Phytochemical composition and biological activities of Geranium robertianum L.: a review

Abstract After a period of a certain indifference, in which synthetic compounds were favored, the interest in the study of the biological properties of plants and the active principles responsible for their therapeutic properties has been growing remarkably. Geranium robertianum L., commonly known as Herb Robert or Red Robin, is a spontaneous, herbaceous plant that has been used for a long time in folk medicine of several countries and in herbalism’s practice for the treatment of a variety of ailments. Herein, we present a comprehensive review on the phytochemical characterization and the biological activities of this species, which, accompanying the remarkable increase of its use in herbal medicine, has been disclosed in the literature mainly in the last decade. The phytochemical characterization of G. robertianum has been focused mostly on the investigation of solid-liquid extracts of the plant, with special emphasis on phenolic compounds, particularly flavonoids. Studies concerning the essential oils of this species are still scarce but the number of identified compounds is high. The chemistry of G. robertianum is clearly dominated by phenolic constituents, the most studied classes of compounds being tannins, flavonoids and phenolic acids. The confirmation of the antioxidant, antimicrobial, anti-inflammatory, anti-hyperglycaemic and cytotoxic activities of G. robertianum, closely related to the high content of phenolic compounds, has come to corroborate in some extent the recognized beneficial proprieties of this medicinal plant.This work is supported by national funds by FCT - Portuguese Foundation for Science and Technology, under the project UID/AGR/04033/2013. V.C. Graça thanks to FCT for a PhD grant (SFRH/BD/52542/2014)

Bioactivity of the Geranium Genus: a Comprehensive Review

Background: Plants from the Geranium genus, which comprises about 400 species, have been used since ancient times in the practice of traditional medicines throughout the world. Therefore, herbal preparations based on Geranium species have found wide usage for the treatment of a variety of ailments. The aim of this work is to present a review, as comprehensive as possible, of the studies concerning different biological activities of Geranium species. Methods: Relevant data were obtained through systematic computer searches from major reputed scientific databases, particularly Web of Science and Scopus. Occasionally, information issued in primary sources not covered by these databases was also included provided published as peer-reviewed literature. This review covers the literature disclosed till the end of 2018. Results: Accompanying the increasing interest in herbal medicines in general, the evaluation of the biological properties of medicinal plants from the Geranium genus has been addressed thoroughly, mostly over the last two decades. Geranium species are endowed with a number of different biological activities. Herein, we present a survey of the results of the studies concerning these different biological activities. Conclusion: Most studies found in the literature effectively contribute to scientifically validate the beneficial properties of Geranium plants claimed by traditional medicines and medical herbalism and demonstrate that many of them possess evident therapeutic properties.This work was supported by European Investment Funds by FEDER/COMPETE/POCI - Operational Competitiveness and Internationalization Programme, under Project POCI-01-0145- FEDER-006958 and National Funds by FCT - Portuguese Foundation for Science and Technology under the projects UID/AGR/00690/2013 (CIMO) and UID/QUI/00616/2013 (CQ-VR). V.C. Graça thanks FCT for her grant (SFRH/BD/52542/2014). The authors are also grateful to Interreg España-Portugal for financial support through the project 0377_Iberphenol_6_E.info:eu-repo/semantics/publishedVersio

Bio-guided fractionation of extracts of Geranium robertianum L.: Relationship between phenolic profile and biological activity

Geranium robertianum L. is used in folk medicine and herbalism practice for the treatment of a variety of ailments. Recently, we studied the bioactivity of several aqueous and organic extracts of this plant. In this work, the more active extracts were fractionated and the fractions evaluated for their antioxidant activity and cytotoxicity against several human tumor cell lines and non-tumor porcine liver primary cells. Some of the fractions from the acetone extract consistently displayed low EC 50 and GI 50 values and presented the higher contents of total phenolic compounds in comparison to other fractions. The phenolic compounds profile of the fractions was determined. The bio-guided fractionation of the extracts resulted in several fractions with improved bioactivity relative to the corresponding extracts. Their lower compositional complexity allowed the identification of more than two dozen compounds, to the best of our knowledge, so far not reported in G. robertianum.This work was supported by European Investment Funds by FEDER/COMPETE/POCI- Operational Competitiveness and Internationalization Programme, under Project POCI-01-0145-FEDER-006958 and National Funds by FCT − Portuguese Foundation for Science and Technology under the projects UID/AGR/04033, UID/AGR/00690/2013 (CIMO) and UID/QUI/00616/2013 (CQ-VR). V.C. Graça, M.I. Dias and L. Barros thank FCT for SFRH/BD/52542/2014, SFRH/BD/84485/2012, and SFRH/BPD/107855/2015 grants, respectively.info:eu-repo/semantics/publishedVersio

