Rosana Filip

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.

Dietary Advanced Glycation End Products and Their Role in Health and Disease

Over the past 2 decades there has been increasing evidence supporting an important contribution from food-derived advanced glycation end products (AGEs) to the body pool of AGEs and therefore increased oxidative stress and inflammation, processes that play a major role in the causation of chronic diseases. A 3-d symposium (1st Latin American Symposium of AGEs) to discuss this subject took place in Guanajuato, Mexico, on 1-3 October 2014 with the participation of researchers from several countries. This review is a summary of the different presentations and subjects discussed, and it is divided into 4 sections. The first section deals with current general knowledge about AGEs. The second section dwells on mechanisms of action of AGEs, with special emphasis on the receptor for advanced glycation end products and the potential role of AGEs in neurodegenerative diseases. The third section discusses different approaches to decrease the AGE burden. The last section discusses current methodologic problems with measurement of AGEs in different samples. The subject under discussion is complex and extensive and cannot be completely covered in a short review. Therefore, some areas of interest have been left out because of space. However, we hope this review illustrates currently known facts about dietary AGEs as well as pointing out areas that require further research.

Mate substitutes or adulterants: study of xanthine content

The xanthine (caffeine, theobromine and theophylline) content of decoctions of seven Ilex spp. was studied by HPLC using UV and a photodiode‐array detector. Ilex paraguariensis (‘Mate’ or ‘Yerba Mate’) is widely used in South America as a tealike beverage and the other six species are used as substitutes or adulterants of it. The results showed that I. paraguariensis has the highest amounts of caffeine and theobromine. Traces of caffeine were detected in I. theezans, I. dumosa, I. microdonta and I. pseudobuxus. Traces of theobromine were detected in I. argentina and I. microdonta. From the seven Ilex species investigated, theophylline was detected in I. theezans, I. dumosa and I. pseudobuxus, but only I. pseudobuxus has quantifiable amounts: 0.6 mg% (6 ppm).

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

Prevention of hydrogen peroxide-induced red blood cells lysis by Ilex paraguariensis aqueous extract: participation of phenolic and xanthine compounds.

The fresh leaves and stems of Ilex paraguariensis (Aquifoliaceae) are employed to prepare the commercial product used in North‐eastern Argentina, Southern Brazil and Eastern Paraguay named yerba maté. The presence of polyphenols and xanthines, which present antioxidant activity, has been described in I. paraguariensis. In living organism, reactive oxygen species can cause tissue damage affecting erythrocyte membranes leading to hemolysis.

Nutritional and Phytochemical Study of Ilex paraguariensis Fruits

Yerba mate is defined as the product constituted by the dried, slightly roasted, and milled leaves of Ilex paraguariensis. However, the fruits of this species are often found in the commercial product. Nowadays the fruits are considered a byproduct. The objective of this work was to obtain the preliminary data of minerals, lipids, methylxanthines and polyphenols in the ripe fruits of I. paraguariensis. The results showed a considerable amount of total dietary fiber ( g/100 g) and nutritionally valuable minerals: potassium ( mg/100 g), iron ( mg/100 g), magnesium ( mg/100 g), calcium ( mg/100 g), copper ( mg/100 g), zinc ( mg/100 g), and sodium ( mg/100 g). The lipid content was 4.5 g/100 g. Oleic acid was the predominant unsaturated fatty acid ( g/100 g). Linoleic acid ( g/100 g) was also present. Methylxanthines were quantified: caffeine () and theobromine () g/100 g. The total polyphenol content was g/100 g. The results obtained in this work suggest the potential value of the fruits of I. paraguariensis for the development of novel products in the food and pharmaceutical industries. This paper aims to contribute to the scientific knowledge of a natural by-product from industry regarding the need of foods and medicines for the new millennium.

Flavonoids of Lotus tenuis (Waldst. & Kit.) as markers of populations growing in soils of different saline and hydrologic conditions

