Caracterización in situ de poblaciones de Aloysia gratissima var. gratissima recolectadas del noreste de la provincia de San Luis, Argentina / In situ characterization of populations of Aloysia gratissima var. gratissima collected from the northeast of the province of San Luis, Argentina

Abstract: The aerial part of Aloysia gratissima (Gil lies & Hook. ex Hook.) Tronc., "Usillo", is used as aromatic and medicinal. It is a shrub of up to 3 meters, distributed in North America, from the south of the USA to the north of Mexico, and in South America up to the 37th parallel. As in other native sp ecies, the demand is covered by harvesting in wild populations, which brings about the deterioration of the resource and lack of homogeneity of the harvested product. The variability was characterized in nine populations of A. gratissima var. gratissima fr om the northeast of San Luis, Argentina, based on morphological and phytochemical characters. It was found that the species in the region presents considerable heterogeneity. Diversity was detected in the chemical characteristics of the essential oils anal yzed and the prevalence of mono and sesquiterpenes was related to the olfactory identities identified. The main components were the sesquiterpene spatulenol and the monoterpene 1,8 cineole

Resumen: La parte aérea de Aloysia gratissima (Gillies & Hook. ex Hook.) Tronc., "usillo", es utilizada como aromática y medicinal. Es un arbusto de hasta 3 metros, distribuido en Norteamerica, desde e l sur de EEUU hasta el norte de México, y en Sudamerica hasta el paralelo 37°. Al igual que en otras especies nativas, la demanda es cubierta por recolección en poblaciones silvestres, lo cual trae aparejado el deterioro del recurso y falta de homogeneidad del producto cosechado. Se caracterizó la variabilidad en nueve poblaciones de A. gratissima var. gratissima del noreste de San Luis, Argentina, en base a caracteres morfológicos y fitoquímicos. Se encontró que la especie en la región presenta una conside rable heterogeneidad. Se detectó diversidad en las características químicas de los aceites esenciales analizados y se relacionó la prevalencia de mono y sesquiterpenos con las identidades olfativas identificadas. Los componentes mayoritarios fueron el sesq uiterpeno espatulenol y el monoterpeno 1,8 cineol.

Protective effect of the hydroalcoholic extract from Lampaya medicinalis Phil. (Verbenaceae) on palmitic acid- impaired insulin signaling in 3T3-L1 adipocytes.

BACKGROUND: Obesity is strongly associated with insulin resistance (IR). IR at the molecular level may be defined as a diminished activation of insulin signaling-related molecules (IRS-1/Akt/AS160) as well as reduced glucose uptake. Subject with obesity have elevated plasma levels of saturated fatty acids, such as palmitic acid (PA), which triggers insulin signaling disruption in vivo and in vitro. Infusions of Lampaya medicinalis Phil. (Verbenaceae) are used in folk medicine of Northern Chile to counteract inflammatory diseases. Hydroethanolic extracts of lampaya (HEL) contain considerable amounts of flavonoids that may explain the biological activity of the plant. The aim of this study was to assess whether HEL exposure protects against PA-disrupted insulin signaling and glucose uptake in adipocytes. METHODS: Cytotoxicity of a range of HEL concentrations (0.01-10 µg/mL) was evaluated in 3T3-L1 adipocytes. Cells were exposed or not to 0.1 µg/mL of HEL before adding 0.65 mM PA or vehicle and incubated with 100 nM insulin (or vehicle) for 15 min. Phosphorylation of Tyr-IRS-1, Ser-Akt, Thr-AS160 was evaluated by Western blot. Glucose uptake was assessed using the 2-NBDG analogue. RESULTS: HEL was not cytotoxic at any concentration assessed. PA-induced reduction in insulin-stimulated phosphorylation of IRS-1, Akt and AS160 and glucose uptake were abolished by co-treatment with HEL. CONCLUSION: These findings give new insights about the effect of HEL ameliorating PA- impaired IRS-1/Akt/AS160 pathway and glucose uptake in adipocytes. More studies should focus on lampaya, since might represent a preventive approach in individuals whose circulating PA levels contribute to IR.

Antioxidant and Anti-Proliferative Activity of Essential Oil and Main Components from Leaves of Aloysia polystachya Harvested in Central Chile.

