ABSTRACT

The biochemical basis for the dietary management of diabetes and its complications with unripe plantain (Musa paradisiacae), cocoyam (Colacassia esculenta) and their combination was investigated in streptozotocin induced diabetic rats. Twenty five male albino rats were' used and were divided into 5 groups of 5 rats each. Groups 1 (non-diabetic control) and 2 (diabetic control (DC) received standard rat feeds. Group 3 received cocoyam pellets; Group 4 received unripe plantain pellets while group 5 received unripe plantain+ cocoyam (50%w/w). The experiment lasted for 28 days. The fasting blood glucose (FBG), glycated hemogkthin (HbA1 ), hepatic isocitrate dehydrogenase (IDH), malic enzyme (ME), serum and hepatic aspartate amino transaminase (AST), alanine amino transaminase (ALT), alkaline phosphatase, serum High Density Lipoprotein-cholesterol (HDL), Low Density Lipoprotein-cholesterol (LDL), Very Low Density Lipoprotein cholesterol (VLDL), triacylglycerol, cholesterol, amylase, lipase, total protein, albumin, total and conjugated bilirubin, urea, creatinine, feed intake, body weight, relative liver weight (RLW), relative kidney weight (RKW) and relative heart weights (RHW) of the rats were determined using standard techniques. Atherogenic index (AT) and coronary risk index (CR1) of. the rats were expressed as the ratio's of LDL to HDL and total 'cholesterol to HDL. The screening for the presence of glucose and proteins in the urine samples of the rats was done using urine glucose and protein strips respectively. Group 2 rats had detectable amounts of glucose and proteins in their urine samples and significant elevation (P<O.05) of FBG, HbA1 , serum triacylglycerol, cholesterol, LDL, Al, CR1, serum AST, ALT, ALP, urea and creatinine compared with group 1 but reduced levels of serum HDL, albumin, hepatic ME, lDH, hepatic AST, ALT and ALP compared with group I. Groips 3 to 5 rats had significant reduction of FBG, cholesterol, triacyiglycerol, VLDL, LDL, Al, CR1, IDH, ME, creatinine, bilirubin, serum and hepatic levels of ALT but significant increase (P<0.05) of l-IDL compared with DC. While groups 3 and 4 rats had significant reduction of HbA j , lipase, urea, serum AST, ALP, total bilirubin, RLW and RKW but significant increase of serum total protein, albumin, hepatic AST, ALP levels compared with the DC, feeding of cocoyam+unripe plantain to the rats of group.5 did not significantly affect their HbA, lipase, total proteins, albumin, urea, total. bilirubin, serum and hepatic AST and ALP, relative liver and kidney weights compared with the DC. The serum amylase levels of the rats of groups 3 or 4 were not significantly different (P>0.05) from that of group 2 while the serum amylase levels of group 5.rats were significantly higher(P<0.05) than that of group 2. There were no significant differences (P>0.05) in the RHW of all the rats in the 5 groups. The feed intake of the experimental rats did not differ significantly from each other (P>0.05) after 28 days of experimentation but were significantly lower (P<0.05) than that of the non-diabetic. Groups 3, 4, 5 and 2 rats had 23.29, 24,91, 3993. and 45.36% losses of weights unlike the group 1 rats that had 15.50% gain in weight. The test feeds contained considerable amount of phenols, crude fiber, ash, fat, proteins, carbohydrates, energy value, Ca, K, Fe and Na but were low in moisture, oxalate and phytate. The cocoyam or unripe plantain feed had strong antioxidant activities close to that of quercetin as seen from their inhibitory actions on 2, 2- diphenyl-1-picrylhydrazyl radical and reducing power assays while their combination had lower antioxidant activity. The study underscores the importance of cocoyam or unripe plantain in the management of diabetes and its complications while their combination at the ratio used was not as effective as when used alone.