after 24 and 48 h exposure to different concentrations, and IC50 values were calculated. The mechanisms underlying toxicity, namely cellular reactive oxygen species (ROS), glutathione (GSH) content, lipid peroxidation, loss of mitochondrial membrane potential (MMP), and apoptosis/necrosis induction were assessed by flow cytometry. Cytotoxic profiles were further correlated with the molecular physicochemical parameters of pesticides, namely: water solubility, partition coefficient in an n-octanol/water (Log Pow) system, topological polar surface area (TPSA), the number of hydrogen-bonds (donor/acceptor), and rotatable bonds. In vitro outputs resulted in the following toxicity level: IMZ (Caco-2:...

Toxics

In this work, three pesticides of different physicochemical properties, namely, glyphosate (herbi... more In this work, three pesticides of different physicochemical properties, namely, glyphosate (herbicide), imidacloprid (insecticide) and imazalil (fungicide), were selected to assess their cytotoxicity against distinct cell models (Caco-2, HepG2, A431, HaCaT, SK-MEL-5 and RAW 264.7 cells) to mimic gastrointestinal and skin exposure with potential systemic effect. Cells were subjected to different concentrations of selected pesticides for 24 h or 48 h. Cell viability was assessed by Alamar Blue assay, morphological changes by bright-field microscopy and the IC50 values were calculated. Cytotoxic profiles were analysed using the physico-chemical parameters of the pesticides, namely: molecular weight, water solubility, the partition coefficient in the n-octanol/water (Log Pow) system, the topological polar surface area (TPSA), and number of hydrogen-bonds (donor/acceptor) and rotatable bonds. Results showed that glyphosate did not reduce cell viability (up to 1 mM), imidacloprid induced ...

Bioengineering

Melanoma is a complex type of cancer that depends on several metabolic factors, while the current... more Melanoma is a complex type of cancer that depends on several metabolic factors, while the currently used therapies are not always effective and have unwanted side effects. In this review, the main factors involved in the etiology of cutaneous carcinoma are highlighted, together with the main genes and proteins that regulate cancer invasion and metastization. The role of five selected flavonoids, namely, apigenin, epigallocatechin-3-gallate, kaempferol, naringenin, and silybin, in the modulating receptor tyrosine kinase (RTK) and Wnt pathways is reported with their relevance in the future design of drugs to mitigate and/or treat melanoma. However, as phenolic compounds have some difficulties in reaching the target site, the encapsulation of these compounds in nanoparticles is a promising strategy to promote improved physicochemical stabilization of the bioactives and achieve greater bioavailability. Scientific evidence is given about the beneficial effects of loading these flavonoids...

International Journal of Molecular Sciences

Lipid nanoparticles are currently used to deliver drugs to specific sites in the body, known as t... more Lipid nanoparticles are currently used to deliver drugs to specific sites in the body, known as targeted therapy. Conjugates of lipids and drugs to produce drug-enriched phospholipid micelles have been proposed to increase the lipophilic character of drugs to overcome biological barriers. However, their applicability at the topical level is still minimal. Phospholipid micelles are amphiphilic colloidal systems of nanometric dimensions, composed of a lipophilic nucleus and a hydrophilic outer surface. They are currently used successfully as pharmaceutical vehicles for poorly water-soluble drugs. These micelles have high in vitro and in vivo stability and high biocompatibility. This review discusses the use of lipid-drug conjugates as biocompatible carriers for cutaneous application. This work provides a metadata analysis of publications concerning the conjugation of cannabidiol with lipids as a suitable approach and as a new delivery system for this drug.

Food Chemistry: X, 2021

Orange thyme (Thymus fragrantissimus) is becoming widely used in food as a condiment and herbal t... more Orange thyme (Thymus fragrantissimus) is becoming widely used in food as a condiment and herbal tea, nevertheless its chemical composition and potential bioactivities are largely unknown. Thus the objective of this work is to obtain a detailed phytochemical profile of T. fragrantissimus by exhaustive ethanolic extraction and by aqueous decoction mimicking its consumption. Extracts showed high content in rosmarinic acid, luteolin-Ohexuronide and eriodictyol-O-hexuronide; these were the main phenolic compounds present in orange thyme accounting for 85% of the total phenolic compounds. Orange thyme extracts presented high scavenging activity against nitric oxide and superoxide radicals. Both extracts presented significant inhibitory effect of tyrosinase activity and moderate anti-acetylcholinesterase activity. Both extracts showed a good in vitro anti-inflammatory activity and a weak anti-proliferative/cytotoxic activity against Caco-2 and HepG2 cell lines supporting its safe use. Orange thyme is a very good source of bioactive compounds with potential use in different food and nutraceutical industries.