The aim of this study was to determine, first, the chemical composition of Aloysia polystachya (Griseb) Moldenke essential oil, from leaves harvested in central Chile; and second, its antioxidant and cytotoxic activity. Eight compounds were identified via gas chromatography-mass spectrometry (GC-MS) analyses, with the most representative being R-carvone (91.03%), R-limonene (4.10%), and dihydrocarvone (1.07%). For Aloysia polystachya essential oil, antioxidant assays (2,2-diphenyl-1-picrylhydrazyl (DPPH), H2O2, ferric reducing antioxidant power (FRAP), and total reactive antioxidant potential (TRAP)) showed good antioxidant activity compared to commercial antioxidant controls; and anti-proliferative assays against three human cancer cell lines (colon, HT-29; prostate, PC-3; and breast, MCF-7) determined an IC50 of 5.85, 6.74, and 9.53 µg/mL, and selectivity indices of 4.75, 4.12, and 2.92 for HT-29, PC-3, and MCF-7, respectively. We also report on assays with CCD 841 CoN (colon epithelial). Overall, results from this study may represent, in the near future, developments for natural-based cancer treatments.

Diversity of leaf endophytic fungi in mangrove plants of Northeast Brazil

With the aim of increasing the knowledge about endophytic fungi, a group of microorganisms with high biotechnological potential and a valuable source of useful metabolites, a survey in leaves of mangrove plants (Avicennia schaueriana, Laguncularia racemosa, and Rhizophora mangle) was performed at the Itamaracá Island, PE, Brazil. Leaves were collected, during two seasons, dry and rainy, superficially sterilized and fragments maintained in Petri dishes with Potato dextrose agar (PDA) at 28º ± 2º C until isolation of the fungi. Fourty taxa were isolated: 25 species representing 19 genera and 15 morphotypes determined as Mycelia sterilia. Leaves of L. racemosa hosted the highest number of colony forming units (CFU) and taxa. Guignardia sp. and Colletotrichum gloeosporioides were the most frequently isolated, while Glomerella cingulata was the only species found in association with the three host plants. The proportional importance of each fungus differed among hosts. The similarity of fungi species between the two seasons reached only 4.2%, and that between the hosts was also low, with the maximum (A. schaueriana x L. racemosa) reaching 24.2%. Sphaerosporium, as well as Chloridium virescens var. virescens, Microsphaeropsis arundinis, Penicillium pinophilum, Periconia cambrensis, Phoma herbarum, P. diachenii, P. obscurans, Sordaria prolifica and Torula elisii are reported for the first time as endophytic in tropical regions.

Antioxidant effects of Citharexylum spinosum in CCl4 induced nephrotoxicity in rat.

The present study was carried out to evaluate the antioxidant effect of the chloroform extract of Citharexylum spinosum (CSCE) (Family: Verbenaceae) leaves in Sprague-Dawley male rats. The different groups of animals were administered with carbon tetrachloride (CCl(4); 20% in olive oil, 2 ml/kg body weight) 7 doses (i.p.) at 48 h interval. The CSCE at the doses of 100 and 200 mg/kg or silymarin at a dose of 50 mg/kg were administered intragastrically after 24 h to the CCl(4) treated rats. The effect of CSCE or silymarin on urine and serum markers (urea, creatinine, creatinine clearance, protein, albumin, urobilinogen and nitrite) was measured in CCl(4)-induced nephrotoxicity in rat. Further, the effects on lipid peroxidation (TBARS), enzymatic antioxidants (catalase, superoxide dismutase, glutathione peroxidase, glutathione-S-transferase, glutathione reductase) and non-enzymatic antioxidant glutathione (GSH) were estimated in the kidney samples. The CSCE and silymarin produced significant renal protective effects by restoring the concentration of urine and serum markers. Activity level of antioxidant enzymes and GSH contents were increased while lipid peroxidation (TBARS) was decreased, dose dependently with CSCE and silymarin. Decrease in body whereas increase in kidney weight induced with CCl(4) was restored with CSCE and silymarin. Chemical composition of CSCE indicated the presence of flavonoids, terpenoids, alkaloids and very low amount of saponins. Total flavonoids estimated were (127 ± 14.6) as rutin equivalent mg/g of the extract. From these results, it is suggested that CSCE possesses potent nephroprotective and antioxidant properties.

