ABSTRACT

 This study investigated the effects ofcrude extract and fractions from Moringa oleifera leaves on glucose transport proteins, AMPkinase, Na+/K+-ATPase and other parameters in streptozotocin ■ induced diabetes male wistar rats using acceptable chemical and biochemical methods. Crude extract and active fractions from M. Oleifera were subjected to gas chromatography- mass spectrophotometer (GCMS) for identification of bioactive compounds in the plant. In Phase 1, 40 male Wistar rats placed in 8 groups of five (5) rats each were used. Group 1 (normal control), group 2(drug control), group 3 (diabetic control), group 4 (Dimethylesulphuroxide control).Group 5and 6 were administered lOOOmg/kgbwt and500mg/kgbwt of aqueous extract while group? and 8 were administeredlOOOmg/kgbwt and 500mg/kgbwt of methanol extract respectively. There was no significant difference (P> 0.05) in the relative heart, lungs, liver and intestinal weight. The blood glucose level, glycated heamoglobin, cholesterol, triacylglycerol, LDL-Cholesterol, VLDL-Cholesterol levels and a-amylase activities increased significantly (P< 0.05) in group 3 and 4 when compared to group 1, 2, 5, 6, 7 and 8. Treatment with glibenclamide and different doses of crude extract in groups 2, 5, 6, 7 and 8 indicated a significant(P<0.05) increase in HDL-Cholesterol level, lipoprotein lipase, phosphate dehydrogenase and Na+/K+-ATPase activities when compared to group 3 and 4. The result revealed a significant increase (P<0.05) in Glucose Transport Protein 1 and 4 and AMPkinase activities in group 2, 5, 6, 7 and 8 respectively when compared to group 3 and 4. A total of 45 animals placed in 9 experimental groups were used in phase 2.Group 1 (normal control), group 2 (drug control), group 3 (diabetic control), group 4(1000mg/kgbwt of aqueous extract) while group 5-9 received fractions 1-5 respectively for 28 days. Result showed no significant difference (P>0.05) in the relative heart, liver, kidney, lungs and intestinal weight. Fractions 3,4 and 5 significantly decreased (P<0.05) the glucose level, a-amylase activity, cholesterol, triacylglycerol, LDL-Cholesterol and VLDL-Cholesterol except HDL-Cholesterol when compared with fractions 1 and 2 respectively. The result revealed that fractions 3, 4 and 5 showed a significant increase (P<0.05) in lipoprotein lipase, phosphate dehydrogenase and Na+/K+-ATPase activities when compared with group 3, fractions 1 and 2 respectively. GLUT 1,GLUT 4 and AMPkinase activities significantly increased(P<0.05) in groups administered glibenclamide, aqueous extract and fractions 3, 4 and 5 when compared with group 3, fraction 1 and 2 respectively. Histopathological investigation of the pancreas showed that the crude extract and fractions 3, 4and 5 regenerated and restored the histoarcheteture ofthe pancreatic acini and reduced the vacuolations of Langerhans islets cell resulting in the absence of necrosis near to normal. GC- MS analysis of crude extract and fractions 3,4 and 5 showed the presence of many bioactive compound out of which hexadecanoic acid, Octadecanoic acid, Octadecenoic acid, Palmitic acid, and Octadecenoic acid ethyl ester were part. This indicated that Crude extract and fractions of M. Oleifera leaves ameliorated the studied indicators of diabetes and its complications in STZ- induced diabetic male wistar rats. The possible synergetic action ofthe bioactive agents present in the leaves might be responsible for the effects.