Aminosquaraines as potential photodynamic agents: Synthesis and evaluation of in vitro cytotoxicity

© 2017 Elsevier Ltd The synthesis of several aminosquaraine cationic dyes displaying strong absorption within the so-called phototherapeutic window (650–850 nm) is described. Their cytotoxicity, under dark and illuminated conditions, was tested against several human tumor cell lines (breast, lung, cervical and hepatocellular carcinomas) and non-tumor porcine liver primary cells. All compounds showed to inhibit the growth of the tumor cells upon irradiation more than in the absence of light, in more or less extension, clearly exhibiting photodynamic activity. The photosensitizing ability against some cell lines, together with the low toxicity for the non-tumor primary PLP2 cells displayed by some of the compounds synthetized, turns them into potential candidates as photosensitizers for PDT.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER for CIMO (UID/AGR/00690/2013) and CQ-VR (UID/QUI/00616/2013) financial support.info:eu-repo/semantics/publishedVersio

Microfluidic immunosensor for rapid and highly-sensitive salivary cortisol quantification

This paper presents a novel poly(dimethylsiloxane) (PDMS) microfluidic immunosensor that integrates a complementary metal-oxide-semiconductor (CMOS) optical detection system for a rapid and highly-sensitive quantification of salivary cortisol. The simple and non-invasive method of saliva sampling provides an interesting alternative to the blood, allowing a fast sampling at short intervals, relevant for many clinical diagnostic applications. The developed approach is based on the covalent immobilization of a coating antibody (Ab), a polyclonal anti-IgG, onto a treated PDMS surface. The coating Ab binds the capture Ab, an IgG specific for cortisol, allowing its correct orientation. Horseradish peroxidase (HRP)-labelled cortisol is added to compete with the cortisol in the sample, for the capture Ab binding sites. The HRP-labelled cortisol, bonded to the capture Ab, is measured through the HRP enzyme and the tetramethylbenzidine (TMB) substrate reaction. The cortisol quantification is performed by colorimetric detection of HRP-labelled cortisol, through optical absorption at 450 nm, using a CMOS silicon photodiode as the photodetector. Under the developed optimized conditions presented here, e.g., microfluidic channels geometry, immobilization method and immunoassay conditions, the immunosensor shows a linear range of detection between 0.01-20 ng/mL, a limit of detection (LOD) of 18 pg/mL and an analysis time of 35 min, featuring a great potential for point-of-care applications requiring continuous monitoring of the salivary cortisol levels during a circadian cycle.FCT with the reference project UID/EEA/04436/2013, by FEDER funds through the COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) with the reference project POCI-01-0145-FEDER-006941. V C Pinto thanks the FCT for the SFRH/BD/81526/2011 PhD grant. P J Sousa thanks the FCT for the SFRH/BD/81562/2011 PhD grant. S.O. Catarino thanks the FCT for the SFRH/BPD/108889/2015 grant, supported by national funds from Ministérios da Ciência, Tecnologia e Ensino Superior and by FSE through the POCH - Programa Operacional Capital Humanoinfo:eu-repo/semantics/publishedVersio

Isolation of secondary metabolites from Geranium molle L. with anticancer potential

Two flavone glycosides, apigenin-6-C-glucoside (1) and lutelin-6-C-glucoside (2), and an anomeric mixture of 2,3-dygalloyl-4,6-HHDP-D-glucose (3a/3b) were isolated for the first time from Geranium molle L., a medicinal plant used in the folk medicine of northeast of Portugal for the treatment of a variety of ailments, including cancer. The cytotoxic activity of the isolated compounds was assessed against several human tumour cell lines and non-tumour porcine liver primary cells. The anomeric mixture of ellagitannins 3a/3b, with the two anomers showing considerably different hydrophobicities, was found to be significantly cytotoxic against cancer cells, with only moderate hepatotoxicity.This work was supported by European Investment Funds by FEDER/ COMPETE/POCI – Operational Competitiveness and Internationalization Programme, under Project POCI-01-0145-FEDER- 006958 and National Funds by FCT – Portuguese Foundation for Science and Technology under the projects UID/AGR/00690/2013 (CIMO) and UID/QUI/00616/2013 (CQ-VR). V.C. Graça thanks FCT for her grant (SFRH/BD/52542/2014) and L. Barros for her contract. The authors are also grateful to Interreg España-Portugal for financial support through the project 0377_Iberphenol_6_E.info:eu-repo/semantics/publishedVersio