Molecules, 2020

Vegetable oils obtained from different plants are known for their beneficial effects on prophylax... more Vegetable oils obtained from different plants are known for their beneficial effects on prophylaxis and supportive treatment of a great deal of inflammatory-mediated conditions. Their wide range of saturated and unsaturated fatty acids, and the presence of other ingredients (e.g., tocopherols, chlorophylls), provide them with anti-inflammatory, antioxidant and anticancer properties, which are worth being exploited. In this study, we have carried out the spectrofluorometric analysis of selected vegetable oils, namely apricot (Prunus armeniaca) kernel oil; blueberry (Vaccinium spp.) seed oil; argan (Argania spinosa) nut oil; kiwi (Actinidia deliciosa) seed oil; grape (Vitis vinifera) seed oil; evening primrose (Oenothera biennis) oil and meadowfoam (Limnanthes alba) seed oil, with the purpose to detect their fluorescent ingredients for further identification and bioactivity comparison. The obtained two- (2D) and three-dimensional (3D) emission spectra offered a complete description of...

Pharmaceutics, 2020

We have developed a new cationic solid lipid nanoparticle (SLN) formulation, composed of Comprito... more We have developed a new cationic solid lipid nanoparticle (SLN) formulation, composed of Compritol ATO 888, poloxamer 188 and cetyltrimethylammonium bromide (CTAB), to load perillaldehyde 1,2-epoxide, and surface-tailored with a monoclonal antibody for site-specific targeting of human epithelial growth receptor 2 (HER2). Perillaldehyde 1,2-epoxide-loaded cationic SLN (cPa-SLN), with a mean particle size (z-Ave) of 275.31 ± 4.78 nm and polydispersity index (PI) of 0.303 ± 0.081, were produced by high shear homogenization. An encapsulation efficiency of cPa-SLN above 80% was achieved. The release of perillaldehyde 1,2-epoxide from cationic SLN followed the Korsemeyer–Peppas kinetic model, which is typically seen in nanoparticle formulations. The lipid peroxidation of cPa-SLN was assessed by the capacity to produce thiobarbituric acid-reactive substances, while the antioxidant activity was determined by the capacity to scavenge the stable radical DPPH. The surface functionalization of ...

Forests, 2020

Medicinal plants, many of which are wild, have recently been under the spotlight worldwide due to... more Medicinal plants, many of which are wild, have recently been under the spotlight worldwide due to growing requests for natural and sustainable eco-compatible remedies for pathological conditions with beneficial health effects that are able to support/supplement a daily diet or to support and/or replace conventional pharmacological therapy. The main requests for these products are: safety, minimum adverse unwanted effects, better efficacy, greater bioavailability, and lower cost when compared with synthetic medications available on the market. One of these popular herbs is hawthorn (Crataegus spp.), belonging to the Rosaceae family, with about 280 species present in Europe, North Africa, West Asia, and North America. Various parts of this herb, including the berries, flowers, and leaves, are rich in nutrients and beneficial bioactive compounds. Its chemical composition has been reported to have many health benefits, including medicinal and nutraceutical properties. Accordingly, the p...

Forests, 2020

Sage species belong to the family of Labiatae/Lamiaceae and are diffused worldwide. More than 900... more Sage species belong to the family of Labiatae/Lamiaceae and are diffused worldwide. More than 900 species of sage have been identified, and many of them are used for different purposes, i.e., culinary uses, traditional medicines and natural remedies and cosmetic applications. Another use of sage is the application of non-distilled sage extracts and essential oils to control phytopathogenic bacteria and fungi, for a sustainable, environmentally friendly agriculture. Biocidal propriety of non-distilled extracts and essential oils of sage are w documented. Antimicrobial effects of these sage extracts/essential oils depend on both sage species and bacteria and fungi species to control. In general, it is possible to choose some specific extracts/essential oils to control specific phytopathogenic bacteria or fungi. In this context, the use of nanotechnology techniques applied to essential oil from salvia could represent a future direction for improving the performance of eco-compatible an...

