Agastache Species (Lamiaceae) as a Valuable Source of Volatile Compounds: GC-MS Profiling and Investigation of In Vitro Antibacterial and Cytotoxic Activities.

Nowadays, there is an increasing interest in the study of medicinal and aromatic plants, due to their therapeutic properties that correlate with the presence of different active compounds. Agastache species (sp.) are aromatic plants that belong to the Lamiaceae family, originating from North America and East Asia. The present study aimed to evaluate the composition of essential oils (EOs) obtained from different Romanian cultivated Agastache sp. and to investigate their antibacterial and cytotoxic activities. The gas chromatography-mass spectrometry (GC-MS) screening revealed that menthone was the dominant constituent of A. foeniculum (31.58%), A. rugosa (39.60%) and A. rugosa 'After Eight' (39.76%) EOs, while estragole was the major constituent of A. foeniculum "Aromat de Buzau" (63.27%) and A. mexicana (41.66%) EOs. The investigation of the antiproliferative effect showed that A. rugosa and A. foeniculum "Aromat de Buzau" EOs had significant cytotoxic activity on MDA-MB-231 and HEPG2 tumour cell lines, with the most promising effect on the MDA-MB-231 breast cancer cell line for A. foeniculum "Aromat de Buzau" EO (IC50 = 203.70 ± 0.24 µg/mL). Regarding the antibacterial activity, A. rugosa EO was most active against E. coli (8.91 ± 3.27 µL/mL) and S. aureus (10.80 ± 0.00 µL/mL). To the best of our knowledge, this is the first report on the cytotoxic effect of Agastache sp. EOs on MDA-MB-231, HCT116 and HEPG2 tumour cell lines. The results of our study provide new and promising information for the subsequent in vivo study of the pharmacological properties of Agastache sp. essential oils.

Evaluation of the Cytotoxic, Antioxidative and Antimicrobial Effects of Dracocephalum moldavica L. Cultivars.

The aim of the present study was to correlate the antioxidant, antimicrobial, and cytotoxic activities of hydroalcoholic extracts obtained from the aerial parts of three Dracocephalum moldavica L. cultivars with their polyphenolic compositions. The polyphenols were identified and quantified using spectrophotometrical methods and LC-MS analysis. Their antioxidant capacities were assessed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) methods. Their in vitro antimicrobial efficacies were assessed using the agar well diffusion and broth microdilution methods. Their cytotoxicity was investigated on normal diploid foreskin fibroblasts (BJ) and on colorectal adenocarcinoma (DLD-1) cell lines. The results pointed out significant amounts of polyphenolic compounds in the compositions of the tested cultivars, with rosmarinic acid as the main compound (amounts ranging between 5.337 ± 0.0411 and 6.320 ± 0.0535 mg/mL). All three cultivars displayed significant antioxidant (IC50 ranging between 35.542 ± 0.043 and 40.901 ± 0.161 µg/mL for the DPPH assay, and for the FRAP assay 293.194 ± 0.213 and 330.165 ± 0.754 µmol Trolox equivalent/mg dry vegetal material) and antimicrobial potential (especially towards the Gram-positive bacteria), as well as a selective toxicity towards the tumoral line. A significant positive correlation was found between antioxidant activity and the total phenolic acids (r2 = 0.987) and polyphenols (r2 = 0.951). These findings bring further arguments for strongly considering D. moldavica cultivars as promising vegetal products, which warrants further investigation.

Antiproliferative and Antimicrobial Effects of Rosmarinus officinalis L. Loaded Liposomes.

Rosmarinus officinalis L. is a species that is widely known for its culinary and medicinal uses. The purpose of the present study consisted of the evaluation of the antiproliferative and antimicrobial effects of R. officinalis-loaded liposomes (L-R). Characterization of the liposomes was performed by establishing specific parameters. The load of the obtained liposomes was analyzed using an LC-MS method, and antiproliferative assays evaluated the cell viability on a liver adenocarcinoma cell line and on a human hepatic stellate cell line. Antimicrobial assays were performed by agar-well diffusion and by broth microdilution assays. The obtained liposomes showed high encapsulation efficiency, suitable particle size, and good stability. High amounts of caffeic (81.07 ± 0.76), chlorogenic (14.10 ± 0.12), carnosic (20.03 ± 0.16), rosmarinic (39.81 ± 0.35), and ellagic (880.02 ± 0.14) acids were found in their composition, together with other polyphenols. Viability and apoptosis assays showed an intense effect on the cancerous cell line and a totally different pattern on the normal cells, indicating a selective toxicity towards the cancerous ones and an anti-proliferative mechanism. Antimicrobial potential was noticed against all tested bacteria, with a better efficacy towards Gram-positive species. These results further confirm the biological activities of R. officinalis leaf extract, and proposes and characterizes novel delivery systems for their encapsulation, enhancing the biological activities of polyphenols, and overcoming their limitations.

