Anti-hyperglycemic effect of cocoyam (Xanthosoma sagittifollium) corm in alloxan-induced diabetic albino rats

Diabetes  mellitus constitutes a global public health concern and dietary approach is key to the control and prevention of lethal complications. This study investigated the hypoglycemic and anti-hyperglycemic effects of Xanthosoma sagittifolium-incorporated diets in normoglycemic and alloxan-induced diabetic rats. Seventy normoglycemic male Wistar strain albino rats (120 to 200 g) were divided into two groups of thirty-five each. Group 1 was randomly distributed into seven subgroups and each subgroup assigned to 100% rat pellets, X. sagittifolium-incorporated rat pellet (25, 50 and 75%), 100% X. sagittifolium , 100% X. sagittifolium + Glibenclamide (oral hypoglycaemic agent for treatment of diabetes) or 100% rat pellets + Glibenclamide. Diabetes was induced in Group 2 rats fasted for 12 h by intraperitoneal injection of Alloxan (100 mg/kg body weight). Initial fasting blood glucose levels (BGL) were recorded, and alloxan-treated rats with BGL >200 mg/dl 48 h post-induction were considered diabetic and divided into seven subgroups. Dietary treatment was carried out, and blood glucose level (BGL) monitored for 14 days. Data obtained were analyzed using one way analysis of variance (ANOVA) and Tukey’s post-hoc test at p< 0.05.  X. sagittifolium caused a significant reduction in the BGL of alloxan-induced diabetic rats (p<0.05) but no hypoglycemic effect in normoglycemic rats. Rats fed 25% (BGL:165.2±16.9 mg/dl), 50% (BGL: 189.2±15.9 mg/dl) and 75% (BGL:152.0±23.0 mg/dl) X. sagittifolium showed better control of BGL by 24 h post-prandial compared with rats administered glibenclamide  (BGL: 195.0±18.6 mg/dl) and 100% X. sagittifolium (BGL: 221.0±17.0 mg/dl). Rats fed 75% (BGL: 118.4±11.0 mg/dl) or 100% (BGL: 97.0±17.1 mg/dl) X. sagittifolium had better controlled BGL compared with rats fed pellets and pellets + glibenclamide (BGL: 154.2±19.8 mg/dl) on day 7. X. sagittifolium corm has an antihyperglycemic effect, and its consumption should be encouraged among diabetic patients as a good replacement for other high-calorie diets. Key words: Antihyperglycemic effect, Xanthosoma sagittifolium, diabetes mellitus, albino rat.