Nutrients, 2020

Eudragit S100-coated chitosan microspheres (S100Ch) are proposed as a new oral delivery system fo... more Eudragit S100-coated chitosan microspheres (S100Ch) are proposed as a new oral delivery system for green tea polyphenon-60 (PP60). PP60 is a mixture of polyphenolic compounds, known for its active role in decreasing oxidative stress and metabolic risk factors involved in diabetes and in other chronic diseases. Chitosan-PP60 microspheres prepared by an emulsion cross-linking method were coated with Eudragit S100 to ensure the release of PP60 in the terminal ileum. Different core–coat ratios of Eudragit and chitosan were tested. Optimized chitosan microspheres were obtained with a chitosan:PP60 ratio of 8:1 (Ch-PP608:1), rotation speed of 1500 rpm, and surfactant concentration of 1.0% (m/v) achieving a mean size of 7.16 µm. Their coating with the enteric polymer (S100Ch-PP60) increased the mean size significantly (51.4 µm). The in vitro modified-release of PP60 from S100Ch-PP60 was confirmed in simulated gastrointestinal conditions. Mathematical fitting models were used to characteriz...

International Journal of Molecular Sciences, 2020

In this work, we developed a solid lipid nanoparticle (SLN) formulation with (+)-limonene 1,2-epo... more In this work, we developed a solid lipid nanoparticle (SLN) formulation with (+)-limonene 1,2-epoxide and glycerol monostearate (Lim-SLNs), stabilized with Poloxamer® 188 in aqueous dispersion to modify the release profile of the loaded monoterpene derivative. We also evaluated the role of SLNs in lipid peroxidation and cytotoxicity in a spontaneously transformed aneuploid immortal keratinocyte cell line from adult human skin (the HaCaT cell line). For the cell viability assay, the colorimetric 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used. Lim-SLNs with a loading capacity and encapsulation efficiency of 0.39% and 63%, respectively, were produced by high pressure homogenization. A mean particle size of 194 ± 3.4 nm and polydispersity index of 0.244 were recorded for the loaded Lim-SLNs, as compared to 203 ± 1.5 nm (PI 0.213) for the non-loaded (blank) SLNs. The loading of the monoterpene derivative into glycerol monostearate SLNs fitted into t...

International Journal of Molecular Sciences, Dec 2, 2022

Plants, 2019

Ginkgo biloba L. leaf extracts and herbal infusions are used worldwide due to the health benefits... more Ginkgo biloba L. leaf extracts and herbal infusions are used worldwide due to the health benefits that are attributed to its use, including anti-neoplastic, anti-aging, neuro-protection, antioxidant and others. The aim of this study was to evaluate the effect of an aqueous Ginkgo biloba extract on HepG2 cell viability, genotoxicity and DNA protection against paraquat-induced oxidative damage. Exposure to paraquat (PQ), over 24 h incubation at 1.0 and 1.5 µM, did not significantly reduce cell viability but induced concentration and time-dependent oxidative DNA damage. Ginkgo biloba leaf extract produced dose-dependent cytotoxicity (IC50 = 540.8 ± 40.5 µg/mL at 24 h exposure), and short incubations (1 h) produced basal and oxidative DNA damage (>750 and 1500 µg/mL, respectively). However, lower concentrations (e.g., 75 µg/mL) of Ginkgo biloba leaf extract were not cytotoxic and reduced basal DNA damage, indicating a protective effect at incubations up to 4 h. On the other hand, lon...