Biological Activities and Chemical Profile of Gentiana asclepiadea and Inula helenium Ethanolic Extracts.

This study aimed to investigate the antioxidant, antimicrobial, and cytotoxic potential of ethanolic extracts obtained from Gentiana asclepiadea L. and Inula helenium L. roots, in relation to their chemical composition. The total polyphenols, flavonoids, and phenolic acids were determined by spectrophotometric methods, while LC-MS analysis was used to evaluate the individual constituents. The antioxidant properties were tested using the FRAP and DPPH methods. The standard well diffusion and broth microdilution assays were carried out to establish in vitro antimicrobial efficacy and minimum inhibitory and bactericidal concentrations. The cytotoxicity was tested on rat intestinal epithelial cells using the MTT assay. The results pointed out important constituents such as secoiridoid glycoside (amarogentin), phenolic acids (caffeic acid, chlorogenic acid, trans-p-coumaric acid, salicylic acid), and flavonoids (apigenin, chrysin, luteolin, luteolin-7-O-glucoside, quercetin, rutoside, and naringenin) and promising antioxidant properties. The in vitro antimicrobial effect was noticed towards several pathogens (Bacillus cereus > Staphylococcus aureus > Enterococcus faecalis > Salmonella typhimurium and Salmonella enteritidis > Escherichia coli), with a pronounced bactericidal activity. Rat intestinal epithelial cell viability was not affected by the selected concentrations of these two extracts. These data support the ethnomedicinal recommendations of these species and highlight them as valuable sources of bioactive compounds.

Evaluation of Hepatoprotective Activity and Oxidative Stress Reduction of Rosmarinus officinalis L. Shoots Tincture in Rats with Experimentally Induced Hepatotoxicity.

Rosmarinus officinalis L. is a widely known species for its medicinal uses, that is also used as raw material for the food and cosmetic industry. The aim of the present study was to offer a novel perspective on the medicinal product originating from this species and to test its hepatoprotective activity. The tested sample consisted in a tincture obtained from the fresh young shoots. Compounds that are evaluated for this activity are polyphenols and terpenoids, that are identified and quantified by HPLC-UV-MS and GC-MS. Antioxidant activity was assessed in vitro, using the DPPH, FRAP and SO assays. Hepatoprotective activity was tested in rats with experimentally-induced hepatotoxicity. In the chemical composition of the tincture, phenolic diterpenes (carnosic acid, carnosol, rosmanol, rosmadial) and rosmarinic acid were found to be the majority compounds, alongside with 1,8-cineole, camphene, linalool, borneol and terpineol among monoterpenes. In vitro, the tested tincture proved significant antioxidant capacity. Results of the in vivo experiment showed that hepatoprotective activity is based on an antioxidant mechanism. In this way, the present study offers a novel perspective on the medicinal uses of the species, proving significant amounts of polyphenols and terpenes in the composition of the fresh young shoots tincture, that has proved hepatoprotective activity through an antioxidant mechanism.

Chemical Profile, Cytotoxic Activity and Oxidative Stress Reduction of Different Syringa vulgaris L. Extracts.

Syringa vulgaris L. (common lilac) is one of the most popular ornamental species, but also a promising not comprehensively studied source of bioactive compounds with important therapeutic potential. Our study was designed to characterize the chemical composition and to assess the antioxidant and cytotoxic properties of ethanolic extracts obtained from S. vulgaris L. flowers, leaves, bark, and fruit. The chemical profile of the ethanolic extracts was investigated using chromatographic (HPLC-DAD-ESI+, GC-MS) and spectral (UV-Vis, FT-IR) methods, while the protective effect against free radicals was evaluated in vitro by different chemical assays (DPPH, FRAP, CUPRAC). The cytotoxic activity was tested on two tumoral cell lines, HeLa, B16F10, using the MTT assay. Significant amounts of free or glycosylated chemical components belonging to various therapeutically important structural classes, such as phenyl-propanoids (syringin, acteoside, echinacoside), flavonoids (quercetin, kaempferol derivatives) and secoiridoids (secologanoside, oleuropein, 10-hydroxy oleuropein, demethyloleuropein, syringalactone A, nuzhenide, lingstroside) were obtained for the flowers, leaves and bark extracts, respectively. Furthermore, MTT tests pointed out a significant cytotoxic potential expressed in a non-dose-dependent manner toward the tumoral lines. The performed methods underlined that S. vulgaris extracts, in particular belonging to flowers and leaves, represent valuable sources of compounds with antioxidant and antitumoral potential.

