Essential Oil of Aniseed (Pimpinella anisum, L.) Influences Effects of Drugs Acting in Central Nervous System in Mice

I Samojlik1, V Mijatovic1, S Petkovic2, B Skrbic3, B Bozin4. 1University of Novi Sad, Faculty of Medicine, Department of Pharmacology, Toxicology and Clinical Pharmacology, Serbia, 2University of Novi Sad, Faculty of Medicine, Department of Forensic Medicine, Serbia, 3University of Novi Sad, Faculty of Technology, Technology, Serbia, 4University of Novi Sad, Faculty of Medicine, Department of Pharmacy, Serbia

The appearance of common usage of various herbal preparations in life and everyday medical practice imposes the question of herb-drug interactions. Since anise (Pimpinella anisum L.; Apiaceae) and its essential oil have been widely used in folk medicine, pharmacy and food industry, the issue of possible interactions with drugs should be considered.

The aim of this survey was to examine the influence of aniseed essential oil (EO) intake on the effects of drugs that act in central nervous system.

The chemical profile of essential oil determined by GC-MS revealed as the main components: trans-anethole (88.49%), γ-himachalene (3.13%), cis-isoeugenol (1.99%), and linalool (1.79%).

Male NMRI mice, body weight 25-35 g, were used in the survey. All animals were divided in two groups according to essential oil pretreatment: control group - pretreated with saline, and the experimental group - pretreated with daily dose of EO (0.3 ml/kg, p.o.) during 5 consecutive days. The last dose of EO was applied 60-90 minutes before the examination. The effects of codeine, diazepam, midazolam, pentobarbital, imipramine and fluoxetine were tested on 5th day of treatment with aniseed EO by appropriate tests. There were 6 animals in group per test. The experimental procedures were approved by Ethical Committee for Animal Use in Experiments, University of Novi Sad. The differences between groups in tests were compared by two tailed t-test, where P values less than 0.05 were considered significant.

The analgesic effect of codeine tested by hot plate method was significantly increased after the intake of EO. The motor impairment caused by midazolam and measured by rota rod method, was enhanced in the group treated by EO when compared to control group. The application of diazepam decreased the number and percentage of entries in open arm in elevated maze plus test in the group pretreated with EO indicating augmented effect of drug on motor activity. The significant shortage of pentobarbital induced sleeping time was noted in the group treated with EO when compared to control. The decrease in antidepressant effect of imipramine, tested by forced swimming test, and fluoxetine, examined by tail suspension test, was diminished by the pretreatment with aniseed EO.

Based on the results of this survey we conclude that concomitant intake of aniseed EO preparations and drugs that act in central nervous system should be avoided due to potential herb-drug interactions, which also need further clinical confirmation. We suppose that proposed pathways of these interactions are related to pharmacokinetic properties of tested drugs and EO.