Evaluation of local anaesthetic efficacy of the crude extract of Sterculia tragacantha using West African Dwarf Goats

The crude extract of Sterculia tragacantha was subcutaneously infiltrated at the scrotum and left flank of West African dwarf goat prior to orchidectomy and non invasive flank procedures respectively. To assess the local anaesthetic efficacy of the extract post orchidectomy, the pain threshold, changes in vital parameters and blood glucose were monitored. Post flank infiltration, the durations of local anaesthesia, degree of analgesia and distances of tissue diffusion of the extract were monitored. Data obtained in the extract group were compared with those of lignocaine group and a control group. Mean heart rate (HR) of the extract group were significantly (p<0.05) lower than HR obtained in the control group at 30 and 120 min while mean respiratory rate (RR) of extract group was significantly (p<0.05) lower than RR of control group at 30, 120 and 240 min. Post orchidectomy, glucose values of extract group were significantly (p<0.05) lower than those in control group. The mean post operative pain scores in extract group were significantly (p<0.05) lower than those obtained in control group. Duration of local anaesthesia at the flank due to lignocaine infiltration was significantly (P<0.05) longer compared to that due to the extract. Avoidance responses to pain exhibited post flank infiltration of the extract and lignocaine were not significantly (p>0.05) different. Similarly, the rate and distances of tissue diffusion of the extract and lignocaine were not significantly different (p>0.05). On scrotal infiltration, S. tragacantha extract significantly attenuated post operative rise in the vital parameters and blood glucose. The extract was as efficacious as lignocaine when infiltrated on the flank. These results showed that an active component with potent local anaesthetic activity could be isolated from the extract if further purified.