Journal of Applied Phycology, Jul 24, 2021

The red seaweeds Grateloupia turuturu and Porphyra umbilicalis are commonly used as human food, m... more The red seaweeds Grateloupia turuturu and Porphyra umbilicalis are commonly used as human food, mainly in East Asia, being valuable nutritional sources. However, studies focusing on their composition and bioactivities are scarce. Thus, G. turuturu and P. umbilicalis hydroethanolic and water (infusion and decoction) extracts were prepared to characterize their bioactive compounds; assess antioxidant activity against ABTS•+, •OH and •NO radicals and evaluate anti-proliferative and anti-inflammatory activities using mouse macrophage (RAW 264.7) cells. Folin–Ciocalteau results showed that G. turuturu and P. umbilicalis water extracts have fourfold and threefold, respectively, higher content in reducing compounds than hydroethanolic extracts, with the water decoctions on the richer ones (15.7 ± 0.3 and 11.9 ± 0.2 mg GAE g−1 dw, respectively; p 0.05) production inhibition capacity (~ 55%), however higher than water extracts (p < 0.05). Grateloupia turuturu water extracts produced the highest inhibition capacity against •NO production, 54–56%. RP-HPLC–DAD analysis revealed the presence of mycosporine-like amino acids (MAAs) shinorine, palythine, porphyra-334 and asterina-330 identified in both seaweeds. All extracts produced dose- and time-dependent anti-proliferative activity, being P. umbilicalis infusion extracts the most active (IC50 = 0.43 mg mL−1). At non-cytotoxic concentrations, dose-dependent anti-inflammatory activity was observed for all extracts, highlighting the P. umbilicalis hydroethanolic extract at 0.2 mg mL−1 that inhibited ~ 55% (of control) of lipopolysaccharide-induced NO release. In conclusion, G. turuturu and P. umbilicalis are rich in bioactive compounds, in particular MAAs, responsible for the bioactivities here reported, reinforcing their potential as functional food as well as sources of bioactive compounds to food and pharmaceutical industries.

Food Chemistry: X, Dec 1, 2021

Orange thyme (Thymus fragrantissimus) is becoming widely used in food as a condiment and herbal t... more Orange thyme (Thymus fragrantissimus) is becoming widely used in food as a condiment and herbal tea, nevertheless its chemical composition and potential bioactivities are largely unknown. Thus the objective of this work is to obtain a detailed phytochemical profile of T. fragrantissimus by exhaustive ethanolic extraction and by aqueous decoction mimicking its consumption. Extracts showed high content in rosmarinic acid, luteolin-Ohexuronide and eriodictyol-O-hexuronide; these were the main phenolic compounds present in orange thyme accounting for 85% of the total phenolic compounds. Orange thyme extracts presented high scavenging activity against nitric oxide and superoxide radicals. Both extracts presented significant inhibitory effect of tyrosinase activity and moderate anti-acetylcholinesterase activity. Both extracts showed a good in vitro anti-inflammatory activity and a weak anti-proliferative/cytotoxic activity against Caco-2 and HepG2 cell lines supporting its safe use. Orange thyme is a very good source of bioactive compounds with potential use in different food and nutraceutical industries.

Molecules, Nov 28, 2020

Vegetable oils obtained from different plants are known for their beneficial effects on prophylax... more Vegetable oils obtained from different plants are known for their beneficial effects on prophylaxis and supportive treatment of a great deal of inflammatory-mediated conditions. Their wide range of saturated and unsaturated fatty acids, and the presence of other ingredients (e.g., tocopherols, chlorophylls), provide them with anti-inflammatory, antioxidant and anticancer properties, which are worth being exploited. In this study, we have carried out the spectrofluorometric analysis of selected vegetable oils, namely apricot (Prunus armeniaca) kernel oil; blueberry (Vaccinium spp.) seed oil; argan (Argania spinosa) nut oil; kiwi (Actinidia deliciosa) seed oil; grape (Vitis vinifera) seed oil; evening primrose (Oenothera biennis) oil and meadowfoam (Limnanthes alba) seed oil, with the purpose to detect their fluorescent ingredients for further identification and bioactivity comparison. The obtained two-(2D) and three-dimensional (3D) emission spectra offered a complete description of the fluorescent components of the mixture and revealed different features for studied oils.

