Effect of <i>Emblica officinalis </i>tannoids on a rat model of tardive dyskinesia

Abstract

Effect of active tannoid principles of <i>E</i>. <i>officinalis</i>,<i> </i>comprising of emblicanin A (37%), emblicanin B (33%), punigluconin (12%) and pedunculagin (14%), was investigated on a rat model of tardive dyskinesia (TD) induced by once daily administration of haloperidol (1.5 mg/kg, ip) for 28 days. Involuntary oro facial movements (chewing movements, buccal

tremors and tongue prolusion) were assessed as TO parameters. The tannoid principles of <i>£.officina/is </i>(EOT) wery administered concomitantly with haloperidol in the doses of 10, 20 and 50 mg/kg, po, for 28 days. Sodium valproate (200 mg/kg, po), a Gaba-mimetic agent, and vitamin E (400 mg/kg, po), an antioxidant, were used as the standard drugs and administered for the same period. EOT induced a dose-related inhibition of all the three TD parameters assessed, as did vitamin E. The effect of sodium valproate remained statistically insignificant. The results suggest that EOT exerts a prophylactive effect against neuroleptic-induced TD which is likely to be due to its earlier reported antioxidant effects in rat brain areas, including striatum.