Lotus tenuis Waldst. et Kit. (=Lotus glaber Mill.) e uma planta leguminosa muito difundida que cresce naturalmente em pastagens da Flooding Pampas, na Argentina. Uma das hipoteses para explicar a disseminacao de L. tenuis nessa area, e a diferenciacao de ecotipos. O objetivo deste trabalho foi investigar os compostos flavonoides presentes em populacoes de L. tenuis que crescem em uma grande variedade de solos. Amostras de cinco populacoes que crescem em solos com diferentes caracteristicas foram coletados, cultivados em estufas e comparados de acordo com seu perfil de flavonoides. Glicosideos dos seguintes flavonoides foram detectados: quercetina, 7-metoxi-quercetina eter, kaempferol, 7-metoxi-kaempferol eter e isorhamnetina. Somente as mostras de solos salino-sodicos mostraram agliconas metiladas: 7-metoxi-kaempferol eter e 7-metoxi-quercetina eter. Os ultimos compostos poderiam, portanto, ser considerados como a expressao de uma adaptacao bioquimica e sugerem uma diferenciacao em ecotipo. Lotus tenuis Waldst. et Kit. (=Lotus glaber Mill.) is a widely spread leguminous plant which grows naturally in low grasslands of the Flooding Pampas of Argentina. One of the hypothesis to explain the succesful spread of L. tenuis in this area, is the ecotypes differentiation. The aim of this work was to investigate the flavonoid compounds present in L. tenuis plant populations which grow in a variety of soils. Individuals from five populations growing in soils having different characterisctics were collected, cultivated in a glasshouse and compared according to their flavonoid profile. Glycosides of the following flavonoids were detected: quercetin, quercetin 7-methyl ether, kaempferol, kaempferol 7-methyl ether and isorhamnetin. Only those samples from a saline-sodic lowland, showed methylated aglycones: kaempferol 7-methyl ether and quercetin 7- methyl ether. The latter compounds could therefore be considered the expression of a biochemical adaptation and suggest an ecotype differentiation.

In vivo immunomodulatory effect of Tilia x viridis extracts on normal lymphocyte proliferation: a direct and an indirect action.

The flowers of Tilia species have been used in Europe for many years to treat colds, bronchitis, fever, inflammations and influenza. It is well known that lymphocytes play a role in acquired immunity related to pathogens and tumor cells attachment. The aim of this study was to determine the effect of an aqueous (AE) and a dichloromethane extract (DM) from Tilia x viridis which is widely used and distributed in Argentina, on normal murine lymphocyte proliferation after being administered to mice. Both extracts presented a stimulatory effect on normal murine lymphocyte proliferation. The effect exerted by DM was principally related to macrophage activation, meanwhile AE exerted an important direct effect on lymphocytes related to the rutin presence. The stimulating effect, exerted on normal lymphocytes was due to a protective effect of apoptosis and also to cell IL2 production. Copyright

Effect of caffeine on the secretion of peroxidase in rat submandibular gland: A study of its mechanism of action

OBJECTIVE In this work, we analysed the mechanism of action of caffeine on peroxidase secretion in the female rat submandibular gland. The signaling molecules cAMP and nitric oxide were monitored as potential mediators. DESIGN The salivary gland peroxidase secretion of female albino Wistar rats was assessed by a spectroscopic method. RESULTS Caffeine was found to exert an increase on peroxidase secretion in a concentration-response manner: the peroxidase secretion stimulation index (SI) (secreted peroxidase from treated/secreted peroxidase from basal) for caffeine 10 microg/ml: 2.2+/-0.18 (P<0.05); caffeine 100 microg/ml alone: 3+/-0.18 (P<0.01); +LNMMA (LN monomethyl arginine): 1+/-0.1 (P<0.05); caffeine 1000 microg/ml alone: 5+/-0.35 (P<0.01); +LNMMA: 2+/-0.2 (P<0.05). These results were associated with an increase in cAMP and total nitrites production. Total nitrites, SI caffeine 100 microg/ml alone: 2.8+/-0.2 (P<0.01); +LNMMA: 1+/-0.08 (P<0.05); caffeine 1000 microg/ml alone: 4.8+/-0.3 (P<0.01); +LNMMA: 2.3+/-0.18 (P<0.05). CONCLUSION It could thus be concluded that cAMP and NO are involved in the mechanism of action displayed by caffeine. This is the first report on the mechanism of action of caffeine on peroxidase secretion.

Food preservation by Larrea divaricata extract: participation of polyphenols

Abstract The aim of this study was to evaluate the antioxidant and protease inhibitor capacities on eggs and milk protein of a nor‐dihydroguaiaretic (NDGA)‐standardized aqueous extract of Larrea divaricata (AE) and to analyze the participation of polyphenols as NDGA in these actions. NDGA was determined by high‐performance liquid chromatography; flavonoids and polyphenols were quantified by spectrophotometric methods as well as inhibition of lipid peroxidation, proteinase inhibitor capacity, advanced glycation end products (AGES) formation, and inhibition of albumin denaturation. The extract protected food for oxidative damage by preventing malondialdehyde formation in egg yolk and by preventing AGE formation in completely cooked eggs, also impeded albumin denaturation, and casein hydrolysis induced by trypsin and heat. Polyphenols, especially flavonoids and NDGA, were involved in these actions.