Journal of Biomedical Nanotechnology, Aug 1, 2009

Lipid-based Delivery Systems (LDS) has been the focus of potential strategies in drug delivery fo... more Lipid-based Delivery Systems (LDS) has been the focus of potential strategies in drug delivery for several years. A great deal of work has been invested on how to exploit their biocompatible and biodegradable nature, in combination with their nanosize range in a profitable way in the field of nanomedicines. A number of drugs loaded in LDS have been already tested in vivo successfully. However, in vivo behaviour of nanosized materials differs from their bulk counterparts (and also change drug properties), mainly depending on the particular LDS physicochemical characteristics. These may have huge impact on the toxicity of the system, despite the physiological nature of the lipid materials. This note on the regulatory concerns and toxicity assessment in LDS suggests that current knowledge of public and scientific communities is lacking, requiring intensive research and policy measures to provide a deep understanding on toxicological risks.

Journal of Thermal Analysis and Calorimetry, Sep 3, 2011

Praziquantel (PZQ) is the drug of choice for oral treatment of schistosomiasis and other fluke in... more Praziquantel (PZQ) is the drug of choice for oral treatment of schistosomiasis and other fluke infections that affect humans. Its low oral bioavailability demands the development of innovative strategies to overcome the first pass metabolism. In this article, solid lipid nanoparticles loaded with PZQ (PZQ-SLN) were prepared by a modified oil-in-water microemulsion method selecting stearic acid as lipid phase after solubility screening studies. The mean particle size (Z-Ave) and zeta potential (ZP) were 500 nm and-34.0 mV, respectively. Morphology and shape of PZQ-SLN were analysed by scanning electron microscopy revealing the presence of spherical particles with smooth surface. Differential scanning calorimetry suggested that SLN comprised a less ordered arrangement of crystals and the drug was molecularly dispersed in the lipid matrix. No supercooled melts were detected. The entrapment efficiency (EE) and loading capacity of PZQ, determined by high performance liquid chromatography, were 99.06 ± 0.3 and 17.48 ± 0.05, respectively. Effective incorporation of PZQ into the particles was confirmed by small angle X-ray scattering revealing the presence of a lipid lamellar structure. Stability parameters of PZQ-SLN stored at room temperature (25°C) and at 4°C were checked by analysing Z-Ave, ZP and the EE for a period of 60 days. Results showed a relatively long-term physical stability after storage at 4°C, without drug expulsion.

Antioxidants, Jun 3, 2020

Thymus zygis subsp. zygis is an endemic Portuguese plant belonging to the Thymus zygis species. A... more Thymus zygis subsp. zygis is an endemic Portuguese plant belonging to the Thymus zygis species. Although T. zygis is commonly used as a condiment and as a medicinal herb, a detailed description of the polyphenol composition of hydroethanolic (HE) and aqueous decoction (AD) extracts is not available. In this work, we describe for the first time a detailed phenolic composition of Thymus zygis subsp. zygis HE and AD extracts, together with their antioxidant, anti-proliferative and anti-inflammatory activities. Unlike other Thymus species, T. zygis subsp. zygis extracts contain higher amounts of luteolin-(?)-O-hexoside. However, the major phenolic compound is rosmarinic acid, and high amounts of salvianolic acids K and I were also detected. T. zygis subsp. zygis extracts exhibited significant scavenging activity of ABTS + , hydroxyl (• OH), and nitric oxide (NO) radicals. Regarding the anti-proliferative/cytotoxic effect, tested against Caco-2 and HepG2 cells, the AD extract only slightly reduced cell viability at higher concentrations (IC 50 > 600 µg/mL, 48 h exposure), denoting very low toxicity, while the HE extract showed a high anti-proliferative effect, especially at 48 h exposure (IC 50 of 85.01 ± 15.10 µg/mL and 82.19 ± 2.46 µg/mL, for Caco-2 and HepG2, respectively). At non-cytotoxic concentrations, both extracts reduced the nitric oxide (NO) release by lipopolysaccharide (LPS)-stimulated RAW 264.7 cells (at 50 µg/mL, HE and AD extracts inhibited NO release in~89% and 48%, respectively). In conclusion, the results highlight the non-toxic effect of aqueous extracts, both resembling the consumption of antioxidants in foodstuff or in functional food. Furthermore, the HE extract of T. zygis subsp. zygis is a source of promising molecules with antioxidant, anti-inflammatory and anticancer activities, highlighting its potential as a source of bioactive ingredients for nutraceutical and pharmaceutical industries.

