IN VITRO ANTIAMOEBIC ACTIVITY OF EXTRACTS AND FRACTIONS FROM IPOMEA BATATAS L. (CONVOLVULACEAE) AND URENA LOBATA (L.) LAM (MALVACEAE) AGAINST THE PROTOZOA ENTAMOEBA HISTOLYTICA, ACUTE AND SUB-ACUTE TOXICITY OF AQUEOUS EXTRACTS

Cimanga K. R.*, Ndala K. N. and Mutambel H. D.

ABSTRACT

Results from the evaluation of antiamoebic activity of extracts and fractions from the two medicinal plants Ipomea batatas and Urena lobata revealed that aqueous and 80% methanol extracts from the two selected medicinal plants exerted pronounced antiameobic activity by inhibiting the growth of Entamoeba histolyca with minimal amoebicidal concentrations (MAC) respectively of 4.25±.01 and 3.15±0.02 µg/ml, and 3.08±0.02 and 1.28±0.00 µg/ml corresponding to inhibitory concentrations IC50) respective of 2.15±0.02 and 1.75±0.00 µg/ml, and IC50 values respectively of 2.15±0.02 and 1.28±0.03 µg/ml. Soluble fractions from the partition of aqueous extract of I. batatas showed antiamoebic activity with MAC and IC50 values ranging respectively between 6.06±0.03 to 12.63±0.01µgml, while those from Urena lobata vary from 5.45±0.01 to 8.54±0.03 µg/ml. All aqueous extracts from both selected medicinal plant didn’t affect the concentration levels of hematological and biochemical parameters. They had not negative action on the organ weights of treated animals since their architecture was normal compared to negative control. No death of treated animals was observed and both aqueous extracts were considered as non-toxic since their lethal doses 50 (LD50) were estimated to be greater than 5000 mg/kg body weight.

Keywords: Ipomea batatas, Convolvulaceae, Urena lobata , Malvaceae, leaves, acute and subacute toxicity, antiamoebic activity.