Assertion: melatonin's activity | /r/CapableOf | play role
Facets:
value: in preventing cardiac arrhythmia
type: TRANSITIVE-OBJECT
Source sentences:
text: The antioxidant activity of melatonin may reduce damage caused by some types of Parkinson's disease, may play a role in preventing cardiac arrhythmia and may increase longevity; it has been shown to increase the average life span of mice by 20% in some studies.