Publications by authors named "Antonia Orsi"

Background: Extracts from Hoodia gordonii have been shown to decrease food intakes and body weights in animals and were proposed as a food supplement or ingredient for weight management.

Objective: We assessed the safety and efficacy of a 15-d repeated consumption of H. gordonii purified extract (HgPE) relative to a placebo in humans.

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Callithrix jacchus (common marmoset) is one of the more primitive non-human primate species and is used widely in fundamental biology, pharmacology and toxicology studies. Marmosets breed well in captivity with good reproductive efficiencies and their sexual maturity is reached within 18 months of age allowing for rapid expansion of colonies and early availability of sexually mature animals permitting an earlier assessment of product candidates in the adult. Their relatively small size allows a reduction in material requirements leading to a reduction in development time and cost.

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The purpose of this work is to study the effect of smilagenin on the mRNA stability of muscarinic receptor subtype 1 (M(1); m1 mRNA) in aged rat brains and its significance in improving memory. The Y-maze avoidance task showed that oral administration of smilagenin significantly improved spatial memory performance in aged rats. Mechanistic studies showed that smilagenin was neither a ligand of the M receptors nor a cholinesterase inhibitor, while radioligand binding assays revealed that smilagenin significantly increased the M(1)-receptor density.

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Many experimental data support the enhancement of neurotrophic factors as a means to modify neurodegeneration in Parkinson's disease. However, the translation of this to the clinic has proven problematic. This is likely due to the complex nature of the surgical gene delivery and cell-based approaches adopted to deliver proteinaceous neurotrophic factors to targets within the central nervous system.

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Tyrosine hydroxylase immunohistochemical analysis revealed that in cultured mesencephalic dopaminergic neurons smilagenin (SMI), added prior to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPP+), protected against the drop of neuron number and neurite outgrowth length caused by MPP+. Addition of anti-GDNF and/or anti-GFR alpha 1 functional antibodies to the medium prior to SMI, eliminated mostly, though incompletely, the action of SMI. The expression of glial cell derived neurotrophic factor (GDNF) mRNA, but not GDNF receptor alpha1 (GFR alpha 1) or receptor tyrosine kinase mRNA in MPP+ intoxicated neurons was markedly elevated as early as 2h after the addition of SMI with a peak at 24-48 h.

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The purpose of this paper is to study the basic pharmacological action of sarsasapogenin, a sapogenin from the Chinese medicinal herb Rhizoma Anemarrhenae, (abbreviated as ZMS in this paper), on learning ability and memory of three animal models: aged rats and two neurodegeneration models produced either by single unilateral injection of beta-amyloid 1-40 (Abeta1-40) plus ibotenic acid (Ibot A) or by bilateral injection of Ibot A alone into nucleus basalis magnocellularis. Y-maze test and step-through test revealed that learning ability and memory were impaired in the three models and were improved by oral administration of ZMS. ZMS did not inhibit acetylcholinesterase nor did it occupy the binding sites of muscarinic acetylcholine receptor (M receptor), hence it is neither an cholinesterase inhibitor nor an agonist or antagonist of M receptors.

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