Journal of Applied Toxicology, Nov 15, 2013

Cationic solid lipid nanoparticles (cSLN) are colloidal carriers for genes or drugs, particularly... more Cationic solid lipid nanoparticles (cSLN) are colloidal carriers for genes or drugs, particularly lipophilic drugs. Several reports exist on their high efficiency, but only a few studies report the effect of cSLNs on living cells. In the present work, internalization, cell viability (alamar blue assay) and genotoxic potential (alkaline comet assay) of three cSLN formulations (A-C) were evaluated in HepG2 and Caco-2 cells. cSLN showed an average hydrodynamic diameter (z-ave) of 141-222 nm, zeta-potential of 55.0-72.5 mV and polidispersity indices (PdI) of 0.336-0.421. Dispersion in physiological buffers increased z-ave and PdI. 0.01 mg ml-1 cSLN unaffected cell viability, but 1.0 mg ml-1 significantly decreased it, being cSLN-C (Compritol-based) the most toxic and HepG2 the most affected. DNA damage was not significantly increased by 0.1 mg ml-1 cSLN but damage was observed at 1.0 mg ml-1 cSLN-C. Thus, no genotoxicity is to be expected at concentrations that do not reduce cell viability.

International Journal of Molecular Sciences

In this work, three pesticides of different physicochemical properties: glyphosate (GLY, herbicid... more In this work, three pesticides of different physicochemical properties: glyphosate (GLY, herbicide), imidacloprid (IMD, insecticide), and imazalil (IMZ, fungicide), were selected to assess their cytotoxicity against Caco-2 and HepG2 cells. Cell viability was assessed by the Alamar Blue assay, after 24 and 48 h exposure to different concentrations, and IC50 values were calculated. The mechanisms underlying toxicity, namely cellular reactive oxygen species (ROS), glutathione (GSH) content, lipid peroxidation, loss of mitochondrial membrane potential (MMP), and apoptosis/necrosis induction were assessed by flow cytometry. Cytotoxic profiles were further correlated with the molecular physicochemical parameters of pesticides, namely: water solubility, partition coefficient in an n-octanol/water (Log Pow) system, topological polar surface area (TPSA), the number of hydrogen-bonds (donor/acceptor), and rotatable bonds. In vitro outputs resulted in the following toxicity level: IMZ (Caco-2:...

Toxics

In this work, three pesticides of different physicochemical properties, namely, glyphosate (herbi... more In this work, three pesticides of different physicochemical properties, namely, glyphosate (herbicide), imidacloprid (insecticide) and imazalil (fungicide), were selected to assess their cytotoxicity against distinct cell models (Caco-2, HepG2, A431, HaCaT, SK-MEL-5 and RAW 264.7 cells) to mimic gastrointestinal and skin exposure with potential systemic effect. Cells were subjected to different concentrations of selected pesticides for 24 h or 48 h. Cell viability was assessed by Alamar Blue assay, morphological changes by bright-field microscopy and the IC50 values were calculated. Cytotoxic profiles were analysed using the physico-chemical parameters of the pesticides, namely: molecular weight, water solubility, the partition coefficient in the n-octanol/water (Log Pow) system, the topological polar surface area (TPSA), and number of hydrogen-bonds (donor/acceptor) and rotatable bonds. Results showed that glyphosate did not reduce cell viability (up to 1 mM), imidacloprid induced ...

Bioengineering

Melanoma is a complex type of cancer that depends on several metabolic factors, while the current... more Melanoma is a complex type of cancer that depends on several metabolic factors, while the currently used therapies are not always effective and have unwanted side effects. In this review, the main factors involved in the etiology of cutaneous carcinoma are highlighted, together with the main genes and proteins that regulate cancer invasion and metastization. The role of five selected flavonoids, namely, apigenin, epigallocatechin-3-gallate, kaempferol, naringenin, and silybin, in the modulating receptor tyrosine kinase (RTK) and Wnt pathways is reported with their relevance in the future design of drugs to mitigate and/or treat melanoma. However, as phenolic compounds have some difficulties in reaching the target site, the encapsulation of these compounds in nanoparticles is a promising strategy to promote improved physicochemical stabilization of the bioactives and achieve greater bioavailability. Scientific evidence is given about the beneficial effects of loading these flavonoids...

