title: A Phaseolus vulgaris Extract Reduces Cue-Induced Reinstatement of Chocolate Seeking in Rats.
abstract: Previous evidence has suggested that treatment with a standardized dry extract of Phaseolus vulgaris reduced intake and operant self-administration of highly palatable foods and fluids in rats and mice. The present study was designed to assess whether such extract was also effective in reducing seeking behavior for a highly hedonic chocolate-flavored beverage, using a "reinstatement" procedure adopted from the drug addiction research field and modeling relapse behavior. Rats were initially trained to lever-respond for the chocolate-flavored beverage under the Fixed Ratio (FR) 10 schedule of reinforcement. Subsequently, rats were exposed to an extinction responding phase, during which lever-responding - being unreinforced - diminished progressively up to extinction. Lever-responding was then powerfully reinstated by the non-contingent presentation of a complex of gustatory, olfactory, auditory, and visual stimuli previously associated to the availability of the chocolate-flavored beverage. Acute, intragastric administration of P. vulgaris dry extract (100 and 500 mg/kg) reduced lever-responding by 40-45%, in comparison to vehicle condition. These results indicate the ability of P. vulgaris dry extract to reduce seeking behavior for a highly palatable nourishment in an experimental model of relapse into disordered eating of palatable foods. The unavailability of the chocolate-flavored beverage in the reinstatement session tends to exclude that the observed effect of the P. vulgaris dry extract was secondary to any inhibition of carbohydrate metabolism; conversely, it is the likely consequence on a central action on the rewarding and hedonic properties of food.
authors.affiliation: Neuroscience Institute, National Research Council of Italy, Section of Cagliari Cagliari, Italy.
authors.forename: Irene
authors.initials: I
authors.lastname: Lorrai
authors.affiliation: Neuroscience Institute, National Research Council of Italy, Section of Cagliari Cagliari, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Piga
authors.affiliation: Cagliari Pharmacological Research s.r.l. Cagliari, Italy.
authors.forename: Mauro A M
authors.initials: MA
authors.lastname: Carai
authors.affiliation: Indena S.p.A Milan, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Riva
authors.affiliation: Indena S.p.A Milan, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Morazzoni
authors.affiliation: Neuroscience Institute, National Research Council of Italy, Section of Cagliari Cagliari, Italy.
authors.forename: Gian Luigi
authors.initials: GL
authors.lastname: Gessa
authors.affiliation: Neuroscience Institute, National Research Council of Italy, Section of Cagliari Cagliari, Italy.
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Colombo
authors.affiliation: Neuroscience Institute, National Research Council of Italy, Section of Cagliari Cagliari, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Maccioni
keywords: Phaseolus vulgaris dry extract (Beanblock®); chocolate-flavored beverage; rats; reinstatement of seeking behavior; relapse-like behavior