Effect of Aqueous Extract of Alstonia Congensis on Glucose Transport and Na+-K+-ATPase Activity in the Everted and Non-Everted Guinea Pig Intestine and Erythrocyte Fragility

The seed of Alstonia congensis has been used as purgative by traditional doctors. It is not known if glucose transport and Na+-K+ ATPase activity are affected during the purging process. The effect of the plant on erythrocytes fragility is also not known. This study was designed to provide this information. The effect of aqueous extract (1:25w/v) of Alstonia congensis on the transportation of glucose ranging from 0.10 to 0.40M from normal and everted guinea pig intestinal strips into the surrounding 0.5M TrisEDTA saline buffer pH 8.2; on Na+-K+- ATPase activity and erythrocytes fragility were measured. Results showed that the aqueous extract reduced glucose transportation; inhibited Na+-k+-ATPase activity and specific activity at higher enzyme protein concentration and activated the enzyme activity and specific activity at lower enzyme protein concentration. Glucose transport reduction was linked to the effect of the extract on the Na+-k+-ATPase system. The extract also increased erythrocytes fragility. The active ingredient(s) in the extract is not known yet and research work is in progress to ascertain it. Keywords: Alstonia congensis, glucose transport, Na+-K+-ATPase activity Nigerian Journal of Health and Biomedical Science Vol. 6 (1) 2007: pp. 5-