Abstract
Toxic effects of the ethyl acetate root extract of Dennettia tripetala. G. Baker (Annonaceae) were studied using in vivo. and in vitro. models. The LD50 of the extract was 1120 mg/kg, i.p. No remarkable change was observed in the major organs on postmortem examination, except for the hyperemia and petechiation of the mucous and serous membranes of gastrointestinal and respiratory tracts. The LC50 of 83.96 ppm and estimated ED50 of 8.4 ppm (95% confidence interval) were obtained following a brine shrimp lethality test. The chronic exposure of mice to the extract showed a significant (p < 0.05) increase in packed cell volume (PCV) and red blood cell (RBC) count. The plant extract (0.5–2.0 g extract/kg feed) also produced a dose- and time-related significant (p < 0.05) reduction in the total white blood cell (WBC) count. The total number of lymphocytes and neutrophils were reduced. There was significant (p < 0.05) decrease in the relative organ weight (ROW) of liver on day 63 for all the treatment groups and spleen for the mice that received 2.0 g extract/kg feed. The extract produced a significant (p < 0.05) increase in ROW of the heart on day 63 in mice fed 2.0 g extract/kg diet. The vascular effects of the extract include degenerative, necrotic, and regenerative changes with cellular (mainly mononuclear leukocytes) infiltration in the portal areas of the liver, which was both dose- and time-dependent. The kidneys showed areas of hyperemia, hemorrhages, tubular epithelial degeneration, and necrosis with mononuclear leukocytes infiltrating the perivascular spaces and interstices.