Antinociceptive activity of swertiamarin isolated from Enicostemma axillare

Many traditional Indian medicinal plants which contain large quantity of a secoiridoid, swertiamarin are being used to relieve pain. Iridoids present in a wide variety of medicinal plants possess a large number of medicinal properties. In the present study in vivo antinociceptive activity of swertiamarin isolated from E. axillare was carried out using three different methods in mice. In the hot plate method, a significant increase in the latency period was observed for the treatment with swertiamarin at 100 and 200mg/kgbw after 30 and 45min. The percent protection observed after 45min was 109.42, 147.42 and 157.14, respectively, for the standard paracetamol and swertiamarin at 100 and 200mg/kgbw treatments. A significant increase in the tail withdrawal reflex was observed for the swertiamarin treatment at both the doses with percent protections of 150 and 200, respectively. In both these methods, swertiamarin produced potent activity than that of standard paracetamol. In the acetic acid induced writhing, swertiamarin at 100 and 200mg/kgbw reduced the number of writhes significantly. Dose dependent results were observed in all the three methods and among the two doses, swertiamarin at 200mg/kgbw showed potent activity. These results prove that swertiamarin possess both peripheral and central antinociceptive activity.