Comparative effects of Rauwolfia vomitoria and chlorpromazine on locomotor behaviour and anxiety in mice.
OBJECTIVE
Since remedies for mental disorders have been sought through both orthodox and traditional medicine this study compared the effects of the antipsychotic, chlorpromazine (Cpz), the herb Rauwolfia vomitoria (RV) and its alkaloid reserpine (Res) in mice.


METHODS
Ninety male CD-1 strain of mice (75-80 days old; 30-34 g body weight) were divided into 3 major groups and each consisting 5 subgroups (n=6). Cpz (0.0, 0.25, 1.0, 2.0 and 4.0 mg/kg, i.p.), was administered 30 min before testing. RV (0.0, 0.25, 1.0, 2.0 and 4.0 mg/kg, i.p.) and Res (0.0, 0.1, 0.4, 0.8, 1.6 mg/kg, i.p.) were administered 24 h before testing. The open field test was used to assess locomotor and exploratory behaviour, acceleratory rotarod for motor coordination, light/dark box for anxiety.


RESULTS
CPZ dose-dependently decreased locomotor and exploration behaviour and impaired motor coordination (p<0.01). RV also decreased locomotor behaviour at 4.0 mg/kg (p<0.5) but did not alter exploration and motor coordination. Res however, decreased locomotion and exploration and impaired motor coordination 0.8 and 1.6 mg/kg (p<0.05). In the light/dark box, CPZ increased anxiety related behaviour at 1.0, 2.0 mg/kg (p<0.05) whereas RV dose-dependently decreased anxiety from 1.0 to 4.0 mg/kg (p<0.01). Res, unlike RV, dose-dependently increased anxiety related behaviour from 0.4 to 1.6 mg/kg.


CONCLUSIONS
Root bark extract from Rauwolfia vomitoria produced better behavioural effects with less distortion in motor coordination when compared to chlorpromazine and so has a great potential as an alternative antipsychotic agent compared to chlorpromazine. Since Res did not produce same effects as RV, the effect of RV may not be due solely to Res as claimed.
Bisong
Sunday Agba
SA
Department of Physiology, College of Medical Sciences, University of Calabar, Calabar PMB 1115, Nigeria. bisongsa@yahoo.com
Brown
Richard
R
Osim
Eme Effiom
EE
D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001007:Anxiety / Q000188:drug therapy*; D001522:Behavior, Animal / Q000187:drug effects*; D002746:Chlorpromazine / Q000494:pharmacology* / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D005106:Exploratory Behavior / Q000187:drug effects; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009043:Motor Activity / Q000187:drug effects*; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use; D018517:Plant Roots / Q000737:chemistry; D011926:Rauwolfia / Q000737:chemistry*; D012110:Reserpine / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use; D045442:Rotarod Performance Test; D046948:Secologanin Tryptamine Alkaloids / Q000302:isolation & purification / Q000494:pharmacology / Q000627:therapeutic use
D014150:Antipsychotic Agents; D010936:Plant Extracts; D046948:Secologanin Tryptamine Alkaloids; D012110:Reserpine; D002746:Chlorpromazine