Claudia Anesini

Total polyphenol content and antioxidant capacity of commercially available tea (Camellia sinensis) in Argentina.

Tea, Camellia sinensis (L.) O. Kuntze (Theaceae) is cultivated in Argentina in the northeastern region (provinces of Misiones and Corrientes), between 26 degrees and 28 degrees south latitude, the southernmost area of the world where tea is cultivated. The objective of this work was to determine the total polyphenol content and the in vitro antioxidant capacity of green and black tea cultivated and industrialized in Argentina. Twelve samples of eight brands were analyzed. The total polyphenol content was determined according to the International Organization for Standardization method (ISO) 14502-1 for the determination of substances characteristic of green and black tea. The antioxidant capacity was determined by the ferric thiocyanate method (FTC) and the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free-radical scavenging assay. Green tea showed a higher polyphenol content than black tea. The total polyphenol concentration in green tea was found to vary from 21.02 +/- 1.54 to 14.32 +/- 0.45% of gallic acid equivalents (GAE), whereas in black tea, the polyphenol content ranged from 17.62 +/- 0.42 to 8.42 +/- 0.55% of GAE (P < 0.05). A similar profile was observed for the antioxidant capacity determined by both methods. The antioxidant activities were well correlated with the total polyphenol content (r (2) = 0.9935 for the ferric thiocyanate method and r (2) = 0.9141 for the 1,1-diphenyl-2-picrylhydrazyl free-radical scavenging assay). This is the first systematic screening for the quantification of polyphenols and antioxidant activity in tea commercialized in Argentine markets. The results obtained herein allow one to conclude that Argentine tea is of very good quality when compared to teas from other sources.

Screening of plants used in Argentine folk medicine for antimicrobial activity

Screening of 132 extracts from Argentine folk-medicinal plants for antimicrobial activity has been conducted using a penicillin G resistant strain of Staphylococcus aureus, Escherichia coli and Aspergillus niger as test microorganisms. Cephazolin, ampicillin and miconazole were used as standard antibiotics and concentration-response curves were obtained using the agar-well diffusion method. Boiling water extracts of plant materials were tested and 12 species were active against Staphylococcus aureus, whereas 10 were effective against Escherichia coli and 4 against Aspergillus niger. Tabebuia impetiginosa bark, Achyrocline sp. aerials parts, Larrea divaricata leaves, Rosa borboniana flowers, Punica granatum fruit pericarp, Psidium guineense fruit pericarp, Lithrea ternifolia leaves and Allium sativum bulbs produced some of the more active extracts.

In vitro antibacterial activity of Argentine folk medicinal plants against Salmonella typhi

Boiling water extracts of 132 samples from 54 plant families, commonly used in Argentine folk medicine, were screened for antibacterial activity against Salmonella typhi. The agar-well diffusion method was used. A reference concentration-response curve for ampicillin was used to estimate the apparent activity of the samples. Twenty four species showed antibacterial activity. Cassia occidentalis roots, Heimia salicifolia aerial parts, Punica granatum fruit pericarp and Rosa borboniana flowers produced some of the more active extracts. Taking into account the multiple resistance of Salmonella typhi, these findings could be useful in the search for new clinically useful antimicrobials.

Antioxidant activity of limonene on normal murine lymphocytes: relation to H2O2 modulation and cell proliferation.

Limonene is a monoterpene present in citrus fruit and is used as flavouring agents of foods. It was shown that monoterpenes possess antioxidant activity. Previously, it was demonstrated that limonene exerts anti-proliferative action on a lymphoma cell line without modifying normal lymphocyte viability. H(2)O(2) has a modulator role in cell proliferation. In the present study, the effect of limonene on normal lymphocytes proliferation and its relation with H(2)O(2) level modulation was analysed, evaluating its effect on the activity of cell antioxidant enzymes, such as catalase, peroxidase and superoxide dismutase. Limonene exerted a biphasic effect on cell proliferation; the increase in cell proliferation was related to the decrease in H(2)O(2) level by the increase in catalase and peroxidase activities. Moreover, limonene protected the cells to the oxidative stress induced by exogenous addition of H(2)O(2). In view of these results, it is possible that limonene could protect normal lymphocytes from diseases related to oxidative stress, including cancer, but further research is necessary to establish the role of limonene as a potential antioxidant that can effectively protect lymphocytes from oxidative stress and mitochondrial dysfunction.

Antifungal activity of the aqueous extract of Ilex paraguariensis against Malassezia furfur.

Malassezia furfur is a lipodependent, dimorphic and saprophyte fungus which causes pityriasis versicolor, dandruff and seborrheic dermatitis in humans. The drugs available to treat this fungal infection are few. These drugs are highly toxic and are costly when used in prolonged treatments. For these reasons, it is necessary to find new compounds to treat these infections. Ilex paraguariensis St Hilaire is a plant that grows in Argentina, Brazil and Paraguay. The aim of this study was to evaluate the effect of the aqueous extract of Ilex paraguariensis on the growth of M. furfur. High performance liquid chromatography (HPLC) was employed to identify and isolate compounds of I. paraguariensis and the agar‐well diffusion method was used to assess the antifungal activity of the extract. The fungicidal/fungistatic effect was evaluated by the modified Thompson assay. The results demonstrated that the aqueous extract of Ilex paraguariensis (1000 mg/ml) possesses inhibitory activity against M. furfur. This antimalassezial activity was equivalent to 2.7 μg/ml of ketoconazole. Therefore, the topical use of Ilex paraguariensis extract as alternative antifungal agent can be suggested. Copyright

Antiadipogenic effect of carnosic acid, a natural compound present in Rosmarinus officinalis, is exerted through the C/EBPs and PPARγ pathways at the onset of the differentiation program.

