Effect of H. tiliaceus on sleeping time induced by ketamine. Effect of methanol extract of H. tiliaceus (MEHT; 3, 10 and 30 mg/kg) and diazepam (0.5 mg/kg) on sleeping time induced by ketamine (100 mg/kg, i.p.) (n = 10). The sleeping time was expressed as mean (± S.E.M.) values. *p < 0.05 compared to saline group (ANOVA followed by Tukey test).