Food & Function PAPER View Article Online View Journal | View Issue Bioactivity and phytochemical characterization of Arenaria montana L. Cite this: Food Funct.,2014,5, 1848 Eliana Pereira,†ab Lillian Barros,†a Ricardo C. Calhelha,ac Montserrat Duenas,˜ b Ana Maria Carvalho,a Celestino Santos-Buelga*b and Isabel C. F. R. Ferreira*a The bioactivity (antioxidant and cytotoxic activities) of the aqueous and methanolic extracts of Arenaria montana L., a plant commonly used in Portuguese folk medicine, was evaluated and compared. Furthermore, the phytochemical composition was determined based on hydrophilic (sugars, organic acids and phenolic compounds) and lipophilic (fatty acids and tocopherols) compounds, in order to valorize this plant material as a functional food/nutraceutical. Fructose, oxalic acid, methyl-luteolin 200- O-feruloylhexosyl-C-hexoside, a-tocopherol, and linoleic acid were the main individual compounds found in A. montana. In general, the aqueous extract showed higher antioxidant and cytotoxic activities than the methanolic extract; the latter showed activity only against HeLa and HepG2 cell lines. Both aqueous and methanolic extracts showed some hepatotoxicity but at higher doses than the ones active Received 12th March 2014 for tumor cell lines. Moreover, the aqueous extract of A. montana may be used as a functional food or Accepted 3rd May 2014 nutraceutical due to the high antioxidant and cytotoxic activities, and due to the presence of bioactive DOI: 10.1039/c4fo00210e compounds. As far as we know, this is the first report on the phytochemical composition and bioactivity www.rsc.org/foodfunction of A. montana. Introduction production of peroxyl radicals, protecting cells of oxidative damage to low density lipoproteins, proteins and DNA, and of The study of plants used in folk medicine has progressively membrane degeneration due to peroxidation of poly- increased over the last few decades.1 Some of their putative unsaturated fatty acids.14,15 Some organic acids are also therapeutic benet arise from a diverse phytochemical excellent antioxidants; for example, ascorbic acid, being a composition, which confers them antioxidant potential along potent reducing agent, has the capacity to reduce the most with other bioactive properties namely, anticarcinogenic/ reactive species of oxygen and nitrogen protecting against Published on 06 May 2014. Downloaded by Instituto Politecnico de Braganca 29/07/2015 09:19:16. antimutagenic, antibacterial, antiviral or anti-inammatory lipid peroxidation.16 The reducing sugars, due to the same properties.2,3 Among the various biologically active molecules, capacity, could also display antioxidant activity.17 Different phenolic compounds are major contributors to the antioxi- health benets of polyunsaturated fatty acids (PUFA) have dant activity of those plants.4–10 The antioxidant activity of also been described. For example, it was reported that PUFA phenolic compounds is inuenced by the number and posi- could be used to sensitize breast cancer cell lines and tion of phenolic hydroxyls and other substituents, and glyco- mammary tumors to anticancer drugs, increasing survival sylation of the molecules.11,12 Furthermore, antitumor and chemotherapy efficacy.18,19 The mentioned phytochemi- properties have also been attributed to different phenolic cals are common in medicinal plants and oen responsible compounds, including avones.13 for their bioactive effects. Other important antioxidant molecules are tocopherols, Arenaria montana L. (Mountain sandwort) is an herbaceous which are considered as one of the most important antioxi- plant native to mountainous regions of southwestern Europe, dants to combat oxidative stress, because they inhibit the being usually gathered in woodlands. The infusion of the dried plant (stems, leaves and owers) is used in Portuguese tradi- tional medicine for its anti-inammatory and diuretic prop- aCIMO-Escola Superior Agraria,´ Instituto Polit´ecnico de Bragança, Campus de Santa erties.20,21 Nevertheless, as far as we know, there are no Apolonia,´ 1172, 5301-855 Bragança, Portugal. E-mail: [email protected]; Fax: +351 previous reports on the phytochemical composition of this 273325405; Tel: +351 273303219 bGIP-USAL, Facultad de Farmacia, Universidad de Salamanca, Campus Miguel de plant. Unamuno, 37007 Salamanca, Spain. E-mail: [email protected]; Fax: +34 923 294515; Theaimofthecurrentstudywastocharacterizethe Tel: +34 923 294537 chemical composition of A. montana and to assess the anti- cCentro de Qu´ımica, Universidade do Minho, Campus de Gualtar 4710-057 Braga, oxidant and cytotoxic properties of their aqueous and meth- Portugal anol extracts. † Both authors contributed equally. 