Maria Leonor Teixeira Pinto de Castro

Dr. Maria Leonor Teixeira Pinto de Castro

orcid

Research Focus & Metrics

Academic Career Length

3Years (2024-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 August 2024 in Molecules
Verified
Journal Article
Open access
PDF file
MCMaria Leonor Teixeira Pinto de Castro
Maria Leonor Teixeira Pinto de Castro
Joao SilvaJoao Silva
Joao Silva
DVDiana Valente
Diana Valente
AMAdriana Rodrigues Machado
Adriana Rodrigues Machado
TRTânia Ribeiro
Tânia Ribeiro
SSSara Silva
Sara Silva
The skin is the largest organ in the human body and serves multiple functions such as barrier protection and thermoregulation. The maintenance of its integrity and healthy structure is of paramount importance. Accordingly, technological advances in cosmetic sciences have been directed towards optimizing these factors. Plant-derived ingredients have been explored for their bioactivity profiles and sustainable sources. Grape by-products contain a group of bioactive molecules that display important biological activities. Nonetheless, many of these molecules (e.g., phenolic compounds) are unstable and susceptible to degradation. So, their encapsulation using nano/microsystems (i.e., microdispersions) has been explored as a promising solution. In this work, two grape seed extracts were obtained, one from a single grape variety (GSE-Ov) and another from a mix of five grape varieties (GSE-Sv). These extracts were analysed for their antioxidant and antimicrobial activities, as well as their chemical composition and molecular structure. The extract that showed the most promising properties was GSE-Ov with a DPPH IC50 of 0.079 mg mL−1. This extract was encapsulated in soy lecithin microdispersions coated with pectin, with an encapsulation efficiency of 88.8%. They showed an in vitro release of polyphenols of 59.4% during 24 h. The particles displayed a zeta potential of −20.3 mV and an average diameter of 13.6 µm. Microdispersions proved to be safe under 5 and 2.5 mg mL−1 in HaCaT and HDF cell models, respectively. Additionally, they demonstrated anti-inflammatory activity against IL-1α when tested at 2 mg mL−1. This work enabled the valorisation of a by-product from the wine industry by using natural extracts in skincare products.

10 October 2024 in Applied Sciences
Verified
Journal Article
Open access
PDF file
EAEduardo Apolinário
Eduardo Apolinário
MCMaria Leonor Teixeira Pinto de Castro
Maria Leonor Teixeira Pinto de Castro
Manuela PintadoManuela Pintado
Manuela Pintado
JFJoão Paulo Medeiros Ferreira
João Paulo Medeiros Ferreira
SSSara Silva
Sara Silva
Sandra F. BorgesSandra F. Borges
Sandra F. Borges
Vaginal infections (VIs) are the result of the nefarious vaginal polymicrobial universe (i.e., Gardnerella vaginalis, Prevotella spp., Staphylococcus spp., Candida albicans, etc.), the inhabitants of which multiply and infect the surface of the vaginal epithelium, which serves as a scaffold for the adhesion of pathogenic poly-complexes with interactive abilities. VIs affect over 1 billion women per year and have a stunning annual relapse rate of 30%. These conditions impact women’s quality of life and fertility and cause oncogenic Human Papillomavirus (HPV) persistence. VIs are typically treated with oral (i.e., Flagyl®) and localized drug tablets and creams/gels (i.e., Clindesse®), with potential leakage from the vaginal tract upon administration leading to the failure of the treatment. This study intends to highlight polyphenols as potential therapeutic agents in terms of their benefits and limitations and suggest strategies to increase their effectiveness. Polyphenols are natural compounds rich in phenolic structures which have an impact on this type of pathology and deserve the utmost attention from researchers. Natural polyphenols have several advantages: renewability, biodegradability, low environmental impact, biocompatibility, application versatility, bioactive properties, and the potential for sustainable applications. These compounds, formulated in advanced delivery systems, may natively exhibit antioxidant, anti-inflammatory, and antimicrobial activities. The main objective of this review is to highlight the importance of researching new and effective formulations to prevent and treat VIs based on natural, controlled, and sustainable systems.

16 April 2024 in Preprints.org
Verified
Preprint
Open access
PDF file
MCMaria Leonor Teixeira Pinto de Castro
Maria Leonor Teixeira Pinto de Castro
Joao SilvaJoao Silva
Joao Silva
DVDiana Valente
Diana Valente
AMAdriana Rodrigues Machado
Adriana Rodrigues Machado
TRTânia Ribeiro
Tânia Ribeiro
SSSara Silva
Sara Silva
The skin is the largest organ in the human body and serves multiple functions such as barrier protection and thermoregulation. The maintenance of its integrity and healthy structure is of paramount importance. Accordingly, technological advances in cosmetic sciences have been directed towards optimizing these factors. Plant-derived ingredients have been explored for their bioactivity profiles and sustainable sources. Grape by-products carry a group of bioactive molecules that display important biological activities. Nonetheless, many of these molecules (e.g., phenolic compounds) are unstable and susceptible to degradation. So, its encapsulation using nano/microsystems (i.e. liposomes) has been explored as a promising solution. In this work, two grape seed extracts were obtained, one from a single grape variety (GSE-Ov), and another from a mix of five grape varieties (GSE-Sv). These extracts were analysed for their antioxidant and antimicrobial activities, as well as for their chemical composition and molecular structure. The extract that showed the most promising properties was the GSE-Ov with a DPPH IC50 of 0.079 mg.mL-1. This extract was encapsulated in soy lecithin liposomes coated with pectin, with an encapsulation efficiency of 88.8%. These showed an in vitro release of polyphenols of 59.4% during 24 h. The particles displayed a zeta potential of -20.3 mV, and an average diameter of 13.6 µm. Loaded liposomes proved to be safe under 5 and 2.5 mg.mL-1, in HaCaT and HDF cell models, respectively. Additionally, they demonstrated anti-inflammatory activity against IL-1α when tested at 2 mg.mL-1. This work enabled the valorization of a by-product from the wine industry, by using natural extracts in skincare products.