Phytochemical Profile and Antimicrobial Potential of Extracts Obtained from Thymus marschallianus Willd.

Thymus marschallianus Willd. is a Lamiaceae species spread in a large variety of habitats worldwide. The aim of the present research was to analyse two different samples belonging to this species, one obtained from the spontaneous flora and one from culture. The total polyphenols, flavonoids, and phenolic acid contents were spectrophotometrically determined. Qualitative and quantitative analysis of polyphenols was performed by an HPLC-DAD-ESI (+)-MS method. For the antibacterial assay, the well-diffusion and the broth microdilution methods were used. Analysis of polyphenols revealed for both samples the presence of flavonoids like luteolin, quercetin, apigenin and their derivatives, but also of rosmarinic acid and methyl-rosmarinate. Differences regarding the amount of these compounds were emphasized. Significantly larger amounts of flavonoids were found for the sample harvested in the spontaneous flora, while for the rosmarinic acid, larger amounts were found for the cultured sample. Both samples displayed promising antibacterial activity, particularly towards Gram positive organisms. T. marschallianus represents, therefore, a rich source of polyphenolic compounds that prove its promising potential as a medicinal species.

Sources for developing new medicinal products: biochemical investigations on alcoholic extracts obtained from aerial parts of some Romanian Amaryllidaceae species.

BACKGROUND: Although Galanthus nivalis L. (snowdrop) is known for the galanthamine content, used in the treatment of Alzheimer disease, the polyphenolic compounds of Amaryllidaceae species are less studied. Proper understanding of the polyphenolics in these extracts and of their antioxidant and antimicrobial properties may allow a reconsideration of their medicinal uses. METHODS: The polyphenolic content of four selected Amaryllidaceae species harvested from Romania (Galanthus nivalis L., Narcissus pseudonarcissus L., N. poeticus L. and Leucojum vernum L.) was determined by spectrophotometric methods; the identification of phenolic compounds was performed by a HPLC-MS method, in order to establish their polyphenolic fingerprints. For the evaluation of the antioxidant potential the following methods were employed: DPPH radical scavenging, FRAP, hemoglobin ascorbate peroxidase activity inhibition (HAPX), inhibition of lipid peroxidation catalyzed by cytochrome c, and electron paramagnetic resonance (EPR) spectroscopy assays. Antimicrobial activity was assessed using the disc diffusion method. RESULTS: Qualitative and quantitative analyses highlight important amount of polyphenols (over 15 mg/g); the main identified compounds are chlorogenic and p-coumaric acids in all species. Only G. nivalis shows antioxidant activity by all the used methods. G. nivalis and L. vernum strongly inhibits the growth of S. aureus, while N. poeticus shows a very good antifungal activity. CONCLUSIONS: The results of this study provide a new approach to the properties and therapeutic uses of some Romanian widespread Amaryllidaceae species that could be considered sources of developing new medicinal products with anti anti-staphylococcal and antifungal activity.

Origanum vulgare ssp. vulgare: Chemical Composition and Biological Studies.

The biological properties and main phenolic compounds of the O. vulgare L. ssp. vulgare extract are described in the present paper. The polyphenolic compounds were analyzed by chromatographic and spectrophotometric techniques. The antioxidant potential was evaluated using several methods: CUPRAC (cupric ion reducing antioxidant capacity), FRAP (ferric reducing ability of plasma), inhibition of lipid peroxidation catalyzed by cytochrome c, and superoxide (SO) scavenging assays. The antimicrobial activity of the oregano extract was evaluated by means of agar-well diffusion assay. The hepatoprotective effect of the O. vulgare extract on CCl4-induced hepatotoxicity was evaluated in rats. Liver injury was estimated by determination of alanine aminotransaminase (ALT), aspartate aminotransaminase (AST), gamma-glutamyl transferase GGT, total protein and albumin concentrations, glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD) and malondialdehyde (MDA). These values were improved by the administration of oregano extract. A specific phenolic profile was evidenced by these data, with large amounts of rosmarinic and chlorogenic acids. The oregano extract showed very strong antioxidant activity in good agreement with the phenolic content. Antimicrobial activity was good, especially against Salmonella enteritidis and Aspergillus niger strains. The high hepatoprotective, antioxidant and antimicrobial activity, along with polyphenol-rich content, can support the use of O. vulgare in therapy. We also expect our results to open new research directions for designing important new drug products, using indigenous plant material.