Spiral inertial microfluidics for size based microalgae separation

The identifcation of toxic microalgae is essential for the sustainable management of activities, such as aquaculture, being also relevant for environmental monitoring and marine research purposes [1]. For these reasons, there is an increasing demand for in situ, reliable, portable, autonomous, low-cost and of easy operation technologies and devices able to detect early signs of potential toxic algal populations within the context of long term monitoring programmes. To this aim, a multisensory platform for in-situ phytoplankton quantifcation and taxonomic identifcation designed for underwater deployment and based on lab-on-chip (LoC) technology has been developed. It combines fow cytometry with optical and electrical measurements. The separation of microalgae based on cell size prior to analysis is key to reduce the complexity and heterogeneous nature of seawater samples while also ofering a degree of distinction between taxonomic groups. This work investigates and develops a simple inertial microfuidic device based on a spiral microchannel that achieves size-based separation of microparticles/ cells. The theoretical principle of their separation was analysed trough numerical simulations and experimental tests were also performed. Using a 5-loop spiral (300 μm width and 100 μm height), 20 μm and 40 μm polystyrene (PS) microparticles were successfully separated for a fow rate of 2000 μl/min, showing its potential for microalgae size-based separation. Furthermore, the simple structure and high throughout makes this technique suitable for integration in LoC devices [2, 3].Peer Reviewe

Synthesis, photochemical and in vitro cytotoxic evaluation of new iodinated aminosquaraines as potential sensitizers for photodynamic therapy

In this work, several benzothiazole-based aminosquaraine dyes, displaying strong absorption within the so-called phototherapeutic window (650–800 nm), were synthesized. The ability, of all the new dyes, to generate singlet oxygen was assessed by determining the correspondent phosphorescence emission and through the comparison with a standard. The quantum yields of singlet oxygen generation were determined and exhibited to be strongly dependent on the nature of the amino substituents introduced in the squaric ring. The photodynamic activity of the synthesized dyes was tested against four human tumor cell lines: breast (MCF-7), lung (NCI-H460), cervical (HeLa) and hepatocellular (HepG2) carcinomas; and a non-tumor porcine liver primary cell culture (PLP2). All the compounds synthesized were found to be able to inhibit tumor cells growth upon irradiation more than in the dark, in most of the cases, very significantly. Considering the photodynamic activity exhibited and the low toxicity displayed for the non-tumor cells, some of the synthetized dyes can be regarded as potential candidates as photosensitizers for PDT.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER for CIMO (UID/AGR/00690/2013) and CQ-VR (UID/QUI/00616/2013) financial support, as also for R. Calhelha contract.info:eu-repo/semantics/publishedVersio

Synthesis, photochemical and in vitro cytotoxic evaluation of benzoselenazole-based aminosquaraines

Squaraine dyes have recently attracted interest as potential second generation photosensitizers for photodynamic therapy. Several cationic aminosquaraine dyes bearing benzoselenazole terminal nuclei were synthezised and their cytotoxic activity was tested against four different human tumor cell lines – breast (MCF-7), non-small cell lung (NCI-H460), cervical (HeLa) and hepatocellular (HepG2) carcinomas – and against a non-tumor porcine liver primary cell line (PLP2), both in the absence of light and under irradiation. All dyes, which displayed strong absorption within the phototherapeutic window, were found to exhibit photodynamic activity and were shown to be, in most cases, more cytotoxic, both in the dark and upon irradiation, than their benzothiazole analogues.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and the FEDER for CIMO (UID/ AGR/00690/2013) and CQ-VR (UID/QUI/00616/2013) financial support.info:eu-repo/semantics/publishedVersio

Development of highly sensitive temperature microsensors for localized measurements

This paper presents the design, fabrication and characterization of temperature microsensors based on Resistance Temperature Detectors (RTDs) with a meander-shaped geometry. Numerical simulations were performed for studying the sensitivity of the RTDs according to their windings numbers as well as for optimizing their layout. These RTDs were fabricated using well-established microfabrication and photolithographic techniques. The fabricated sensors feature high sensitivity (0.3542 mV/°C), linearity and reproducibility in a temperature range of 35 to 45 °C. Additionally, each sensor has a small size with a strong potential for their integration in microfluidic devices, as organ-on-a-chip, allowing the possibility for in-situ monitoring the physiochemical properties of the cellular microenvironment.This work is the result of the project NORTE-01-0145-FEDER-029394, RTChip4Theranostics, and was supported by Programa Operacional Regional do Norte–Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement through the European Regional Development Fund (FEDER) and by Fundação para a Ciência e Tecnologia (FCT), IP, project reference PTDC/EMD-EMD/29394/2017. The authors also acknowledge the partial financial support by the projects UIDB/04436/2020 and UIDP/04436/2020