The Effect of Oral Feeding of Aerial Part of Vaccinium Myrtillus on Learning and Memory in Diabetic Rats

Diabetes mellitus accompanies disturbances in learning, memory, and cognitive skills in the human society and experimental animals. There is some evidence for anti-diabetic activity of Vaccinium myrtillus(VM) and the beneficial effect of its fruit on learning and memory in normal animals. Therefore, this research study was conducted to evaluate the effect of chronic oral administration of VM on learning and memory in diabetic rats. In this experimental study, female Wistar rats(n=36) were divided randomly into four: control, VM-treated control, diabetic, and VM-treated diabetic groups. Treatment groups received rat chow containing 6.25% VM with no restriction for 4 weeks. For induction of diabetes, streptozotocin was injected i.p. at a single dose of 60 mg/kg. For evaluation of learning and memory, initial(IL) and step-through latencies(STL) were determined at the end of study using passive avoidance test and alternation behavior percentage was obtained using Y maze. For statistical analysis, one-way ANOVA and repeated measure ANOVA were used for weight and glucose data and Kruskal-Wallis test was used for behavioral parameters. There was a significant increase in IL in diabetic and VM-treated diabetic groups after 4 weeks as compared to control group(P<0.05). Meanwhile, STL significantly decreased(P<0.05) in diabetic group and significantly increased(P<0.05) in VM-treated diabetic group. In addition, STL did significantly change in VM-treated control group in comparison with control group(P<0.05). Alternation percentage was significantly lower in diabetic group relative to control(P<0.05), treated diabetic group did not show a significant difference in comparison with diabetic group, and VM treatment in control group also did not produce a significant difference as compared to control. VM treatment could enhance the capability of consolidation and recall in diabetic animals.