Mucosal and blood-brain barrier transport kinetics of the plant N-alkylamide spilanthol using in vitro and in vivo models.
BACKGROUND
N-alkylamides (NAAs) are a large group of secondary metabolites occurring in more than 25 plant families which are often used in traditional medicine. A prominent active NAA is spilanthol. The general goal was to quantitatively investigate the gut mucosa and blood-brain barrier (BBB) permeability pharmacokinetic properties of spilanthol.


METHODS
Spilanthes acmella (L.) L. extracts, as well as purified spilanthol were used to investigate (1) the permeation of spilanthol through a Caco-2 cell monolayer in vitro, (2) the absorption from the intestinal lumen after oral administration to rats, and (3) the permeation through the BBB in mice after intravenous injection. Quantification of spilanthol was performed using a validated bio-analytical UPLC-MS(2) method.


RESULTS
Spilanthol was able to cross the Caco-2 cell monolayer in vitro from the apical-to-basolateral side and from the basolateral-to-apical side with apparent permeability coefficients Papp between 5.2 · 10(-5) and 10.2 · 10(-5) cm/h. This in vitro permeability was confirmed by the in vivo intestinal absorption in rats after oral administration, where an elimination rate constant ke of 0.6 h(-1) was obtained. Furthermore, once present in the systemic circulation, spilanthol rapidly penetrated the blood-brain barrier: a highly significant influx of spilanthol into the brains was observed with a unidirectional influx rate constant K1 of 796 μl/(g · min).


CONCLUSIONS
Spilanthol shows a high intestinal absorption from the gut into the systemic circulation, as well as a high BBB permeation rate from the blood into the brain.
Drug Quality and Registration (DruQuaR) group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000, Ghent, Belgium.
Lieselotte
L
Veryser
Drug Quality and Registration (DruQuaR) group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000, Ghent, Belgium.
Lien
L
Taevernier
C.U. Shah College of Pharmacy, S.N.D.T. Women's University, Santacruz (W), Mumbai, 400 049, India.
Tanmayee
T
Joshi
C.U. Shah College of Pharmacy, S.N.D.T. Women's University, Santacruz (W), Mumbai, 400 049, India.
Pratima
P
Tatke
Drug Quality and Registration (DruQuaR) group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000, Ghent, Belgium.
Evelien
E
Wynendaele
Drug Quality and Registration (DruQuaR) group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000, Ghent, Belgium.
Nathalie
N
Bracke
Drug Quality and Registration (DruQuaR) group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000, Ghent, Belgium.
Sofie
S
Stalmans
Department of Medical Imaging and Small Animal Orthopedics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium.
Kathelijne
K
Peremans
Department of Comparative Physiology and Biometrics, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820, Merelbeke, Belgium.
Christian
C
Burvenich
Laboratory of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000, Ghent, Belgium.
Martijn
M
Risseeuw
Drug Quality and Registration (DruQuaR) group, Faculty of Pharmaceutical Sciences, Ghent University, Ottergemsesteenweg 460, B-9000, Ghent, Belgium. Bart.DeSpiegeleer@UGent.be.
Bart
B
De Spiegeleer
D000284:Administration, Oral; D000577:Amides / Q000008:administration & dosage / Q000493:pharmacokinetics*; D000818:Animals; D019659:Asteraceae / Q000737:chemistry; D001692:Biological Transport; D001812:Blood-Brain Barrier / Q000378:metabolism*; D001921:Brain / Q000378:metabolism; D018938:Caco-2 Cells; D002196:Capillaries / Q000378:metabolism; D042783:Endothelial Cells / Q000378:metabolism; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism*; D008813:Mice, Inbred ICR; D010539:Permeability; D010936:Plant Extracts / Q000493:pharmacokinetics*; D053284:Polyunsaturated Alkamides; D051381:Rats
D000577:Amides; C489347:N-isobutyl-2E-decenamide; D010936:Plant Extracts; D053284:Polyunsaturated Alkamides
Blood-brain barrier; Caco-2 cells; Oral absorption; Plant N-alkylamide spilanthol