BACKGROUND Obesity is a serious health problem all over the world, and inhibition of adipogenesis constitutes one of the therapeutic strategies for its treatment. Carnosic acid (CA), the main bioactive compound of Rosmarinus officinalis extract, inhibits 3T3-L1 preadipocytes differentiation. However, very little is known about the molecular mechanism responsible for its antiadipogenic effect. METHODS We evaluated the effect of CA on the differentiation of 3T3-L1 preadipocytes analyzing the process of mitotic clonal expansion, the level of adipogenic markers, and the subcellular distribution of C/EBPβ. RESULTS CA treatment only during the first day of 3T3-L1 differentiation process was enough to inhibit adipogenesis. This inhibition was accompanied by a blockade of mitotic clonal expansion. CA did not interfere with C/EBPβ and C/EBPδ mRNA levels but blocked PPARγ, and FABP4 expression. C/EBPβ has different forms known as LIP and LAP. CA induced an increase in the level of LIP within 24h of differentiation, leading to an increment in LIP/LAP ratio. Importantly, overexpression of LAP restored the capacity of 3T3-L1 preadipocytes to differentiate in the presence of CA. Finally, CA promoted subnuclear de-localization of C/EBPβ. CONCLUSIONS CA exerts its anti-adipogenic effect in a multifactorial manner by interfering mitotic clonal expansion, altering the ratio of the different C/EBPβ forms, inducing the loss of C/EBPβ proper subnuclear distribution, and blocking the expression of C/EBPα and PPARγ. GENERAL SIGNIFICANCE Understanding the molecular mechanism by which CA blocks adipogenesis is relevant because CA could be new a food additive beneficial for the prevention and/or treatment of obesity.

Antibacterial activity of alimentary plants against Staphylococcus aureus growth.

Alimentary plants were screened for antibacterial activity against a penicillin G resistant strain of Staphylococcus aureus. Twenty-five samples of plant material corresponding to 21 species from 13 families were used. Both aqueous and ethanol extracts were obtained from them. Antibacterial activity was determined by the agar-well diffusion method, using cephazolin as a standard antibiotic. Seventeen ethanol extracts were found active. Eugenia caryophyllata (clavo de olor*) flowers, Myristica fragans (nuez moscada*) seeds, Theobroma cacao (cacao*) seed bark, Triticum sp (trigo*) fruit, Zea mays (maíz*) fruit and Piper nigrum (pimienta*) ripe fruit produced some of the more active extracts (* = Argentine vulgar names).

Vicenin-2, a potential anti-inflammatory constituent of Urtica circularis.

Vicenin-2 (1), a flavonoid glycoside, was isolated and identified from an ethanol extract of the aerial parts of Urtica circularis. This crude extract was found to possess significant anti-inflammatory activity in a carrageenan-induced rat hind paw edema model (41.5% inhibition at a dose of 300 mg/kg; ip). The effects of 1 on several inflammatory mediators were investigated. In cultured murine macrophages, this compound modified LPS-induced total nitrite and TNF-α production, in addition to the LPS-induced translocation of the nuclear factor NF-κB.

Antiproliferative Activity of Larrea Divaricata Cav. on Lymphoma Cell Line: Participation of Hydrogen Peroxide in Its Action

ABSTRACT Larrea divaricata is a plant used in Argentina. The aim was to analyze the participation of H2O2 in the antiproliferative effect of L divaricata on BW5147 cells. Different studies were performed: proliferation, viability, nitrite production, apoptosis, oxygen reducing activity, NF-κ B translocation, H2O2 production, H2O2 scavenging activity, and effect on exogenous superoxide dismutase. The extract decreased proliferation and induced apoptosis through P-38 and ERK pathways. The extract activated Mn2 +–SOD, increasing H2O2, which was implicated in the antiproliferative mechanism by the increase of Nitric oxide (NO). New drugs, which can increase H2O2, could be a therapeutic strategy for the treatment of cancer.

Limonene Exerts Antiproliferative Effects and Increases Nitric Oxide Levels on a Lymphoma Cell Line by Dual Mechanism of the ERK Pathway: Relationship with Oxidative Stress

ABSTRACT D-limonene is a common monoterpene found in nature. Previously, it has been demonstrated that it has antiproliferative effects on a lymphoma cell line by increasing the nitric oxide (NO) level. In the present work this mechanism is analyzed by evaluating the participation of MAP38 and ERK pathways. Limonene increased the NO levels by inducing cell apoptosis by two mechanisms: through the production of H2O2 and ERK pathway activation at low concentrations, and through the inhibition of farnesylation of proteins and O2− production at high concentrations. Both mechanisms were related to the increase in total nitrites, and the production of oxidative stress intermediates was involved.