25551
These results demonstrated that AHS administration may prevent spatial learning and memory decline by scavenging free radicals , up - regulating the activity of antioxidant enzymes , decreasing the level of A beta , ameliorating dysfunction in synaptic plasticity , and reversing abnormal changes in Ach level and AchE activity .
 Chemical: Ach
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: Ach