The anemonin content of four different Ranunculus species.

The Ranunculus species are poorly known as medicinal plants. They have potential toxicity given by the ranunculin and its enzymatic degradation compounds: protoanemonin and anemonin. This paper aims to evaluate the anemonin content of four species: R. bulbosus, R. ficaria, R. sardous and R. sceleratus. The evaluation was performed by TLC and HPLC. There were evaluated two types of extracts hydroalcoholic (HA) and glycerol-ethanol (GE). The most concentrated extract in anemonin was found to be the R. sardous aerial part HA extract: 2.66 mg/ml. The lowest anemonin content is in R. sceleratus: 0.13-0.19 mg/ml. In R. bulbosus aerial part the anemonin content is less than the used HPLC method detection limits (7.68 mg/ml). In all cases the GE extracts are less concentrated in anemonin, being more safely for human administration.

Antioxidant capacity and polyphenolic content of the Echinocystis lobata (Michx.) Torr. et A.Gray flowers.

Echinocystis lobata (Michx.) Torr. et A.Gray is a spontaneous species in the Romanian flora, lesser studied by scientific literature, but which has proved significant activities in traditional medicine. The present study is aimed to provide data on the polyphenolic compounds in the composition of the flowers of this species and to test their biological potential. Polyphenols were identified and quantified using an HPLC-MS method. Tested biological activities were the cytotoxic, anti-plasmodial and antioxidant ones. Methods used for testing the antioxidant activity were the DPPH, CUPRAC, FRAP, TEAC, EPR and SNPAC assays. Cytotoxic activity was tested on cancerous and healthy cell lines and anti-plasmodial activity was assesed on two strains of Plasmodium falciparum. Ethanolic extracts of the flowers of E. lobata proved to contain isoquercitrin, rutin, quercitrin, kaempferol, p-coumaric and ferulic acid. No cytotoxic and anti-plasmodial activity was found, but antioxidant assays showed an important antioxidant capacity. The obtained results show that flowers of E. lobata are important sources of antioxidant compounds. It is the first approach of the kind on the flowers of this species and it offers a new perspective on possible sources of antioxidant compounds.

Antiproliferative and Apoptotic Potential of Cyanidin-Based Anthocyanins on Melanoma Cells.

Elderberries are known for their high anthocyanins content, which have been shown to possess anti-proliferative and anti-cancer effects. Anthocyanins enriched extract (AEE) was obtained from elderberries and was characterized by LC/DAD/ESI-MS analysis. Five cyanidin-based anthocyanins were identified, among which Cy-3-O-samb was the major compound (51%). The total anthocyanins content of AEE was 495 mg Cy-3-O-samb/100 g FW. AEE inhibited proliferation of metastatic B16-F10 murine melanoma cells, in a concentration-dependent manner, with an IC50 of 264.3 µg/mL. LDH (lactate dehydrogenase), as a marker of membrane integrity, increased 74% in B16-F10 cells treated with 250 µg/mL AEE, compared to control. It was observed that apoptosis is the mechanism of melanoma cell death after AEE treatment, confirmed morphologically by acridine orange/ethidium bromide double staining and TUNEL analysis. These results indicate that elderberry-derived anthocyanins might be utilized in future applications as topical adjuvant in skin cancer therapy.

Cytotoxicity and Antioxidant Potential of Novel 2-(2-((1H-indol-5yl)methylene)-hydrazinyl)-thiazole Derivatives.

