Chemical and biological study of natural substances active on the central nervous system

Abstract

The research project "Chemical and biological study of natural substances active on the Central Nervous System" has been focused on the possible effects of essential oils, their main constituents (in particular monoterpenes), plant extracts and/or their fractions and/or their constituents on the expression of some proteins involved in the adenylate cyclase 1 pathway, on cell electrophysiology and their potential effect on in vivo models. Eight species were selected including three aromatic plants (Lavandula angustifolia, Coriandrum sativum, Laurus nobilis); two Citrus medica cultivars (cv 'liscia' and cv 'rugosa'); two species of Ipomea genus known because also Ipomea violacea, a famous 'smart drugs', belongs to this genus; and Hypericum hircinum belonging to the same genus of Hypericum perforatum known for its antidepressive properties. Essential oils have been obtained from the aerial parts of L. angustifolia and L. nobilis, from C. sativum fruits and from the two cultivars of C. medica flavedo, while from the aerial parts of the two Ipomea species and H. hircinum we obtained different extracts by using solvents with increasing polarity. We analyzed the chemical composition of essential oils and the extracts by GC-MS for the first one, and by thin-layer chromatography (TLC), adsorption chromatography and HPLC for the second one. With this procedure it was possible to identify the main constituents of essential oils and the fractions with a chemical profile of interest. Subsequently, were performed several in vitro and in vivo assays following a bioassay guided fractionation. We evaluated the cytotoxicity of the substances on human neuroblastoma cells (SHSY5Y) in order to determine the most appropriate concentrations to treat the cells to study the effect on adenylate cyclase 1, protein kinase A, pERK and ERK protein expression. In collaboration with the University of Genoa, we evaluated the possible effects on cellular electrophysiology of L. angustifolia essential oil, its main constituent and of H. hircinum methanolic extract. Finally, in the period of research carried out at the Department of Psychobiology of the University of Valencia in Spain, we evaluated the effects of the essential oil of L. angustifolia and of the linalool on stress and social interactions with different experimental procedures in vivo. [edited by author]