Effects Of Vitex doniana (Sweet) stem bark aqueous extract on ketamine anaesthesia in rabbits

Abstract

The effects of Vitex doniana (sweet), black plum, stem bark aqueous extract alone on vital parameters (temperature, respiratory rate, heart rate), and sleeping time as well as the effects of the extract on the same parameters before and after ketamine anaesthesia in rabbits were investigated. Twenty rabbits were randomly separated into four equal groups and were administered 400, 600, 800 and 1200mgkg-1 respectively of the aqueous extract of Vitex doniana (sweet) stem bark intraperitoneally. The temperature, respiratory and heart rates of the rabbits were taken before and after extract administration at 10th, 20th, 30th, 60th and 180th minutes. Fifteen other rabbits were randomly selected and separated into three groups of five each. Group I was administered 50mg/kg of ketamine alone intramuscularly. Groups II and III were administered 200 and 400mg/kg body weight respectively of the extract intraperitoneally 30 minutes prior to the administration of the same dose of ketamine as in group I. Temperature, heart and respiratory rates, as well as onset of, and recovery from, anaesthesia were measured prior to and after the administration of the agents. The administration of the extract alone to rabbits produced increase in temperature and decrease in respiratory rate and in heart rate. The increase in temperature and respiratory rates was associated with presence of reducing sugars in the extract and its analeptic/toxic effects respectively, while the decrease in all the parameters was associated with central nervous system depression. The administration of the extract prior to ketamine administration produced less significant (P<0.05) decrease in respiratory rate and higher percentage decrease in heart rate but no significant (P>0.05) effect on temperature compared with ketamine used alone. It is therefore concluded that the aqueous extract of Vitex doniana (sweet) stem bark used alone altered the vital parameters while it has a reversal action on respiratory rate and it intensifies the depression of heart rate when used prior to ketamine anaesthesia.