Newly synthesized 2-(2-((1H-indol-5yl)methylene)-hydrazinyl)-thiazole derivatives were evaluated for their in vitro cytotoxicity on two carcinoma cell lines A2780 and HeLa. Significant cytotoxic activity for 2-(2-((1H-indol-5-yl)methylene)hydrazinyl)-4-methylthiazole (1) and 2-(2-((1H-indol-5-yl)methylene)hydrazinyl)-4-phenylthiazole (3), on both A2780 [IC50: 11.6 µM (1), and 12.4 µM (3)] and HeLa [IC50: 22.4 µM (1) and 19.4µM (3)] cell lines is reported. Their antioxidant potential was evaluated by spectrophotometric method, using DPPH radical or Fe (TPTZ)3+ complex, and EPR spectroscopy, therefore the compounds 1 and 3 showed remarkable antioxidant activity simultaneously with a cytotoxic effect on A2780 and HeLa cell lines. Furthermore, based on theoretical quantum chemical calculation, the present study analyzed the chemoselectivity of the hydrogen extraction from the indolyl-hydrazinil-thiazoles in reaction with free radicals.

Terpenic profile of different Rosmarinus officinalis extracts.

The Rosemary (Rosmarinus officinalis L.), a well-known medicinal and culinary herb, was studied to compare the terpenic profile of different extracts obtained from dry and fresh herb. There were studied the volatile oil extracted by hydro distillation from dry plant, the hydroalcoholic extracts obtained from fresh respectively dry plant and the glycerol macerate obtained from fresh plant, by GC-MS using headspace injection. The separated compounds were identified using a MS spectra library. The quantitative determination was performed by normalization respectively by calibration curve method for 1,8-cineole, alpha-pinene and D-limonene. The main separated compounds were alpha-pinene, 1,8-cineol, camphene, camphor, D-limonene and cymene. A significant difference was observed between the 4 samples volatile profiles. 1,8-cineole was found major component of the essential oil (VO-21.39%) and glycerol macerate (GM-35.60%), while and α-pinene was detected as the main constituent of the two tinctures (T-46.05%; MT-31.93%). The highest 1,8-cineol content, determined by calibration curve method, was found in the volatile oil, while the fresh plant hydroalcoholic extract was richer in α-pinene and D-limonene.

Achillea schurii Flowers: Chemical, Antioxidant, and Antimicrobial Investigations.

This study aims to evaluate the phenolic profile, and antioxidant and antimicrobial activity of Achillea schurii Sch.-Bip., an endemic species from Romania that has not been investigated yet. The chromatographic profile of the phenolic components was obtained using the HPLC-MS method, while the total polyphenol, flavonoid, caffeic acid derivative contents were quantified using spectrophotometric methods. The antioxidant activity was evaluated using different methods: DPPH radical scavenging, hemoglobin ascorbate peroxidase activity inhibition (HAPX), inhibition of lipid peroxidation catalyzed by cytochrome c, and direct detection of plant-derived free radicals using electron paramagnetic resonance (EPR). The antimicrobial test was performed using the disk diffusion assay. The phenolic profile has revealed high amounts of isoquercitrin, rutin, luteolin, and apigenin. The A. schurii extract exhibited a good antioxidant capacity, and high phenolic contents (76.93 mg/g polyphenols, 18.61 mg/g flavonoids and 41.48 mg/g caffeic acid derivatives, respectively). The antimicrobial tests reveal a remarkable inhibitory activity against Listeria monocytogenes, Staphylococcus aureus, and Salmonella typhimurium. Considering the above, A. schurii may be deemed to offer good perspectives for pharmaceutical and industrial applications.

Comparative polyphenolic content and antioxidant activities of Genista tinctoria L. and Genistella sagittalis (L.) Gams (Fabaceae).

The aim of this study was focused on the polyphenolic composition and antioxidant capacity of Genista tinctoria L. and Genistella sagittalis (L.) Gams. A qualitative and quantitative characterization of the main phenolic compounds from the extracts were carried out using a HPLC-MS method. The total polyphenolic and flavonoid content was spectrophotometrically determined. The antioxidant activity towards various radicals generated in different systems was evaluated usingDPPH bleaching method, Trolox equivalent antioxidant capacity assay (TEAC) and Oxygen radical absorbance capacity (ORAC), and all indicated that G. tinctoria extract was more antioxidant than G. sagittalis extract.That was in good agreement with the total polyphenolic and flavonoidic content.Chlorogenic acid, p-coumaric acid, isoquercitrin and apigenin were identified in bothspecies. Caffeic acid, ferulic acid, hyperoside, rutin, quercitrin and luteolin were found only in G. tinctoria, while quercetin was determined in G. sagittalis.

