Abstract

ANTIDIARRHEAL ACTIVITY OF EXTRACTS AND FRACTIONS FROM URENA LOBATA OLIV (MALVACEAE) LEAVESS IN WISTAR RATS

Ndala K.N. and Cimanga K. R.*

ABSTRACT

The present study was initiated to prove the acclaimed antidiarrheal activity of aqueous extract and its soluble fractions as well as 80% methanol extract from Urena lobata leaves against castor oil and magnesium sulphate-induced diarrhea in animals model, gastro-intestinal motility and enteropooling or castor oil-induced fluid accumulation. In castor oil-induced diarrhea, results indicated that aqueous and 80% methanol extracts administrated at the highest oral dose of 200 mg/kg body weight to treated normal diarrheic Wistar rats significantly delayed or extended onset time to 149.6±04 and 162.3±0.1 minutes compared to negative control with 85.2±0.3 minutes. They also carried significant decrease of diarrheic parameters wet and hard faeces to 1.6±0.3 and 1.1±0.0, 1.3±0.2 to 0.9±0.3 respectively, and secreted intestinal fluid volume to 0.3±0.1 and 0.2±0.0 respectively. They produced 85.7±0.3 and 90.1±0.2%, and 84.4±0.2 and 90.6±003% of diarrhea and defecation inhibition
Respectively. Loperamide induced onset time to 167.3±0.2 minutes and significant reduction of diarrhoeal parameter levels wet and hard faeces to 1.0±0.1 and 08±.0.2, and secreted intestinal volume to 0.2±0.1 respectively. It showed inhibition of diarrhea and defecation production by 91.0±0.2% and 92.5±0.2%, all compared to negative control presenting a low onset time of 85.2±0.3 minutes accompanied with high diarrheic parameter levels wet and hard faeces of 11.2±0.1 and 10.7±0.3 respectively, and secreted intestinal fluid volume of 8.5±0.3. In sulphate magnesium induced-diarrhea, aqueous and 80% methanol extracts, caused significant increase of onset time to 160.6±0.2 and 163.7±0.1 minutes, and significant decrease of diarrheic parameters wet and hard faeces at 2.1±0.3 and 1.5±0.1, and 1.9±0.2 and 1.2±0.0 respectively, and secreted intestinal fluid volume at 0.3±0.1 to 0.2±0.0 respectively. Loperamide showed an onset time at 166.3±0.2 minutes with low diarrheic parameters levels wet and hard faeces of 1.2±0.1 and 0.9±0.0 respectively, and secreted intestinal fluid volume of 0.1±0.0. All compared to negative control presenting an onset time of 90.2±0.1 minutes and high level of diarrheic parameters wet and hard faeces of 10.2±0.2 and 8.7±0.2 respectively, and secreted intestinal fluid volume of 5.5±0.3. They inhibited the defecation and diarrhea production by 80.4±0.0, 85.3 ±0.2 and 88.2±0.0 respectively and 78.1±0.3, 86.2±0.2 and 89.6±0.2% respectively. All soluble fractions chloroform, ethylacetate, n-butanol and residual aqueous soluble fractions displayed the same effects as aqueous extract at different extents in both antidiarrheal tests. All samples from U. lobatta also provoked significant inhibition of gastro-intestinal motility and castor oil-induced fluid accumulation. Loperamide showed high activities compared to aqueous and 80% methanol extracts, and soluble fractions while 80% methanol extract exhibited high antidiarrheal activity compared to aqueous extracts and its soluble fractions in both antidiarrheal tests. These reported results clearly demonstrated that all samples from Urena lobata leaves possessed good and intersting antidiarrheal activity supporting thus, the traditional use of the plant part for the treating of diarrhea in Democratic Republic of Congo and other African countries where it was used for the same medical indication.

Keywords: Urena lobata, Convolvulaceae, leaves, aqueous and 80% methanol extracts, fractions, diarrhea, antidiarrheal activity.