Phenolic profile and antioxidant activity of Coleostephus myconis (L.) Rchb.f.: an underexploited and highly disseminated species

Coleostephus myconis (L.) Rchb.f. (Asteraceae) is a species with ruderal growth and persistence in abandoned soils, being characterized for its plentiful yellow flowering between March and August. Despite its botanical relevance, C. myconis had never been studied neither for its antioxidant activity, nor individual phenolic compounds. Herein, the antioxidant activity of different botanical parts: stems and leaves (green parts), floral buds, flowers in anthesis and senescent flowers, was studied in selected extracts (ethanol, ethanol:water 1:1 and water) through different chemical and biochemical assays. In addition, the phenolic profiles of the hydroethanolic extracts of each botanical part were also characterized by liquid chromatography with dioade array detection and electrospray ionization tandem mass spectrometry (LC-DAD-ESI/MSn). The antioxidant activity was significantly modulated by the extract type, with the hydroethanolic extracts showing the highest antioxidant activity, especially those obtained from the senescent flowers and floral buds. The phenolic profiles were the same for all flowering stages (with quantitative differences), but that characterized in the green parts was quite different. Floral buds gave the highest contents in phenolic compounds, mainly due to the contribution of 3,5-O-dicaffeoylquinic acid and myricetin-O-methyl-hexoside. Overall, C. myconis showed an interesting potential to be included in different industrial applications.The authors are grateful to Foundation for Science and Technology (FCT, Portugal) for financial support to CIMO (PEst-OE/AGR/UI0690/2014), REQUIMTE (PEst-C/EQB/LA0006/2014), J.C.M. Barreira (SFRH/BPD/72802/2010) and L. Barros SFRH/BPD/107855/2015)

Antioxidant activity of polar extracts from different botanical parts of Coleostephus myconis

Under stress, human body produce more reactive oxygen and nitrogen species (ROS/RNS) than enzymatic antioxidants and non-enzymatic antioxidants (e.g., vitamin C, vitamin E, glutathione, carotenoids, and flavonoids), causing an imbalance that may lead to cell damage and health problems [1]. Antioxidants can block the complex networks of oxidative damage pathways at different levels, yielding an overall therapeutic effect. Consequently, antioxidants that are exogenously acquired from diet may have important functions in redox cell homeostasis and can be important for cellular function and disease prevention [2]. Antioxidant compounds might be isolated and characterized from different plant parts like roots, stem, bark, leaves, flowers, fruits and seeds [3]. Herein, different polar extracts (water, ethanol and water:ethanol 1:1) obtained from the green parts and three floral stages of Coleostephus myconis (Asteraceae) were evaluated for their antioxidant activity, using different in vitro chemical and biochemical assays. All the studied botanical parts showed high antioxidant potential, either considering their reducing power, radical scavenging activity and lipid peroxidation inhibition. Independently of the studied botanical part or antioxidant assay, the hydro-alcoholic extract gave the best results. Furthermore, significant differences were detected among the green parts and each of the flowering stages. In conclusion, the results highlighted the possibility of using C. myconis as a potential source of bioactive compounds with several possible application

Evaluation of the cytotoxicity (HepG2) and chemical composition of polar extracts from the ruderal species Coleostephus myconis (L.) Rchb.f.

Coleostephus myconis (L.) Rchb.f. (Asteraceae) is a highly disseminated plant species with ruderal and persistent growth. Owing to its advantageous agronomic properties, C. myconis might have industrial applications. However, this species needs to be comprehensively characterized before any potential use. In a previous study, the phenolic composition and antioxidant activity of different C. myconis tissues were characterized. This investigation was extended to examine the cytotoxic potential of selected plant tissues (flowers and green parts) using a HepG2 cell line by utilizing the lysosomal neutral red uptake assay or mitochondrial (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide assay. In addition, the macronutrients content, lipophilic compounds (fatty acids, tocopherols), and amino acids were also determined. C. myconis flowers were used in the senescence stage, which was previously identified as the stage that presented maximal phenolic content and highest antioxidant activity. In contrast, stems and leaves were employed due to their high biomass proportion. Regarding cytotoxicity, mitochondrial and lysosomal damage was only significant when HepG2 cells were exposed to the highest extract concentrations (stems and leaves, 0.9 mg/ml; senescent flowers, 0.3 mg/ml). Chemically, the senescent flowers were mostly characterized by their high levels of fat, amino acids (especially threonine), oleic acid, ß-, and ?-tocopherol, while stems and leaves contained high concentrations of carbohydrates, linolenic acid, and a-tocopherol. In general, these results provide information regarding the threshold concentrations of C. myconis extracts that might be used in different applications without toxicity hazards.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) for financial support to REQUIMTE (PEst-C/EQB/LA0006/2014) and to CIMO (UID/AGR/00690/2013). J.C.M. Barreira, Carla Costa, and Filipa B. Pimentel thank FCT, POPH-QREN, and FSE for their grants (SFRH/BPD/72802/2010, SFRH/BPD/96196/2013 and SFRH/BD/109042/2015, respectively).info:eu-repo/semantics/publishedVersio

Asteraceae species with most prominent bioactivity and their potential applications: a review