In vitro study of antioxidant activity and phenolic content of Chrysanthemum balsamita varieties.

The purpose of our study was to identify the phenolic substances of two varieties of Chrysanthemum balsamita (balsamita and tanacetoides) and to measure the overall antioxidant activity. The phenolic compounds were determined by HPLC. The evaluation of the polyphenolic content was performed by colorimetric analysis. The antioxidant activity was measured by three in vitro assay models: the DPPH, the silver nanoparticles antioxidant capacity (SNPAC) and EPR radical detection. Using HPLC-MS analysis, phenolic acids, flavonoids and flavonoid aglycone were detected. The highest antioxidant activity was showed by Chrysanthemum balsamita var. balsamita, while the lowest for the Chrysanthemum balsamita var. tanacetoides extract, in accord with the polyphenolic content. The results show that Chrysanthemum balsamita var. balsamita might be a source of antioxidant flavonoids, especially rutin and isoquercitrin.

The study of polyphenolic compounds profile of some Rosmarinus officinalis L. extracts.

The purpose of this study was to compare the polyphenol profile of different Rosemary (Rosmarinus officinalis) extracts obtained from dry and fresh herb and the evaluation of their antioxidant effect. There were studied the polyphenols from hydroalcoholic extracts (1:5- dry plant:solvent) obtained from fresh respectively dry plant and the gemmotherapic extract obtained from fresh plant (1:20- dry plant: solvent). The polyphenol profile was evaluated by UV-Vis spectrophotometry, TLC and HPLC. The total polyphenol respectively flavonoids content were determined by UV-V is spectrophotometry. The antioxidant effect was evaluated by DPPH, ABTS, FRAP, CUPRAC and silver nanoparticle (SNP) methods. The hydroalcoholic extract obtained from fresh plant contains the highest concentration of total polyphenols, (0.601mg/ml rosmarinic acid), total flavonoids, (0.270mg/ml luteoline) and rosmarinic acid (0.350 mg/ml). The less concentrated is the gemmotherapic extract, but also the extraction ratio is higher than the hydroalcoholic extracts. The high content in polyphenols of the mentioned hydroalcoholic extract was confirmed by highest values of antioxidant activity: 39.1ml (DPPH), 7.7 ml (ABTS), 698mM ET/100 ml (FRAP), 1947 mM ET/100 ml (CUPRAC), 4570mM ET/100 ml (SNP). These differences in the polyphenols profiles show the importance of use the fresh plants for obtaining the good quality extracts.

Assessment of rosmarinic acid content in six Lamiaceae species extracts and their antioxidant and antimicrobial potential.

In the present study, six indigenous species of Lamiaceae family (Origanum vulgare L., Melissa officinalis L., Rosmarinus officinalis L., Ocimum basilicum L., Salvia officinalis L. and Hyssopus officinalis L.), have been analyzed to assess the rosmarinic acid, phenyl propane derivatives and polyphenolic contents and their antioxidant and antimicrobial potential. HPLC-MS method has been used for the analysis ofrosmarinicacid. The phenyl propane derivatives and total phenolic contents were determined using spectrophotometric method. The ethanolic extracts were screened for antioxidant activities by DPPH radical scavenging, HAPX (hemoglobin ascorbate per oxidase activity inhibition), and EPR (electron paramagnetic resonance) methods. The ethanolic extracts revealed the presence of rosmarinic acid in the largest amount in O. vulgare (12.40mg/g) and in the lowest in R. officinalis (1.33 mg/g). O. vulgare extracts exhibited the highest antioxidant capacity, in line with the rosmarinic acid and polyphenolic contents. The antimicrobial testing showed a significant activity against L. monocytogenes, S. aureus and C. albicans for all six extracts.

Comparative studies on antioxidant activity and polyphenolic content of Lycium barbarum L. and Lycium chinense Mill. leaves.

The purpose of this research was to bring new data regarding the phenolic composition and the antioxidant activity of L. barbarum L. and L. chinense Mill. leaves. The determination of the main polyphenolic compounds was performed using a HPLC-UV-MS method. The dominant compound found for both species was rutin, with its highest amount registered in L. chinense (24141.90±21.3 µ/g plant material) leaves. Among the flavonoidic aglycones, quercetin was found in both samples, being quantified in a higher amount in L. chinense. In the antioxidant assays, both extracts exhibited important antioxidant activities, as witnessed by the three methods, both correlated with their total polyphenolic content.