International Journal of Molecular Sciences

Lipid nanoparticles are currently used to deliver drugs to specific sites in the body, known as t... more Lipid nanoparticles are currently used to deliver drugs to specific sites in the body, known as targeted therapy. Conjugates of lipids and drugs to produce drug-enriched phospholipid micelles have been proposed to increase the lipophilic character of drugs to overcome biological barriers. However, their applicability at the topical level is still minimal. Phospholipid micelles are amphiphilic colloidal systems of nanometric dimensions, composed of a lipophilic nucleus and a hydrophilic outer surface. They are currently used successfully as pharmaceutical vehicles for poorly water-soluble drugs. These micelles have high in vitro and in vivo stability and high biocompatibility. This review discusses the use of lipid-drug conjugates as biocompatible carriers for cutaneous application. This work provides a metadata analysis of publications concerning the conjugation of cannabidiol with lipids as a suitable approach and as a new delivery system for this drug.

Food Chemistry: X, 2021

Orange thyme (Thymus fragrantissimus) is becoming widely used in food as a condiment and herbal t... more Orange thyme (Thymus fragrantissimus) is becoming widely used in food as a condiment and herbal tea, nevertheless its chemical composition and potential bioactivities are largely unknown. Thus the objective of this work is to obtain a detailed phytochemical profile of T. fragrantissimus by exhaustive ethanolic extraction and by aqueous decoction mimicking its consumption. Extracts showed high content in rosmarinic acid, luteolin-Ohexuronide and eriodictyol-O-hexuronide; these were the main phenolic compounds present in orange thyme accounting for 85% of the total phenolic compounds. Orange thyme extracts presented high scavenging activity against nitric oxide and superoxide radicals. Both extracts presented significant inhibitory effect of tyrosinase activity and moderate anti-acetylcholinesterase activity. Both extracts showed a good in vitro anti-inflammatory activity and a weak anti-proliferative/cytotoxic activity against Caco-2 and HepG2 cell lines supporting its safe use. Orange thyme is a very good source of bioactive compounds with potential use in different food and nutraceutical industries.

Molecules, 2020

Vegetable oils obtained from different plants are known for their beneficial effects on prophylax... more Vegetable oils obtained from different plants are known for their beneficial effects on prophylaxis and supportive treatment of a great deal of inflammatory-mediated conditions. Their wide range of saturated and unsaturated fatty acids, and the presence of other ingredients (e.g., tocopherols, chlorophylls), provide them with anti-inflammatory, antioxidant and anticancer properties, which are worth being exploited. In this study, we have carried out the spectrofluorometric analysis of selected vegetable oils, namely apricot (Prunus armeniaca) kernel oil; blueberry (Vaccinium spp.) seed oil; argan (Argania spinosa) nut oil; kiwi (Actinidia deliciosa) seed oil; grape (Vitis vinifera) seed oil; evening primrose (Oenothera biennis) oil and meadowfoam (Limnanthes alba) seed oil, with the purpose to detect their fluorescent ingredients for further identification and bioactivity comparison. The obtained two- (2D) and three-dimensional (3D) emission spectra offered a complete description of...

Pharmaceutics, 2020

We have developed a new cationic solid lipid nanoparticle (SLN) formulation, composed of Comprito... more We have developed a new cationic solid lipid nanoparticle (SLN) formulation, composed of Compritol ATO 888, poloxamer 188 and cetyltrimethylammonium bromide (CTAB), to load perillaldehyde 1,2-epoxide, and surface-tailored with a monoclonal antibody for site-specific targeting of human epithelial growth receptor 2 (HER2). Perillaldehyde 1,2-epoxide-loaded cationic SLN (cPa-SLN), with a mean particle size (z-Ave) of 275.31 ± 4.78 nm and polydispersity index (PI) of 0.303 ± 0.081, were produced by high shear homogenization. An encapsulation efficiency of cPa-SLN above 80% was achieved. The release of perillaldehyde 1,2-epoxide from cationic SLN followed the Korsemeyer–Peppas kinetic model, which is typically seen in nanoparticle formulations. The lipid peroxidation of cPa-SLN was assessed by the capacity to produce thiobarbituric acid-reactive substances, while the antioxidant activity was determined by the capacity to scavenge the stable radical DPPH. The surface functionalization of ...

