Johannes Le Coutre | EPFL Graph Search

Dr le Coutre obtained his Ph.D. at the Max Planck Institute for Molecular Physiology, Dortmund, Germany in 1995. Between 1996-2000, he held a postdoctoral post and was a research associate at HHMI / UCLA, Los Angeles. Since 2000 he has been a Senior Research Scientist and Head of Perception Physiology at the Nestlé Research Center, Lausanne, Switzerland. Dr le Coutre holds a teaching assignment at the Ecole Polytechnique Fédérale de Lausanne (EPFL) and he is a visiting Professor at Todai University of Tokyo, Japan. Since 2017 le Coutre is responsible for Nestlé Research in the greater London area, where he holds a visiting Professorship at Imperial College London. Over the past decade le Coutre has initiated various large scale global research programs integrating the private and the public sectors. With a strong track record of membrane biophysics his research focus has been shifting from taste physiology at the periphery toward central representation of stimulation in the brain.

Anti-Obesity and Anti-Hyperglycemic Effects of Cinnamaldehyde via altered Ghrelin Secretion and Functional impact on Food Intake and Gastric Emptying

Susana Camacho Romero, Johannes Le Coutre, Henry Markram, Julie Meystre, Maurizio Ferdinando Pezzoli

Cinnamon extract is associated to different health benefits but the active ingredients or pathways are unknown. Cinnamaldehyde (CIN) imparts the characteristic flavor to cinnamon and is known to be the main agonist of transient receptor potential-ankyrin receptor 1 (TRPA1). Here, expression of TRPA1 in epithelial mouse stomach cells is described. After receiving a single-dose of CIN, mice significantly reduce cumulative food intake and gastric emptying rates. Co-localization of TRPA1 and ghrelin in enteroendocrine cells of the duodenum is observed both in vivo and in the MGN3-1 cell line, a ghrelin secreting cell model, where incubation with CIN up-regulates expression of TRPA1 and Insulin receptor genes. Ghrelin secreted in the culture medium was quantified following CIN stimulation and we observe that octanoyl and total ghrelin are significantly lower than in control conditions. Additionally, obese mice fed for five weeks with CIN-containing diet significantly reduce their cumulative body weight gain and improve glucose tolerance without detectable modification of insulin secretion. Finally, in adipose tissue up-regulation of genes related to fatty acid oxidation was observed. Taken together, the results confirm anti-hyperglycemic and anti-obesity effects of CIN opening a new approach to investigate how certain spice derived compounds regulate endogenous ghrelin release for therapeutic intervention.

Nature Publishing Group2015

Dampened neural activity and abolition of epileptic-like activity in cortical slices by active ingredients of spices

Susana Camacho Romero, Sara Lillian Gonzalez Andino, Johannes Le Coutre, Henry Markram, Julie Meystre, Maurizio Ferdinando Pezzoli

Active ingredients of spices (AIS) modulate neural response in the peripheral nervous system, mainly through interaction with TRP channel/receptors. The present study explores how different AIS modulate neural response in layer 5 pyramidal neurons of S1 neocortex. The AIS tested are agonists of TRPV1/3, TRPM8 or TRPA1. Our results demonstrate that capsaicin, eugenol, menthol, icilin and cinnamaldehyde, but not AITC dampen the generation of APs in a voltage- and time-dependent manner. This effect was further tested for the TRPM8 ligands in the presence of a TRPM8 blocker (BCTC) and on TRPM8 KO mice. The observable effect was still present. Finally, the influence of the selected AIS was tested on in vitro gabazine-induced seizures. Results coincide with the above observations: except for cinnamaldehyde, the same AIS were able to reduce the number, duration of the AP bursts and increase the concentration of gabazine needed to elicit them. In conclusion, our data suggests that some of these AIS can modulate glutamatergic neurons in the brain through a TRP-independent pathway, regardless of whether the neurons are stimulated intracellularly or by hyperactive microcircuitry.

Nature Publishing Group2014