Effect of Royal Jelly on Learning and Memory Performance of Aged Rats

Adult SD rats were used as experimental subjects to establish a subacute aging model by intraperitoneally injecting D-galactose.After the aging model was successfully established,the aged rats were administered intragastrically with royal jelly.The learning and memory of the rats in each group were evaluated by Morris water maze.The contents of monoamine transmitters such as norepinephrine(NE) and dopamine(DA) in the brain tissue were determined in a fluorescence spectrophotometer.Meanwhile,cerebral SOD activity and DNA content in the rats were also determined.The results showed that the learning and memory of aged rats revealed a significant decrease when compared with those of normal rats.The average latency of the rats from the model group exhibited an obvious extension,which was prolonged from 15.52 s to 21.62 s.Meanwhile,the number of traversing original platform was dropped obviously,which was dropped from 7.5 to 4.25(P 0.05).Moreover,the swimming track of the rats from the model group also exhibited a remarkable change.The contents of NE and DA,and the activity of SOD in the brain tissue of aged rats were significantly decreased;in contrast,the content of MDA was increased greatly(P 0.05).On the other hand,the learning and memory of the rats from the royal jelly group were improved significantly when compared with that of aged rats from the model group.The average latency was shortened from 21.62 s to 14.34 s(P 0.05),the contents of NE and DA in the brain and the activity of SOD were enhanced,but the content of MDA was dropped obviously.These results indicated that royal jelly can improve spatial learning and memory performance of aged rats and the contents of monoamine neurotransmitters as well as SOD activity,and reduce MDA content.Therefore,royal jelly can regulate the metabolism of monoamine transmitters to result in its anti-aging function and improve learning and memory capability.