Acute and Subacute Toxicological Assessment of the Leaf Aqueous Extract of Eremomastax speciosa (Acanthaceae) in Wistar Rats

Aim: The present study was carried out to investigate the possible toxic effects of the leaf aqueous extract from Eremomastax speciosa and also to evaluate the acceptable safety level of this extract in Wistar rats.

Place and Duration of Study: Department of Animal Biology and Physiology, Faculty of Sciences of the University of Yaounde I, between September and December 2013.

Methodology: The acute assay used 9 female rats distributed into 3 groups of 3 rats each. A control group received distilled water and the two test groups received by oral route a unique dose of the extract at 2000 mg/kg with 48 hours interval. In the subacute assay, 60 rats of both sexes were distributed into 6 groups of 10 rats each (5 males and 5 females) and received the extract by oral route for 28 days consecutively. The tests groups received the extract at doses of 400, 800 and 1600 mg/kg. The controls and satellite test groups received, respectively, distilled water and extract at the dose of 1600 mg/kg. Anthropometric, hematological and biochemical parameters were measured and histological sections of liver, kidneys and lungs were realized.

Results: The results showed no signs of toxicity such as general behavior change, mortality or change in gross appearance of internal organs even at high dose (2 g/kg). In subacute toxicity assay few modifications were observed in hematological and biochemical parameters. Histopathology showed the presence of disturbances at the dose of 800 and 1600 mg/kg particularly in the females.

Conclusion: The aqueous extract of the leaves of E. speciosa could be moderately toxic at high doses and adequate caution should be exercised in its use in ethnomedicine.