1848 | Food Funct.,2014,5,1848–1855 This journal is © The Royal Society of Chemistry 2014 View Article Online Paper Food & Function Experimental Methanolic and aqueous extracts were redissolved in (i) methanol and water, respectively (nal concentration: 2.5 mg À Sample mL 1) for antioxidant activity evaluation, or (ii) water (nal À Arenaria montana L. (Caryophyllaceae) owers and leafy stems concentration: 8 mg mL 1) for cytotoxicity evaluation. The nal (approximately the upper 15 cm of the dense clumps produced solutions were further diluted to different concentrations to be in spring) are commonly wild gathered in Bragança (North- submitted for distinct bioactivity evaluation in vitro assays. The eastern Portugal). Then these plant materials are dried, results were expressed in (i) EC50 values (sample concentration prepared in infusion, recommended and used as homemade providing 50% of antioxidant activity or 0.5 of absorbance in the 21 remedies. Considering the availability and local consumers' reducing power assay) for antioxidant activity, or (ii) GI50 values criteria for its medicinal use, the species was collected in full (the sample concentration that inhibited 50% of the net cell bloom, in spring along paths through the oak trees, in Oleiros, growth) for cytotoxicity. Trolox and ellipticine were used as Bragança. A sample for analysis was made by putting together positive controls in antioxidant and cytotoxic activity evaluation the material from different plants. Voucher specimens are assays, respectively. deposited at the Herbarium of the Escola Superior Agr´aria de Antioxidant activity. DPPH radical-scavenging activity was Bragança (BRESA). The sample was lyophilized (FreeZone 4.5, evaluated by using an ELX800 microplate reader (Bio-Tek Instru- Labconco, Kansas City, MO, USA), reduced to a ne dried ments, Inc; Winooski, VT, USA), and calculated as a percentage of powder (20 mesh) and mixed to obtain homogeneity. DPPH discolouration using the formula: [(ADPPH À AS)/ADPPH]  100, where AS is the absorbance of the solution containing the Standards and reagents sample at 515 nm and ADPPH istheabsorbanceoftheDPPH solution. Reducing power was evaluated by the capacity to convert Acetonitrile 99.9%, n-hexane 95% and ethyl acetate 99.8% were Fe3+ into Fe2+, measuring the absorbance at 690 nm in the of HPLC grade from Fisher Scientic (Lisbon, Portugal). The microplate reader mentioned above. Inhibition of b-carotene fatty acids methyl ester (FAME) reference standard mixture 37 bleaching was evaluated though the b-carotene/linoleate assay; (standard 47885-U) was purchased from Sigma (St. Louis, MO, the neutralization of linoleate free radicals avoids b-carotene USA), as also were other individual fatty acid isomers, L-ascorbic bleaching, which is measured by the formula: (b-carotene absor- acid, tocopherols (a-, b-, g-, and d-isoforms), sugars (D(À)-fruc- bance aer 2 h of assay/initial absorbance)  100. Lipid perox- tose, D(+)-sucrose, D(+)-glucose, D(+)-trehalose and D(+)-raffinose idation inhibition in porcine (Sus scrofa) brain homogenates was pentahydrate), trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2- evaluated by the decrease in thiobarbituric acid reactive carboxylic acid), gallic acid and (+)-catechin standards. Racemic À substances (TBARS); the colour intensity of the malondialdehyde– tocol, 50 mg mL 1, was purchased from Matreya (Plesant Gap, thiobarbituric acid (MDA–TBA) was measured by its absorbance at PA, USA). 2,2-Diphenyl-1-picrylhydrazyl (DPPH) was obtained 532 nm; the inhibition ratio (%) was calculated using the from Alfa Aesar (Ward Hill, MA, USA). Fetal bovine serum (FBS), following formula: [(A À B)/A]  100%, where A and B were the L-glutamine, hank's balanced salt solution (HBSS), trypsin– absorbance of the control and the sample solution, respectively.22 EDTA (ethylenediaminetetraacetic acid), penicillin–strepto- À À Cytotoxicity for tumor cell lines. Five human tumour cell mycin solution (100 U mL 1 and 100 mg mL 1, respectively), lines were used: MCF-7 (breast adenocarcinoma), NCI-H460 RPMI-1640 and DMEM media were from Hyclone (Logan, Utah, Published on 06 May 2014. Downloaded by Instituto Politecnico de Braganca 29/07/2015 09:19:16. (non-small cell lung cancer), HCT-15 (colon carcinoma), HeLa USA). Acetic acid, ellipticine, sulforhodamine B (SRB), trypan (cervical carcinoma) and HepG2 (hepatocellular carcinoma). blue, trichloroacetic acid (TCA) and Tris were from Sigma Cells were routinely maintained as adherent cell cultures in Chemical Co. (Saint Louis, MO, USA). All other chemicals and RPMI-1640 medium containing 10% heat-inactivated FBS solvents were of analytical grade and purchased from common (MCF-7, NCI-H460 and HCT-15) and 2 mM glutamine or in sources. Water was treated in a Milli-Q water purication DMEM supplemented with 10% FBS, 2 mM glutamine, 100 U system (TGI Pure Water Systems, Greenville, SC, USA). À À mL 1 penicillin and 100 mg mL 1 streptomycin (HeLa and HepG2 cells), at 37 C, in a humidied air incubator containing Evaluation of bioactivity 5% CO2. Each cell line was plated at an appropriate density (7.5 Sample preparation. The methanolic extract was obtained  103 cells per well for MCF-7, NCI-H460 and HCT-15 or 1.0  from the lyophilized plant material. The sample (1 g) was 104 cells per well for HeLa and HepG2) in 96-well plates and extracted by stirring with 25 mL of methanol (25 C at 150 rpm) allowed to attach for 24 h. Cells were then treated for 48 h with for 1 h and subsequently ltered through the Whatman no.