Antioxidant and antimutagenic activities of Viscum album fruit ethanolic extract in human lymphocytes

Polyphenolic compounds are widely distributed in plants and known to be excellent antioxidants in vitro. They have the capacity to reduce free-radical formation by scavenging free-radicals. In this studywe have evaluated the antioxidant and antimutagenic potencies of polyphenolic compounds of Viscum album against trichloroethylene (TCE)-induced oxidative and genotoxic damage. V. album extract (VAE0.5 g/ml) protected human lymphocytes against TCE. In chromosomal aberration (CA) analysis, no significant increase in total aberrations were found after treatment with TCE and all VAE concentrations. The mitotic index (MI) showed significant increase in 0.5 ìg/ml VAE samples whencompared with TCE-treated (2 ìM) group. VAE (0.5 ìg/ml) reduced the levels of malondialdehyde (MDA) significantly wherease VAE (1.0 and 2.0 ìg/ml) samples increased MDA concentrations significantly. We have also shown that the various DNA effects of TCE treatment seem to be DNA damages, but not mutations as TCE treated profiles were reverted back to the control like profiles by most probably DNA repair mechanisms in VAE 0.5 g/ml treated group

Eco-physiological behaviour of some mediterranean plants as suitable candidates for reclamation of degraded areas

WOS: 000220181600001Diurnal time course of the water relations of Ceratonia siliqua, Quercus coccifera, Pistacia terebinthus and Olea oleaster was studied on healthy and degraded sites for getting a suitable parameter describing the water stress impact on vegetation, and selecting the species suitable for reforestation. Out of the species used C. siliqua, showed high maximum stomatal conductance (g(L)), with high relative water content (RWC) under field conditions, and relatively constant minimum (midday) water potential (Psi(min)) and pre-dawn water potential (Psi(pd)'s). O. oleaster plants appeared to be unable to prevent dehydration inspite of consistent decrease of stomatal conductance (g(L)), when subjected to increasing water stress. Stomatal closure in fact, was not sufficient to prevent water loss and relative water content (RWC) dropped to about 70%. P. terebinthus species is water spender. Under water shortage condition inspite of complete closure of stomata (stomatal conductance dropped to 0.08 s cm(-1)), relative water content showed variable values. Q. coccifera typically showed high stomatal conductance activity and also high relative water content (average 83%) on healthy site, but on the degraded site it reduced, stomatal conductance, thus maintaining high RWCs (over 80%) and preventing leaf water potential (Psi(L)) to drop to critical values. (C) 2003 Elsevier Ltd. All rights reserved

Carob trees (Ceratonia siliqua L.) regenerated in vitro can acclimatize successfully to match the field performance of seed-derived plants

The use of in vitro regenerated plants in forestry and orchard depends ultimately on the development of efficient transplantation protocols, ensuring high survival rates and successful establishment under field conditions. We tested the performance of micropropagated carob trees (Ceratonia siliqua L.) throughout the acclimatization process in terms of survival, growth and physiological traits, including field comparisons with seed-derived and mother plants. The field trial was 100 %successful, i.e. we found no major differences between micropropagated, seed-derived and mother plants in terms of growth rate, height, number of leaves, photosynthetic efficiency, chlorophyll fluorescence, chlorophyll content and soluble protein content, although these parameters changed significantly during acclimatization. Stomatal conductance (gs) was reduced by fourfold when plants were transferred from in vitro culture to the growth chamber, thus preventing uncontrolled wilting. The photosynthetic rate (PN) was relatively low in vitro, in the growth chamber and the greenhouse, but increased to match seed-derived and mother plants in the field. The chlorophyll a/b ratio in leaves from in vitro and growth chamber plants was typical of shade plants (2.1) but became more characteristic of sun plants in the subsequent acclimatization stages (3.1–3.5). The maximum efficiency of photosystem II (Fv/Fm) remained mostly constant at ~0.80 throughout acclimatization, as is typical for healthy, non-stressed plants. We conclude that our micropropagation and acclimatization protocols provide a suitable alternative to traditional mass propagation techniques for the carob tree.M.L. Osório and S. Gonçalves acknowledge a grant from the Portuguese Science and Technology Foundation (FCT, Grant SFRH/BPD/35410/2007 and SFRH/BPD/31534/2006