Neurotrophins are proteins that regulate neuronal survival, axonal growth, synaptic plasticity and neurotransmission. They are members of the neurotrophic factors family and include factors such as the nerve growth factor (NGF), the brain derived neurotrophic factor (BDNF), the neurotrophin-3 (NT-3), and the neurotrophin-4/5 (NT-4/5). These molecules bind to two types of receptors: i) tyrosine kinase receptors (TrkA, TrkB, TrkC) and ii) a common neurotrophin receptor (p75NTR). The two receptor types can either suppress or enhance each other's actions. Neurotrophins have a multifunctional role both in the central and peripheral nervous system. They have been suggested as axonal guidance molecules during the growth and regeneration of nerves. It has also been proven that they stimulate axonal growth by mediating the polymerization and accumulation of F-actin in growth cones and axon shafts. Neurotrophins, as other neurotrophic factors, have been shown that they reduce neuronal injury by exposure to excitotoxins, glucose deprivation, or ischemia. Furthermore, the nerve regeneration promoting effect of these growth factors is well documented for many different models of central or peripheral nervous system injury. Several studies have shown that exogenous administration of these factors has protective properties for injured neurons and stimulates axonal regeneration. Based on these properties, these molecules may be used as therapeutic agents for treating degenerative diseases and traumatic injuries of both the central and peripheral nervous system.

Tumourigenesis is the result of cell cycle disorganisation, leading to an uncontrolled cellular proliferation. Specific cellular processes-mechanisms that control cell cycle progression and checkpoint traversation through the intermitotic phases are deregulated. Normally, these events are highly conserved due to the existence of conservatory mechanisms and molecules such as cell cycle genes and their products: cyclins, cyclin dependent kinases (Cdks), Cdk inhibitors (CKI) and extra cellular factors (i.e. growth factors). Revolutionary techniques using laser cytometry and commercial software are available to quantify and evaluate cell cycle processes and cellular growth. S-phase fraction measurements, including ploidy values, using histograms and estimation of indices such as the mitotic index and tumour-doubling time indices, provide adequate information to the clinician to evaluate tumour aggressiveness, prognosis and the strategies for radiotherapy and chemotherapy in experimental researches.

A new mixed ligand-silver(I) complex of formula [Ag(tpp)(2)(p-Hbza)] (1) (p-HbzaH = 4-hydroxybenzoic acid and tpp = triphenylphosphine) has been synthesized and characterized by elemental analysis, mp, vibrational spectroscopy (mid- and far-FT-IR), (1)H-NMR, UV-vis, ESI-MS spectroscopic techniques and X-ray crystallography. Complex 1 and the already known mixed ligand-silver(I) complexes of formulae [Ag(tpp)(2)(salH)] (2) (salH(2) = salicylic acid or 2-hydroxy-benzoic acid) and {[Ag(tpp)(3)(asp)](dmf)} (3) (aspH = o-acetylsalicylic acid) were used for the clarification of the cytostatic activity mechanism. Thus, 1-3 were tested for their in vitro cytotoxic activity against leiomyosarcoma (LMS) and human breast adenocarcinoma (MCF-7) cells with trypan blue and Thiazolyl Blue Tetrazolium Bromide (MTT) assays. For both cell lines, complexes 1-3 were found to be more active than cisplatin. Due to the morphology of the LMS cells after incubation with 1-3, the type of cell death was evaluated by flow cytometry assay and DNA fragmentation. The results show that LMS cells undergo programmed cell death (apoptosis). DNA binding tests indicate the ability of complexes 1-3 to modify the activity of the cells. The binding constants of 1-3 towards calf-thymus DNA (CT-DNA) ((27.7 ± 7.9) × 10(4) (1), (13.3 ± 6.5) × 10(4) (2) and (11 ± 2.8) × 10(4) (3) M(-1)) indicate strong interaction. Moreover, the influence of complexes 1-3 on the catalytic peroxidation of linoleic acid to hydroperoxylinoleic acid by the enzyme lipoxygenase (LOX) was kinetically studied. Finally, docking studies on DNA binding interactions were performed.

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