title: Rationale of using Vinca minor Linne dry extract phytocomplex as a vincamine's oral bioavailability enhancer.
abstract: Vincamine is a poorly soluble potent neuroprotector and cerebral vasodilator, used for the treatment for CNS disorders. In some cases, the bioavailability of pure compounds is strongly influenced by the co-administration of other constituents, and in some cases, the so called 'phytocomplex' may act as enhancer of absorption of selected phytochemicals. In this paper, the oral bioavailability of vincamine when administered as a standardised Vinca minor L. leaf dry extract rather than pure indole alkaloid is demonstrated to be higher. The chosen alkaloid-enriched and standardised dry extract was widely characterised by means of HPLC-MS, PXRD, DSC, XPS, (13)C and (15)N solid-state NMR (SSNMR) using pure vincamine as a matter of comparison. Then, the in vitro dissolution performances of the two products and their in vivo bioavailability in rats were evaluated. The sevenfold improvement in oral bioavailability of the dry extract with respect to the pure vincamine was ascribed to interactions between the indole alkaloid and the corollary of ingredients of the dry extract, giving rise to the protonation of the alkaloid vincamine, thus enhancing its dissolution in physiological fluids. Present data demonstrate that alkaloid vincamine administered as a whole plant extract has a higher bioavailability compared to the pure chemical compound.
authors.affiliation: Department of Chemical and Pharmaceutical Sciences, University of Trieste, Trieste, Italy.
authors.forename: Dritan
authors.initials: D
authors.lastname: Hasa
authors.forename: Beatrice
authors.initials: B
authors.lastname: Perissutti
authors.forename: Stefano
authors.initials: S
authors.lastname: Dall'Acqua
authors.forename: Michele R
authors.initials: MR
authors.lastname: Chierotti
authors.forename: Roberto
authors.initials: R
authors.lastname: Gobetto
authors.forename: Iztok
authors.initials: I
authors.lastname: Grabnar
authors.forename: Cinzia
authors.initials: C
authors.lastname: Cepek
authors.forename: Dario
authors.initials: D
authors.lastname: Voinovich
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D004357:Drug Synergism; D010936:Plant Extracts / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics; D018515:Plant Leaves; D051381:Rats; D017207:Rats, Sprague-Dawley; D015854:Up-Regulation / Q000187:drug effects; D031053:Vinca; D014749:Vincamine / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics
chemical_list: D010936:Plant Extracts; D014749:Vincamine