Maria Eduarda M. Araújo

In vitro digestion, antioxidant and antiacetylcholinesterase activities of two species of Ruta: Ruta chalepensis and Ruta montana

Abstract Context: Ruta genus (Rutaceae) is abundantly used and described in the most ancient systematic records of medical practice of the Mediterranean world. In Tunisia, this genus is represented by two medicinal and aromatic shrubs: Ruta chalepensis L. and Ruta montana L. Objective: This study investigates the antioxidant and acetylcholinesterase inhibition (AChE) activities before and after in vitro gastrointestinal metabolism of leaf decoction of R. chalepensis and R. montana. Materials and methods: We study, in vitro, the effect of the gastrointestinal juices gastric (1.75 mL) or pancreatic (2.5 mL) juices, on the biological activity by the measurement of the antioxidant activity and AChE inhibition during 4 h of decoction extract obtained from the leaves of the two species of Ruta. Results: The results showed that the ability to inhibit the AChE enzyme was similar; being the greatest inhibitory activity exhibited by the ethanol extract (IC50 = 12 ± 1.1 μg/mL) obtained from leaves of R. chalepensis. Conclusion: In conclusion, we showed that there was no appreciable degradation and that the activity was kept constant after gastric and pancreatic juice digestion.

Choline- versus imidazole-based ionic liquids as functional ingredients in topical delivery systems: cytotoxicity, solubility, and skin permeation studies

Abstract Background: Poor drug solubility represents a problem for the development of topical formulations. Since ionic liquids (ILs) can be placed in either lipophilic or hydrophilic solutions, they may be advantageous vehicles in such delivery systems. Nonetheless, it is vital to determine their usefulness when used at concentrations were cell viability is maintained, which was considered herein. Method: Five different ILs were prepared—three imidazole-based ILs: [C2mim][Br], [C4mim][Br], and [C6mim][Br]; and two choline-based ILs: [Cho][Phe] and [Cho][Glu]. Their cytotoxicity in human keratinocytes (HaCat cells), their influence in drug solubility and in percutaneous permeation, using pig skin membranes, was evaluated. Results: Caffeine and salicylic acid were used as model actives. Choline-based ILs proved to be more suitable as functional ingredients, since they showed higher impact on drug solubility and a lower cytotoxicity. The major solubility enhancement was observed for caffeine and further solubility studies were carried out with this active in several concentrations of the choline-based ILs (0.1; 0.2; 0.5; 1.0; 3.0 and 5.0%, w/w) at 25 °C and 32 °C. Solubility was greatly influenced by concentrations up to 0.5%. The choline-based ILs showed no significant impact on the skin permeation, for both actives. The size of the imidazole-based ILs alkyl chain enhances the caffeine solubility and permeation, but also the ILs cytotoxicity. Stable O/W emulsions and gels were prepared containing the less toxic choline-based ILs and caffeine. Conclusions: Our results indicate that the choline-based ILs were effective functional ingredients, since, when used at nontoxic concentrations, they allowed a higher drug loading, while maintaining the stability of the formulations.

Influence of salt stress on essential oil yield and composition of lemon grass (Cymbopogon schoenanthus L. Spreng. ssp. Laniger (Hook) Maire et Weil)

Cymbopogon is an aromatic plant valued for its citrus scent aroma. In this article, the effect of saline irrigation water on yield and quality of Cymbopogon schoenanthus L. was evaluated. Compounds of essential oils were identified by gas chromatography–mass spectrometry and/or 13C-NMR spectroscopy. Results showed that the growth of the aerial part was not affected at a concentration of 50 mmol NaCl. Under salt stress, the content of major chemical compounds was affected differently by the treatment level.