Forests, 2020

Medicinal plants, many of which are wild, have recently been under the spotlight worldwide due to... more Medicinal plants, many of which are wild, have recently been under the spotlight worldwide due to growing requests for natural and sustainable eco-compatible remedies for pathological conditions with beneficial health effects that are able to support/supplement a daily diet or to support and/or replace conventional pharmacological therapy. The main requests for these products are: safety, minimum adverse unwanted effects, better efficacy, greater bioavailability, and lower cost when compared with synthetic medications available on the market. One of these popular herbs is hawthorn (Crataegus spp.), belonging to the Rosaceae family, with about 280 species present in Europe, North Africa, West Asia, and North America. Various parts of this herb, including the berries, flowers, and leaves, are rich in nutrients and beneficial bioactive compounds. Its chemical composition has been reported to have many health benefits, including medicinal and nutraceutical properties. Accordingly, the p...

Forests, 2020

Sage species belong to the family of Labiatae/Lamiaceae and are diffused worldwide. More than 900... more Sage species belong to the family of Labiatae/Lamiaceae and are diffused worldwide. More than 900 species of sage have been identified, and many of them are used for different purposes, i.e., culinary uses, traditional medicines and natural remedies and cosmetic applications. Another use of sage is the application of non-distilled sage extracts and essential oils to control phytopathogenic bacteria and fungi, for a sustainable, environmentally friendly agriculture. Biocidal propriety of non-distilled extracts and essential oils of sage are w documented. Antimicrobial effects of these sage extracts/essential oils depend on both sage species and bacteria and fungi species to control. In general, it is possible to choose some specific extracts/essential oils to control specific phytopathogenic bacteria or fungi. In this context, the use of nanotechnology techniques applied to essential oil from salvia could represent a future direction for improving the performance of eco-compatible an...

Nutrients, 2020

Eudragit S100-coated chitosan microspheres (S100Ch) are proposed as a new oral delivery system fo... more Eudragit S100-coated chitosan microspheres (S100Ch) are proposed as a new oral delivery system for green tea polyphenon-60 (PP60). PP60 is a mixture of polyphenolic compounds, known for its active role in decreasing oxidative stress and metabolic risk factors involved in diabetes and in other chronic diseases. Chitosan-PP60 microspheres prepared by an emulsion cross-linking method were coated with Eudragit S100 to ensure the release of PP60 in the terminal ileum. Different core–coat ratios of Eudragit and chitosan were tested. Optimized chitosan microspheres were obtained with a chitosan:PP60 ratio of 8:1 (Ch-PP608:1), rotation speed of 1500 rpm, and surfactant concentration of 1.0% (m/v) achieving a mean size of 7.16 µm. Their coating with the enteric polymer (S100Ch-PP60) increased the mean size significantly (51.4 µm). The in vitro modified-release of PP60 from S100Ch-PP60 was confirmed in simulated gastrointestinal conditions. Mathematical fitting models were used to characteriz...

International Journal of Molecular Sciences, 2020

In this work, we developed a solid lipid nanoparticle (SLN) formulation with (+)-limonene 1,2-epo... more In this work, we developed a solid lipid nanoparticle (SLN) formulation with (+)-limonene 1,2-epoxide and glycerol monostearate (Lim-SLNs), stabilized with Poloxamer® 188 in aqueous dispersion to modify the release profile of the loaded monoterpene derivative. We also evaluated the role of SLNs in lipid peroxidation and cytotoxicity in a spontaneously transformed aneuploid immortal keratinocyte cell line from adult human skin (the HaCaT cell line). For the cell viability assay, the colorimetric 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was used. Lim-SLNs with a loading capacity and encapsulation efficiency of 0.39% and 63%, respectively, were produced by high pressure homogenization. A mean particle size of 194 ± 3.4 nm and polydispersity index of 0.244 were recorded for the loaded Lim-SLNs, as compared to 203 ± 1.5 nm (PI 0.213) for the non-loaded (blank) SLNs. The loading of the monoterpene derivative into glycerol monostearate SLNs fitted into t...