Salvia divinorum increases alcohol intake and tonic immobility whilst decreasing food intake in wistar rats

Abstract

The kappa-opioid system (KOP) is the key in drug abuse. Of all the compounds isolated from Salvia divinorum (S. divinorum), salvinorin-A (Sal-A) is predominant. Further, Sal-A is the only compound within S. divinorum which is reported to have psychoactive properties as a powerful kappa-opioid receptor (KOPr) agonist. Based on the key role of the KOP system in the consumption of drugs, S. divinorum extract (SDE) and Sal-A may modify the alcohol intake in Wistar rats. Assessing voluntary alcohol intake as a drug consummatory behavior, food intake as natural reward behavior and tonic immobility as indicative of anxiety-like behavior, the present study sought to identify the role of both SDE and Sal-A in the Wistar rat model. Forty-eight adult male rats were randomly divided into six groups: control, alcohol naive and vehicle, alcohol-naive and SDE, alcohol-naive and Sal-A, alcohol-consumption and vehicle, alcohol-consumption and SDE, and alcohol-consumption and Sal-A. Alcohol and food intake were assessed for two weeks. In the middle of these two weeks, vehicle, SDE (containing ~1 mg/kg of Sal-A) or Sal-A was injected intraperitoneally once a day for a week. Tonic immobility testing was performed once. The administration of SDE produced a significant increase in voluntary alcohol intake especially in rats with a history of forced alcohol consumption from a juvenile age, Sal-A elicited an increase in alcohol intake in animals with or without previous alcohol exposure, SDE and Sal-A prolonged the tonic immobility duration and decreased food intake. In conclusion, S. divinorum or Sal-A stimulated alcohol consumption in rats with a history of alcohol intake and independent of previous exposure respectively, also SDE or Sal-A elicited an anorexigenic effect, and increased tonic immobility as indicative of anxious-like behavior.