A Comparative study of the antiproliferative activity of iron chelators PIH, SIH and their light-activated caged derivatives in skin cells

In the present study, we investigated the long term antiproliferative potential of iron chelators Salicylaldehyde Isonicotinoyl Hydrazone (SIH), Pyridoxal Isonicotinoyl Hydrazone (PIH) and their caged-derivatives 2-Nitrophenyl Ethyl-SIH and –PIH (2NPE-SIH and 2NPE-PIH) using human primary fibroblast cell line FEK4 and the spontaneously immortalised human keratinocyte cell line, HaCaT as models. We then extended the study to additional hyperproliferative skin keratinocyte cell lines notably MKPS (immortalised psoriatic cell line) as well as PM1 and MET2 that represent two cancerous skin cell lines isolated at different stages of malignant transformation of squameous cell carcinoma (SCC) from a single adult individual. Iron depletion with SIH and its UVA-activated caged-derivative (i.e. 2NPE-SIH) led to significant cell death in all cell models presumably as a result of inhibition of G1/S progression in cell cycle. PIH and 2NPE-PIH on the other hand only caused transient growth retardation in cells due to delayed S Phase but with no apparent toxicity. The growth inhibitory/retardation effects of SIH/PIH or UVA-activated caged-SIH/PIH were related to their iron-chelating properties, as their saturation with iron could reverse their antiproliferative activity in the analysed skin cells. Taken together the results suggested that 2NPE-PIH which possesses very high iron chelating potential, but low antiproliferative activity (i.e. upon uncaging by UVA) is more suitable for skin photoprotection. In contrast, 2NPE-SIH which remains inactive inside the cells until its strong iron binding activity and high antiproliferative properties are activated by UVA, may offer a highly selective and dose-controlled alternative for treatment of hyperproliferative skin disorders such as skin cancer.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Sinteza i karakterizacija novih magnetičnih zrna za adsorpciju salicilne kiseline iz vodene otopine

The study focuses on the synthesis of two adsorbent forms that were prepared: magnetic nonporous hybrid beads (MNPHB), and magnetic macroporous hybrid beads (MMPHB). The salicylic acid adsorption tests on MNPHB and MMPHB were carried out at a temperature of 25 °C, pH 4, adsorbent mass of 10 mg, and an initial concentration of 10 mg l–1. The adsorption capacity was found to be for MNPHP and MMPHB to 9 mg g–1 and 152 mg g–1, respectively. The adsorption kinetic was described by the pseudo-second order model and Freundlich isotherm for the MMPHB beads. This work is licensed under a Creative Commons Attribution 4.0 International License.Istraživanje je usmjereno na sintezu dvaju pripremljenih oblika adsorbenta: magnetskičkih neporoznih hibridnih zrna (MNPHB) i magnetičnih makroporoznih hibridnih zrna (MMPHB). Ispitivanja adsorpcije salicilne kiseline na MNPHB i MMPHB provedena su pri temperaturi od 25 °C, pH-vrijednosti 4, masi adsorbenta od 10 mg i početnoj koncentraciji salicilne kiseline od 10 mg l–1. Utvrđeno je da je adsorpcijski kapacitet MNPHP i MMPHB 9 mg g–1 odnosno 152 mg g–1. Kinetika adsorpcije opisana je modelom pseudo-drugog reda i Freundlichovom izotermom za zrna MMPHB. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna

Théodore Dubois / d'après une charge d'Aroun al Rascid

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Temporal variations in the life-cycles of aphids (Sternorrhyncha: Aphididae) and their coccinellid predators

International audienceAphids are either monoecious living either on trees or herbaceous plants, or heteroecious, which involves host alternating between a tree (primary host) and a herbaceous plant (secondary host). We described the temporal variations in abundance and richness of aphids in an Algerian orchard, over a 6 month period. We recorded the choice of basin colour, the relative height of traps, and monthly Barycenter of winged populations. We also recorded temporal variations in the structure of ladybird communities. Tree-living species of aphids are the last to be caught with most caught by the yellow traps, possibly because of the predominant greenness of the vegetation in April. Most were also caught by high traps. Their phenology coincides with that of the second peak of ladybirds. In contrast, the phenology of species of aphids living on herbaceous plants differs greatly, which reflects their host plant diversity. In March relatively more of these aphids were caught by the green traps, possibly because at that time the ground was not yet covered by vegetation. Early and late species of aphids are at greater risk of being attacked by ladybirds as they are also most active early and late in the season. The highest catches of the heteroecious species of aphids were recorded in the middle of the trapping period and between those of the two groups of monoecious species of aphids. The adaptive significance of the differences in the behaviour and ecology of the aphids in the three groups is discussed