Oxidative stress has a relevant part in the etiology of several diseases and metabolic disorders, being reasonable to expect that antioxidant compounds might have beneficial effects in health maintenance or disease prevention. Antioxidant compounds might be isolated and characterized from different plant constituents, such as roots, stems, bark, leaves, flowers, fruits and seeds, using proper extraction methods. The Asteraceae family has a worldwide distribution, with special relevance in the Mediterranean, Eastern Europe and Asia Minor, being acknowledged about 25 000 species integrated in approximately 1000 genera. In addition to the anti-inflammatory, analgesic and antipyretic potential of some of these species, their high antioxidant power, as proven in research works with extracts (of roots, stems, bark, leaves, flowers, fruits and seeds) should be highlighted. Herein, the Asteraceae species with highest potential as sources of natural antioxidants with potential uses in medicine and in pharmaceutical, cosmetic and food industries were identified. The species were selected based on their botanical representativeness, being identified the 9 most relevant species: Achillea millefolium L., Acmella oleraceae Murr., Artemisia absinthium L., Bidens pilosa L., Carthamus tinctorius L., Inula crithmoides L., Matricaria recutita L., Otanthus maritimus L. and Parthenium hysterophorus L.. With the obtained information, it could be concluded that the bioactivity of the selected Asteraceae species lacks a complete characterization, constituting a research scope with great potential to be exploited in the development of dietary supplements, bioactive food ingredients or pharmaceutical based products with application in food industry, dermocosmetics or medicine.João C.M. Barreira is grateful to Fundação para a Ciência e a Tecnologia (FCT) for his post-doctoral research grant (SFRH/BPD/72802/2012), financed by POPH-QREN and subsidizedby FSE and MCTES. This work received financial support from theEuropean Union (FEDER funds through COMPETE) and NationalFunds (FCT) through project Pest-C/EQB/LA0006/2013. The workalso received financial support from the European Union (FEDERfunds) under the framework of QREN through Project NORTE-07-0124 FEDER-000069.info:eu-repo/semantics/publishedVersio

Development of paraben-free hydrogel based on Coleostephus myconis (L.) Rchb.f. plant extracts for topical application

Coleostephus myconis (L.) Rchb.f. is a rich source of phenolic acids which are possibly associated with its high antioxidant activity. In the present study, hydroethanolic extracts from two different botanical parts of C. myconis (senescent flowers; green parts) were incorporated into hydrosoluble gels. Bearing in mind the EC50 values from previous antioxidant activity evaluation assays, gels were prepared using a concentration of 0.25 mg/mL (senescent flowers) and 0.50 mg/mL (green parts). Since the inclusion of parabens is nowadays poorly accepted by the consumers, imidazolidinyl urea was included as the antimicrobial component. Gels had a non-greasy texture and good dermic absorption dynamics. Regarding pH evaluation, there were no significant alterations during the 180 days of observation (5.5 and 6.5). The antioxidant activity of the prepared hydrogels was assessed and compared with a blank formulation and also with the results obtained for the extracts alone. The antioxidant activity measured in each hydrosoluble gel was very similar to the value obtained for the isolated extract, in what regards TBARS and β-carotene bleaching inhibition, DPPH and reducing power, thereby indicating the suitability of the C. myconis extract to prepare this type of dermocosmetic products.info:eu-repo/semantics/publishedVersio

Phenolic compounds in Coleostephus myconis (L.) Rchb.f.: characterization by HPLC-DAD-ESI/MS and phenology effects

The Asteraceae family is spread worldwide. In Portugal, there are more than 300 species, standing out as one of the botanical families with largest representation in the Portuguese flora. Coleostephus myconis (L.) Rchb.f. is a scarcely studied Asteraceae species, characterized as having ruderal growth and persistence in abandoned soils (an expanding problem due to the desertification phenomena in rural areas). In this work, the flowers of C. myconis were collected in three different flowering stages (i: flower bud; ii: flower in anthesis; iii: senescent flower) from the Northwestern area of the Portuguese territory. Powdered samples (1 g) were extracted twice with ethanol:water 50:50 (v/v). After removing solvents, the combined extracts were re-dissolved, filtered through 0.22-μm disposable LC filter disks and analyzed by high performance liquid chromatography coupled to a diode array detector and electrospray ionization-mass spectrometry (HPLC-DAD/ESI-MS). The phenolic compounds were characterized according to their UV and mass spectra, and retention times. For the quantitative analysis, calibration curves of standard compounds were used. According to the UV spectra (λmax = 314-330 nm) and pseudomolecular ions ([M-H]-) at m/z 353 and 515, all producing an m/z 191 ion, four compounds derived from quinic acid were detected: 3-O-caffeoylquinic acid (Figure 1A), 5-O-caffeoylquinic acid (Figure 1B), 3,5-O-dicaffeoylquinic acid (Figure 1C) and 4,5-O-dicaffeoylquinic acid (Figure 1D), as also supported by the literature [1,2]. A fifth phenolic acid was identified as protocatechuic acid. The detected flavonoid were quercetin-O-glucuronide, quercetin-3-Oglucoside, myricetin-O-methyl-hexoside and a second glycosylated myricetin (not possible to identify completely). Some statistically significant changes were detected among the different assayed flowering stages; nevertheless, 3,5-O-dicaffeoylquinic acid was the major compound, independently of the phenologic stage. According to the previous results, C. myconis might be considered as a potential natural source of these valuable bioactive compounds, especially considering the high botanical representativeness of this plant and its inexpensiveness