Elevated atmospheric CO2 mitigated photoinhibition in a tropical tree species, Gmelina arborea.

Effects of elevated CO2 on photosynthetic CO2 assimilation, PSII photochemistry and photoinhibition were investigated in the leaves of a fast growing tropical tree species, Gmelina arborea (Verbenaceae) during summer days of peak growth season under natural light. Elevated CO2 had a significant effect on CO2 assimilation rates and maximal efficiency of PSII photochemistry. Chlorophyll a fluorescence induction kinetics were measured to determine the influence of elevated CO2 on PSII efficiency. During midday, elevated CO2-grown Gmelina showed significantly higher net photosynthesis (p<0.001) and greater F(V)/F(M) (p<0.001) than those grown under ambient CO2. The impact of elevated CO2 on photosynthetic rates and Chl a fluorescence were more pronounced during midday depression where the impact of high irradiance decreased in plants grown under elevated CO2 compared to ambient CO2-grown plants. Our results clearly demonstrate that decreased susceptibility to photoinhibition in elevated CO2 grown plants was associated with increased accumulation of active PSII reaction centers and efficient photochemical quenching. We conclude that elevated CO2 treatment resulted in easy diminution of midday photosynthetic depression.

Physiological and isotopic (delta(13)C and delta(18)O) responses of three tropical tree species to water and nutrient availability.

Water-use efficiency and stable isotope composition were studied in three tropical tree species. Seedlings of Tectona grandis, Swietenia macrophylla and Platymiscium pinnatum were grown at either high or low water supply, and with or without added fertilizer. These three species previously exhibited low, intermediate and high whole-plant water-use efficiency (TE) when grown at high water supply in unfertilized soil. Responses of TE to water and nutrient availability varied among species. The TE was calculated as experiment-long dry matter production divided by cumulative water use. Species-specific offsets were observed in relationships between TE and whole-plant (13)C discrimination (Delta(13)C(p)). These offsets could be attributed to a breakdown in the relationship between Delta(13)C(p) and the ratio of intercellular to ambient CO(2) partial pressures (c(i)/c(a)) in P. pinnatum, and to variation among species in the leaf-to-air vapour pressure difference (v). Thus, a plot of v.TE against c(i)/c(a) showed a general relationship among species. Relationships between delta(18)O of stem dry matter and stomatal conductance ranged from strongly negative for S. macrophylla to no relationship for T. grandis. Results suggest inter-specific variation among tropical tree species in relationships between stable isotope ratios (delta(13)C and delta(18)O) and the gas exchange processes thought to affect them.

Aerenchyma tissue development and gas-pathway structure in root of Avicennia marina (Forsk.) Vierh.

The aerenchyma differentiation in cable roots, pneumatophores, anchor roots, and feeding roots of the mangrove plant, Avicennia marina (Verbenaceae) was analyzed using a light microscope and scanning electron microscope. In all types, cortex cells were arranged in longitudinal columns extending from the endodermis to the epidermis. No cells in the cortex had intercellular spaces at the root tip (0-150 microm), and aerenchyma started developing at 200 microm from the root apex. The aerenchyma formation was due to cell separation (schizogeny) rather than cell lysis. The cell separation occurred between the longitudinal cell columns, forming long intercellular spaces along the root axis. During aerenchyma formation, the cortex cells enlarged longitudinally by 1.8-3.9 times and widened horizontally by 2.2-2.9 times. As a result, the aerenchyma had a pronounced tubular structure that was radially long, elliptical or oval in cross section and that ran parallel to the root axis. The tube had tapering ends, as did vessel elements, although there were no perforated plates. The interconnection between neighboring tubes was made by abundant small pores or canals that were schizogenous intercellular spaces between the wall cells. All aerenchyma tubes in the root were interconnected by these small pores serving as a gas pathway.

Microbial transformation of zaluzanin-D.

Microbial transformation of zaluzanin-D using different fungi gave 11,13-dihydrozaluzanin-C, zaluzanin-C, 4,16,11,13 - tetrahydro zaluzanin-C, estafiatone, dihydroestafiatol and dihydroestafiatone.