Synthesis of benzoazole ionic liquids and evaluation of their antimicrobial activity: Síntese de líquidos iónicos derivados de benzoazóis e avaliação da sua atividade antimicrobiana

A new class of chemicals composed not of molecules but ions, an organic cation and an organic or inorganic anion, has recently attracted attention. When these new kind of salts are in the liquid state below 100 oC, they are named ionic liquids (ILs). In this work, the synthesis of ionic liquids obtained from a 2-mercaptobenzimidazole, 2-mercaptobenzoxazole or 2-mercaptobenzothiazole anion and 1-alkyl-3-methylimidazolium or choline cation are described. The antimicrobial activity against several Gram-positive and Gram-negative bacteria and a yeast was also evaluated.

Supplemental calcium nitrate mitigates NaCl-induced biochemical, physiological, and antioxidant changes in sesame

ABSTRACT Sodic soils reduce growth and production of most vegetables, including sesame (Sesamum indicum L.), and NaCl interferes with the nutrient balance of the rhizosphere. A greenhouse experiment was undertaken to investigate the effects of calcium nitrate fertigation and NaCl concentration on growth and development of sesame. The NaCl concentrations applied in the irrigation water were 0, 30, 70, or 100 mM, and the calcium nitrate levels were 0 or 100 mg·L−1. Leaf area and shoot dry weight did not change with addition of calcium nitrate (100 mg∙L−1) at all NaCl levels. At 100 mM, plants supplemented with 100 mg∙L−1 calcium nitrate produced 51% and 136% more chlorophyll (a) and carotenoids, respectively, and enhanced proline content by 45% and total soluble proteins by 25%. Calcium nitrate supplemented plants accumulated more Na+ ions at roots (+26%) and less Na+ ions at leaves (−20%). These plants generally had higher K+ content at roots (+30%) and at leaves (+94%) owing to 100 mM NaCl. Calcium nitrate (100 mg·L−1) enhanced catalase activity (+43%) and phenolic compounds. Calcium nitrate supplemented plants (100 mg∙L−1) accumulated less malondialdehyde (−50%) and had the highest antioxidant activity compared to 0 mg·L−1. Calcium nitrate may be used to moderate some adverse physiological effects of NaCl for sesame in sodic soils. However, the calcium nitrate concentration was not sufficiently high to benefit yield.

Photostabilization of sunscreens by incorporation of tea as the external phase: Fotoestabilização de protectores solares por incorporação de chás como fase externa

The use of isolated ultraviolet (UV) filters in photoprotective formulations creates products with limited protection against radiation, emphasising the need to develop formulations containing UVA and UVB filter combinations. However, most of the formulations developed to include both filters are unstable as a result of this combination, as well as by exposure to UV radiation. It is, therefore, crucial to include additives that enable photostabilization. Tea is the second most widely consumed beverage in the world and represents a good source of bioactive compounds, particularly polyphenols, which provide antioxidant activity. In the present work formulations containing green tea or black tea, as well as the sunscreens avobenzone (UVA sunscreen) and octilmetoxinamato (UVB sunscreen), were developed and evaluated in order to develop new and effective photostable formulations providing broad spectrum photoprotection. These formulations have been developed with complete replacement of the external phase of the oil in water (O/W) emulsion by these teas. The results showed that both teas presented photostabilizing capacity, particularly for green tea in the storage conditions at room temperature and at 5 °C, and black tea for the samples stored at 40 °C. Key-words: green tea, black tea, photoprotective formulations, photostabilizing capacity, octyl methoxynnamate, avobenzone

Caracterização através de análise química da escultura portuguesa sobre madeira de produção erudita e de produção popular da época barroca

Making use of several analytical techniques, four erudite and four popular Portuguese baroque wooden sculptures were studied. The materials and techniques employed were identified and the relationship between their artistic quality and the materials used was investigated. In general, the pigments were common at the time, but one pigment discovered in the beginning of the 18th century and two rare arsenic pigments were also identified. In popular sculptures cost-saving was detected, particularly concerning the gold leaf. Regarding some technical procedures identified, recommendations found in historical documents did not seem to have been entirely followed, neither in erudite nor in popular sculptures.